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Shoemaker LG, Hallett LM, Zhao L, Reuman DC, Wang S, Cottingham KL, Hobbs RJ, Castorani MCN, Downing AL, Dudney JC, Fey SB, Gherardi LA, Lany N, Portales-Reyes C, Rypel AL, Sheppard LW, Walter JA, Suding KN. The long and the short of it: Mechanisms of synchronous and compensatory dynamics across temporal scales. Ecology 2022; 103:e3650. [PMID: 35112356 PMCID: PMC9285558 DOI: 10.1002/ecy.3650] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 09/23/2021] [Indexed: 11/07/2022]
Abstract
Synchronous dynamics (fluctuations that occur in unison) are universal phenomena with widespread implications for ecological stability. Synchronous dynamics can amplify the destabilizing effect of environmental variability on ecosystem functions such as productivity, whereas the inverse, compensatory dynamics, can stabilize function. Here we combine simulation and empirical analyses to elucidate mechanisms that underlie patterns of synchronous versus compensatory dynamics. In both simulated and empirical communities, we show that synchronous and compensatory dynamics are not mutually exclusive but instead can vary by timescale. Our simulations identify multiple mechanisms that can generate timescale‐specific patterns, including different environmental drivers, diverse life histories, dispersal, and non‐stationary dynamics. We find that traditional metrics for quantifying synchronous dynamics are often biased toward long‐term drivers and may miss the importance of short‐term drivers. Our findings indicate key mechanisms to consider when assessing synchronous versus compensatory dynamics and our approach provides a pathway for disentangling these dynamics in natural systems.
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Affiliation(s)
| | - Lauren M Hallett
- Environmental Studies Program and Department of Biology, University of Oregon, Eugene, Oregon, USA
| | - Lei Zhao
- Beijing Key Laboratory of Biodiversity and Organic Farming, College of Resources and Environmental Sciences, China Agricultural University, Beijing, China
| | - Daniel C Reuman
- Department of Ecology and Evolutionary Biology and Kansas Biological Survey, University of Kansas, Higuchi Hall, 2101 Constant Ave, Lawrence, Kansas, USA
| | - Shaopeng Wang
- Department of Ecology, College of Urban and Environmental Science, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, China
| | - Kathryn L Cottingham
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, USA
| | - Richard J Hobbs
- School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Max C N Castorani
- Department of Environmental Sciences, University of Virginia, Charlottesville, Virginia, USA
| | - Amy L Downing
- Department of Zoology, Ohio Wesleyan University, Delaware, Ohio, USA
| | - Joan C Dudney
- Department of Plant Sciences, UC Davis, Davis, California, United States.,Department of Environmental Science Policy and Management, University of California at Berkeley, Berkeley, California, USA
| | - Samuel B Fey
- Department of Biology, Reed College, Portland, Oregon, USA
| | - Laureano A Gherardi
- Global Drylands Center and School of Life Sciences, Arizona State University, Tempe, Arizona, USA
| | - Nina Lany
- Department of Forestry, Michigan State University, East Lansing, Michigan, USA
| | - Cristina Portales-Reyes
- Department of Ecology, Evolution, and Behavior, University of Minnesota, Saint Paul, Minnesota, USA
| | - Andrew L Rypel
- Department of Fish, Wildlife & Conservation Biology, and Center for Watershed Sciences, University of California, Davis, California, USA
| | - Lawrence W Sheppard
- Department of Ecology and Evolutionary Biology and Kansas Biological Survey, University of Kansas, Higuchi Hall, 2101 Constant Ave, Lawrence, Kansas, USA
| | - Jonathan A Walter
- Department of Environmental Sciences, University of Virginia, Charlottesville, Virginia, USA.,Ronin Institute for Independent Scholarship, Montclair, New Jersey, United States
| | - Katharine N Suding
- Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, Colorado, USA
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Priming of microbial microcystin degradation in biomass-fed gravity driven membrane filtration biofilms. Syst Appl Microbiol 2017; 41:221-231. [PMID: 29358063 DOI: 10.1016/j.syapm.2017.11.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 11/22/2017] [Accepted: 11/23/2017] [Indexed: 11/21/2022]
Abstract
Gravity-driven membrane (GDM) filtration is a promising tool for low-cost decentralized drinking water production. The biofilms in GDM systems are able of removing harmful chemical components, particularly toxic cyanobacterial metabolites such as microcystins (MCs). This is relevant for the application of GDM filtration because anthropogenic nutrient input and climate change have led to an increase of toxic cyanobacterial blooms. However, removal of MCs in newly developing GDM biofilms is only established after a prolonged period of time. Since cyanobacterial blooms are transient phenomena, it is important to understand MC removal in mature biofilms with or without prior toxin exposure. In this study, the microbial community composition of GDM biofilms was investigated in systems fed with water from a lake with periodic blooms of MC-producing cyanobacteria. Two out of three experimental treatments were supplemented with dead biomass of a MC-containing cyanobacterial strain, or of a non-toxic mutant, respectively. Analysis of bacterial rRNA genes revealed that both biomass-amended treatments were significantly more similar to each other than to a non-supplemented control. Therefore, it was hypothesized that biofilms could potentially be 'primed' for rapid MC removal by prior addition of non-toxic biomass. A subsequent experiment showed that MC removal developed significantly faster in mature biofilms that were pre-fed with biomass from the mutant strain than in unamended controls, indicating that MC degradation was a facultative trait of bacterial populations in GDM biofilms. The significant enrichment of bacteria related to both aerobic and anaerobic MC degraders suggested that this process might have occurred in parallel in different microniches.
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Lindström T, Phillips BL, Brown GP, Shine R. Identifying the time scale of synchronous movement: a study on tropical snakes. MOVEMENT ECOLOGY 2015; 3:12. [PMID: 25941572 PMCID: PMC4418100 DOI: 10.1186/s40462-015-0038-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 03/09/2015] [Indexed: 06/04/2023]
Abstract
BACKGROUND Individual movement is critical to organismal fitness and also influences broader population processes such as demographic stochasticity and gene flow. Climatic change and habitat fragmentation render the drivers of individual movement especially critical to understand. Rates of movement of free-ranging animals through the landscape are influenced both by intrinsic attributes of an organism (e.g., size, body condition, age), and by external forces (e.g., weather, predation risk). Statistical modelling can clarify the relative importance of those processes, because externally-imposed pressures should generate synchronous displacements among individuals within a population, whereas intrinsic factors should generate consistency through time within each individual. External and intrinsic factors may vary in importance at different time scales. RESULTS In this study we focused on daily displacement of an ambush-foraging snake from tropical Australia (the Northern Death Adder Acanthophis praelongus), based on a radiotelemetric study. We used a mixture of spectral representation and Bayesian inference to study synchrony in snake displacement by phase shift analysis. We further studied autocorrelation in fluctuations of displacement distances as "one over f noise". Displacement distances were positively autocorrelated with all considered noise colour parameters estimated as >0. We show how the methodology can reveal time scales of particular interest for synchrony and found that for the analysed data, synchrony was only present at time scales above approximately three weeks. CONCLUSION We conclude that the spectral representation combined with Bayesian inference is a promising approach for analysis of movement data. Applying the framework to telemetry data of A. praelongus, we were able to identify a cut-off time scale above which we found support for synchrony, thus revealing a time scale where global external drivers have a larger impact on the movement behaviour. Our results suggest that for the considered study period, movement at shorter time scales was primarily driven by factors at the individual level; daily fluctuations in weather conditions had little effect on snake movement.
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Affiliation(s)
- Tom Lindström
- />Department of Physics, Biology and Chemistry, Linköping University, 58183 Linköping, Sweden
| | - Benjamin L Phillips
- />School of Biosciences, University of Melbourne, Melbourne, VIC 3010 Australia
| | - Gregory P Brown
- />School of Biological Sciences, University of Sydney, Sydney, NSW 2006 Australia
| | - Richard Shine
- />School of Biological Sciences, University of Sydney, Sydney, NSW 2006 Australia
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Abstract
Dispersal biology at an invasion front differs from that of populations within the range core, because novel evolutionary and ecological processes come into play in the nonequilibrium conditions at expanding range edges. In a world where species' range limits are changing rapidly, we need to understand how individuals disperse at an invasion front. We analyzed an extensive dataset from radio-tracking invasive cane toads (Rhinella marina) over the first 8 y since they arrived at a site in tropical Australia. Movement patterns of toads in the invasion vanguard differed from those of individuals in the same area postcolonization. Our model discriminated encamped versus dispersive phases within each toad's movements and demonstrated that pioneer toads spent longer periods in dispersive mode and displayed longer, more directed movements while they were in dispersive mode. These analyses predict that overall displacement per year is more than twice as far for toads at the invasion front compared with those tracked a few years later at the same site. Studies on established populations (or even those a few years postestablishment) thus may massively underestimate dispersal rates at the leading edge of an expanding population. This, in turn, will cause us to underpredict the rates at which invasive organisms move into new territory and at which native taxa can expand into newly available habitat under climate change.
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