1
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Dial RJ, Maher CT, Hewitt RE, Sullivan PF. Sufficient conditions for rapid range expansion of a boreal conifer. Nature 2022; 608:546-551. [PMID: 35948635 PMCID: PMC9385489 DOI: 10.1038/s41586-022-05093-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 07/08/2022] [Indexed: 11/14/2022]
Abstract
Unprecedented modern rates of warming are expected to advance boreal forest into Arctic tundra1, thereby reducing albedo2–4, altering carbon cycling4 and further changing climate1–4, yet the patterns and processes of this biome shift remain unclear5. Climate warming, required for previous boreal advances6–17, is not sufficient by itself for modern range expansion of conifers forming forest–tundra ecotones5,12–15,17–20. No high-latitude population of conifers, the dominant North American Arctic treeline taxon, has previously been documented5 advancing at rates following the last glacial maximum (LGM)6–8. Here we describe a population of white spruce (Picea glauca) advancing at post-LGM rates7 across an Arctic basin distant from established treelines and provide evidence of mechanisms sustaining the advance. The population doubles each decade, with exponential radial growth in the main stems of individual trees correlating positively with July air temperature. Lateral branches in adults and terminal leaders in large juveniles grow almost twice as fast as those at established treelines. We conclude that surpassing temperature thresholds1,6–17, together with winter winds facilitating long-distance dispersal, deeper snowpack and increased soil nutrient availability promoting recruitment and growth, provides sufficient conditions for boreal forest advance. These observations enable forecast modelling with important insights into the environmental conditions converting tundra into forest. A boreal conifer is advancing northwards into Arctic tundra, with this treeline advance facilitated by climate warming together with winter winds, deeper snow and increased soil nutrient availability.
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Affiliation(s)
- Roman J Dial
- Institute of Culture and Environment, Alaska Pacific University, Anchorage, AK, USA.
| | - Colin T Maher
- Environment and Natural Resources Institute, University of Alaska Anchorage, Anchorage, AK, USA.
| | - Rebecca E Hewitt
- Department of Environmental Studies, Amherst College, Amherst, MA, USA. .,Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.
| | - Patrick F Sullivan
- Environment and Natural Resources Institute, University of Alaska Anchorage, Anchorage, AK, USA.
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2
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Raiho AM, Scharf HR, Roland CA, Swanson DK, Stehn SE, Hooten MB. Searching for refuge: A framework for identifying site factors conferring resistance to climate‐driven vegetation change. DIVERS DISTRIB 2022. [DOI: 10.1111/ddi.13492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Affiliation(s)
- Ann M. Raiho
- Department of Fish, Wildlife, and Conservation Biology Colorado State University Fort Collins Colorado USA
| | - Henry R. Scharf
- Department of Mathematics and Statistics San Diego State University San Diego California USA
| | - Carl A. Roland
- Denali National Park and Preserve National Park Service Anchorage Alaska USA
| | | | - Sarah E. Stehn
- Denali National Park and Preserve National Park Service Anchorage Alaska USA
- Arctic Network National Park Service Anchorage Alaska USA
| | - Mevin B. Hooten
- Department of Fish, Wildlife, and Conservation Biology Colorado State University Fort Collins Colorado USA
- Department of Statistics Colorado State University Fort Collins Colorado USA
- Colorado Cooperative Fish and Wildlife Research Unit U.S. Geological Survey Fort Collins Colorado USA
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3
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Raiho AM, Nicklen EF, Foster AC, Roland CA, Hooten MB. Bridging implementation gaps to connect large ecological datasets and complex models. Ecol Evol 2021; 11:18271-18287. [PMID: 35003672 PMCID: PMC8717344 DOI: 10.1002/ece3.8420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 11/12/2021] [Accepted: 11/16/2021] [Indexed: 11/09/2022] Open
Abstract
Merging robust statistical methods with complex simulation models is a frontier for improving ecological inference and forecasting. However, bringing these tools together is not always straightforward. Matching data with model output, determining starting conditions, and addressing high dimensionality are some of the complexities that arise when attempting to incorporate ecological field data with mechanistic models directly using sophisticated statistical methods. To illustrate these complexities and pragmatic paths forward, we present an analysis using tree-ring basal area reconstructions in Denali National Park (DNPP) to constrain successional trajectories of two spruce species (Picea mariana and Picea glauca) simulated by a forest gap model, University of Virginia Forest Model Enhanced-UVAFME. Through this process, we provide preliminary ecological inference about the long-term competitive dynamics between slow-growing P. mariana and relatively faster-growing P. glauca. Incorporating tree-ring data into UVAFME allowed us to estimate a bias correction for stand age with improved parameter estimates. We found that higher parameter values for P. mariana minimum growth under stress and P. glauca maximum growth rate were key to improving simulations of coexistence, agreeing with recent research that faster-growing P. glauca may outcompete P. mariana under climate change scenarios. The implementation challenges we highlight are a crucial part of the conversation for how to bring models together with data to improve ecological inference and forecasting.
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Affiliation(s)
- Ann M. Raiho
- Department of Fish, Wildlife, and Conservation BiologyColorado State UniversityFort CollinsColoradoUSA
| | - E. Fleur Nicklen
- Denali National Park and PreserveNational Park ServiceFairbanksAlaskaUSA
| | - Adrianna C. Foster
- School of Informatics, Computing, and Cyber SystemsNorthern Arizona UniversityFlagstaffArizonaUSA
| | - Carl A. Roland
- Denali National Park and PreserveNational Park ServiceFairbanksAlaskaUSA
| | - Mevin B. Hooten
- Department of Fish, Wildlife, and Conservation BiologyColorado State UniversityFort CollinsColoradoUSA
- Department of StatisticsColorado State UniversityFort CollinsColoradoUSA
- Colorado Cooperative Fish and Wildlife Research UnitU.S. Geological SurveyFort CollinsColoradoUSA
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4
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Nicklen EF, Roland CA, Ruess RW, Scharnweber T, Wilmking M. Divergent responses to permafrost and precipitation reveal mechanisms for the spatial variation of two sympatric spruce. Ecosphere 2021. [DOI: 10.1002/ecs2.3622] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- E. Fleur Nicklen
- Central Alaska Network National Park Service Fairbanks Alaska99709USA
- Department of Biology and Wildlife University of Alaska Fairbanks Alaska99775USA
| | - Carl A. Roland
- Central Alaska Network National Park Service Fairbanks Alaska99709USA
- Denali National Park and Preserve National Park Service Fairbanks Alaska99709USA
| | - Roger W. Ruess
- Department of Biology and Wildlife University of Alaska Fairbanks Alaska99775USA
- Institute of Arctic Biology University of Alaska Fairbanks Alaska99775USA
| | - Tobias Scharnweber
- Institute of Botany and Landscape Ecology University of Greifswald Greifswald17489Germany
| | - Martin Wilmking
- Institute of Botany and Landscape Ecology University of Greifswald Greifswald17489Germany
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5
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Li Q, Kou X, Beierkuhnlein C, Liu S, Ge J. Global patterns of nonanalogous climates in the past and future derived from thermal and hydraulic factors. GLOBAL CHANGE BIOLOGY 2018; 24:2463-2475. [PMID: 29476633 DOI: 10.1111/gcb.14104] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 01/28/2018] [Accepted: 01/30/2018] [Indexed: 06/08/2023]
Abstract
Nonanalogous climates (NACs), climates without modern analogs on Earth, challenge our understanding of eco-evolutionary processes that shape global biodiversity, particularly because of their propensity to promote novel ecosystems. However, NAC studies are generally inadequate and partial. Specifically, systematic comparisons between the future and the past are generally lacking, and hydraulic NACs tend to be underemphasized. In the present study, by adopting a frequency distribution-based method that facilitates the procedures of contributions parsing and conducting multiple comparisons, we provide a global overview of multidimensional NACs for both the past and the future within a unified framework. We show that NACs are globally prevalent, covering roughly half of the land area across the time-periods under investigation, and have a high degree of spatial structure. Patterns of NACs differ dramatically between the past and the future. Hydraulic NACs are more complex both in spatial patterns and in major contributions of variables than are thermal NACs. However, hydraulic NACs are more predictable than originally thought. Generally, hydraulic NACs in the future (2100 AD) exhibit comparable predictability to thermal NACs in the last glacial maximum (LGM) (21k BP). Identifying these NAC patterns has potential implications on climate-adaptive managements and preparing in advance to possibly frequent novel ecosystems. However, a learning-from-the-past strategy might be of limited utility for management under present circumstances.
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Affiliation(s)
- Qin Li
- College of Life Sciences, Beijing Normal University, Beijing, China
- Department of Botany, University of British Columbia, Vancouver, BC, Canada
| | - Xiaojun Kou
- College of Life Sciences, Beijing Normal University, Beijing, China
- Key Laboratory for Biodiversity Science and Ecological Engineering of Ministry of Education, Beijing Normal University, Beijing, China
| | - Carl Beierkuhnlein
- Department of Biogeography, BayCEER, GIB, University of Bayreuth, Bayreuth, Germany
| | - Shirong Liu
- Key Laboratory of China's State Forestry Administration for Forest Ecology and Environment, Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, China
| | - Jianping Ge
- College of Life Sciences, Beijing Normal University, Beijing, China
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6
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Miller AE, Wilson TL, Sherriff RL, Walton J. Warming drives a front of white spruce establishment near western treeline, Alaska. GLOBAL CHANGE BIOLOGY 2017; 23:5509-5522. [PMID: 28712139 DOI: 10.1111/gcb.13814] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 06/20/2017] [Indexed: 06/07/2023]
Abstract
Regional warming has led to increased productivity near the boreal forest margin in Alaska. To date, the effects of warming on seedling recruitment have received little attention, in spite of forecasted forest expansion. Here, we used stand structure and environmental data from 95 white spruce (Picea glauca) plots sampled across a longitudinal gradient in southwest Alaska to explore factors influencing spruce establishment and recruitment near western treeline. We used total counts of live seedlings, saplings, and trees, representing five life stages, to evaluate whether geospatial, climate, and measured plot covariates predicted abundance, using current abundance distributions as a surrogate for climate conditions in the past. We used generalized linear models to test the null hypothesis that conditions favorable for recruitment were similar along the environmental gradient represented by longitude, by exploring relationships between per-plot counts of each life stage and the covariates hypothesized to affect abundance. We also examined the relationship between growing degree days (GDD) and seedling establishment over a period of three decades using tree-ring chronologies obtained from cores taken at a subset of our sites (n = 30). Our results indicated that seedling, sapling, and tree abundance were positively correlated with temperature across the study area. The response to longitude was mixed, with earlier life stages (seedlings, saplings) most abundant at the western end of the gradient, and later life stages (trees) most abundant to the east. The differential relationship between longitude and life-stage abundance suggests a moving front of white spruce establishment through time, driven by changes in environmental conditions near the species' western range limit. Likewise, we found a positive relationship between periods of seedling establishment and GDD, suggesting that longer summers and/or greater heat accumulation might enhance establishment, consistent with the positive relationship we found between life-stage abundance and temperature.
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Affiliation(s)
- Amy E Miller
- National Park Service, Inventory & Monitoring Program, Southwest Alaska Network, Anchorage, AK, USA
| | - Tammy L Wilson
- National Park Service, Inventory & Monitoring Program, Southwest Alaska Network, Anchorage, AK, USA
- Department of Natural Resource Management, South Dakota State University, Brookings, SD, USA
| | - Rosemary L Sherriff
- Geography Department and Forest, Watershed & Wildland Sciences Graduate Program, Humboldt State University, Arcata, CA, USA
| | - James Walton
- National Park Service, Inventory & Monitoring Program, Southwest Alaska Network, Anchorage, AK, USA
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7
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Copenhaver‐Parry PE, Shuman BN, Tinker DB. Toward an improved conceptual understanding of North American tree species distributions. Ecosphere 2017. [DOI: 10.1002/ecs2.1853] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Affiliation(s)
| | - Bryan N. Shuman
- Program in Ecology and Department of Geology & Geophysics University of Wyoming 1000 E. University Avenue Laramie Wyoming 82071 USA
| | - Daniel B. Tinker
- Program in Ecology and Department of Botany University of Wyoming 1000 E. University Avenue Laramie Wyoming 82071 USA
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8
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Li F, Sundermann A, Stoll S, Haase P. A newly developed dispersal metric indicates the succession of benthic invertebrates in restored rivers. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 569-570:1570-1578. [PMID: 27443455 DOI: 10.1016/j.scitotenv.2016.06.251] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 06/30/2016] [Accepted: 06/30/2016] [Indexed: 06/06/2023]
Abstract
Dispersal capacity plays a fundamental role in the riverine benthic invertebrate colonization of new habitats that emerges following flash floods or restoration. However, an appropriate measure of dispersal capacity for benthic invertebrates is still lacking. The dispersal of benthic invertebrates occurs mainly during the aquatic (larval) and aerial (adult) life stages, and the dispersal of each stage can be further subdivided into active and passive modes. Based on these four possible dispersal modes, we first developed a metric (which is very similar to the well-known and widely used saprobic index) to estimate the dispersal capacity for 802 benthic invertebrate taxa by incorporating a weight for each mode. Second, we tested this metric using benthic invertebrate community data from a) 23 large restored river sites with substantial improvements of river bottom habitats dating back 1 to 10years, b) 23 unrestored sites very close to the restored sites, and c) 298 adjacent surrounding sites (mean±standard deviation: 13.0±9.5 per site) within a distance of up to 5km for each restored site in the low mountain and lowland areas of Germany. We hypothesize that our metric will reflect the temporal succession process of benthic invertebrate communities colonizing the restored sites, whereas no temporal changes are expected in the unrestored and surrounding sites. By applying our metric to these three river treatment categories, we found that the average dispersal capacity of benthic invertebrate communities in the restored sites significantly decreased in the early years following restoration, whereas there were no changes in either the unrestored or the surrounding sites. After all taxa had been divided into quartiles representing weak to strong dispersers, this pattern became even more obvious; strong dispersers colonized the restored sites during the first year after restoration and then significantly decreased over time, whereas weak dispersers continued to increase. The successful application of our metric to river restoration might be promising in further applications of this metric, for example, in analyzing metacommunity structure or community's recovery from extreme events such as floods, droughts or catastrophic pollution episodes.
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Affiliation(s)
- Fengqing Li
- Senckenberg Research Institute and Natural History Museum Frankfurt, Department of River Ecology and Conservation, Gelnhausen, Germany.
| | - Andrea Sundermann
- Senckenberg Research Institute and Natural History Museum Frankfurt, Department of River Ecology and Conservation, Gelnhausen, Germany
| | - Stefan Stoll
- Senckenberg Research Institute and Natural History Museum Frankfurt, Department of River Ecology and Conservation, Gelnhausen, Germany
| | - Peter Haase
- Senckenberg Research Institute and Natural History Museum Frankfurt, Department of River Ecology and Conservation, Gelnhausen, Germany; Faculty of Biology, University of Duisburg-Essen, Germany
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9
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Nicklen EF, Roland CA, Ruess RW, Schmidt JH, Lloyd AH. Local site conditions drive climate–growth responses of
Picea mariana
and
Picea glauca
in interior Alaska. Ecosphere 2016. [DOI: 10.1002/ecs2.1507] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- E. Fleur Nicklen
- Central Alaska Network National Park Service 4175 Geist Road Fairbanks Alaska 99709 USA
- Department of Biology and Wildlife Institute of Arctic Biology University of Alaska Fairbanks Fairbanks Alaska 99775 USA
| | - Carl A. Roland
- Central Alaska Network National Park Service 4175 Geist Road Fairbanks Alaska 99709 USA
- Denali National Park and Preserve National Park Service 4175 Geist Road Fairbanks Alaska 99709 USA
| | - Roger W. Ruess
- Department of Biology and Wildlife Institute of Arctic Biology University of Alaska Fairbanks Fairbanks Alaska 99775 USA
| | - Joshua H. Schmidt
- Central Alaska Network National Park Service 4175 Geist Road Fairbanks Alaska 99709 USA
| | - Andrea H. Lloyd
- Department of Biology Middlebury College Middlebury Vermont 05753 USA
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10
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Tautenhahn S, Lichstein JW, Jung M, Kattge J, Bohlman SA, Heilmeier H, Prokushkin A, Kahl A, Wirth C. Dispersal limitation drives successional pathways in Central Siberian forests under current and intensified fire regimes. GLOBAL CHANGE BIOLOGY 2016; 22:2178-2197. [PMID: 26649652 DOI: 10.1111/gcb.13181] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 11/06/2015] [Accepted: 11/18/2015] [Indexed: 06/05/2023]
Abstract
Fire is a primary driver of boreal forest dynamics. Intensifying fire regimes due to climate change may cause a shift in boreal forest composition toward reduced dominance of conifers and greater abundance of deciduous hardwoods, with potential biogeochemical and biophysical feedbacks to regional and global climate. This shift has already been observed in some North American boreal forests and has been attributed to changes in site conditions. However, it is unknown if the mechanisms controlling fire-induced changes in deciduous hardwood cover are similar among different boreal forests, which differ in the ecological traits of the dominant tree species. To better understand the consequences of intensifying fire regimes in boreal forests, we studied postfire regeneration in five burns in the Central Siberian dark taiga, a vast but poorly studied boreal region. We combined field measurements, dendrochronological analysis, and seed-source maps derived from high-resolution satellite images to quantify the importance of site conditions (e.g., organic layer depth) vs. seed availability in shaping postfire regeneration. We show that dispersal limitation of evergreen conifers was the main factor determining postfire regeneration composition and density. Site conditions had significant but weaker effects. We used information on postfire regeneration to develop a classification scheme for successional pathways, representing the dominance of deciduous hardwoods vs. evergreen conifers at different successional stages. We estimated the spatial distribution of different successional pathways under alternative fire regime scenarios. Under intensified fire regimes, dispersal limitation of evergreen conifers is predicted to become more severe, primarily due to reduced abundance of surviving seed sources within burned areas. Increased dispersal limitation of evergreen conifers, in turn, is predicted to increase the prevalence of successional pathways dominated by deciduous hardwoods. The likely fire-induced shift toward greater deciduous hardwood cover may affect climate-vegetation feedbacks via surface albedo, Bowen ratio, and carbon cycling.
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Affiliation(s)
- Susanne Tautenhahn
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Strasse 10, 07745, Jena, Germany
- Department of Biosciences, TU Bergakademie Freiberg, Leipziger Strasse 29, 09596, Freiberg, Germany
| | - Jeremy W Lichstein
- Department of Biology, University of Florida, Gainesville, FL, 32611, USA
| | - Martin Jung
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Strasse 10, 07745, Jena, Germany
| | - Jens Kattge
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Strasse 10, 07745, Jena, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103, Leipzig, Germany
| | - Stephanie A Bohlman
- School of Forest Resources and Conservation, University of Florida, Gainesville, FL, 32611, USA
| | - Hermann Heilmeier
- Department of Biosciences, TU Bergakademie Freiberg, Leipziger Strasse 29, 09596, Freiberg, Germany
| | - Anatoly Prokushkin
- Sukachev Institute of Forest, Siberian Branch, Russian Academy of Sciences, Akademgorodok 50/28, Krasnoyarsk, 660036, Russia
| | - Anja Kahl
- University of Leipzig, Johannisallee 21-23, 04103, Leipzig, Germany
| | - Christian Wirth
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103, Leipzig, Germany
- University of Leipzig, Johannisallee 21-23, 04103, Leipzig, Germany
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11
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Roland CA, Schmidt JH, Nicklen EF. Landscape-scale patterns in tree occupancy and abundance in subarctic Alaska. ECOL MONOGR 2013. [DOI: 10.1890/11-2136.1] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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12
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Beyond distance-invariant survival in inverse recruitment modeling: A case study in Siberian Pinus sylvestris forests. Ecol Modell 2012. [DOI: 10.1016/j.ecolmodel.2012.03.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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13
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Nitschke CR, Amoroso M, Coates KD, Astrup R. The influence of climate change, site type, and disturbance on stand dynamics in northwest British Columbia, Canada. Ecosphere 2012. [DOI: 10.1890/es11-00282.1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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14
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Plants on the move: The role of seed dispersal and initial population establishment for climate-driven range expansions. ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY 2011. [DOI: 10.1016/j.actao.2011.05.001] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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15
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Continued warming could transform Greater Yellowstone fire regimes by mid-21st century. Proc Natl Acad Sci U S A 2011; 108:13165-70. [PMID: 21788495 DOI: 10.1073/pnas.1110199108] [Citation(s) in RCA: 215] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Climate change is likely to alter wildfire regimes, but the magnitude and timing of potential climate-driven changes in regional fire regimes are not well understood. We considered how the occurrence, size, and spatial location of large fires might respond to climate projections in the Greater Yellowstone ecosystem (GYE) (Wyoming), a large wildland ecosystem dominated by conifer forests and characterized by infrequent, high-severity fire. We developed a suite of statistical models that related monthly climate data (1972-1999) to the occurrence and size of fires >200 ha in the northern Rocky Mountains; these models were cross-validated and then used with downscaled (~12 km × 12 km) climate projections from three global climate models to predict fire occurrence and area burned in the GYE through 2099. All models predicted substantial increases in fire by midcentury, with fire rotation (the time to burn an area equal to the landscape area) reduced to <30 y from the historical 100-300 y for most of the GYE. Years without large fires were common historically but are expected to become rare as annual area burned and the frequency of regionally synchronous fires increase. Our findings suggest a shift to novel fire-climate-vegetation relationships in Greater Yellowstone by midcentury because fire frequency and extent would be inconsistent with persistence of the current suite of conifer species. The predicted new fire regime would transform the flora, fauna, and ecosystem processes in this landscape and may indicate similar changes for other subalpine forests.
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16
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Messaoud Y, Chen HYH. The influence of recent climate change on tree height growth differs with species and spatial environment. PLoS One 2011; 6:e14691. [PMID: 21358817 PMCID: PMC3040169 DOI: 10.1371/journal.pone.0014691] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Accepted: 01/25/2011] [Indexed: 11/18/2022] Open
Abstract
Tree growth has been reported to increase in response to recent global climate change in controlled and semi-controlled experiments, but few studies have reported response of tree growth to increased temperature and atmospheric carbon dioxide (CO₂) concentration in natural environments. This study addresses how recent global climate change has affected height growth of trembling aspen (Populus tremuloides Michx) and black spruce (Picea mariana Mill B.S.) in their natural environments. We sampled 145 stands dominated by aspen and 82 dominated by spruce over the entire range of their distributions in British Columbia, Canada. These stands were established naturally after fire between the 19th and 20th centuries. Height growth was quantified as total heights of sampled dominant and co-dominant trees at breast-height age of 50 years. We assessed the relationships between 50-year height growth and environmental factors at both spatial and temporal scales. We also tested whether the tree growth associated with global climate change differed with spatial environment (latitude, longitude and elevation). As expected, height growth of both species was positively related to temperature variables at the regional scale and with soil moisture and nutrient availability at the local scale. While height growth of trembling aspen was not significantly related to any of the temporal variables we examined, that of black spruce increased significantly with stand establishment date, the anomaly of the average maximum summer temperature between May-August, and atmospheric CO₂ concentration, but not with the Palmer Drought Severity Index. Furthermore, the increase of spruce height growth associated with recent climate change was higher in the western than in eastern part of British Columbia. This study demonstrates that the response of height growth to recent climate change, i.e., increasing temperature and atmospheric CO₂ concentration, did not only differ with tree species, but also their growing spatial environment.
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Affiliation(s)
- Yassine Messaoud
- Faculty of Natural Resources Management, Lakehead University, Thunder Bay, Canada
| | - Han Y. H. Chen
- Faculty of Natural Resources Management, Lakehead University, Thunder Bay, Canada
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17
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Abstract
Disturbance regimes are changing rapidly, and the consequences of such changes for ecosystems and linked social-ecological systems will be profound. This paper synthesizes current understanding of disturbance with an emphasis on fundamental contributions to contemporary landscape and ecosystem ecology, then identifies future research priorities. Studies of disturbance led to insights about heterogeneity, scale, and thresholds in space and time and catalyzed new paradigms in ecology. Because they create vegetation patterns, disturbances also establish spatial patterns of many ecosystem processes on the landscape. Drivers of global change will produce new spatial patterns, altered disturbance regimes, novel trajectories of change, and surprises. Future disturbances will continue to provide valuable opportunities for studying pattern-process interactions. Changing disturbance regimes will produce acute changes in ecosystems and ecosystem services over the short (years to decades) and long-term (centuries and beyond). Future research should address questions related to (1) disturbances as catalysts of rapid ecological change, (2) interactions among disturbances, (3) relationships between disturbance and society, especially the intersection of land use and disturbance, and (4) feedbacks from disturbance to other global drivers. Ecologists should make a renewed and concerted effort to understand and anticipate the causes and consequences of changing disturbance regimes.
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Affiliation(s)
- Monica G Turner
- Department of Zoology, University of Wisconsin, Madison, Wisconsin 53706, USA.
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18
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Johnstone JF, McIntire EJB, Pedersen EJ, King G, Pisaric MJF. A sensitive slope: estimating landscape patterns of forest resilience in a changing climate. Ecosphere 2010. [DOI: 10.1890/es10-00102.1] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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