1
|
Wanner MS, Walter JA, Reuman DC, Bell TW, Castorani MCN. Dispersal synchronizes giant kelp forests. Ecology 2024; 105:e4270. [PMID: 38415343 DOI: 10.1002/ecy.4270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 12/07/2023] [Accepted: 01/22/2024] [Indexed: 02/29/2024]
Abstract
Spatial synchrony is the tendency for population fluctuations to be correlated among different locations. This phenomenon is a ubiquitous feature of population dynamics and is important for ecosystem stability, but several aspects of synchrony remain unresolved. In particular, the extent to which any particular mechanism, such as dispersal, contributes to observed synchrony in natural populations has been difficult to determine. To address this gap, we leveraged recent methodological improvements to determine how dispersal structures synchrony in giant kelp (Macrocystis pyrifera), a global marine foundation species that has served as a useful system for understanding synchrony. We quantified population synchrony and fecundity with satellite imagery across 11 years and 880 km of coastline in southern California, USA, and estimated propagule dispersal probabilities using a high-resolution ocean circulation model. Using matrix regression models that control for the influence of geographic distance, resources (seawater nitrate), and disturbance (destructive waves), we discovered that dispersal was an important driver of synchrony. Our findings were robust to assumptions about propagule mortality during dispersal and consistent between two metrics of dispersal: (1) the individual probability of dispersal and (2) estimates of demographic connectivity that incorporate fecundity (the number of propagules dispersing). We also found that dispersal and environmental conditions resulted in geographic clusters with distinct patterns of synchrony. This study is among the few to statistically associate synchrony with dispersal in a natural population and the first to do so in a marine organism. The synchronizing effects of dispersal and environmental conditions on foundation species, such as giant kelp, likely have cascading effects on the spatial stability of biodiversity and ecosystem function.
Collapse
Affiliation(s)
- Miriam S Wanner
- Department of Environmental Sciences, University of Virginia, Charlottesville, Virginia, USA
| | - Jonathan A Walter
- Department of Environmental Sciences, University of Virginia, Charlottesville, Virginia, USA
- Center for Watershed Sciences, University of California, Davis, California, USA
| | - Daniel C Reuman
- Department of Ecology and Evolutionary Biology and Center for Ecological Research, University of Kansas, Lawrence, Kansas, USA
| | - Tom W Bell
- Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
| | - Max C N Castorani
- Department of Environmental Sciences, University of Virginia, Charlottesville, Virginia, USA
| |
Collapse
|
2
|
Mintrone C, Rindi L, Benedetti-Cecchi L. Stabilizing effects of spatially heterogeneous disturbance via reduced spatial synchrony on a rocky shore community. Ecology 2024; 105:e4246. [PMID: 38286517 DOI: 10.1002/ecy.4246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 10/24/2023] [Accepted: 12/05/2023] [Indexed: 01/31/2024]
Abstract
Understanding how synchronous species fluctuations affect community stability is a main research topic in ecology. Yet experimental studies evaluating how changes in disturbance regimes affect the synchrony and stability of populations and communities remain rare. We hypothesized that spatially heterogeneous disturbances of moderate intensity would promote metacommunity stability by decreasing the spatial synchrony of species fluctuations. To test this hypothesis, we exposed rocky shore communities of algae and invertebrates to homogeneous and gradient-like spatial patterns of disturbance at two levels of intensity for 4 years and used synchrony networks to characterize community responses to these disturbances. The gradient-like disturbance at low intensity enhanced spatial β diversity compared to the other treatments and produced the most heterogeneous and least synchronized network, which was also the most stable in terms of population and community fluctuations. In contrast, homogeneous disturbance destabilized the community, enhancing spatial synchronization. Intense disturbances always reduced spatial β diversity, indicating that strong perturbations could destabilize communities via biotic homogenization regardless of their spatial structure. Our findings corroborated theoretical predictions, emphasizing the importance of spatially heterogeneous disturbances in promoting stability by amplifying asynchronous spatial and temporal fluctuations in population and community abundance. In contrast to other networks, synchrony networks are vulnerable to the removal of most peripheral nodes, which are less synchronized, but may contribute more to stability than other nodes by dampening large fluctuations in species abundance. Our findings suggest that climate change and direct anthropogenic disturbance can compromise the stability of ecological communities through combined effects on diversity and synchrony, as well as further affecting ecosystems through habitat loss.
Collapse
Affiliation(s)
- Caterina Mintrone
- Department of Biology, University of Pisa, Pisa, Italy
- CoNISMa, Rome, Italy
| | - Luca Rindi
- Department of Biology, University of Pisa, Pisa, Italy
- CoNISMa, Rome, Italy
| | | |
Collapse
|
3
|
Walter JA, Emery KA, Dugan JE, Hubbard DM, Bell TW, Sheppard LW, Karatayev VA, Cavanaugh KC, Reuman DC, Castorani MCN. Spatial synchrony cascades across ecosystem boundaries and up food webs via resource subsidies. Proc Natl Acad Sci U S A 2024; 121:e2310052120. [PMID: 38165932 PMCID: PMC10786303 DOI: 10.1073/pnas.2310052120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 11/28/2023] [Indexed: 01/04/2024] Open
Abstract
Cross-ecosystem subsidies are critical to ecosystem structure and function, especially in recipient ecosystems where they are the primary source of organic matter to the food web. Subsidies are indicative of processes connecting ecosystems and can couple ecological dynamics across system boundaries. However, the degree to which such flows can induce cross-ecosystem cascades of spatial synchrony, the tendency for system fluctuations to be correlated across locations, is not well understood. Synchrony has destabilizing effects on ecosystems, adding to the importance of understanding spatiotemporal patterns of synchrony transmission. In order to understand whether and how spatial synchrony cascades across the marine-terrestrial boundary via resource subsidies, we studied the relationship between giant kelp forests on rocky nearshore reefs and sandy beach ecosystems that receive resource subsidies in the form of kelp wrack (detritus). We found that synchrony cascades from rocky reefs to sandy beaches, with spatiotemporal patterns mediated by fluctuations in live kelp biomass, wave action, and beach width. Moreover, wrack deposition synchronized local abundances of shorebirds that move among beaches seeking to forage on wrack-associated invertebrates, demonstrating that synchrony due to subsidies propagates across trophic levels in the recipient ecosystem. Synchronizing resource subsidies likely play an underappreciated role in the spatiotemporal structure, functioning, and stability of ecosystems.
Collapse
Affiliation(s)
- Jonathan A. Walter
- Department of Environmental Sciences, University of Virginia, Charlottesville, VA22904
- Center for Watershed Sciences, University of California, Davis, CA95616
| | - Kyle A. Emery
- Department of Geography, University of California, Los Angeles, CA90095
- Marine Science Institute, University of California, Santa Barbara, CA93106
| | - Jenifer E. Dugan
- Marine Science Institute, University of California, Santa Barbara, CA93106
| | - David M. Hubbard
- Marine Science Institute, University of California, Santa Barbara, CA93106
| | - Tom W. Bell
- Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, MA02543
| | - Lawrence W. Sheppard
- Marine Biological Association of the United Kingdom, PlymouthPL1 2PB, United Kingdom
- Department of Ecology and Evolutionary Biology and Kansas Biological Survey and Center for Ecological Research, University of Kansas, Lawrence, KS66047
| | - Vadim A. Karatayev
- Department of Ecology and Evolutionary Biology and Kansas Biological Survey and Center for Ecological Research, University of Kansas, Lawrence, KS66047
| | - Kyle C. Cavanaugh
- Department of Geography, University of California, Los Angeles, CA90095
| | - Daniel C. Reuman
- Department of Ecology and Evolutionary Biology and Kansas Biological Survey and Center for Ecological Research, University of Kansas, Lawrence, KS66047
| | - Max C. N. Castorani
- Department of Environmental Sciences, University of Virginia, Charlottesville, VA22904
| |
Collapse
|
4
|
Walter JA, Reuman DC, Hall KR, Shugart HH, Shoemaker LG. Seasonality in Environment and Population Processes Alters Population Spatial Synchrony. Am Nat 2023; 202:399-412. [PMID: 37792915 DOI: 10.1086/725804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/06/2023]
Abstract
AbstractPopulation spatial synchrony-the tendency for temporal population fluctuations to be correlated across locations-is common and important to metapopulation stability and persistence. One common cause of spatial synchrony, termed the Moran effect, occurs when populations respond to environmental fluctuations, such as weather, that are correlated over space. Although the degree of spatial synchrony in environmental fluctuations can differ between seasons and different population processes occur in different seasons, the impact on population spatial synchrony is uncertain because prior work has largely assumed that the spatial synchrony of environmental fluctuations and their effect on populations are consistent over annual sampling intervals. We used theoretical models to examine how seasonality in population processes and the spatial synchrony of environmental drivers affect population spatial synchrony. We found that population spatial synchrony can depend not only on the spatial synchrony of environmental drivers but also on the degree to which environmental fluctuations are correlated across seasons, locally, and across space. Moreover, measurements of synchrony from "snapshot" population censuses may not accurately reflect synchrony during other parts of the year. Together, these results show that neglecting seasonality in environmental conditions and population processes is consequential for understanding population spatial synchrony and its driving mechanisms.
Collapse
|
5
|
Bell JR, Clark SJ, Stevens M, Mead A. Quantifying inherent predictability and spatial synchrony in the aphid vector Myzus persicae: field-scale patterns of abundance and regional forecasting error in the UK. Pest Manag Sci 2023; 79:1331-1341. [PMID: 36412050 PMCID: PMC10952309 DOI: 10.1002/ps.7292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 09/30/2022] [Accepted: 11/22/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND Sugar beet is threatened by virus yellows, a disease complex vectored by aphids that reduces sugar content. We present an analysis of Myzus persicae population dynamics with and without neonicotinoid seed treatment. We use 6 years' yellow water trap and field-collected aphid data and two decades of 12.2 m suction-trap aphid migration data. We investigate both spatial synchrony and forecasting error to understand the structure and spatial scale of field counts and why forecasting aphid migrants lacks accuracy. Our aim is to derive statistical parameters to inform regionwide pest management strategies. RESULTS Spatial synchrony, indicating the coincident change in counts across the region over time, is rarely present and is best described as stochastic. Uniquely, early season field populations in 2019 did show spatial synchrony to 90 km compared to the overall average weekly correlation length of 23 km. However, 70% of the time series were spatially heterogenous, indicating patchy between-field dynamics. Field counts lacked the same seasonal trend and did not peak in the same week. Forecasts tended to under-predict mid-season log10 counts. A strongly negative correlation between forecasting error and the proportion of zeros was shown. CONCLUSION Field populations are unpredictable and stochastic, regardless of neonicotinoid seed treatment. This outcome presents a problem for decision-support that cannot usefully provide a single regionwide solution. Weighted permutation entropy inferred that M. persicae 12.2 m suction-trap time series had moderate to low intrinsic predictability. Early warning using a migration model tended to predict counts at lower levels than observed. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Collapse
Affiliation(s)
- James R. Bell
- Rothamsted Insect SurveyRothamsted ResearchWest CommonHarpendenUK
| | | | | | - Andrew Mead
- Statistics and Data ScienceRothamsted ResearchHarpendenUK
| |
Collapse
|
6
|
Emery SE, Klapwijk M, Sigvald R, Bommarco R, Lundin O. Cold winters drive consistent and spatially synchronous 8-year population cycles of cabbage stem flea beetle. J Anim Ecol 2023; 92:594-605. [PMID: 36484622 DOI: 10.1111/1365-2656.13866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 11/29/2022] [Indexed: 12/14/2022]
Abstract
Population cycles have been observed in mammals as well as insects, but consistent population cycling has rarely been documented in agroecosystems and never for a beetle. We analysed the long-term population patterns of the cabbage stem flea beetle Psylliodes chrysocephala in winter oilseed rape over 50 years. Psylliodes chrysocephala larval density from 3045 winter oilseed rape fields in southern Sweden showed strong 8-year population cycles in regional mean density. Fluctuations in larval density were synchronous over time across five subregional populations. Subregional mean environmental variables explained 90.6% of the synchrony in P. chrysocephala populations at the 7-11 year time-scale. The number of days below -10°C showed strong anti-phase coherence with larval densities in the 7-11 year time-scale, such that more cold days resulted in low larval densities. High levels of the North Atlantic Oscillation weather system are coherent and anti-phase with cold weather in Scania, Sweden. At the field-scale, later crop planting date and more cold winter days were associated with decreased overwintering larval density. Warmer autumn temperatures, resulting in greater larval accumulated degree days early in the season, increased overwintering larval density. Despite variation in environmental conditions and crop management, 8-year cycles persisted for cabbage stem flea beetle throughout the 50 years of data collection. Moran effects, influenced by the North Atlantic Oscillation weather patterns, are the primary drivers of this cycle and synchronicity. Insect pest data collected in commercial agriculture fields is an abundant source of long-term data. We show that an agricultural pest can have the same periodic population cycles observed in perennial and unmanaged ecosystems. This unexpected finding has implications for sustainable pest management in agriculture and shows the value of long-term pest monitoring projects as an additional source of time-series data to untangle the drivers of population cycles.
Collapse
Affiliation(s)
- Sara E Emery
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden.,Department of Wildlife Fish and Conservation Biology, University of California Davis, Davis, California, USA
| | - Maartje Klapwijk
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Roland Sigvald
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Riccardo Bommarco
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Ola Lundin
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| |
Collapse
|
7
|
Phillips JS, Einarsson Á, Strickland K, Ives AR, Kristjánsson BK, Räsänen K. Demographic Basis of Spatially Structured Fluctuations in a Threespine Stickleback Metapopulation. Am Nat 2023; 201:E41-E55. [PMID: 36848516 DOI: 10.1086/722741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractUncovering the demographic basis of population fluctuations is a central goal of population biology. This is particularly challenging for spatially structured populations, which require disentangling synchrony in demographic rates from coupling via movement between locations. In this study, we fit a stage-structured metapopulation model to a 29-year time series of threespine stickleback abundance in the heterogeneous and productive Lake Mývatn, Iceland. The lake comprises two basins (North and South) connected by a channel through which the stickleback disperse. The model includes time-varying demographic rates, allowing us to assess the potential contributions of recruitment and survival, spatial coupling via movement, and demographic transience to the population's large fluctuations in abundance. Our analyses indicate that recruitment was only modestly synchronized between the two basins, whereas survival probabilities of adults were more strongly synchronized, contributing to cyclic fluctuations in the lake-wide population size with a period of approximately 6 years. The analyses further show that the two basins were coupled through movement, with the North Basin subsidizing the South Basin and playing a dominant role in driving the lake-wide dynamics. Our results show that cyclic fluctuations of a metapopulation can be explained in terms of the combined effects of synchronized demographic rates and spatial coupling.
Collapse
|
8
|
Vriend SJG, Grøtan V, Gamelon M, Adriaensen F, Ahola MP, Álvarez E, Bailey LD, Barba E, Bouvier JC, Burgess MD, Bushuev A, Camacho C, Canal D, Charmantier A, Cole EF, Cusimano C, Doligez BF, Drobniak SM, Dubiec A, Eens M, Eeva T, Erikstad KE, Ferns PN, Goodenough AE, Hartley IR, Hinsley SA, Ivankina E, Juškaitis R, Kempenaers B, Kerimov AB, Kålås JA, Lavigne C, Leivits A, Mainwaring MC, Martínez-Padilla J, Matthysen E, van Oers K, Orell M, Pinxten R, Reiertsen TK, Rytkönen S, Senar JC, Sheldon BC, Sorace A, Török J, Vatka E, Visser ME, Saether BE. Temperature synchronizes temporal variation in laying dates across European hole-nesting passerines. Ecology 2023; 104:e3908. [PMID: 36314902 PMCID: PMC10078612 DOI: 10.1002/ecy.3908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 09/02/2022] [Accepted: 09/20/2022] [Indexed: 02/03/2023]
Abstract
Identifying the environmental drivers of variation in fitness-related traits is a central objective in ecology and evolutionary biology. Temporal fluctuations of these environmental drivers are often synchronized at large spatial scales. Yet, whether synchronous environmental conditions can generate spatial synchrony in fitness-related trait values (i.e., correlated temporal trait fluctuations across populations) is poorly understood. Using data from long-term monitored populations of blue tits (Cyanistes caeruleus, n = 31), great tits (Parus major, n = 35), and pied flycatchers (Ficedula hypoleuca, n = 20) across Europe, we assessed the influence of two local climatic variables (mean temperature and mean precipitation in February-May) on spatial synchrony in three fitness-related traits: laying date, clutch size, and fledgling number. We found a high degree of spatial synchrony in laying date but a lower degree in clutch size and fledgling number for each species. Temperature strongly influenced spatial synchrony in laying date for resident blue tits and great tits but not for migratory pied flycatchers. This is a relevant finding in the context of environmental impacts on populations because spatial synchrony in fitness-related trait values among populations may influence fluctuations in vital rates or population abundances. If environmentally induced spatial synchrony in fitness-related traits increases the spatial synchrony in vital rates or population abundances, this will ultimately increase the risk of extinction for populations and species. Assessing how environmental conditions influence spatiotemporal variation in trait values improves our mechanistic understanding of environmental impacts on populations.
Collapse
Affiliation(s)
- Stefan J G Vriend
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Vidar Grøtan
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Marlène Gamelon
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway.,Laboratoire de Biométrie et Biologie Evolutive UMR 5558, CNRS, Université Claude Bernard Lyon 1, Villeurbanne, France
| | - Frank Adriaensen
- Evolutionary Ecology Group, Department of Biology, University of Antwerp, Antwerp, Belgium
| | - Markus P Ahola
- Environmental Research and Monitoring, Swedish Museum of Natural History, Stockholm, Sweden
| | - Elena Álvarez
- Ecology of Terrestrial Vertebrates, 'Cavanilles' Institute of Biodiversity and Evolutionary Biology, University of Valencia, Valencia, Spain
| | - Liam D Bailey
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.,Department of Evolutionary Genetics, Leibniz Institute for Zoo and Wildlife Research (IZW) in the Forschungsverbund Berlin e.V, Berlin, Germany
| | - Emilio Barba
- Ecology of Terrestrial Vertebrates, 'Cavanilles' Institute of Biodiversity and Evolutionary Biology, University of Valencia, Valencia, Spain
| | | | - Malcolm D Burgess
- RSPB Centre for Conservation Science, Sandy, UK.,Centre for Research in Animal Behaviour, University of Exeter, Exeter, UK
| | - Andrey Bushuev
- Department of Vertebrate Zoology, Moscow State University, Moscow, Russia
| | - Carlos Camacho
- Department of Biological Conservation and Ecosystem Restoration, Pyrenean Institute of Ecology (IPE-CSIC), Jaca, Spain
| | - David Canal
- Institute of Ecology and Botany, Centre for Ecological Research, Vácrátót, Hungary
| | | | - Ella F Cole
- Department of Zoology, Edward Grey Institute, University of Oxford, Oxford, UK
| | | | - Blandine F Doligez
- Laboratoire de Biométrie et Biologie Evolutive UMR 5558, CNRS, Université Claude Bernard Lyon 1, Villeurbanne, France.,Department of Ecology and Genetics/Animal Ecology, Uppsala University, Uppsala, Sweden
| | - Szymon M Drobniak
- Institute of Environmental Sciences, Jagiellonian University, Krakow, Poland.,Evolution & Ecology Research Centre, School of Biological, Environmental and Earth Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Anna Dubiec
- Museum and Institute of Zoology, Polish Academy of Sciences, Warsaw, Poland
| | - Marcel Eens
- Behavioural Ecology & Ecophysiology Group, Department of Biology, University of Antwerp, Wilrijk, Belgium
| | - Tapio Eeva
- Department of Biology, University of Turku, Turku, Finland.,Kevo Subarctic Research Institute, University of Turku, Turku, Finland
| | - Kjell Einar Erikstad
- Norwegian Institute for Nature Research (NINA), FRAM High North Research Centre for Climate and the Environment, Tromsø, Norway
| | - Peter N Ferns
- Cardiff School of Biosciences, Cardiff University, Cardiff, UK
| | - Anne E Goodenough
- School of Natural and Social Sciences, University of Gloucestershire, Cheltenham, UK
| | - Ian R Hartley
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | | | - Elena Ivankina
- Zvenigorod Biological Station, Moscow State University, Moscow, Russia
| | | | - Bart Kempenaers
- Department of Behavioural Ecology and Evolutionary Genetics, Max Planck Institute for Ornithology, Seewiesen, Germany
| | - Anvar B Kerimov
- Department of Vertebrate Zoology, Moscow State University, Moscow, Russia
| | - John Atle Kålås
- Department of Terrestrial Ecology, Norwegian Institute for Nature Research (NINA), Trondheim, Norway
| | - Claire Lavigne
- INRAE, Plantes et Systèmes de culture Horticoles, Avignon, France
| | - Agu Leivits
- Department of Nature Conservation, Environmental Board, Saarde, Estonia
| | | | - Jesús Martínez-Padilla
- Department of Biological Conservation and Ecosystem Restoration, Pyrenean Institute of Ecology (IPE-CSIC), Jaca, Spain
| | - Erik Matthysen
- Evolutionary Ecology Group, Department of Biology, University of Antwerp, Antwerp, Belgium
| | - Kees van Oers
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Markku Orell
- Ecology and Genetics Research Unit, University of Oulu, Oulu, Finland
| | - Rianne Pinxten
- Research Group Didactica, Antwerp School of Education, University of Antwerp, Antwerp, Belgium
| | - Tone Kristin Reiertsen
- Norwegian Institute for Nature Research (NINA), FRAM High North Research Centre for Climate and the Environment, Tromsø, Norway
| | - Seppo Rytkönen
- Ecology and Genetics Research Unit, University of Oulu, Oulu, Finland
| | - Juan Carlos Senar
- Evolutionary and Behavioural Ecology Research Unit, Museu de Ciències Naturals de Barcelona, Barcelona, Spain
| | - Ben C Sheldon
- Department of Zoology, Edward Grey Institute, University of Oxford, Oxford, UK
| | - Alberto Sorace
- Institute for Environmental Protection and Research, Rome, Italy
| | - János Török
- Behavioural Ecology Group, Department of Systematic Zoology and Ecology, Eötvös Loránd University (ELTE), Budapest, Hungary
| | - Emma Vatka
- Ecology and Genetics Research Unit, University of Oulu, Oulu, Finland.,Ecological Genetics Research Unit, Organismal and Evolutionary Biology Research Programme, University of Helsinki, Helsinki, Finland
| | - Marcel E Visser
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Bernt-Erik Saether
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| |
Collapse
|
9
|
Castorani MCN, Bell TW, Walter JA, Reuman D, Cavanaugh KC, Sheppard LW. Disturbance and nutrients synchronise kelp forests across scales through interacting Moran effects. Ecol Lett 2022; 25:1854-1868. [PMID: 35771209 PMCID: PMC9541195 DOI: 10.1111/ele.14066] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/20/2022] [Accepted: 06/02/2022] [Indexed: 11/30/2022]
Abstract
Spatial synchrony is a ubiquitous and important feature of population dynamics, but many aspects of this phenomenon are not well understood. In particular, it is largely unknown how multiple environmental drivers interact to determine synchrony via Moran effects, and how these impacts vary across spatial and temporal scales. Using new wavelet statistical techniques, we characterised synchrony in populations of giant kelp Macrocystis pyrifera, a widely distributed marine foundation species, and related synchrony to variation in oceanographic conditions across 33 years (1987-2019) and >900 km of coastline in California, USA. We discovered that disturbance (storm-driven waves) and resources (seawater nutrients)-underpinned by climatic variability-act individually and interactively to produce synchrony in giant kelp across geography and timescales. Our findings demonstrate that understanding and predicting synchrony, and thus the regional stability of populations, relies on resolving the synergistic and antagonistic Moran effects of multiple environmental drivers acting on different timescales.
Collapse
Affiliation(s)
- Max C. N. Castorani
- Department of Environmental SciencesUniversity of VirginiaCharlottesvilleVirginiaUSA
| | - Tom W. Bell
- Department of Applied Ocean Physics & EngineeringWoods Hole Oceanographic InstitutionWoods HoleMassachusettsUSA
- Earth Research InstituteUniversity of CaliforniaSanta BarbaraCaliforniaUSA
| | - Jonathan A. Walter
- Department of Environmental SciencesUniversity of VirginiaCharlottesvilleVirginiaUSA
| | - Daniel C. Reuman
- Department of Ecology and Evolutionary BiologyUniversity of KansasLawrenceKansasUSA
- Center for Ecological ResearchUniversity of KansasLawrenceKansasUSA
- Laboratory of PopulationsRockefeller UniversityNew YorkNew YorkUSA
| | - Kyle C. Cavanaugh
- Department of GeographyUniversity of CaliforniaLos AngelesCaliforniaUSA
| | - Lawrence W. Sheppard
- Department of Ecology and Evolutionary BiologyUniversity of KansasLawrenceKansasUSA
- Marine Biological Association of the United KingdomPlymouthUK
| |
Collapse
|
10
|
Abstract
Although it has long been recognized that seed production by many forest trees varies greatly from year to year, masting (along with 'mast fruiting', 'mast seeding' and 'masting behaviour') as a concept referring to such variability is a relatively recent development. Here, I provide a brief history of masting research, highlighting some of the early contributions by foresters, zoologists and others that paved the way for the burgeoning number of studies currently being conducted by researchers around the world. Of particular current interest is work attempting to understand the proximate mechanisms, evolutionary drivers and community effects of this important ecological phenomenon as well as the ways that climate change may influence masting behaviour in the future. This article is part of the theme issue 'The ecology and evolution of synchronized seed production in plants'.
Collapse
Affiliation(s)
- Walter D Koenig
- Hastings Natural History Reservation, University of California Berkeley, Carmel Valley, CA 93924, USA.,Cornell Lab of Ornithology, Cornell University, Ithaca, NY 14850, USA
| |
Collapse
|
11
|
Abstract
Climate change is reshaping global vegetation through its impacts on plant mortality, but recruitment creates the next generation of plants and will determine the structure and composition of future communities. Recruitment depends on mean seed production, but also on the interannual variability and among-plant synchrony in seed production, the phenomenon known as mast seeding. Thus, predicting the long-term response of global vegetation dynamics to climate change requires understanding the response of masting to changing climate. Recently, data and methods have become available allowing the first assessments of long-term changes in masting. Reviewing the literature, we evaluate evidence for a fingerprint of climate change on mast seeding and discuss the drivers and impacts of these changes. We divide our discussion into the main characteristics of mast seeding: interannual variation, synchrony, temporal autocorrelation and mast frequency. Data indicate that masting patterns are changing but the direction of that change varies, likely reflecting the diversity of proximate factors underlying masting across taxa. Experiments to understand the proximate mechanisms underlying masting, in combination with the analysis of long-term datasets, will enable us to understand this observed variability in the response of masting. This will allow us to predict future shifts in masting patterns, and consequently ecosystem impacts of climate change via its impacts on masting. This article is part of the theme issue 'The ecology and evolution of synchronized seed production in plants'.
Collapse
Affiliation(s)
- Andrew Hacket-Pain
- Department of Geography and Planning, School of Environmental Sciences, University of Liverpool, Liverpool L69 7ZT, UK
| | - Michał Bogdziewicz
- Department of Systematic Zoology, Faculty of Biology, Adam Mickiewicz University in Poznań, Ulica Uniwersytetu Poznańskiego 6, Poznań, 61‐614 Poland
- INRAE, LESSEM, University Grenoble Alpes, 2 rue de la Papeterie, BP 76, Saint‐Martin‐d'Hères, 38400 France
| |
Collapse
|
12
|
Sarremejane R, Stubbington R, England J, Sefton CEM, Eastman M, Parry S, Ruhi A. Drought effects on invertebrate metapopulation dynamics and quasi-extinction risk in an intermittent river network. Glob Chang Biol 2021; 27:4024-4039. [PMID: 34032337 DOI: 10.1111/gcb.15720] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 05/06/2021] [Accepted: 05/09/2021] [Indexed: 06/12/2023]
Abstract
Ecological communities can remain stable in the face of disturbance if their constituent species have different resistance and resilience strategies. In turn, local stability scales up regionally if heterogeneous landscapes maintain spatial asynchrony across discrete populations-but not if large-scale stressors synchronize environmental conditions and biological responses. Here, we hypothesized that droughts could drastically decrease the stability of invertebrate metapopulations both by filtering out poorly adapted species locally, and by synchronizing their dynamics across a river network. We tested this hypothesis via multivariate autoregressive state-space (MARSS) models on spatially replicated, long-term data describing aquatic invertebrate communities and hydrological conditions in a set of temperate, lowland streams subject to seasonal and supraseasonal drying events. This quantitative approach allowed us to assess the influence of local (flow magnitude) and network-scale (hydrological connectivity) drivers on invertebrate long-term trajectories, and to simulate near-future responses to a range of drought scenarios. We found that fluctuations in species abundances were heterogeneous across communities and driven by a combination of hydrological and stochastic drivers. Among metapopulations, increasing extent of dry reaches reduced the abundance of functional groups with low resistance or resilience capacities (i.e. low ability to persist in situ or recolonize from elsewhere, respectively). Our simulations revealed that metapopulation quasi-extinction risk for taxa vulnerable to drought increased exponentially as flowing habitats contracted within the river network, whereas the risk for taxa with resistance and resilience traits remained stable. Our results suggest that drought can be a synchronizing agent in riverscapes, potentially leading to regional quasi-extinction of species with lower resistance and resilience abilities. Better recognition of drought-driven synchronization may increase realism in species extinction forecasts as hydroclimatic extremes continue to intensify worldwide.
Collapse
Affiliation(s)
- Romain Sarremejane
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, CA, USA
- INRAE, UR RiverLY, Centre de Lyon-Grenoble Auvergne-Rhône-Alpes, Villeurbanne, France
| | - Rachel Stubbington
- School of Science and Technology, Nottingham Trent University, Nottingham, UK
| | | | | | - Michael Eastman
- UK Centre for Ecology & Hydrology, Wallingford, Oxfordshire, UK
| | - Simon Parry
- UK Centre for Ecology & Hydrology, Wallingford, Oxfordshire, UK
| | - Albert Ruhi
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, CA, USA
| |
Collapse
|
13
|
Walter JA, Shoemaker LG, Lany NK, Castorani MCN, Fey SB, Dudney JC, Gherardi L, Portales-Reyes C, Rypel AL, Cottingham KL, Suding KN, Reuman DC, Hallett LM. The spatial synchrony of species richness and its relationship to ecosystem stability. Ecology 2021; 102:e03486. [PMID: 34289105 PMCID: PMC9286696 DOI: 10.1002/ecy.3486] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 05/03/2021] [Accepted: 05/18/2021] [Indexed: 11/26/2022]
Abstract
Synchrony is broadly important to population and community dynamics due to its ubiquity and implications for extinction dynamics, system stability, and species diversity. Investigations of synchrony in community ecology have tended to focus on covariance in the abundances of multiple species in a single location. Yet, the importance of regional environmental variation and spatial processes in community dynamics suggests that community properties, such as species richness, could fluctuate synchronously across patches in a metacommunity, in an analog of population spatial synchrony. Here, we test the prevalence of this phenomenon and the conditions under which it may occur using theoretical simulations and empirical data from 20 marine and terrestrial metacommunities. Additionally, given the importance of biodiversity for stability of ecosystem function, we posit that spatial synchrony in species richness is strongly related to stability. Our findings show that metacommunities often exhibit spatial synchrony in species richness. We also found that richness synchrony can be driven by environmental stochasticity and dispersal, two mechanisms of population spatial synchrony. Richness synchrony also depended on community structure, including species evenness and beta diversity. Strikingly, ecosystem stability was more strongly related to richness synchrony than to species richness itself, likely because richness synchrony integrates information about community processes and environmental forcing. Our study highlights a new approach for studying spatiotemporal community dynamics and emphasizes the spatial dimensions of community dynamics and stability.
Collapse
Affiliation(s)
- Jonathan A Walter
- Department of Environmental Sciences, University of Virginia, Charlottesville, Virginia, USA
| | | | - Nina K Lany
- Department of Forestry, Michigan State University, East Lansing, Michigan, USA
| | - Max C N Castorani
- Department of Environmental Sciences, University of Virginia, Charlottesville, Virginia, USA
| | - Samuel B Fey
- Department of Biology, Reed College, Portland, Oregon, USA
| | - Joan C Dudney
- Department of Plant Sciences, University of California-Davis, Davis, California, USA
| | - Laureano Gherardi
- School of Life Sciences, Arizona State University, Tempe, Arizona, USA
| | - Cristina Portales-Reyes
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, Minnesota, USA
| | - Andrew L Rypel
- Department of Wildlife, Fish, and Conservation Biology, University of California, Davis, California, USA
| | - Kathryn L Cottingham
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, USA
| | - Katharine N Suding
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado, USA
| | - Daniel C Reuman
- Department of Ecology and Evolutionary Biology and Kansas Biological Survey, University of Kansas, Lawrence, Kansas, USA
| | - Lauren M Hallett
- Environmental Studies Program and Department of Biology, University of Oregon, Eugene, Oregon, USA
| |
Collapse
|
14
|
Bogdziewicz M, Hacket-Pain A, Ascoli D, Szymkowiak J. Environmental variation drives continental-scale synchrony of European beech reproduction. Ecology 2021; 102:e03384. [PMID: 33950521 DOI: 10.1002/ecy.3384] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 01/05/2021] [Accepted: 03/16/2021] [Indexed: 11/07/2022]
Abstract
Spatial synchrony is the tendency of spatially separated populations to display similar temporal fluctuations. Synchrony affects regional ecosystem functioning, but it remains difficult to disentangle its underlying mechanisms. We leveraged regression on distance matrices and geography of synchrony to understand the processes driving synchrony of European beech masting over the European continent. Masting in beech shows distance-decay, but significant synchrony is maintained at spatial scales of up to 1,500 km. The spatial synchrony of the weather cues that drive interannual variation in reproduction also explains the regional spatial synchrony of masting. Proximity played no apparent role in influencing beech masting synchrony after controlling for synchrony in environmental variation. Synchrony of beech reproduction shows a clear biogeographical pattern, decreasing from the northwest to southeast Europe. Synchrony networks for weather cues resemble networks for beech masting, indicating that the geographical structure of weather synchrony underlies the biogeography of masting synchrony. Our results support the hypothesis that environmental factors, the Moran effect, are key drivers of spatial synchrony in beech seed production at regional scales. The geographical patterns of regional synchronization of masting have implications for regional forest production, gene flow, carbon cycling, disease dynamics, biodiversity, and conservation.
Collapse
Affiliation(s)
- Michał Bogdziewicz
- Department of Systematic Zoology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| | - Andrew Hacket-Pain
- Department of Geography and Planning, School of Environmental Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Davide Ascoli
- Department of Agricultural, Forestry and Food Sciences, University of Torino, Grugliasco, Italy
| | - Jakub Szymkowiak
- Population Ecology Research Unit, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| |
Collapse
|
15
|
Morrongiello JR, Horn PL, Ó Maolagáin C, Sutton PJH. Synergistic effects of harvest and climate drive synchronous somatic growth within key New Zealand fisheries. Glob Chang Biol 2021; 27:1470-1484. [PMID: 33502819 DOI: 10.1111/gcb.15490] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 11/18/2020] [Accepted: 11/30/2020] [Indexed: 06/12/2023]
Abstract
Fisheries harvest has pervasive impacts on wild fish populations, including the truncation of size and age structures, altered population dynamics and density, and modified habitat and assemblage composition. Understanding the degree to which harvest-induced impacts increase the sensitivity of individuals, populations and ultimately species to environmental change is essential to ensuring sustainable fisheries management in a rapidly changing world. Here we generated multiple long-term (44-62 years), annually resolved, somatic growth chronologies of four commercially important fishes from New Zealand's coastal and shelf waters. We used these novel data to investigate how regional- and basin-scale environmental variability, in concert with fishing activity, affected individual somatic growth rates and the magnitude of spatial synchrony among stocks. Changes in somatic growth can affect individual fitness and a range of population and fishery metrics such as recruitment success, maturation schedules and stock biomass. Across all species, individual growth benefited from a fishing-induced release of density controls. For nearshore snapper and tarakihi, regional-scale wind and temperature also additively affected growth, indicating that future climate change-induced warming and potentially strengthened winds will initially promote the productivity of more poleward populations. Fishing increased the sensitivity of deep-water hoki and ling growth to the Interdecadal Pacific Oscillation (IPO). A forecast shift to a positive IPO phase, in concert with current harvest strategies, will likely promote individual hoki and ling growth. At the species level, historical fishing practices and IPO synergized to strengthen spatial synchrony in average growth between stocks separated by 400-600 nm of ocean. Increased spatial synchrony can, however, increase the vulnerability of stocks to deleterious stochastic events. Together, our individual- and species-level results show how fishing and environmental factors can conflate to initially promote individual growth but then possibly heighten the sensitivity of stocks to environmental change.
Collapse
Affiliation(s)
| | - Peter L Horn
- National Institute of Water and Atmospheric Research (NIWA, Christchurch, New Zealand
| | | | - Philip J H Sutton
- National Institute of Water and Atmospheric Research (NIWA, Christchurch, New Zealand
| |
Collapse
|
16
|
Larsen S, Comte L, Filipa Filipe A, Fortin MJ, Jacquet C, Ryser R, Tedesco PA, Brose U, Erős T, Giam X, Irving K, Ruhi A, Sharma S, Olden JD. The geography of metapopulation synchrony in dendritic river networks. Ecol Lett 2021; 24:791-801. [PMID: 33619868 PMCID: PMC8049041 DOI: 10.1111/ele.13699] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 09/30/2020] [Accepted: 01/07/2021] [Indexed: 02/07/2023]
Abstract
Dendritic habitats, such as river ecosystems, promote the persistence of species by favouring spatial asynchronous dynamics among branches. Yet, our understanding of how network topology influences metapopulation synchrony in these ecosystems remains limited. Here, we introduce the concept of fluvial synchrogram to formulate and test expectations regarding the geography of metapopulation synchrony across watersheds. By combining theoretical simulations and an extensive fish population time‐series dataset across Europe, we provide evidence that fish metapopulations can be buffered against synchronous dynamics as a direct consequence of network connectivity and branching complexity. Synchrony was higher between populations connected by direct water flow and decayed faster with distance over the Euclidean than the watercourse dimension. Likewise, synchrony decayed faster with distance in headwater than mainstem populations of the same basin. As network topology and flow directionality generate fundamental spatial patterns of synchrony in fish metapopulations, empirical synchrograms can aid knowledge advancement and inform conservation strategies in complex habitats.
Collapse
Affiliation(s)
- Stefano Larsen
- Unit of Computational Biology, Research and Innovation Centre, Fondazione Edmund Mach, via E. Mach 1, San Michele all'Adige, 38010, Italy.,Department of Civil Environmental and Mechanical Engineering, University of Trento, Trento, Italy
| | - Lise Comte
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA, 98105, USA.,School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - Ana Filipa Filipe
- CIBIO/InBio, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Vairão, Portugal.,Instituto Superior de Agronomia, Universidade de Lisboa, Lisboa, Portugal
| | - Marie-Josée Fortin
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, M5S 3B2, Canada
| | - Claire Jacquet
- Department of Aquatic Ecology, Swiss Federal Institute of Aquatic Science and Technology, Eawag, Dübendorf, Switzerland.,Complex Systems Lab, INRAE - Centre Clermont-Auvergne-Rhône-Alpes, 9 avenue Blaise Pascal, Aubière,, 63170, France.,Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zürich, Switzerland
| | - Remo Ryser
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, 04103, Germany.,Institute of Biodiversity, Friedrich-Schiller-University Jena, Jena, 07743, Germany
| | - Pablo A Tedesco
- UMR EDB, CNRS 5174, UPS, Université Paul Sabatier, IRD 253, Toulouse, France
| | - Ulrich Brose
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, 04103, Germany.,Institute of Biodiversity, Friedrich-Schiller-University Jena, Jena, 07743, Germany
| | - Tibor Erős
- MTA Centre for Ecological Research, Balaton Limnological Institute, Klebelsberg K. u. 3, Tihany, 8237, Hungary
| | - Xingli Giam
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - Katie Irving
- Biology Department, Southern California Coastal Water Research Project, Costa Mesa, CA, 92626, USA.,Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Albert Ruhi
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Sapna Sharma
- Department of Biology, York University, 4700 Keele Street, Toronto, ON, M3J 1P3, Canada
| | - Julian D Olden
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA, 98105, USA
| |
Collapse
|
17
|
Abstract
Long-range synchrony from short-range interactions is a familiar pattern in biological and physical systems, many of which share a common set of 'universal' properties at the point of synchronization. Common biological systems of coupled oscillators have been shown to be members of the Ising universality class, meaning that the very simple Ising model replicates certain spatial statistics of these systems at stationarity. This observation is useful because it reveals which aspects of spatial pattern arise independently of the details governing local dynamics, resulting in both deeper understanding of and a simpler baseline model for biological synchrony. However, in many situations a system's dynamics are of greater interest than their static spatial properties. Here, we ask whether a dynamical Ising model can replicate universal and non-universal features of ecological systems, using noisy coupled metapopulation models with two-cycle dynamics as a case study. The standard Ising model makes unrealistic dynamical predictions, but the Ising model with memory corrects this by using an additional parameter to reflect the tendency for local dynamics to maintain their phase of oscillation. By fitting the two parameters of the Ising model with memory to simulated ecological dynamics, we assess the correspondence between the Ising and ecological models in several of their features (location of the critical boundary in parameter space between synchronous and asynchronous dynamics, probability of local phase changes and ability to predict future dynamics). We find that the Ising model with memory is reasonably good at representing these properties of ecological metapopulations. The correspondence between these models creates the potential for the simple and well-known Ising class of models to become a valuable tool for understanding complex biological systems.
Collapse
Affiliation(s)
| | - Jonathan Machta
- Department of Physics, University of Massachusetts, Amherst, MA 01003, USA.,Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM 87501, USA
| | - Karen C Abbott
- Department of Biology, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA
| | - Shadisadat Esmaeili
- Department of Environmental Science and Policy, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Alan Hastings
- Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM 87501, USA.,Department of Environmental Science and Policy, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| |
Collapse
|
18
|
Ward SF, Aukema BH, Fei S, Liebhold AM. Warm temperatures increase population growth of a nonnative defoliator and inhibit demographic responses by parasitoids. Ecology 2020; 101:e03156. [PMID: 32740922 DOI: 10.1002/ecy.3156] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 06/01/2020] [Accepted: 06/19/2020] [Indexed: 11/06/2022]
Abstract
Changes in thermal regimes that disparately affect hosts and parasitoids could release hosts from biological control. When multiple natural enemy species share a host, shifts in host-parasitoid dynamics could depend on whether natural enemies interact antagonistically vs. synergistically. We investigated how biotic and abiotic factors influence the population ecology of larch casebearer (Coleophora laricella), a nonnative pest, and two imported parasitoids, Agathis pumila and Chrysocharis laricinellae, by analyzing (1) temporal dynamics in defoliation from 1962 to 2018, and (2) historical, branch-level data on densities of larch casebearer and parasitism rates by the two imported natural enemies from 1972 to 1995. Analyses of defoliation indicated that, prior to the widespread establishment of parasitoids (1962 to ~1980), larch casebearer outbreaks occurred in 2-6 yr cycles. This pattern was followed by a >15-yr period during which populations were at low, apparently stable densities undetectable via aerial surveys, presumably under control from parasitoids. However, since the late 1990s and despite the persistence of both parasitoids, outbreaks exhibiting unstable dynamics have occurred. Analyses of branch-level data indicated that growth of casebearer populations, A. pumila populations, and within-casebearer densities of C. laricinellae-a generalist whose population dynamics are likely also influenced by use of alternative hosts-were inhibited by density dependence, with high intraspecific densities in one year slowing growth into the next. Casebearer population growth was also inhibited by parasitism from A. pumila, but not C. laricinellae, and increased with warmer autumnal temperatures. Growth of A. pumila populations and within-casebearer densities of C. laricinellae increased with casebearer densities but decreased with warmer annual maximum temperatures. Moreover, parasitism by A. pumila was associated with increased growth of within-casebearer densities of C. laricinellae without adverse effects on its own demographics, indicating a synergistic interaction between these parasitoids. Our results indicate that warming can be associated with opposing effects between trophic levels, with deleterious effects of warming on one natural enemy species potentially being exacerbated by similar impacts on another. Coupling of such parasitoid responses with positive responses of hosts to warming might have contributed to the return of casebearer outbreaks to North America.
Collapse
Affiliation(s)
- Samuel F Ward
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana, 47907, USA
| | - Brian H Aukema
- Department of Entomology, University of Minnesota, Saint Paul, Minnesota, 55108, USA
| | - Songlin Fei
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana, 47907, USA
| | - Andrew M Liebhold
- USDA Forest Service, Northern Research Station, Morgantown, West Virginia, 26505, USA.,Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, CZ 165 21, Praha 6-Suchdol, Czech Republic
| |
Collapse
|
19
|
Hansen BB, Pedersen ÅØ, Peeters B, Le Moullec M, Albon SD, Herfindal I, Sæther B, Grøtan V, Aanes R. Spatial heterogeneity in climate change effects decouples the long-term dynamics of wild reindeer populations in the high Arctic. Glob Chang Biol 2019; 25:3656-3668. [PMID: 31435996 PMCID: PMC6851690 DOI: 10.1111/gcb.14761] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 03/05/2019] [Indexed: 05/18/2023]
Abstract
The 'Moran effect' predicts that dynamics of populations of a species are synchronized over similar distances as their environmental drivers. Strong population synchrony reduces species viability, but spatial heterogeneity in density dependence, the environment, or its ecological responses may decouple dynamics in space, preventing extinctions. How such heterogeneity buffers impacts of global change on large-scale population dynamics is not well studied. Here, we show that spatially autocorrelated fluctuations in annual winter weather synchronize wild reindeer dynamics across high-Arctic Svalbard, while, paradoxically, spatial variation in winter climate trends contribute to diverging local population trajectories. Warmer summers have improved the carrying capacity and apparently led to increased total reindeer abundance. However, fluctuations in population size seem mainly driven by negative effects of stochastic winter rain-on-snow (ROS) events causing icing, with strongest effects at high densities. Count data for 10 reindeer populations 8-324 km apart suggested that density-dependent ROS effects contributed to synchrony in population dynamics, mainly through spatially autocorrelated mortality. By comparing one coastal and one 'continental' reindeer population over four decades, we show that locally contrasting abundance trends can arise from spatial differences in climate change and responses to weather. The coastal population experienced a larger increase in ROS, and a stronger density-dependent ROS effect on population growth rates, than the continental population. In contrast, the latter experienced stronger summer warming and showed the strongest positive response to summer temperatures. Accordingly, contrasting net effects of a recent climate regime shift-with increased ROS and harsher winters, yet higher summer temperatures and improved carrying capacity-led to negative and positive abundance trends in the coastal and continental population respectively. Thus, synchronized population fluctuations by climatic drivers can be buffered by spatial heterogeneity in the same drivers, as well as in the ecological responses, averaging out climate change effects at larger spatial scales.
Collapse
Affiliation(s)
- Brage Bremset Hansen
- Centre for Biodiversity Dynamics (CBD)Department of BiologyNorwegian University of Science and Technology (NTNU)TrondheimNorway
| | | | - Bart Peeters
- Centre for Biodiversity Dynamics (CBD)Department of BiologyNorwegian University of Science and Technology (NTNU)TrondheimNorway
| | - Mathilde Le Moullec
- Centre for Biodiversity Dynamics (CBD)Department of BiologyNorwegian University of Science and Technology (NTNU)TrondheimNorway
| | | | - Ivar Herfindal
- Centre for Biodiversity Dynamics (CBD)Department of BiologyNorwegian University of Science and Technology (NTNU)TrondheimNorway
| | - Bernt‐Erik Sæther
- Centre for Biodiversity Dynamics (CBD)Department of BiologyNorwegian University of Science and Technology (NTNU)TrondheimNorway
| | - Vidar Grøtan
- Centre for Biodiversity Dynamics (CBD)Department of BiologyNorwegian University of Science and Technology (NTNU)TrondheimNorway
| | - Ronny Aanes
- Centre for Biodiversity Dynamics (CBD)Department of BiologyNorwegian University of Science and Technology (NTNU)TrondheimNorway
- Norwegian Polar Institute (NPI)Fram CentreTromsøNorway
| |
Collapse
|
20
|
Ramiadantsoa T, Stegner MA, Williams JW, Ives AR. The potential role of intrinsic processes in generating abrupt and quasi-synchronous tree declines during the Holocene. Ecology 2019; 100:e02579. [PMID: 30707453 DOI: 10.1002/ecy.2579] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 06/13/2018] [Accepted: 10/24/2018] [Indexed: 11/08/2022]
Abstract
Multiple abrupt and sometimes near-synchronous declines in tree populations have been detected in the temperate forests of eastern North America and Europe during the Holocene. Traditional approaches to understanding these declines focus on searching for climatic or other broad-scale extrinsic drivers. These approaches include multi-proxy studies that match reconstructed changes in tree abundance to reconstructed changes in precipitation or temperature. Although these correlative approaches are informative, they neglect the potential role of intrinsic processes, such as competition and dispersal, in shaping tree community dynamics. We developed a simple process-based community model that includes competition among tree species, density-dependent survival, and dispersal to investigate how these processes might generate abrupt changes in tree abundances even when extrinsic climatic factors do not themselves change abruptly. Specifically, a self-reinforcing (i.e., positive) feedback between abundance and survival can produce abrupt changes in tree abundance in the absence of long-term climatic changes. Furthermore, spatially correlated, short-term environmental variation and seed dispersal can increase the synchrony of abrupt changes. Using the well-studied, late-Holocene crash of Tsuga canadensis (eastern hemlock) populations as an empirical case study, we find that our model generates abrupt and quasi-synchronized crashes qualitatively similar to the observed hemlock patterns. Other tree taxa vary in the frequency and clustering of abrupt change and the proportion of increases and decreases. This complexity argues for caution in interpreting abrupt changes in species abundances as indicative of abrupt climatic changes. Nonetheless, some taxa show patterns that the model cannot produce: observed abrupt declines in hemlock abundance are more synchronized than abrupt increases, whereas the degree of synchronization is the same for abrupt decreases and increases in the model. Our results show that intrinsic processes can be significant contributing factors in abrupt tree population changes and highlight the diagnostic value of analyzing entire time series rather than single events when testing hypotheses about abrupt changes. Thus, intrinsic processes should be considered along with extrinsic drivers when seeking to explain rapid changes in community composition.
Collapse
Affiliation(s)
- Tanjona Ramiadantsoa
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - M Allison Stegner
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - John W Williams
- Department of Geography and Center for Climatic Research, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Anthony R Ives
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, 53706, USA
| |
Collapse
|
21
|
Soranno PA, Wagner T, Collins SM, Lapierre JF, Lottig NR, Oliver SK. Spatial and temporal variation of ecosystem properties at macroscales. Ecol Lett 2019; 22:1587-1598. [PMID: 31347258 DOI: 10.1111/ele.13346] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 06/03/2019] [Accepted: 06/26/2019] [Indexed: 01/16/2023]
Abstract
Although spatial and temporal variation in ecological properties has been well-studied, crucial knowledge gaps remain for studies conducted at macroscales and for ecosystem properties related to material and energy. We test four propositions of spatial and temporal variation in ecosystem properties within a macroscale (1000 km's) extent. We fit Bayesian hierarchical models to thousands of observations from over two decades to quantify four components of variation - spatial (local and regional) and temporal (local and coherent); and to model their drivers. We found strong support for three propositions: (1) spatial variation at local and regional scales are large and roughly equal, (2) annual temporal variation is mostly local rather than coherent, and, (3) spatial variation exceeds temporal variation. Our findings imply that predicting ecosystem responses to environmental changes at macroscales requires consideration of the dominant spatial signals at both local and regional scales that may overwhelm temporal signals.
Collapse
Affiliation(s)
- Patricia A Soranno
- Department of Fisheries and Wildlife, Michigan St. University, 480 Wilson Rd, East Lansing, MI, 48824, USA
| | - Tyler Wagner
- U.S. Geological Survey, Pennsylvania Cooperative Fish & Wildlife Research Unit, Pennsylvania State University, 402 Forest Resources Building, University Park, PA, 16802, USA
| | - Sarah M Collins
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY, 82071, USA
| | - Jean-Francois Lapierre
- Department of Biological Science, University of Montreal, Montreal, Quebec, Canada, H3C 3J7
| | - Noah R Lottig
- Trout Lake Research Station, Univ. of Wisconsin, 3110 Trout Lake Station Drive, Boulder Junction, WI, 54512, USA
| | - Samantha K Oliver
- Upper Midwest Water Science Center, U.S. Geological Survey, 8505 Research Way, Middleton, WI, 53562, USA
| |
Collapse
|
22
|
Abstract
Explaining why fluctuations in abundances of spatially disjunct populations often are correlated through time is a major goal of population ecologists. We address two hypotheses receiving little to no testing in wild populations: (i) that population cycling facilitates synchronization given weak coupling among populations, and (ii) that the ability of periodic external forces to synchronize oscillating populations is a function of the mismatch in timescales (detuning) between the force and the population. Here, we apply new analytical methods to field survey data on gypsy moth outbreaks. We report that at timescales associated with gypsy moth outbreaks, spatial synchrony increased with population periodicity via phase locking. The extent to which synchrony in temperature and precipitation influenced population synchrony was associated with the degree of mismatch in dominant timescales of oscillation. Our study provides new empirical methods and rare empirical evidence that population cycling and low detuning can promote population spatial synchrony.
Collapse
Affiliation(s)
- Kyle J Haynes
- 1 The Blandy Experimental Farm, University of Virginia , Boyce, VA , USA.,2 Department of Environmental Sciences, University of Virginia , Charlottesville, VA , USA
| | - Jonathan A Walter
- 2 Department of Environmental Sciences, University of Virginia , Charlottesville, VA , USA
| | - Andrew M Liebhold
- 3 US Forest Service Northern Research Station , Morgantown, WV 26505 , USA.,4 Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences , Praha 6 - Suchdol, Czechia 16521 , Czech Republic
| |
Collapse
|
23
|
Hopson J, Fox JW. Occasional long distance dispersal increases spatial synchrony of population cycles. J Anim Ecol 2018; 88:154-163. [PMID: 30280379 DOI: 10.1111/1365-2656.12905] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 08/30/2018] [Indexed: 11/29/2022]
Abstract
Spatially separated populations of the same species often exhibit correlated fluctuations in abundance, a phenomenon known as spatial synchrony. Dispersal can generate spatial synchrony. In nature, most individuals disperse short distances with a minority dispersing long distances. The effect of occasional long distance dispersal on synchrony is untested, and theoretical predictions are contradictory. Occasional long distance dispersal might either increase both overall synchrony and the spatial scale of synchrony, or reduce them. We conducted a protist microcosm experiment to test whether occasional long distance dispersal increases or decreases overall synchrony and the spatial scale of synchrony. We assembled replicate 15-patch ring metapopulations of the protist predator Euplotes patella and its protist prey Tetrahymena pyriformis. All metapopulations experienced the same dispersal rate, but differed in dispersal distance. Some metapopulations experienced strictly short distance (nearest neighbour) dispersal, others experienced a mixture of short- and long distance dispersal. Occasional long distance dispersal increased overall spatial synchrony and the spatial scale of synchrony for both prey and predators, though the effects were not statistically significant for predators. As predicted by theory, dispersal generated spatial synchrony by entraining the phases of the predator-prey cycles in different patches, a phenomenon known as phase locking. Our results are consistent with theoretical models predicting that occasional long distance dispersal increases spatial synchrony. However, our results also illustrate that the spatial scale of synchrony need not match the spatial scale of the processes generating synchrony. Even strictly short distance dispersal maintained high spatial synchrony for many generations at spatial scales much longer than the dispersal distance, thanks to phase locking.
Collapse
Affiliation(s)
- Jessica Hopson
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Jeremy W Fox
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| |
Collapse
|
24
|
Alcalay Y, Tsurim I, Ovadia O. Modelling the effects of spatial heterogeneity and temporal variation in extinction probability on mosquito populations. Ecol Appl 2017; 27:2342-2358. [PMID: 28851019 DOI: 10.1002/eap.1612] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Revised: 07/02/2017] [Accepted: 08/03/2017] [Indexed: 06/07/2023]
Abstract
Spatial synchrony plays an important role in dictating the dynamics of spatial and stage-structured populations. Here we argue that, unlike the Moran effect where spatial synchrony is driven by exogenous factors, spatial correlation in intrinsic/local-scale processes can affect the level of spatial synchrony among distinct sub-populations, and therefore the persistence of the entire population. To explore this mechanism, we modelled the consequences of spatial heterogeneity in aquatic habitat quality, and that of temporal variation in local extinction probability, on the persistence of stage-structured mosquito populations. As a model system, we used two widely distributed mosquito species, Aedes albopictus and Culex pipiens, both key vectors of a range of infectious diseases. Spatial heterogeneity in aquatic habitat quality led to increased population persistence, and this pattern was more pronounced at intermediate dispersal rates, and in the long-dispersing species (C. pipiens). The highest regional persistence was obtained at high dispersal rates. This is probably because dispersal, in our model, did not carry any additional costs. Population persistence of both species was negatively correlated with increased temporal variation in local extinction probability. These differences were stronger in the short-dispersing species (A. albopictus), especially at intermediate dispersal rates. The dispersal of A. albopictus adults in each time step was limited to the nearest habitat patches, weakening the positive effect of spatial heterogeneity in aquatic habitat quality on population persistence. In contrast, C. pipiens adults could disperse into more remote sub-populations, resulting in much higher recolonization rates. Hence, the negative effect of temporal variation in local extinction probability on patch occupancy disappeared at intermediate dispersal rates. We suggest that effectively controlling these two mosquito species requires making few spatially synchronized control efforts (i.e., generating high temporal variation in local extinction probability), rather than many asynchronized local control efforts. Finally, our model can be easily fitted to other organisms characterized by complex life cycles, and it can be also used to examine alternative scenarios, including the effect of spatial configuration of local habitat patches and dispersal kernel shape on population persistence.
Collapse
Affiliation(s)
- Yehonatan Alcalay
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel
| | - Ido Tsurim
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel
- Department of Life Sciences, Achva Academic College, Arugot, 7980400, Israel
| | - Ofer Ovadia
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel
| |
Collapse
|
25
|
Koenig WD, Knops JMH, Pesendorfer MB, Zaya DN, Ashley MV. Drivers of synchrony of acorn production in the valley oak (Quercus lobata) at two spatial scales. Ecology 2017; 98:3056-3062. [PMID: 28881003 DOI: 10.1002/ecy.2010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 08/26/2017] [Accepted: 08/31/2017] [Indexed: 11/08/2022]
Abstract
We investigated spatial synchrony of acorn production by valley oaks (Quercus lobata) among individual trees at the within-population, local level and at the among-population, statewide level spanning the geographic range of the species. At the local level, the main drivers of spatial synchrony were water availability and flowering phenology of individual trees, while proximity, temperature differences between trees, and genetic similarity failed to explain a significant proportion of variance in spatial synchrony. At the statewide level, annual rainfall was the primary driver, while proximity was significant by itself but not when controlling for rainfall; genetic similarity was again not significant. These results support the hypothesis that environmental factors, the Moran effect, are key drivers of spatial synchrony in acorn production at both small and large geographic scales. The specific environmental factors differed depending on the geographic scale, but were in both cases related to water availability. In addition, flowering phenology, potentially affecting either density-independent pollination failure (the pollination Moran effect) or density-dependent pollination efficiency (pollen coupling), plays a key role in driving spatial synchrony at the local geographic scale.
Collapse
Affiliation(s)
- Walter D Koenig
- Cornell Lab of Ornithology, 159 Sapsucker Woods Road, Ithaca, New York, 14850, USA.,Department of Neurobiology and Behavior, Cornell University, Ithaca, New York, 14853, USA
| | - Johannes M H Knops
- School of Biological Sciences, University of Nebraska, 211A Manter Hall, Lincoln, Nebraska, 68588, USA
| | - Mario B Pesendorfer
- Cornell Lab of Ornithology, 159 Sapsucker Woods Road, Ithaca, New York, 14850, USA
| | - David N Zaya
- Illinois Natural History Survey, 1816 S. Oak Street, Champaign, Illinois, 61820, USA
| | - Mary V Ashley
- Department of Biological Sciences, University of Illinois at Chicago, 845 West Taylor Street, Chicago, Illinois, 60607, USA
| |
Collapse
|
26
|
Bittner TD, Hajek AE, Liebhold AM, Thistle H. Modification of a Pollen Trap Design To Capture Airborne Conidia of Entomophaga maimaiga and Detection of Conidia by Quantitative PCR. Appl Environ Microbiol 2017; 83:e00724-17. [PMID: 28625988 DOI: 10.1128/AEM.00724-17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The goal of this study was to develop effective and practical field sampling methods for quantification of aerial deposition of airborne conidia of Entomophaga maimaiga over space and time. This important fungal pathogen is a major cause of larval death in invasive gypsy moth (Lymantria dispar) populations in the United States. Airborne conidia of this pathogen are relatively large (similar in size to pollen), with unusual characteristics, and require specialized methods for collection and quantification. Initially, dry sampling (settling of spores from the air onto a dry surface) was used to confirm the detectability of E. maimaiga at field sites with L. dispar deaths caused by E. maimaiga, using quantitative PCR (qPCR) methods. We then measured the signal degradation of conidial DNA on dry surfaces under field conditions, ultimately rejecting dry sampling as a reliable method due to rapid DNA degradation. We modified a chamber-style trap commonly used in palynology to capture settling spores in buffer. We tested this wet-trapping method in a large-scale (137-km) spore-trapping survey across gypsy moth outbreak regions in Pennsylvania undergoing epizootics, in the summer of 2016. Using 4-day collection periods during the period of late instar and pupal development, we detected variable amounts of target DNA settling from the air. The amounts declined over the season and with distance from the nearest defoliated area, indicating airborne spore dispersal from outbreak areas.IMPORTANCE We report on a method for trapping and quantifying airborne spores of Entomophaga maimaiga, an important fungal pathogen affecting gypsy moth (Lymantria dispar) populations. This method can be used to track dispersal of E. maimaiga from epizootic areas and ultimately to provide critical understanding of the spatial dynamics of gypsy moth-pathogen interactions.
Collapse
|
27
|
Pardikes NA, Harrison JG, Shapiro AM, Forister ML. Synchronous population dynamics in California butterflies explained by climatic forcing. R Soc Open Sci 2017; 4:170190. [PMID: 28791146 PMCID: PMC5541541 DOI: 10.1098/rsos.170190] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 06/21/2017] [Indexed: 05/16/2023]
Abstract
A long-standing challenge for population biology has been to understand why some species are characterized by populations that fluctuate in size independently, while populations of other species fluctuate synchronously across space. The effects of climatic variation and dispersal have been invoked to explain synchronous population dynamics, however an understanding of the relative influence of these drivers in natural populations is lacking. Here we compare support for dispersal- versus climate-driven models of interspecific variation in synchrony using 27 years of observations of 65 butterfly species at 10 sites spanning 2750 m of elevation in Northern California. The degree of spatial synchrony exhibited by each butterfly species was used as a response in a unique approach that allowed us to investigate whether interspecific variation in response to climate or dispersal propensity was most predictive of interspecific variation in synchrony. We report that variation in sensitivity to climate explained 50% of interspecific variation in synchrony, whereas variation in dispersal propensity explained 23%. Sensitivity to the El Niño Southern Oscillation, a primary driver of regional climate, was the best predictor of synchrony. Combining sensitivity to climate and dispersal propensity into a single model did not greatly increase model performance, confirming the primacy of climatic sensitivity for driving spatial synchrony in butterflies. Finally, we uncovered a relationship between spatial synchrony and population decline that is consistent with theory, but small in magnitude, which suggests that the degree to which populations fluctuate in synchrony is of limited use for understanding the ongoing decline of the Northern California butterfly fauna.
Collapse
Affiliation(s)
- Nicholas A. Pardikes
- Program in Ecology, Evolution, and Conservation Biology, Department of Biology, University of Nevada, Reno, NV, USA
- Department of Biology, University of Nevada, Reno, NV, USA
- Authors for correspondence: Nicholas A. Pardikes e-mail:
| | - Joshua G. Harrison
- Program in Ecology, Evolution, and Conservation Biology, Department of Biology, University of Nevada, Reno, NV, USA
- Department of Biology, University of Nevada, Reno, NV, USA
- Authors for correspondence: Joshua G. Harrison e-mail:
| | - Arthur M. Shapiro
- Center for Population Biology, University of California, Davis, CA, USA
| | - Matthew L. Forister
- Program in Ecology, Evolution, and Conservation Biology, Department of Biology, University of Nevada, Reno, NV, USA
- Department of Biology, University of Nevada, Reno, NV, USA
| |
Collapse
|
28
|
Walter JA, Sheppard LW, Anderson TL, Kastens JH, Bjørnstad ON, Liebhold AM, Reuman DC. The geography of spatial synchrony. Ecol Lett 2017; 20:801-814. [PMID: 28547786 DOI: 10.1111/ele.12782] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 01/20/2017] [Accepted: 04/12/2017] [Indexed: 02/03/2023]
Abstract
Spatial synchrony, defined as correlated temporal fluctuations among populations, is a fundamental feature of population dynamics, but many aspects of synchrony remain poorly understood. Few studies have examined detailed geographical patterns of synchrony; instead most focus on how synchrony declines with increasing linear distance between locations, making the simplifying assumption that distance decay is isotropic. By synthesising and extending prior work, we show how geography of synchrony, a term which we use to refer to detailed spatial variation in patterns of synchrony, can be leveraged to understand ecological processes including identification of drivers of synchrony, a long-standing challenge. We focus on three main objectives: (1) showing conceptually and theoretically four mechanisms that can generate geographies of synchrony; (2) documenting complex and pronounced geographies of synchrony in two important study systems; and (3) demonstrating a variety of methods capable of revealing the geography of synchrony and, through it, underlying organism ecology. For example, we introduce a new type of network, the synchrony network, the structure of which provides ecological insight. By documenting the importance of geographies of synchrony, advancing conceptual frameworks, and demonstrating powerful methods, we aim to help elevate the geography of synchrony into a mainstream area of study and application.
Collapse
Affiliation(s)
- Jonathan A Walter
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS, USA.,Department of Biology, Virginia Commonwealth University, Richmond, VA, USA.,Kansas Biological Survey, University of Kansas, Lawrence, KS, USA
| | - Lawrence W Sheppard
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS, USA.,Kansas Biological Survey, University of Kansas, Lawrence, KS, USA
| | - Thomas L Anderson
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS, USA.,Kansas Biological Survey, University of Kansas, Lawrence, KS, USA
| | - Jude H Kastens
- Kansas Biological Survey, University of Kansas, Lawrence, KS, USA
| | - Ottar N Bjørnstad
- Department of Entomology, Pennsylvania State University, University Park, PA, USA.,Departments of Entomology and Biology, Pennsylvania State University, University Park, PA, USA
| | | | - Daniel C Reuman
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS, USA.,Kansas Biological Survey, University of Kansas, Lawrence, KS, USA.,Laboratory of Populations, Rockefeller University, 1230 York Ave, New York, NY, USA
| |
Collapse
|
29
|
Swengel AB, Swengel SR. Complex Messages in Long-Term Monitoring of Regal Fritillary (Speyeria idalia) (Lepidoptera: Nymphalidae) in the State of Wisconsin, USA, 1988-2015. Insects 2017; 8:E6. [PMID: 28075377 DOI: 10.3390/insects8010006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 12/12/2016] [Accepted: 01/02/2017] [Indexed: 11/17/2022]
Abstract
The regal fritillary ("regal") (Speyeria idalia) is endangered in Wisconsin, USA, and declining and at risk range-wide. During 1988-2015, we surveyed 24 known regal sites and >100 areas of potential habitat in Wisconsin. We recorded 9037 individuals in 742.7 km on the peak survey per year at occupied sites. At six sites surveyed over 5-25 years, we found regal fritillaries in only one year, mostly in the latter half of the study. The three populations in the state with more favorable trends than the median had a never-burned refugium and/or infrequent fire management. They also all had substantial amounts of grazing, haying, and/or mowing managements. Sites with trends below the regional median trend had frequent or moderate fire management, and either a diminishing never-burned refugium or none at all. Regal populations at sites with ≤15 ha of grassland have become undetectable. Nonetheless, Hogback, a slightly larger than 15 ha site, had the most favorable trend, a significant increase. Nearly all Wisconsin Regal populations known before 1990 declined to consistent non-findability, even though these were conserved sites. More favorable trends at more recently discovered populations may be attributable to species-specific habitat management protocols implemented in the 1990s. Two sites with better than median long-term trends represent the longest consistent land ownership of known Regal populations in the state. This wide range of population outcomes illustrates both the need for long-term monitoring and the challenges of explaining the outcomes. Despite evidence of increasing Regal dispersal, this species remains very localized, indicating the unsuitability of the wider landscape as regal habitat. The number of significantly declining or no longer detectable populations in Wisconsin indicates an ever more adverse landscape for this species. Sites will need to have habitat characteristics that are ever more optimal in a wide range of climatic conditions for Regal populations to persist.
Collapse
|
30
|
Tack AJM, Mononen T, Hanski I. Increasing frequency of low summer precipitation synchronizes dynamics and compromises metapopulation stability in the Glanville fritillary butterfly. Proc Biol Sci 2016; 282:20150173. [PMID: 25854888 DOI: 10.1098/rspb.2015.0173] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Climate change is known to shift species' geographical ranges, phenologies and abundances, but less is known about other population dynamic consequences. Here, we analyse spatio-temporal dynamics of the Glanville fritillary butterfly (Melitaea cinxia) in a network of 4000 dry meadows during 21 years. The results demonstrate two strong, related patterns: the amplitude of year-to-year fluctuations in the size of the metapopulation as a whole has increased, though there is no long-term trend in average abundance; and there is a highly significant increase in the level of spatial synchrony in population dynamics. The increased synchrony cannot be explained by increasing within-year spatial correlation in precipitation, the key environmental driver of population change, or in per capita growth rate. On the other hand, the frequency of drought during a critical life-history stage (early larval instars) has increased over the years, which is sufficient to explain the increasing amplitude and the expanding spatial synchrony in metapopulation dynamics. Increased spatial synchrony has the general effect of reducing long-term metapopulation viability even if there is no change in average metapopulation size. This study demonstrates how temporal changes in weather conditions can lead to striking changes in spatio-temporal population dynamics.
Collapse
Affiliation(s)
- Ayco J M Tack
- Metapopulation Research Centre, Department of Biosciences, University of Helsinki, PO Box 65 (Viikinkaari 1), Helsinki 00014, Finland Department of Ecology, Environment and Plant Sciences, Stockholm University, Lilla Frescati, Stockholm 106 91, Sweden
| | - Tommi Mononen
- Metapopulation Research Centre, Department of Biosciences, University of Helsinki, PO Box 65 (Viikinkaari 1), Helsinki 00014, Finland Department of Neuroscience and Biomedical Engineering, Aalto University, PO Box 12200, Aalto 00076, Finland
| | - Ilkka Hanski
- Metapopulation Research Centre, Department of Biosciences, University of Helsinki, PO Box 65 (Viikinkaari 1), Helsinki 00014, Finland
| |
Collapse
|
31
|
Shestakova TA, Gutiérrez E, Kirdyanov AV, Camarero JJ, Génova M, Knorre AA, Linares JC, Resco de Dios V, Sánchez-Salguero R, Voltas J. Forests synchronize their growth in contrasting Eurasian regions in response to climate warming. Proc Natl Acad Sci U S A 2016; 113:662-7. [PMID: 26729860 DOI: 10.1073/pnas.1514717113] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Forests play a key role in the carbon balance of terrestrial ecosystems. One of the main uncertainties in global change predictions lies in how the spatiotemporal dynamics of forest productivity will be affected by climate warming. Here we show an increasing influence of climate on the spatial variability of tree growth during the last 120 y, ultimately leading to unprecedented temporal coherence in ring-width records over wide geographical scales (spatial synchrony). Synchrony in growth patterns across cold-constrained (central Siberia) and drought-constrained (Spain) Eurasian conifer forests have peaked in the early 21st century at subcontinental scales (∼ 1,000 km). Such enhanced synchrony is similar to that observed in trees co-occurring within a stand. In boreal forests, the combined effects of recent warming and increasing intensity of climate extremes are enhancing synchrony through an earlier start of wood formation and a stronger impact of year-to-year fluctuations of growing-season temperatures on growth. In Mediterranean forests, the impact of warming on synchrony is related mainly to an advanced onset of growth and the strengthening of drought-induced growth limitations. Spatial patterns of enhanced synchrony represent early warning signals of climate change impacts on forest ecosystems at subcontinental scales.
Collapse
|
32
|
Seidl R, Müller J, Hothorn T, Bässler C, Heurich M, Kautz M. Small beetle, large-scale drivers: how regional and landscape factors affect outbreaks of the European spruce bark beetle. J Appl Ecol 2015. [PMID: 27041769 DOI: 10.5061/dryad.c5g9s] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
1. Unprecedented bark beetle outbreaks have been observed for a variety of forest ecosystems recently, and damage is expected to further intensify as a consequence of climate change. In Central Europe, the response of ecosystem management to increasing infestation risk has hitherto focused largely on the stand level, while the contingency of outbreak dynamics on large-scale drivers remains poorly understood. 2. To investigate how factors beyond the local scale contribute to the infestation risk from Ips typographus (Col., Scol.), we analysed drivers across seven orders of magnitude in scale (from 103 to 1010 m2) over a 23-year period, focusing on the Bavarian Forest National Park. Time-discrete hazard modelling was used to account for local factors and temporal dependencies. Subsequently, beta regression was applied to determine the influence of regional and landscape factors, the latter characterized by means of graph theory. 3. We found that in addition to stand variables, large-scale drivers also strongly influenced bark beetle infestation risk. Outbreak waves were closely related to landscape-scale connectedness of both host and beetle populations as well as to regional bark beetle infestation levels. Furthermore, regional summer drought was identified as an important trigger for infestation pulses. Large-scale synchrony and connectivity are thus key drivers of the recently observed bark beetle outbreak in the area. 4.Synthesis and applications. Our multiscale analysis provides evidence that the risk for biotic disturbances is highly dependent on drivers beyond the control of traditional stand-scale management. This finding highlights the importance of fostering the ability to cope with and recover from disturbance. It furthermore suggests that a stronger consideration of landscape and regional processes is needed to address changing disturbance regimes in ecosystem management.
Collapse
Affiliation(s)
- Rupert Seidl
- Department of Forest- and Soil Sciences, Institute of Silviculture, University of Natural Resources and Life Sciences (BOKU) Vienna, Peter Jordan Straße 82, 1190 Wien, Austria
| | - Jörg Müller
- Bavarian Forest National Park, Freyungerstr. 2, 94481 Grafenau, Germany ; Terrestrial Ecology Research Group, Department of Ecology and Ecosystem Management, Center for Food and Life Sciences Weihenstephan, Technische Universität München, Hans-Carl-von-Carlowitz-Platz 2, 85354 Freising, Germany
| | - Torsten Hothorn
- Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Hirschengraben 84, 8001 Zurich, Switzerland
| | - Claus Bässler
- Bavarian Forest National Park, Freyungerstr. 2, 94481 Grafenau, Germany
| | - Marco Heurich
- Bavarian Forest National Park, Freyungerstr. 2, 94481 Grafenau, Germany
| | - Markus Kautz
- Institute of Meteorology and Climate Research - Atmospheric Environmental Research, Karlsruhe Institute of Technology (KIT), Kreuzeckbahnstraße 19, 82467 Garmisch-Partenkirchen, Germany
| |
Collapse
|
33
|
Seidl R, Müller J, Hothorn T, Bässler C, Heurich M, Kautz M. Small beetle, large-scale drivers: how regional and landscape factors affect outbreaks of the European spruce bark beetle. J Appl Ecol 2015; 53:530-540. [PMID: 27041769 DOI: 10.1111/1365-2664.12540] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
1. Unprecedented bark beetle outbreaks have been observed for a variety of forest ecosystems recently, and damage is expected to further intensify as a consequence of climate change. In Central Europe, the response of ecosystem management to increasing infestation risk has hitherto focused largely on the stand level, while the contingency of outbreak dynamics on large-scale drivers remains poorly understood. 2. To investigate how factors beyond the local scale contribute to the infestation risk from Ips typographus (Col., Scol.), we analysed drivers across seven orders of magnitude in scale (from 103 to 1010 m2) over a 23-year period, focusing on the Bavarian Forest National Park. Time-discrete hazard modelling was used to account for local factors and temporal dependencies. Subsequently, beta regression was applied to determine the influence of regional and landscape factors, the latter characterized by means of graph theory. 3. We found that in addition to stand variables, large-scale drivers also strongly influenced bark beetle infestation risk. Outbreak waves were closely related to landscape-scale connectedness of both host and beetle populations as well as to regional bark beetle infestation levels. Furthermore, regional summer drought was identified as an important trigger for infestation pulses. Large-scale synchrony and connectivity are thus key drivers of the recently observed bark beetle outbreak in the area. 4.Synthesis and applications. Our multiscale analysis provides evidence that the risk for biotic disturbances is highly dependent on drivers beyond the control of traditional stand-scale management. This finding highlights the importance of fostering the ability to cope with and recover from disturbance. It furthermore suggests that a stronger consideration of landscape and regional processes is needed to address changing disturbance regimes in ecosystem management.
Collapse
Affiliation(s)
- Rupert Seidl
- Department of Forest- and Soil Sciences, Institute of Silviculture, University of Natural Resources and Life Sciences (BOKU) Vienna, Peter Jordan Straße 82, 1190 Wien, Austria
| | - Jörg Müller
- Bavarian Forest National Park, Freyungerstr. 2, 94481 Grafenau, Germany ; Terrestrial Ecology Research Group, Department of Ecology and Ecosystem Management, Center for Food and Life Sciences Weihenstephan, Technische Universität München, Hans-Carl-von-Carlowitz-Platz 2, 85354 Freising, Germany
| | - Torsten Hothorn
- Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Hirschengraben 84, 8001 Zurich, Switzerland
| | - Claus Bässler
- Bavarian Forest National Park, Freyungerstr. 2, 94481 Grafenau, Germany
| | - Marco Heurich
- Bavarian Forest National Park, Freyungerstr. 2, 94481 Grafenau, Germany
| | - Markus Kautz
- Institute of Meteorology and Climate Research - Atmospheric Environmental Research, Karlsruhe Institute of Technology (KIT), Kreuzeckbahnstraße 19, 82467 Garmisch-Partenkirchen, Germany
| |
Collapse
|
34
|
Penczykowski RM, Walker E, Soubeyrand S, Laine AL. Linking winter conditions to regional disease dynamics in a wild plant-pathogen metapopulation. New Phytol 2015; 205:1142-1152. [PMID: 25382661 DOI: 10.1111/nph.13145] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 09/25/2014] [Indexed: 06/04/2023]
Abstract
Pathogens are considered to drive ecological and evolutionary dynamics of plant populations, but we lack data measuring the population-level consequences of infection in wild plant-pathogen interactions. Moreover, while it is often assumed that offseason environmental conditions drive seasonal declines in pathogen population size, little is known about how offseason environmental conditions impact the survival of pathogen resting stages, and how critical the offseason is for the next season's epidemic. The fungal pathogen Podosphaera plantaginis persists as a dynamic metapopulation in the large network of Plantago lanceolata host populations. Here, we analyze long-term data to measure the spatial synchrony of epidemics and consequences of infection for over 4000 host populations. Using a theoretical model, we study whether large-scale environmental change could synchronize disease occurrence across the metapopulation. During 2001-2013 exposure to freezing decreased, while pathogen extinction-colonization-persistence rates became more synchronized. Simulations of a theoretical model suggest that increasingly favorable winter conditions for pathogen survival could drive such synchronization. Our data also show that infection decreases host population growth. These results confirm that mild winter conditions increase pathogen overwintering success and thus increase disease prevalence across the metapopulation. Further, we conclude that the pathogen can drive host population growth in the Plantago-Podosphaera system.
Collapse
Affiliation(s)
- Rachel M Penczykowski
- Metapopulation Research Group, Department of Biosciences, University of Helsinki, PO Box 65, (Viikinkaari 1), Helsinki, FI-00014, Finland
| | - Emily Walker
- INRA, UR546 Biostatistics and Spatial Processes, 84914, Avignon, France
| | - Samuel Soubeyrand
- INRA, UR546 Biostatistics and Spatial Processes, 84914, Avignon, France
| | - Anna-Liisa Laine
- Metapopulation Research Group, Department of Biosciences, University of Helsinki, PO Box 65, (Viikinkaari 1), Helsinki, FI-00014, Finland
| |
Collapse
|
35
|
Büntgen U, Liebhold A, Jenny H, Mysterud A, Egli S, Nievergelt D, Stenseth NC, Bollmann K. European springtime temperature synchronises ibex horn growth across the eastern Swiss Alps. Ecol Lett 2013; 17:303-13. [PMID: 24341995 PMCID: PMC4257578 DOI: 10.1111/ele.12231] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 10/09/2013] [Accepted: 11/12/2013] [Indexed: 12/03/2022]
Abstract
Direct effects of climate change on animal physiology, and indirect impacts from disruption of seasonal synchrony and breakdown of trophic interactions are particularly severe in Arctic and Alpine ecosystems. Unravelling biotic from abiotic drivers, however, remains challenging because high-resolution animal population data are often limited in space and time. Here, we show that variation in annual horn growth (an indirect proxy for individual performance) of 8043 male Alpine ibex (Capra ibex) over the past four decades is well synchronised among eight disjunct colonies in the eastern Swiss Alps. Elevated March to May temperatures, causing premature melting of Alpine snowcover, earlier plant phenology and subsequent improvement of ibex food resources, fuelled annual horn growth. These results reveal dependency of local trophic interactions on large-scale climate dynamics, and provide evidence that declining herbivore performance is not a universal response to global warming even for high-altitude populations that are also harvested.
Collapse
Affiliation(s)
- Ulf Büntgen
- Swiss Federal Institute for Forest Snow and Landscape Research (WSL), Birmensdorf, CH-8903, Switzerland; Oeschger Centre for Climate Change Research (OCCR), University of Bern, Bern, CH-3012, Switzerland; Global Change Research Centre AS CR, v.v.i., Bělidla 986/4a, Brno, CZ-60300, Czech Republic
| | | | | | | | | | | | | | | |
Collapse
|
36
|
Duncan AB, Gonzalez A, Kaltz O. Stochastic environmental fluctuations drive epidemiology in experimental host-parasite metapopulations. Proc Biol Sci 2013; 280:20131747. [PMID: 23966645 DOI: 10.1098/rspb.2013.1747] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Environmental fluctuations are important for parasite spread and persistence. However, the effects of the spatial and temporal structure of environmental fluctuations on host-parasite dynamics are not well understood. Temporal fluctuations can be random but positively autocorrelated, such that the environment is similar to the recent past (red noise), or random and uncorrelated with the past (white noise). We imposed red or white temporal temperature fluctuations on experimental metapopulations of Paramecium caudatum, experiencing an epidemic of the bacterial parasite Holospora undulata. Metapopulations (two subpopulations linked by migration) experienced fluctuations between stressful (5 °C) and permissive (23 °C) conditions following red or white temporal sequences. Spatial variation in temperature fluctuations was implemented by exposing subpopulations to the same (synchronous temperatures) or different (asynchronous temperatures) temporal sequences. Red noise, compared with white noise, enhanced parasite persistence. Despite this, red noise coupled with asynchronous temperatures allowed infected host populations to maintain sizes equivalent to uninfected populations. It is likely that this occurs because subpopulations in permissive conditions rescue declining subpopulations in stressful conditions. We show how patterns of temporal and spatial environmental fluctuations can impact parasite spread and host population abundance. We conclude that accurate prediction of parasite epidemics may require realistic models of environmental noise.
Collapse
Affiliation(s)
- Alison B Duncan
- Institut des Sciences de l'Evolution de Montpellier, UMR 5554, Université Montpellier 2, Place Eugene Bataillon, 34095 Montpellier Cedex 05, France.
| | | | | |
Collapse
|
37
|
Wimberly MC, Midekisa A, Semuniguse P, Teka H, Henebry GM, Chuang TW, Senay GB. Spatial synchrony of malaria outbreaks in a highland region of Ethiopia. Trop Med Int Health 2012; 17:1192-201. [PMID: 22863170 DOI: 10.1111/j.1365-3156.2012.03058.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
To understand the drivers and consequences of malaria in epidemic-prone regions, it is important to know whether epidemics emerge independently in different areas as a consequence of local contingencies, or whether they are synchronised across larger regions as a result of climatic fluctuations and other broad-scale drivers. To address this question, we collected historical malaria surveillance data for the Amhara region of Ethiopia and analysed them to assess the consistency of various indicators of malaria risk and determine the dominant spatial and temporal patterns of malaria within the region. We collected data from a total of 49 districts from 1999-2010. Data availability was better for more recent years and more data were available for clinically diagnosed outpatient malaria cases than confirmed malaria cases. Temporal patterns of outpatient malaria case counts were correlated with the proportion of outpatients diagnosed with malaria and confirmed malaria case counts. The proportion of outpatients diagnosed with malaria was spatially clustered, and these cluster locations were generally consistent from year to year. Outpatient malaria cases exhibited spatial synchrony at distances up to 300 km, supporting the hypothesis that regional climatic variability is an important driver of epidemics. Our results suggest that decomposing malaria risk into separate spatial and temporal components may be an effective strategy for modelling and forecasting malaria risk across large areas. They also emphasise both the value and limitations of working with historical surveillance datasets and highlight the importance of enhancing existing surveillance efforts.
Collapse
Affiliation(s)
- Michael C Wimberly
- Geographic Information Science Center of Excellence, South Dakota State University, Brookings, SD, USA Health, Development, and Anti-Malaria Association, Addis Ababa, Ethiopia United States Agency for International Development, Addis Ababa, Ethiopia USGS Earth Resources Observation and Science Center, Sioux Falls, SD, USA
| | | | | | | | | | | | | |
Collapse
|
38
|
Kendall BE, Bjørnstad ON, Bascompte J, Keitt TH, Fagan WF. Dispersal, Environmental Correlation, and Spatial Synchrony in Population Dynamics. Am Nat 2000; 155:628-636. [PMID: 10777435 DOI: 10.1086/303350] [Citation(s) in RCA: 169] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Many species exhibit widespread spatial synchrony in population fluctuations. This pattern is of great ecological interest and can be a source of concern when the species is rare or endangered. Both dispersal and spatial correlations in the environment have been implicated as possible causes of this pattern, but these two factors have rarely been studied in combination. We develop a spatially structured population model, simple enough to obtain analytic solutions for the population correlation, that incorporates both dispersal and environmental correlation. We ask whether these two synchronizing factors contribute additively to the total spatial population covariance. We find that there is always an interaction between these two factors and that this interaction is small only when one or both of the environmental correlation and the dispersal rate are small. The interaction is opposite in sign to the environmental correlation; so, in the normal case of positive environmental correlation across sites, the population synchrony will be lower than predicted by simply adding the effects of dispersal and environmental correlation. We also find that population synchrony declines as the strength of population regulation increases. These results indicate that dispersal and environmental correlation need to be considered in combination as explanations for observed patterns of population synchrony.
Collapse
|