1
|
Prata JC, Silva CJM, Serpa D, Soares AMVM, Gravato C, Patrício Silva AL. Mechanisms influencing the impact of microplastics on freshwater benthic invertebrates: Uptake dynamics and adverse effects on Chironomus riparius. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 859:160426. [PMID: 36427728 DOI: 10.1016/j.scitotenv.2022.160426] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 11/18/2022] [Accepted: 11/19/2022] [Indexed: 06/16/2023]
Abstract
Chironomids inhabit freshwater benthic ecosystems which are prone to microplastic contamination. This work aimed at understanding the factors and mechanisms influencing microplastic uptake and related adverse effects on Chironomus riparius, by exploring an extensive project database, conducting a literature review, and performing an agent-based model to explore trends in data. Results reveal that high concentrations of small microplastics fill the gut of fourth instar C. riparius (99.7 %). Ingested microplastics had an average size of 38-61 μm, presenting slower elimination rates than undigested organic or mineral particles. Ingestion rates of microplastics depend mainly on encounter rates, and therefore on available concentrations, until reaching a plateau corresponding to the maximum gut volume. Short-term toxicity of microplastics seems to result from damage to gut epithelium, with inflammatory reactions, production of reactive oxygen species, and a negative energy balance exacerbated by the lack of food (organic matter). Long-term toxicity is characterized by a reduction in larval body length and increase in mean time to emergence, seemly from increased energy costs rather than a decrease in nutrient absorption. Wild chironomids already present microplastics in their guts and environmental concentrations in hotspots may already exceed no effect concentrations. Therefore, environmental exposure to microplastics may induce adverse effects to wild C. riparius in freshwater benthic ecosystems, which could compromise their ecologic role as deposit-feeders (e.g., reducing their nutrient cycling ability) and key-stone species in aquatic food webs.
Collapse
Affiliation(s)
- Joana C Prata
- Centre for Environmental and Marine Studies (CESAM) & Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Carlos J M Silva
- Centre for Environmental and Marine Studies (CESAM) & Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Dalila Serpa
- Centre for Environmental and Marine Studies (CESAM) & Department of Environment and Planning, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Amadeu M V M Soares
- Centre for Environmental and Marine Studies (CESAM) & Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Carlos Gravato
- Faculty of Sciences of the University of Lisbon & CESAM, Campo Grande, 1749-016 Lisbon, Portugal.
| | - Ana L Patrício Silva
- Centre for Environmental and Marine Studies (CESAM) & Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal
| |
Collapse
|
2
|
Luiz KS, Organista J, Cirilo ER, Romeiro NML, Natti PL. Numerical convergence of a Telegraph Predator-Prey system. SEMINA: CIÊNCIAS EXATAS E TECNOLÓGICAS 2022. [DOI: 10.5433/1679-0375.2022v43n1espp51] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Numerical convergence of a Telegraph Predator-Prey system is studied. This partial differential equation (PDE) system can describe various biological systems with reactive, diffusive, and delay effects. Initially, the PDE system was discretized by the Finite Differences method. Then, a system of equations in a time-explicit form and in a space-implicit form was obtained. The consistency of the Telegraph Predator-Prey system discretization was verified. Von Neumann stability conditions were calculated for a Predator-Prey system with reactive terms and for a Delayed Telegraph system. On the other hand, for our Telegraph Predator-Prey system, it was not possible to obtain the von Neumann conditions analytically. In this context, numerical experiments were carried out and it was verified that the mesh refinement and the model parameters, reactive constants, diffusion coefficients and delay constants, determine the stability/instability conditions of the discretized equations. The results of numerical experiments were presented.
Collapse
|
3
|
Roos D, Caminero-Saldaña C, Elston D, Mougeot F, García-Ariza MC, Arroyo B, Luque-Larena JJ, Revilla FJR, Lambin X. From pattern to process? Dual travelling waves, with contrasting propagation speeds, best describe a self-organised spatio-temporal pattern in population growth of a cyclic rodent. Ecol Lett 2022; 25:1986-1998. [PMID: 35908289 PMCID: PMC9543711 DOI: 10.1111/ele.14074] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 05/19/2022] [Accepted: 06/23/2022] [Indexed: 11/29/2022]
Abstract
The dynamics of cyclic populations distributed in space result from the relative strength of synchronising influences and the limited dispersal of destabilising factors (activators and inhibitors), known to cause multi‐annual population cycles. However, while each of these have been well studied in isolation, there is limited empirical evidence of how the processes of synchronisation and activation–inhibition act together, largely owing to the scarcity of datasets with sufficient spatial and temporal scale and resolution. We assessed a variety of models that could be underlying the spatio‐temporal pattern, designed to capture both theoretical and empirical understandings of travelling waves using large‐scale (>35,000 km2), multi‐year (2011–2017) field monitoring data on abundances of common vole (Microtus arvalis), a cyclic agricultural rodent pest. We found most support for a pattern formed from the summation of two radial travelling waves with contrasting speeds that together describe population growth rates across the region.
Collapse
Affiliation(s)
- Deon Roos
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK.,Área de Plagas, Instituto Tecnológico Agrario de Castilla-y-León (ITACyL), Valladolid, Spain
| | | | - David Elston
- Biomathematics & Statistics Scotland, Aberdeen, UK
| | - François Mougeot
- Instituto de Investigación en Recursos Cinegéticos, IREC (CSIC-UCLM-JCCM), Ciudad Real, Spain
| | | | - Beatriz Arroyo
- Instituto de Investigación en Recursos Cinegéticos, IREC (CSIC-UCLM-JCCM), Ciudad Real, Spain
| | - Juan José Luque-Larena
- Dpto. Ciencias Agroforestales, ETSIIAA, Universidad de Valladolid, Palencia, Spain.,Instituto Universitario de Investigación en Gestión Forestal Sostenible, Palencia, Spain
| | | | - Xavier Lambin
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
| |
Collapse
|
4
|
Michalska-Smith M, VanderWaal K, Craft ME. Asymmetric host movement reshapes local disease dynamics in metapopulations. Sci Rep 2022; 12:9365. [PMID: 35672422 PMCID: PMC9171740 DOI: 10.1038/s41598-022-12774-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 05/11/2022] [Indexed: 11/13/2022] Open
Abstract
Understanding how the movement of individuals affects disease dynamics is critical to accurately predicting and responding to the spread of disease in an increasingly interconnected world. In particular, it is not yet known how movement between patches affects local disease dynamics (e.g., whether pathogen prevalence remains steady or oscillates through time). Considering a set of small, archetypal metapopulations, we find three surprisingly simple patterns emerge in local disease dynamics following the introduction of movement between patches: (1) movement between identical patches with cyclical pathogen prevalence dampens oscillations in the destination while increasing synchrony between patches; (2) when patches differ from one another in the absence of movement, adding movement allows dynamics to propagate between patches, alternatively stabilizing or destabilizing dynamics in the destination based on the dynamics at the origin; and (3) it is easier for movement to induce cyclical dynamics than to induce a steady-state. Considering these archetypal networks (and the patterns they exemplify) as building blocks of larger, more realistically complex metapopulations provides an avenue for novel insights into the role of host movement on disease dynamics. Moreover, this work demonstrates a framework for future predictive modelling of disease spread in real populations.
Collapse
Affiliation(s)
- Matthew Michalska-Smith
- Department of Veterinary Population Medicine, University of Minnesota, St. Paul, MN, USA. .,Department of Plant Pathology, University of Minnesota, St. Paul, MN, USA.
| | - Kimberly VanderWaal
- Department of Veterinary Population Medicine, University of Minnesota, St. Paul, MN, USA
| | - Meggan E Craft
- Department of Veterinary Population Medicine, University of Minnesota, St. Paul, MN, USA.,Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, MN, USA
| |
Collapse
|
5
|
Ledru L, Garnier J, Gallet C, Noûs C, Ibanez S. Spatial structure of natural boxwood and the invasive box tree moth can promote coexistence. Ecol Modell 2022. [DOI: 10.1016/j.ecolmodel.2021.109844] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
6
|
Gallagher CA, Chudzinska M, Larsen-Gray A, Pollock CJ, Sells SN, White PJC, Berger U. From theory to practice in pattern-oriented modelling: identifying and using empirical patterns in predictive models. Biol Rev Camb Philos Soc 2021; 96:1868-1888. [PMID: 33978325 DOI: 10.1111/brv.12729] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 04/14/2021] [Accepted: 04/16/2021] [Indexed: 01/21/2023]
Abstract
To robustly predict the effects of disturbance and ecosystem changes on species, it is necessary to produce structurally realistic models with high predictive power and flexibility. To ensure that these models reflect the natural conditions necessary for reliable prediction, models must be informed and tested using relevant empirical observations. Pattern-oriented modelling (POM) offers a systematic framework for employing empirical patterns throughout the modelling process and has been coupled with complex systems modelling, such as in agent-based models (ABMs). However, while the production of ABMs has been rising rapidly, the explicit use of POM has not increased. Challenges with identifying patterns and an absence of specific guidelines on how to implement empirical observations may limit the accessibility of POM and lead to the production of models which lack a systematic consideration of reality. This review serves to provide guidance on how to identify and apply patterns following a POM approach in ABMs (POM-ABMs), specifically addressing: where in the ecological hierarchy can we find patterns; what kinds of patterns are useful; how should simulations and observations be compared; and when in the modelling cycle are patterns used? The guidance and examples provided herein are intended to encourage the application of POM and inspire efficient identification and implementation of patterns for both new and experienced modellers alike. Additionally, by generalising patterns found especially useful for POM-ABM development, these guidelines provide practical help for the identification of data gaps and guide the collection of observations useful for the development and verification of predictive models. Improving the accessibility and explicitness of POM could facilitate the production of robust and structurally realistic models in the ecological community, contributing to the advancement of predictive ecology at large.
Collapse
Affiliation(s)
- Cara A Gallagher
- Department of Plant Ecology and Conservation Biology, University of Potsdam, Am Mühlenberg 3, Potsdam, 14469, Germany.,Department of Bioscience, Aarhus University, Frederiksborgvej 399, Roskilde, 4000
| | - Magda Chudzinska
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, KY16 9ST, U.K
| | - Angela Larsen-Gray
- Department of Integrative Biology, University of Wisconsin-Madison, 250 N. Mills St., Madison, WI, 53706, U.S.A
| | | | - Sarah N Sells
- Montana Cooperative Wildlife Research Unit, The University of Montana, 205 Natural Sciences, Missoula, MT, 59812, U.S.A
| | - Patrick J C White
- School of Applied Sciences, Edinburgh Napier University, 9 Sighthill Ct., Edinburgh, EH11 4BN, U.K
| | - Uta Berger
- Institute of Forest Growth and Computer Science, Technische Universität Dresden, Dresden, 01062, Germany
| |
Collapse
|
7
|
Barraquand F, Gimenez O. Fitting stochastic predator-prey models using both population density and kill rate data. Theor Popul Biol 2021; 138:1-27. [PMID: 33515551 DOI: 10.1016/j.tpb.2021.01.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 11/23/2020] [Accepted: 01/14/2021] [Indexed: 12/01/2022]
Abstract
Most mechanistic predator-prey modelling has involved either parameterization from process rate data or inverse modelling. Here, we take a median road: we aim at identifying the potential benefits of combining datasets, when both population growth and predation processes are viewed as stochastic. We fit a discrete-time, stochastic predator-prey model of the Leslie type to simulated time series of densities and kill rate data. Our model has both environmental stochasticity in the growth rates and interaction stochasticity, i.e., a stochastic functional response. We examine what the kill rate data brings to the quality of the estimates, and whether estimation is possible (for various time series lengths) solely with time series of population counts or biomass data. Both Bayesian and frequentist estimation are performed, providing multiple ways to check model identifiability. The Fisher Information Matrix suggests that models with and without kill rate data are all identifiable, although correlations remain between parameters that belong to the same functional form. However, our results show that if the attractor is a fixed point in the absence of stochasticity, identifying parameters in practice requires kill rate data as a complement to the time series of population densities, due to the relatively flat likelihood. Only noisy limit cycle attractors can be identified directly from population count data (as in inverse modelling), although even in this case, adding kill rate data - including in small amounts - can make the estimates much more precise. Overall, we show that under process stochasticity in interaction rates, interaction data might be essential to obtain identifiable dynamical models for multiple species. These results may extend to other biotic interactions than predation, for which similar models combining interaction rates and population counts could be developed.
Collapse
Affiliation(s)
- Frédéric Barraquand
- CNRS, Institute of Mathematics of Bordeaux, France; University of Bordeaux, Integrative and Theoretical Ecology, LabEx COTE, France.
| | - Olivier Gimenez
- CNRS, Center for Evolutionary and Functional Ecology, Montpellier, France
| |
Collapse
|
8
|
Farber DH, De Leenheer P, Mundt CC. Dispersal Kernels may be Scalable: Implications from a Plant Pathogen. JOURNAL OF BIOGEOGRAPHY 2019; 46:2042-2055. [PMID: 33041433 PMCID: PMC7546428 DOI: 10.1111/jbi.13642] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Accepted: 05/05/2019] [Indexed: 06/11/2023]
Abstract
AIM Understanding how spatial scale of study affects observed dispersal patterns can provide insights into spatiotemporal population dynamics, particularly in systems with significant long-distance dispersal (LDD). We aimed to investigate the dispersal gradients of two rusts of wheat with spores of similar size, mass, and shape, over multiple spatial scales. We hypothesized that a single dispersal kernel could fit the dispersal from all spatial scales well, and that it would be possible to obtain similar results in spatiotemporal increase of disease when modeling based on differing scales. LOCATION Central Oregon and St. Croix Island. TAXA Puccinia striiformis f. sp. tritici, Puccinia graminis f. sp. tritici, Triticum aestivum. METHODS We compared empirically-derived primary disease gradients of cereal rust across three spatial scales: local (inoculum source and sampling unit = 0.0254 m, spatial extent = 1.52m) field-wide (inoculum source = 1.52 m, sampling unit = 0.305 m, and spatial extent = 91.44 m), and regional (inoculum source and sampling unit = 152 m, spatial extent = 10.7 km). We then examined whether disease spread in spatially explicit simulations depended upon the scale at which data were collected by constructing a compartmental time-step model. RESULTS The three data sets could be fit well by a single inverse-power law dispersal kernel. Simulating epidemic spread at different spatial resolutions resulted in similar patterns of spatiotemporal spread. Dispersal kernel data obtained at one spatial scale can be used to represent spatiotemporal disease spread at a larger spatial scale. MAIN CONCLUSIONS Organisms spread by aerially dispersed small propagules that exhibit LDD may follow similar dispersal patterns over a several hundred- or thousand-fold expanse of spatial scale. Given that the primary mechanisms driving aerial dispersal remain constant, it may be possible to extrapolate across scales when empirical data are unavailable at a scale of interest.
Collapse
|
9
|
Barrios-O'Neill D, Kelly R, Emmerson MC. Biomass encounter rates limit the size scaling of feeding interactions. Ecol Lett 2019; 22:1870-1878. [PMID: 31436021 PMCID: PMC6852157 DOI: 10.1111/ele.13380] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 05/06/2019] [Accepted: 08/01/2019] [Indexed: 11/30/2022]
Abstract
The rate that consumers encounter resources in space necessarily limits the strength of feeding interactions that shape ecosystems. To explore the link between encounters and feeding, we first compiled the largest available dataset of interactions in the marine benthos by extracting data from published studies and generating new data. These data indicate that the size-scaling of feeding interactions varies among consumer groups using different strategies (passive or active) to encounter different resource types (mobile or static), with filter feeders exhibiting the weakest feeding interactions. Next, we used these data to develop an agent-based model of resource biomass encounter rates, underpinned by consumer encounter strategy and resource biomass density. Our model demonstrates that passive strategies for encountering small, dispersed resources limits biomass encounter rates, necessarily limiting the strength of feeding interactions. Our model is based on generalisable assumptions, providing a framework to assess encounter-based drivers of consumption and coexistence across systems.
Collapse
Affiliation(s)
- Daniel Barrios-O'Neill
- Environment and Sustainability Institute, Penryn Campus, University of Exeter, Penryn, Cornwall, TR10 9EZ, UK.,School of Biological Sciences and Institute of Global Food Security, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, Northern Ireland
| | - Ruth Kelly
- School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland
| | - Mark C Emmerson
- School of Biological Sciences and Institute of Global Food Security, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, Northern Ireland
| |
Collapse
|
10
|
Lin W, Pennings SC. Predator-prey interactions in a ladybeetle-aphid system depend on spatial scale. Ecol Evol 2018; 8:6537-6546. [PMID: 30038755 PMCID: PMC6053568 DOI: 10.1002/ece3.4117] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 02/09/2018] [Accepted: 03/22/2018] [Indexed: 11/29/2022] Open
Abstract
The outcome of species interactions may manifest differently at different spatial scales; therefore, our interpretation of observed interactions will depend on the scale at which observations are made. For example, in ladybeetle-aphid systems, the results from small-scale cage experiments usually cannot be extrapolated to landscape-scale field observations. To understand how ladybeetle-aphid interactions change across spatial scales, we evaluated predator-prey interactions in an experimental system. The experimental habitat consisted of 81 potted plants and was manipulated to facilitate analysis across four spatial scales. We also simulated a spatially explicit metacommunity model parallel to the experiment. In the experiment, we found that the negative effect of ladybeetles on aphids decreased with increasing spatial scales. This pattern can be explained by ladybeetles strongly suppressing aphids at small scales, but not colonizing distant patches fast enough to suppress aphids at larger scales. In the experiment, the positive effects of aphids on ladybeetles were strongest at three-plant scale. In a model scenario where predators did not have demographic dynamics, we found, consistent with the experiment, that both the effects of ladybeetles on aphids and the effects of aphids on ladybeetles decreased with increasing spatial scales. These patterns suggest that dispersal was the primary cause of ladybeetle population dynamics in our experiment: aphids increased ladybeetle numbers at smaller scales because ladybeetles stayed in a patch longer and performed area-restricted searches after encountering aphids; these behaviors did not affect ladybeetle numbers at larger spatial scales. The parallel experimental and model results illustrate how predator-prey interactions can change across spatial scales, suggesting that our interpretation of observed predator-prey dynamics would differ if observations were made at different scales. This study demonstrates how studying ecological interactions at a range of scales can help link the results of small-scale ecological experiments to landscape-scale ecological problems.
Collapse
Affiliation(s)
- Wei‐Ting Lin
- Department of Biology and BiochemistryUniversity of HoustonHoustonTexasUSA
| | - Steven C. Pennings
- Department of Biology and BiochemistryUniversity of HoustonHoustonTexasUSA
| |
Collapse
|
11
|
Effects of a Supraseasonal Drought on the Ecological Attributes of Plagioscion squamosissimus (Heckel, 1840) (Pisces, Sciaenidae) in a Brazilian Reservoir. ScientificWorldJournal 2017; 2017:5930516. [PMID: 28326431 PMCID: PMC5343567 DOI: 10.1155/2017/5930516] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 01/07/2017] [Accepted: 01/29/2017] [Indexed: 11/25/2022] Open
Abstract
The aim of this study was to evaluate the effect of a supraseasonal drought on the ecological attributes of Plagioscion squamosissimus. The fish were caught quarterly from February 2010 to November 2014 using gill nets in the reservoir of Santa Cruz, Rio Grande do Norte, Brazil. The abundance of the species was evaluated with the catch per unit effort (CPUE) metric and then correlated with the accumulated rainfall and water volume of the reservoir. The diet of the fish was evaluated using the feeding index (IAi). The proportional similarity index (PSi) was used to evaluate the variation in the niches of the fish. The body condition was inferred through the relative condition factor, and its variation was assessed with ANOVA. A reduction in the abundance of the species that were positively correlated with the reservoir water volume was observed. The diet of the fish comprised shrimp, gastropods, fish, insects, shrimp larvae, and vegetable matter, with shrimp being the major component. PSi showed the occurrence of individual specialization during November 2013 and November 2014. The relative condition factor was not correlated with a reduction in the water volume of the reservoir. The supraseasonal drought did not affect the relative condition factor, diet, and the trophic niche, but it did affect the species abundance.
Collapse
|
12
|
Betini GS, Avgar T, McCann KS, Fryxell JM. Daphnia inhibits the emergence of spatial pattern in a simple consumer-resource system. Ecology 2017; 98:1163-1170. [PMID: 28130817 DOI: 10.1002/ecy.1752] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 11/06/2016] [Accepted: 01/03/2017] [Indexed: 11/10/2022]
Abstract
Spatial self-organization can occur in many ecosystems with important effects on food web dynamics and the maintenance of biodiversity. The consumer-resource interaction is known to generate spatial patterning, but only a few empirical studies have investigated the effect of the consumer on resource distribution. Here we report results from a large aquatic mesocosm experiment used to investigate the effect of the consumer Daphnia magna on the distribution of its resource, the green algae Chlorella vulgaris. We maintained large tanks with capacity for 26 ,000 L with either algae or both algae and Daphnia in different temperature conditions. We found that the presence of D. magna inhibited spatial structure in algal distribution that arose as a consequence of increasing temperature. We conjecture that this homogenization effect might be caused by a combination of high mobility combined with high rates of algal consumption by Daphnia. Our study emphasizes the importance of both local constraints on growth and behavioral responses in either promoting or suppressing spatial self-organization in natural populations.
Collapse
Affiliation(s)
- Gustavo S Betini
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
| | - Tal Avgar
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2E9, Canada
| | - Kevin S McCann
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
| | - John M Fryxell
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
| |
Collapse
|
13
|
Bistability induced by generalist natural enemies can reverse pest invasions. J Math Biol 2017; 75:543-575. [PMID: 28097417 DOI: 10.1007/s00285-017-1093-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 10/18/2016] [Indexed: 10/20/2022]
Abstract
Analytical modeling of predator-prey systems has shown that specialist natural enemies can slow, stop and even reverse pest invasions, assuming that the prey population displays a strong Allee effect in its growth. We aimed to formalize the conditions in which spatial biological control can be achieved by generalists, through an analytical approach based on reaction-diffusion equations. Using comparison principles, we obtain sufficient conditions for control and for invasion, based on scalar bistable partial differential equations. The ability of generalist predators to control prey populations with logistic growth lies in the bistable dynamics of the coupled system, rather than in the bistability of prey-only dynamics as observed for specialist predators attacking prey populations displaying Allee effects. As a consequence, prey control is predicted to be possible when space is considered in additional situations other than those identified without considering space. The reverse situation is also possible. None of these considerations apply to spatial predator-prey systems with specialist natural enemies.
Collapse
|
14
|
|
15
|
Jiao J, Pilyugin SS, Osenberg CW. Random movement of predators can eliminate trophic cascades in marine protected areas. Ecosphere 2016. [DOI: 10.1002/ecs2.1421] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Jing Jiao
- Department of Biology University of Florida Gainesville Florida 32611 USA
| | - Sergei S. Pilyugin
- Department of Mathematics University of Florida Gainesville Florida 32611 USA
| | - Craig W. Osenberg
- Odum School of Ecology University of Georgia Athens Georgia 30602 USA
| |
Collapse
|
16
|
Nisbet RM, Martin BT, de Roos AM. Integrating ecological insight derived from individual-based simulations and physiologically structured population models. Ecol Modell 2016. [DOI: 10.1016/j.ecolmodel.2015.08.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
17
|
Dambros CS, Morais JW, Vasconcellos A, Souza JLP, Franklin E, Gotelli NJ. Association of Ant Predators and Edaphic Conditions with Termite Diversity in an Amazonian Rain Forest. Biotropica 2016. [DOI: 10.1111/btp.12270] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
| | - José W. Morais
- Coordenação de Biodiversidade National Institute of Amazonian Research CP 2223 69067‐375 Manaus AM Brazil
| | - Alexandre Vasconcellos
- Departamento de Sistemática e Ecologia Laboratório de Termitologia Universidade Federal da Paraíba CCEN 58051‐900 João Pessoa PB Brazil
| | - Jorge L. P. Souza
- Coordenação de Biodiversidade National Institute of Amazonian Research CP 2223 69067‐375 Manaus AM Brazil
| | - Elizabeth Franklin
- Coordenação de Biodiversidade National Institute of Amazonian Research CP 2223 69067‐375 Manaus AM Brazil
| | | |
Collapse
|
18
|
Brickhill D, Evans PG, Reid JM. Spatio-temporal variation in European starling reproductive success at multiple small spatial scales. Ecol Evol 2015; 5:3364-77. [PMID: 26380670 PMCID: PMC4569032 DOI: 10.1002/ece3.1615] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Revised: 06/13/2015] [Accepted: 06/16/2015] [Indexed: 11/06/2022] Open
Abstract
Understanding population dynamics requires spatio-temporal variation in demography to be measured across appropriate spatial and temporal scales. However, the most appropriate spatial scale(s) may not be obvious, few datasets cover sufficient time periods, and key demographic rates are often incompletely measured. Consequently, it is often assumed that demography will be spatially homogeneous within populations that lack obvious subdivision. Here, we quantify small-scale spatial and temporal variation in a key demographic rate, reproductive success (RS), within an apparently contiguous population of European starlings. We used hierarchical cluster analysis to define spatial clusters of nest sites at multiple small spatial scales and long-term data to test the hypothesis that small-scale spatio-temporal variation in RS occurred. RS was measured as the number of chicks alive ca. 12 days posthatch either per first brood or per nest site per breeding season (thereby incorporating multiple breeding attempts). First brood RS varied substantially among spatial clusters and years. Furthermore, the pattern of spatial variation was stable across years; some nest clusters consistently produced more chicks than others. Total seasonal RS also varied substantially among spatial clusters and years. However, the magnitude of variation was much larger and the pattern of spatial variation was no longer temporally consistent. Furthermore, the estimated magnitude of spatial variation in RS was greater at smaller spatial scales. We thereby demonstrate substantial spatial, temporal, and spatio-temporal variation in RS occurring at very small spatial scales. We show that the estimated magnitude of this variation depended on spatial scale and that spatio-temporal variation would not have been detected if season-long RS had not been measured. Such small-scale spatio-temporal variation should be incorporated into empirical and theoretical treatments of population dynamics.
Collapse
Affiliation(s)
- Daisy Brickhill
- Institute of Biological & Environmental Sciences, School of Biological Sciences, University of Aberdeen Zoology Building, Tillydrone Avenue, Aberdeen, AB24 2TZ, U.K
| | - Peter Gh Evans
- School of Ocean Sciences, University of Bangor Menai Bridge, Anglesey, Wales, LL59 5AB, U.K
| | - Jane M Reid
- Institute of Biological & Environmental Sciences, School of Biological Sciences, University of Aberdeen Zoology Building, Tillydrone Avenue, Aberdeen, AB24 2TZ, U.K
| |
Collapse
|
19
|
Maciel GA, Kraenkel RA. How population loss through habitat boundaries determines the dynamics of a predator–prey system. ECOLOGICAL COMPLEXITY 2014. [DOI: 10.1016/j.ecocom.2014.07.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
20
|
Gounand I, Mouquet N, Canard E, Guichard F, Hauzy C, Gravel D. The Paradox of Enrichment in Metaecosystems. Am Nat 2014; 184:752-63. [DOI: 10.1086/678406] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
21
|
LeCraw RM, Kratina P, Srivastava DS. Food web complexity and stability across habitat connectivity gradients. Oecologia 2014; 176:903-15. [DOI: 10.1007/s00442-014-3083-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 09/04/2014] [Indexed: 11/24/2022]
|
22
|
Abrams PA. Why ratio dependence is (still) a bad model of predation. Biol Rev Camb Philos Soc 2014; 90:794-814. [DOI: 10.1111/brv.12134] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 06/29/2014] [Accepted: 07/02/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Peter A. Abrams
- Department of Ecology and Evolutionary Biology; University of Toronto; 25 Harbord St. Toronto Ontario M5S 3G5 Canada
| |
Collapse
|
23
|
Klecka J, Boukal DS. The effect of habitat structure on prey mortality depends on predator and prey microhabitat use. Oecologia 2014; 176:183-91. [DOI: 10.1007/s00442-014-3007-6] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 06/25/2014] [Indexed: 11/30/2022]
|
24
|
Guichard F, Gouhier TC. Non-equilibrium spatial dynamics of ecosystems. Math Biosci 2014; 255:1-10. [PMID: 24984261 DOI: 10.1016/j.mbs.2014.06.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 06/16/2014] [Accepted: 06/19/2014] [Indexed: 11/20/2022]
Abstract
Ecological systems show tremendous variability across temporal and spatial scales. It is this variability that ecologists try to predict and that managers attempt to harness in order to mitigate risk. However, the foundations of ecological science and its mainstream agenda focus on equilibrium dynamics to describe the balance of nature. Despite a rich body of literature on non-equilibrium ecological dynamics, we lack a well-developed set of predictions that can relate the spatiotemporal heterogeneity of natural systems to their underlying ecological processes. We argue that ecology needs to expand its current toolbox for the study of non-equilibrium ecosystems in order to both understand and manage their spatiotemporal variability. We review current approaches and outstanding questions related to the study of spatial dynamics and its application to natural ecosystems, including the design of reserves networks. We close by emphasizing the importance of ecosystem function as a key component of a non-equilibrium ecological theory, and of spatial synchrony as a central phenomenon for its inference in natural systems.
Collapse
Affiliation(s)
- Frederic Guichard
- Department of Biology, McGill University, 1205 Docteur Penfield, Montreal, Quebec H3A 1B1, Canada.
| | - Tarik C Gouhier
- Marine Science Center, Northeastern University, 430 Nahant Road, Nahant, MA 01908, USA.
| |
Collapse
|
25
|
Hauzy C, Nadin G, Canard E, Gounand I, Mouquet N, Ebenman B. Confronting the paradox of enrichment to the metacommunity perspective. PLoS One 2013; 8:e82969. [PMID: 24358242 PMCID: PMC3865114 DOI: 10.1371/journal.pone.0082969] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 11/05/2013] [Indexed: 12/04/2022] Open
Abstract
Resource enrichment can potentially destabilize predator-prey dynamics. This phenomenon historically referred as the "paradox of enrichment" has mostly been explored in spatially homogenous environments. However, many predator-prey communities exchange organisms within spatially heterogeneous networks called metacommunities. This heterogeneity can result from uneven distribution of resources among communities and thus can lead to the spreading of local enrichment within metacommunities. Here, we adapted the original Rosenzweig-MacArthur predator-prey model, built to study the paradox of enrichment, to investigate the effect of regional enrichment and of its spatial distribution on predator-prey dynamics in metacommunities. We found that the potential for destabilization was depending on the connectivity among communities and the spatial distribution of enrichment. In one hand, we found that at low dispersal regional enrichment led to the destabilization of predator-prey dynamics. This destabilizing effect was more pronounced when the enrichment was uneven among communities. In the other hand, we found that high dispersal could stabilize the predator-prey dynamics when the enrichment was spatially heterogeneous. Our results illustrate that the destabilizing effect of enrichment can be dampened when the spatial scale of resource enrichment is lower than that of organismss movements (heterogeneous enrichment). From a conservation perspective, our results illustrate that spatial heterogeneity could decrease the regional extinction risk of species involved in specialized trophic interactions. From the perspective of biological control, our results show that the heterogeneous distribution of pest resource could favor or dampen outbreaks of pests and of their natural enemies, depending on the spatial scale of heterogeneity.
Collapse
Affiliation(s)
- Céline Hauzy
- Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden
- Université Pierre et Marie Curie, UMR7625 - Ecologie et Evolution, Paris, France
- Institut National de la Recherche Agronomique, USC2031 - Ecologie des Populations et Communautés, Paris, France
- * E-mail:
| | - Grégoire Nadin
- CNRS, UMR7598 - Laboratoire Jacques-Louis Lions, Paris, France
| | - Elsa Canard
- Institut des Sciences de l′Evolution, Université de Montpellier II, Montpellier, France
| | - Isabelle Gounand
- Institut des Sciences de l′Evolution, Université de Montpellier II, Montpellier, France
| | - Nicolas Mouquet
- Institut des Sciences de l′Evolution, Université de Montpellier II, Montpellier, France
| | - Bo Ebenman
- Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden
| |
Collapse
|
26
|
Barraquand F. Functional responses and predator–prey models: a critique of ratio dependence. THEOR ECOL-NETH 2013. [DOI: 10.1007/s12080-013-0201-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
27
|
Wodarz D, Sun Z, Lau JW, Komarova NL. Nearest-neighbor interactions, habitat fragmentation, and the persistence of host-pathogen systems. Am Nat 2013; 182:E94-E111. [PMID: 23933732 DOI: 10.1086/671185] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Spatial interactions are known to promote stability and persistence in enemy-victim interactions if instability and extinction occur in well-mixed settings. We investigate the effect of spatial interactions in the opposite case, where populations can persist in well-mixed systems. A stochastic agent-based model of host-pathogen dynamics is considered that describes nearest-neighbor interactions in an undivided habitat. Contrary to previous notions, we find that in this setting, spatial interactions in fact promote extinction. The reason is that, in contrast to the mass-action system, the outcome of the nearest-neighbor model is governed by dynamics in small "local neighborhoods." This is an abstraction that describes interactions in a minimal grid consisting of an individual plus its nearest neighbors. The small size of this characteristic scale accounts for the higher extinction probabilities. Hence, nearest-neighbor interactions in a continuous habitat lead to outcomes reminiscent of a fragmented habitat, which is underlined further with a metapopulation model that explicitly assumes habitat fragmentation. Beyond host-pathogen dynamics, axiomatic modeling shows that our results hold for generic enemy-victim interactions under specified assumptions. These results are used to interpret a set of published experiments that provide a first step toward model testing and are discussed in the context of the literature.
Collapse
Affiliation(s)
- Dominik Wodarz
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA 92697, USA
| | | | | | | |
Collapse
|
28
|
Cavanaugh KC, Kendall BE, Siegel DA, Reed DC, Alberto F, Assis J. Synchrony in dynamics of giant kelp forests is driven by both local recruitment and regional environmental controls. Ecology 2013; 94:499-509. [PMID: 23691668 DOI: 10.1890/12-0268.1] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
Populations of many species display spatially synchronous fluctuations in abundance. Synchrony is most commonly attributed to three processes: factors that influence recruitment (e.g., dispersal, early survival), large-scale environmental variability, and spatially autocorrelated trophic interactions. However it is often difficult to link population synchrony to a specific dominant process, particularly when multiple synchronizing forces are operating. We utilized a new satellite-based data set of giant kelp (Macrocystis pyrifera) canopy biomass to examine population synchrony in southern California kelp forests on spatial scales ranging from 50 m to 300 km and temporal scales ranging from 1 to 11 years. We examined the relationship between synchrony and distance for adult kelp populations, kelp recruits, sea urchin abundance (a major grazer of kelp), and environmental variables known to influence kelp population dynamics. Population synchrony in giant kelp decreased with distance between populations: an initial rapid exponential decrease between 50 m and 1.3 km was followed by a second, large-scale decrease between distances of 1.3 km and 172 km. The 50-m to 1.3-km spatial scale corresponded to the scales of synchrony in the abundance of sea urchins and young kelp recruits, suggesting that local drivers of predation and recruitment influence small-scale synchrony in kelp populations. The spatial correlation patterns of environmental variables, particularly wave height, were similar to the synchrony-distance relationship of kelp populations from 1.3 km to 172 km, suggesting that regional environmental variability, i.e., the Moran effect, was the dominant process affecting synchrony at larger spatial scales. This two-step pattern in the relationship between kelp biomass synchrony and distance was apparent in each of the 11 years of our study. Our results highlight the potential for synthesizing approaches from both landscape and population ecology in order to identify the multiple processes that generate synchrony in population dynamics.
Collapse
Affiliation(s)
- Kyle C Cavanaugh
- Earth Research Institute, University of California, Santa Barbara, California 93106, USA.
| | | | | | | | | | | |
Collapse
|
29
|
Dispersal and noise: Various modes of synchrony in ecological oscillators. J Math Biol 2012; 67:1669-90. [DOI: 10.1007/s00285-012-0607-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Revised: 09/16/2012] [Indexed: 10/27/2022]
|
30
|
Polidori C, Santoro D, Blüthgen N. Does prey mobility affect niche width and individual specialization in hunting wasps? A network-based analysis. OIKOS 2012. [DOI: 10.1111/j.1600-0706.2012.20387.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
31
|
Wodarz D, Hofacre A, Lau JW, Sun Z, Fan H, Komarova NL. Complex spatial dynamics of oncolytic viruses in vitro: mathematical and experimental approaches. PLoS Comput Biol 2012; 8:e1002547. [PMID: 22719239 PMCID: PMC3375216 DOI: 10.1371/journal.pcbi.1002547] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Accepted: 04/22/2012] [Indexed: 12/25/2022] Open
Abstract
Oncolytic viruses replicate selectively in tumor cells and can serve as targeted treatment agents. While promising results have been observed in clinical trials, consistent success of therapy remains elusive. The dynamics of virus spread through tumor cell populations has been studied both experimentally and computationally. However, a basic understanding of the principles underlying virus spread in spatially structured target cell populations has yet to be obtained. This paper studies such dynamics, using a newly constructed recombinant adenovirus type-5 (Ad5) that expresses enhanced jellyfish green fluorescent protein (EGFP), AdEGFPuci, and grows on human 293 embryonic kidney epithelial cells, allowing us to track cell numbers and spatial patterns over time. The cells are arranged in a two-dimensional setting and allow virus spread to occur only to target cells within the local neighborhood. Despite the simplicity of the setup, complex dynamics are observed. Experiments gave rise to three spatial patterns that we call "hollow ring structure", "filled ring structure", and "disperse pattern". An agent-based, stochastic computational model is used to simulate and interpret the experiments. The model can reproduce the experimentally observed patterns, and identifies key parameters that determine which pattern of virus growth arises. The model is further used to study the long-term outcome of the dynamics for the different growth patterns, and to investigate conditions under which the virus population eliminates the target cells. We find that both the filled ring structure and disperse pattern of initial expansion are indicative of treatment failure, where target cells persist in the long run. The hollow ring structure is associated with either target cell extinction or low-level persistence, both of which can be viewed as treatment success. Interestingly, it is found that equilibrium properties of ordinary differential equations describing the dynamics in local neighborhoods in the agent-based model can predict the outcome of the spatial virus-cell dynamics, which has important practical implications. This analysis provides a first step towards understanding spatial oncolytic virus dynamics, upon which more detailed investigations and further complexity can be built.
Collapse
Affiliation(s)
- Dominik Wodarz
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California, United States of America.
| | | | | | | | | | | |
Collapse
|
32
|
Petrovskii S, Petrovskaya N. Computational ecology as an emerging science. Interface Focus 2012; 2:241-54. [PMID: 23565336 DOI: 10.1098/rsfs.2011.0083] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Accepted: 12/06/2011] [Indexed: 11/12/2022] Open
Abstract
It has long been recognized that numerical modelling and computer simulations can be used as a powerful research tool to understand, and sometimes to predict, the tendencies and peculiarities in the dynamics of populations and ecosystems. It has been, however, much less appreciated that the context of modelling and simulations in ecology is essentially different from those that normally exist in other natural sciences. In our paper, we review the computational challenges arising in modern ecology in the spirit of computational mathematics, i.e. with our main focus on the choice and use of adequate numerical methods. Somewhat paradoxically, the complexity of ecological problems does not always require the use of complex computational methods. This paradox, however, can be easily resolved if we recall that application of sophisticated computational methods usually requires clear and unambiguous mathematical problem statement as well as clearly defined benchmark information for model validation. At the same time, many ecological problems still do not have mathematically accurate and unambiguous description, and available field data are often very noisy, and hence it can be hard to understand how the results of computations should be interpreted from the ecological viewpoint. In this scientific context, computational ecology has to deal with a new paradigm: conventional issues of numerical modelling such as convergence and stability become less important than the qualitative analysis that can be provided with the help of computational techniques. We discuss this paradigm by considering computational challenges arising in several specific ecological applications.
Collapse
Affiliation(s)
- Sergei Petrovskii
- Department of Mathematics, University of Leicester, Leicester LE1 7RH, UK
| | | |
Collapse
|
33
|
Evolutionarily stable consumer home range size in relation to resource demography and consumer spatial organization. THEOR ECOL-NETH 2011. [DOI: 10.1007/s12080-011-0148-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
34
|
Effects of local interaction range and mobility on the spatio-temporal dynamics of competing animals in uniform habitats. POPUL ECOL 2011. [DOI: 10.1007/s10144-011-0298-x] [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]
|
35
|
Hausken K, Moxnes JF. Systematization of a set of closure techniques. Theor Popul Biol 2011; 80:175-84. [PMID: 21767557 DOI: 10.1016/j.tpb.2011.07.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Revised: 06/28/2011] [Accepted: 07/01/2011] [Indexed: 11/29/2022]
Abstract
Approximations in population dynamics are gaining popularity since stochastic models in large populations are time consuming even on a computer. Stochastic modeling causes an infinite set of ordinary differential equations for the moments. Closure models are useful since they recast this infinite set into a finite set of ordinary differential equations. This paper systematizes a set of closure approximations. We develop a system, which we call a power p closure of n moments, where 0≤p≤n. Keeling's (2000a,b) approximation with third order moments is shown to be an instantiation of this system which we call a power 3 closure of 3 moments. We present an epidemiological example and evaluate the system for third and fourth moments compared with Monte Carlo simulations.
Collapse
Affiliation(s)
- Kjell Hausken
- Faculty of Social Sciences, University of Stavanger, N-4036 Stavanger, Norway.
| | | |
Collapse
|
36
|
Giacomini HC, Lima Jr. DP, Latini AO, Espírito-Santo HMV. Spatio-temporal segregation and size distribution of fish assemblages as related to non-native species occurrence in the middle rio Doce Valley, MG, Brazil. NEOTROPICAL ICHTHYOLOGY 2011. [DOI: 10.1590/s1679-62252011005000011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The lakes in the middle rio Doce Valley (MG) are suffering impacts due to the introduction of invasive fish species, mainly piscivorous species like red piranha Pygocentrus nattereri and peacock bass Cichla kelberi. Fishes were collected in bimonthly samples conducted at ten lakes along a year. The present study showed that the composition of native fish assemblages is significantly related to the presence and type of non-native species. Fish species distribution among lakes can be explained by differences in species body size: smaller native species are less concentrated in lakes with invasive piscivores, which is in accordance with the hypothesis that they have greater susceptibility to predation by invaders. Another probable cause for this correlation is the proximity of lakes to the drainage system, which could explain both the non-native incidence and the turnover of native species composition. Furthermore, temporal variability in species composition was significantly higher in invaded lakes. This last factor may be linked to seasonal flood pulses, which carry immigrant fishes from streams in the vicinity. The metacommunity framework can bring insights for future studies in such spatially structured systems, and the approach should improve our understanding of processes underlying species composition as well as help direct conservation-focused management plans.
Collapse
|
37
|
|
38
|
Density-dependent dispersal and relative dispersal affect the stability of predator–prey metacommunities. J Theor Biol 2010; 266:458-69. [PMID: 20638390 DOI: 10.1016/j.jtbi.2010.07.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2009] [Revised: 07/12/2010] [Accepted: 07/12/2010] [Indexed: 11/20/2022]
|
39
|
|
40
|
Marleau JN, Guichard F, Mallard F, Loreau M. Nutrient flows between ecosystems can destabilize simple food chains. J Theor Biol 2010; 266:162-74. [PMID: 20600133 DOI: 10.1016/j.jtbi.2010.06.022] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2009] [Revised: 04/14/2010] [Accepted: 06/14/2010] [Indexed: 11/17/2022]
Abstract
Dispersal of organisms has large effects on the dynamics and stability of populations and communities. However, current metacommunity theory largely ignores how the flows of limiting nutrients across ecosystems can influence communities. We studied a meta-ecosystem model where two autotroph-consumer communities are spatially coupled through the diffusion of the limiting nutrient. We analyzed regional and local stability, as well as spatial and temporal synchrony to elucidate the impacts of nutrient recycling and diffusion on trophic dynamics. We show that nutrient diffusion is capable of inducing asynchronous local destabilization of biotic compartments through a diffusion-induced spatiotemporal bifurcation. Nutrient recycling interacts with nutrient diffusion and influences the susceptibility of the meta-ecosystem to diffusion-induced instabilities. This interaction between nutrient recycling and transport is further shown to depend on ecosystem enrichment. It more generally emphasizes the importance of meta-ecosystem theory for predicting species persistence and distribution in managed ecosystems.
Collapse
Affiliation(s)
- Justin N Marleau
- Department of Biology, McGill University, 1205 ave Docteur Penfield, Montréal, Québec, Canada H3A 1B1.
| | | | | | | |
Collapse
|
41
|
CASTELO MARCELAK, CORLEY JUANC. Spatial density-dependent parasitism and specificity in the robber flyMallophora ruficauda(Diptera: Asilidae). AUSTRAL ECOL 2010. [DOI: 10.1111/j.1442-9993.2009.02013.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
42
|
Rammig A, Fahse L. Simulating forest succession after blowdown events: The crucial role of space for a realistic management. Ecol Modell 2009. [DOI: 10.1016/j.ecolmodel.2009.06.040] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
43
|
Bailey SF, McCauley E. Extrinsically and intrinsically generated spatial patterns of algal abundance in an experimental stream. ECOLOGICAL COMPLEXITY 2009. [DOI: 10.1016/j.ecocom.2009.01.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
44
|
Impacts of Foraging Facilitation Among Predators on Predator-prey Dynamics. Bull Math Biol 2009; 72:94-121. [DOI: 10.1007/s11538-009-9439-1] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2008] [Accepted: 06/12/2009] [Indexed: 10/20/2022]
|
45
|
Local interactions between predators and prey call into question commonly used functional responses. Ecol Modell 2009. [DOI: 10.1016/j.ecolmodel.2009.02.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
46
|
Affiliation(s)
- Priyanga Amarasekare
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California 90095-1606;
| |
Collapse
|
47
|
Peltomäki M, Rost M, Alava M. Oscillations and patterns in interacting populations of two species. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2008; 78:050903. [PMID: 19113088 DOI: 10.1103/physreve.78.050903] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Indexed: 05/27/2023]
Abstract
Interacting populations often create complicated spatiotemporal behavior, and understanding it is a basic problem in the dynamics of spatial systems. We study the two-species case by simulations of a host-parasitoid model. In the case of coexistence, there are spatial patterns leading to noise-sustained oscillations. We introduce a measure for the patterns, and explain the oscillations as a consequence of a time-scale separation and noise. They are linked together with the patterns by letting the spreading rates depend on instantaneous population densities. Applications are discussed.
Collapse
Affiliation(s)
- Matti Peltomäki
- Department of Applied Physics, Helsinki University of Technology, P.O. Box 1100, 02015 Helsinki Institute of Technology, Espoo, Finland
| | | | | |
Collapse
|
48
|
Abstract
Ecologists have long searched for structures and processes that impart stability in nature. In particular, food web ecology has held promise in tackling this issue. Empirical patterns in food webs have consistently shown that the distributions of species and interactions in nature are more likely to be stable than randomly constructed systems with the same number of species and interactions. Food web ecology still faces two fundamental challenges, however. First, the quantity and quality of food web data required to document both the species richness and the interaction strengths among all species within food webs is largely prohibitive. Second, where food webs have been well documented, spatial and temporal variation in food web structure has been ignored. Conversely, research that has addressed spatial and temporal variation in ecosystems has generally ignored the full complexity of food web architecture. Here, we incorporate empirical patterns, largely from macroecology and behavioural ecology, into a spatially implicit food web structure to construct a simple landscape theory of food web architecture. Such an approach both captures important architectural features of food webs and allows for an exploration of food web structure across a range of spatial scales. Finally, we demonstrated that food webs are hierarchically organized along the spatial and temporal niche axes of species and their utilization of food resources in ways that stabilize ecosystems.
Collapse
Affiliation(s)
- Neil Rooney
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada N1G 2W1.
| | | | | |
Collapse
|
49
|
Berec L, Boukal DS, Berec M. Linking the allee effect, sexual reproduction, and temperature-dependent sex determination via spatial dynamics. Am Nat 2008; 157:217-30. [PMID: 18707273 DOI: 10.1086/318626] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We develop a spatially explicit, two-sex, individual-based model (IBM) and a derived spatially homogeneous model (SHM) to describe the Allee effect due to scarcity of mating possibilities at low population sizes or densities. The SHM, based on coupled difference equations, represents the first spatially homogeneous approach to this phenomenon, which differentiates between sexes and relies only on measurable population parameters. The IBM reinforces the findings of the SHM by adopting more realistic mate search strategies of diffusive movement and active search. Both models are characterized by a hyperbolic-shaped extinction boundary in the male-female state space, which contrasts with a linear boundary in one-dimensional models of the Allee effect. We examine how the position of the extinction boundary depends on population demography (primary sex ratio, reproduction and mortality probabilities) and adopted mate search strategies. The investigation of different phases in the IBM dynamics emphasizes the differences between local and global densities and shows the importance of scale when assessing the Allee effect. To demonstrate the potential application of our models, we combine the SHM and available data to predict the impact of environmental temperature changes on two turtle species with temperature-dependent sex determination.
Collapse
Affiliation(s)
- L Berec
- Department of Theoretical Biology, Institute of Entomology, Academy of Sciences of the Czech Republic and Faculty of Biological Sciences, University of South Bohemia, Branisovská 31, 370 05 Ceské Budejovice, Czech Republic
| | | | | |
Collapse
|
50
|
de Valpine P, Rosenheim JA. Field-scale roles of density, temperature, nitrogen, and predation on aphid population dynamics. Ecology 2008; 89:532-41. [PMID: 18409442 DOI: 10.1890/06-1996.1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Robust analyses of noisy, stage-structured, irregularly spaced, field-scale data incorporating multiple sources of variability and nonlinear dynamics remain very limited, hindering understanding of how small-scale studies relate to large-scale population dynamics. We used a novel, complementary Bayesian and frequentist state-space model analysis to ask how density, temperature, plant nitrogen, and predators affect cotton aphid (Aphis gossypii) population dynamics in weekly data from 18 field-years and whether estimated effects are consistent with small-scale studies. We found clear roles of density and temperature but not of plant nitrogen or predators, for which Bayesian and frequentist evidence differed. However, overall predictability of field-scale dynamics remained low. This study demonstrates stage-structured state-space model analysis incorporating bottom-up, top-down, and density-dependent effects for within-season (nearly continuous time), nonlinear population dynamics. The analysis combines Bayesian posterior evidence with maximum-likelihood estimation and frequentist hypothesis testing using average one-step-ahead residuals.
Collapse
Affiliation(s)
- Perry de Valpine
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94720-3114, USA.
| | | |
Collapse
|