1
|
Wang S, Hong P, Adler PB, Allan E, Hautier Y, Schmid B, Spaak JW, Feng Y. Towards mechanistic integration of the causes and consequences of biodiversity. Trends Ecol Evol 2024; 39:689-700. [PMID: 38503639 DOI: 10.1016/j.tree.2024.02.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 02/21/2024] [Accepted: 02/23/2024] [Indexed: 03/21/2024]
Abstract
The global biodiversity crisis has stimulated decades of research on three themes: species coexistence, biodiversity-ecosystem functioning relationships (BEF), and biodiversity-ecosystem functional stability relationships (BEFS). However, studies on these themes are largely independent, creating barriers to an integrative understanding of the causes and consequences of biodiversity. Here we review recent progress towards mechanistic integration of coexistence, BEF, and BEFS. Mechanisms underlying the three themes can be linked in various ways, potentially creating either positive or negative relationships between them. That said, we generally expect positive associations between coexistence and BEF, and between BEF and BEFS. Our synthesis represents an initial step towards integrating causes and consequences of biodiversity; future developments should include more mechanistic approaches and broader ecological contexts.
Collapse
Affiliation(s)
- Shaopeng Wang
- Key Laboratory for Earth Surface Processes of the Ministry of Education, Institute of Ecology, College of Urban and Environmental Science, Peking University, Beijing 100871, China.
| | - Pubin Hong
- Key Laboratory for Earth Surface Processes of the Ministry of Education, Institute of Ecology, College of Urban and Environmental Science, Peking University, Beijing 100871, China
| | - Peter B Adler
- Department of Wildland Resources and the Ecology Center, Utah State University, Logan, UT 84322, USA
| | - Eric Allan
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013 Bern, Switzerland; Centre for Development and Environment, University of Bern, Mittelstrasse 43, Bern 3012, Switzerland
| | - Yann Hautier
- Ecology and Biodiversity Group, Department of Biology, Utrecht University, Padualaan 8, 3584, CH, Utrecht, The Netherlands
| | - Bernhard Schmid
- Remote Sensing Laboratories, Department of Geography, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Jurg W Spaak
- Landscape ecology, RPTU Kaiserslautern Landau, 76829 Landau, Germany
| | - Yanhao Feng
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China
| |
Collapse
|
2
|
Song C, Spaak JW. Trophic tug-of-war: Coexistence mechanisms within and across trophic levels. Ecol Lett 2024; 27:e14409. [PMID: 38590122 DOI: 10.1111/ele.14409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 02/26/2024] [Accepted: 03/06/2024] [Indexed: 04/10/2024]
Abstract
Ecological communities encompass rich diversity across multiple trophic levels. While modern coexistence theory has been widely applied to understand community assembly, its traditional formalism only allows assembly within a single trophic level. Here, using an expanded definition of niche and fitness differences applicable to multitrophic communities, we study how diversity within and across trophic levels affects species coexistence. If each trophic level is analysed separately, both lower- and higher trophic levels are governed by the same coexistence mechanisms. In contrast, if the multitrophic community is analysed as a whole, different trophic levels are governed by different coexistence mechanisms: coexistence at lower trophic levels is predominantly limited by fitness differences, whereas coexistence at higher trophic levels is predominantly limited by niche differences. This dichotomy in coexistence mechanisms is supported by theoretical derivations, simulations of phenomenological and trait-based models, and a case study of a primeval forest ecosystem. Our work provides a general and testable prediction of coexistence mechanism operating in multitrophic communities.
Collapse
Affiliation(s)
- Chuliang Song
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, USA
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California, USA
| | - Jurg W Spaak
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
- Institute for Environmental Sciences, RPTU Kaiserslautern-Landau, Landau, Germany
| |
Collapse
|
3
|
Fung T, Pande J, Shnerb NM, O'Dwyer JP, Chisholm RA. Processes governing species richness in communities exposed to temporal environmental stochasticity: A review and synthesis of modelling approaches. Math Biosci 2024; 369:109131. [PMID: 38113973 DOI: 10.1016/j.mbs.2023.109131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 11/10/2023] [Accepted: 12/15/2023] [Indexed: 12/21/2023]
Abstract
Research into the processes governing species richness has often assumed that the environment is fixed, whereas realistic environments are often characterised by random fluctuations over time. This temporal environmental stochasticity (TES) changes the demographic rates of species populations, with cascading effects on community dynamics and species richness. Theoretical and applied studies have used process-based mathematical models to determine how TES affects species richness, but under a variety of frameworks. Here, we critically review such studies to synthesise their findings and draw general conclusions. We first provide a broad mathematical framework encompassing the different ways in which TES has been modelled. We then review studies that have analysed models with TES under the assumption of negligible interspecific interactions, such that a community is conceptualised as the sum of independent species populations. These analyses have highlighted how TES can reduce species richness by increasing the frequency at which a species becomes rare and therefore prone to extinction. Next, we review studies that have relaxed the assumption of negligible interspecific interactions. To simplify the corresponding models and make them analytically tractable, such studies have used mean-field theory to derive fixed parameters representing the typical strength of interspecific interactions under TES. The resulting analyses have highlighted community-level effects that determine how TES affects species richness, for species that compete for a common limiting resource. With short temporal correlations of environmental conditions, a non-linear averaging effect of interspecific competition strength over time gives an increase in species richness. In contrast, with long temporal correlations of environmental conditions, strong selection favouring the fittest species between changes in environmental conditions results in a decrease in species richness. We compare such results with those from invasion analysis, which examines invasion growth rates (IGRs) instead of species richness directly. Qualitative differences sometimes arise because the IGR is the expected growth rate of a species when it is rare, which does not capture the variation around this mean or the probability of the species becoming rare. Our review elucidates key processes that have been found to mediate the negative and positive effects of TES on species richness, and by doing so highlights key areas for future research.
Collapse
Affiliation(s)
- Tak Fung
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore 117558, Singapore.
| | - Jayant Pande
- Department of Physical and Natural Sciences, FLAME University, Pune, Maharashtra 412115, India
| | - Nadav M Shnerb
- Department of Physics, Bar-Ilan University, Ramat Gan 52900, Israel
| | - James P O'Dwyer
- Department of Plant Biology, School of Integrative Biology, University of Illinois, 505, South Goodwin Avenue, Urbana, IL 61801, United States
| | - Ryan A Chisholm
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore 117558, Singapore
| |
Collapse
|
4
|
Yamamichi M, Letten AD, Schreiber SJ. Eco-evolutionary maintenance of diversity in fluctuating environments. Ecol Lett 2023; 26 Suppl 1:S152-S167. [PMID: 37840028 DOI: 10.1111/ele.14286] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 06/23/2023] [Accepted: 06/24/2023] [Indexed: 10/17/2023]
Abstract
Growing evidence suggests that temporally fluctuating environments are important in maintaining variation both within and between species. To date, however, studies of genetic variation within a population have been largely conducted by evolutionary biologists (particularly population geneticists), while population and community ecologists have concentrated more on diversity at the species level. Despite considerable conceptual overlap, the commonalities and differences of these two alternative paradigms have yet to come under close scrutiny. Here, we review theoretical and empirical studies in population genetics and community ecology focusing on the 'temporal storage effect' and synthesise theories of diversity maintenance across different levels of biological organisation. Drawing on Chesson's coexistence theory, we explain how temporally fluctuating environments promote the maintenance of genetic variation and species diversity. We propose a further synthesis of the two disciplines by comparing models employing traditional frequency-dependent dynamics and those adopting density-dependent dynamics. We then address how temporal fluctuations promote genetic and species diversity simultaneously via rapid evolution and eco-evolutionary dynamics. Comparing and synthesising ecological and evolutionary approaches will accelerate our understanding of diversity maintenance in nature.
Collapse
Affiliation(s)
- Masato Yamamichi
- School of Biological Sciences, The University of Queensland, St. Lucia, Brisbane, Queensland, Australia
- Department of International Health and Medical Anthropology, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - Andrew D Letten
- School of Biological Sciences, The University of Queensland, St. Lucia, Brisbane, Queensland, Australia
| | - Sebastian J Schreiber
- Department of Evolution and Ecology and Center for Population Biology, University of California, Davis, California, USA
| |
Collapse
|
5
|
Spaak JW, Adler PB, Ellner SP. Mechanistic Models of Trophic Interactions: Opportunities for Species Richness and Challenges for Modern Coexistence Theory. Am Nat 2023; 202:E1-E16. [PMID: 37384764 DOI: 10.1086/724660] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2023]
Abstract
AbstractMany potential mechanisms promote species coexistence, but we know little about their relative importance. To compare multiple mechanisms, we modeled a two-trophic planktonic food web based on mechanistic species interactions and empirically measured species traits. We simulated thousands of possible communities under realistic and altered interaction strengths to assess the relative importance of three potential drivers of phytoplankton and zooplankton species richness: resource-mediated coexistence mechanisms, predator-prey interactions, and trait trade-offs. Next, we computed niche and fitness differences of competing zooplankton to obtain a deeper understanding of how these mechanisms determine species richness. We found that predator-prey interactions were the most important driver of phytoplankton and zooplankton species richness and that large zooplankton fitness differences were associated with low species richness, but zooplankton niche differences were not associated with species richness. However, for many communities we could not apply modern coexistence theory to compute niche and fitness differences of zooplankton because of conceptual issues with the invasion growth rates arising from trophic interactions. We therefore need to expand modern coexistence theory to fully investigate multitrophic-level communities.
Collapse
|
6
|
Schreiber SJ, Levine JM, Godoy O, Kraft NJB, Hart SP. Does deterministic coexistence theory matter in a finite world? Ecology 2023; 104:e3838. [PMID: 36168209 DOI: 10.1002/ecy.3838] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 03/12/2022] [Accepted: 03/22/2022] [Indexed: 02/01/2023]
Abstract
Contemporary studies of species coexistence are underpinned by deterministic models that assume that competing species have continuous (i.e., noninteger) densities, live in infinitely large landscapes, and coexist over infinite time horizons. By contrast, in nature, species are composed of discrete individuals subject to demographic stochasticity and occur in habitats of finite size where extinctions occur in finite time. One consequence of these discrepancies is that metrics of species' coexistence derived from deterministic theory may be unreliable predictors of the duration of species coexistence in nature. These coexistence metrics include invasion growth rates and niche and fitness differences, which are now commonly applied in theoretical and empirical studies of species coexistence. In this study, we tested the efficacy of deterministic coexistence metrics on the duration of species coexistence in a finite world. We introduce new theoretical and computational methods to estimate coexistence times in stochastic counterparts of classic deterministic models of competition. Importantly, we parameterized this model using experimental field data for 90 pairwise combinations of 18 species of annual plants, allowing us to derive biologically informed estimates of coexistence times for a natural system. Strikingly, we found that for species expected to deterministically coexist, community sizes containing only 10 individuals had predicted coexistence times of more than 1000 years. We also found that invasion growth rates explained 60% of the variation in intrinsic coexistence times, reinforcing their general usefulness in studies of coexistence. However, only by integrating information on both invasion growth rates and species' equilibrium population sizes could most (>99%) of the variation in species coexistence times be explained. This integration was achieved with demographically uncoupled single-species models solely determined by the invasion growth rates and equilibrium population sizes. Moreover, because of a complex relationship between niche overlap/fitness differences and equilibrium population sizes, increasing niche overlap and increasing fitness differences did not always result in decreasing coexistence times, as deterministic theory would predict. Nevertheless, our results tend to support the informed use of deterministic theory for understanding the duration of species' coexistence while highlighting the need to incorporate information on species' equilibrium population sizes in addition to invasion growth rates.
Collapse
Affiliation(s)
- Sebastian J Schreiber
- Department of Evolution and Ecology and Center for Population Biology, University of California, Davis, California, USA
| | - Jonathan M Levine
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, USA
| | - Oscar Godoy
- Departamento de Biología, Instituto Universitario de Investigación Marina (INMAR), Universidad de Cádiz, Puerto Real, Spain
| | - Nathan J B Kraft
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, California, USA
| | - Simon P Hart
- School of Biological Sciences, University of Queensland, Brisbane, Australia
| |
Collapse
|
7
|
Zhou X, Xue B. Effect of compositional fluctuation on the survival of bet-hedging species. J Theor Biol 2022; 553:111270. [PMID: 36075454 DOI: 10.1016/j.jtbi.2022.111270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 08/24/2022] [Accepted: 08/30/2022] [Indexed: 11/20/2022]
Abstract
Understanding the coexistence of diverse species in a changing environment is an important problem in community ecology. Bet-hedging is a strategy that helps species survive in such changing environments. However, studies of bet-hedging have often focused on the expected long-term growth rate of the species by itself, neglecting competition with other coexisting species. Here we study the extinction risk of a bet-hedging species in competition with others. We show that there are three contributions to the extinction risk. The first is the usual demographic fluctuation due to stochastic reproduction and selection processes in finite populations. The second, due to the fluctuation of population growth rate caused by environmental changes, may actually reduce the extinction risk for small populations. Besides those two, we reveal a third contribution, which is unique to bet-hedging species that diversify into multiple phenotypes: The phenotype composition of the population will fluctuate over time, resulting in increased extinction risk. We compare such compositional fluctuation to the demographic and environmental contributions, showing how they have different effects on the extinction risk depending on the population size, generation overlap, and environmental correlation.
Collapse
Affiliation(s)
- Xiao Zhou
- Department of Physics, University of Florida, 2001 Museum Road, Gainesville, 32611, FL, United States.
| | - BingKan Xue
- Department of Physics, University of Florida, 2001 Museum Road, Gainesville, 32611, FL, United States.
| |
Collapse
|
8
|
Johnson EC, Hastings A. Towards a heuristic understanding of the storage effect. Ecol Lett 2022; 25:2347-2358. [PMID: 36181717 DOI: 10.1111/ele.14112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 07/05/2022] [Accepted: 07/11/2022] [Indexed: 11/26/2022]
Abstract
The storage effect is a general explanation for coexistence in a variable environment. Unfortunately, the storage effect is poorly understood, in part because the generality of the storage effect precludes an interpretation that is simultaneously simple, intuitive and correct. Here, we explicate the storage effect by dividing one of its key conditions-covariance between environment and competition-into two pieces, namely that there must be a strong causal relationship between environment and competition, and that the effects of the environment do not change too quickly. This finer-grained definition can explain a number of previous results, including (1) that the storage effect promotes annual plant coexistence when the germination rate fluctuates, but not when the seed yield fluctuates, (2) that the storage effect is more likely to be induced by resource competition than the apparent competition, and (3) why the storage effect arises readily in models with either stage structure or environmental autocorrelation. Additionally, our expanded definition suggests two novel mechanisms by which the temporal storage effect can arise-transgenerational plasticity and causal chains of environmental variables-thus suggesting that the storage effect is a more common phenomenon than previously thought.
Collapse
Affiliation(s)
- Evan C Johnson
- Department of Environmental Science and Policy, University of California Davis, Davis, California, USA.,Center for Population Biology, University of California Davis, Davis, California, USA
| | - Alan Hastings
- Department of Environmental Science and Policy, University of California Davis, Davis, California, USA
| |
Collapse
|
9
|
Schreiber SJ. Temporally auto-correlated predator attacks structure ecological communities. Biol Lett 2022; 18:20220150. [PMID: 35857890 PMCID: PMC9256083 DOI: 10.1098/rsbl.2022.0150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
For species primarily regulated by a common predator, the P* rule of Holt & Lawton (Holt & Lawton, 1993. Am. Nat.142, 623–645. (doi:10.1086/285561)) predicts that the prey species that supports the highest mean predator density (P*) excludes the other prey species. This prediction is re-examined in the presence of temporal fluctuations in the vital rates of the interacting species including predator attack rates. When the fluctuations in predator attack rates are temporally uncorrelated, the P* rule still holds even when the other vital rates are temporally auto-correlated. However, when temporal auto-correlations in attack rates are positive but not too strong, the prey species can coexist due to the emergence of a positive covariance between predator density and prey vulnerability. This coexistence mechanism is similar to the storage effect for species regulated by a common resource. Negative or strongly positive auto-correlations in attack rates generate a negative covariance between predator density and prey vulnerability and a stochastic priority effect can emerge: with non-zero probability either prey species is excluded. These results highlight how temporally auto-correlated species’ interaction rates impact the structure and dynamics of ecological communities.
Collapse
Affiliation(s)
- Sebastian J Schreiber
- Department of Evolution and Ecology, and Center for Population Biology, University of California, Davis, CA 95616, USA
| |
Collapse
|
10
|
Pande J, Tsubery Y, Shnerb NM. Quantifying invasibility. Ecol Lett 2022; 25:1783-1794. [PMID: 35717561 PMCID: PMC9543749 DOI: 10.1111/ele.14031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 04/25/2022] [Accepted: 05/03/2022] [Indexed: 11/27/2022]
Abstract
Invasibility, the chance of a population to grow from rarity and become established, plays a fundamental role in population genetics, ecology, epidemiology and evolution. For many decades, the mean growth rate of a species when it is rare has been employed as an invasion criterion. Recent studies show that the mean growth rate fails as a quantitative metric for invasibility, with its magnitude sometimes even increasing while the invasibility decreases. Here we provide two novel formulae, based on the diffusion approximation and a large‐deviations (Wentzel–Kramers–Brillouin) approach, for the chance of invasion given the mean growth and its variance. The first formula has the virtue of simplicity, while the second one holds over a wider parameter range. The efficacy of the formulae, including their accompanying data analysis technique, is demonstrated using synthetic time series generated from canonical models and parameterised with empirical data.
Collapse
Affiliation(s)
- Jayant Pande
- Department of Physics, Bar-Ilan University, Ramat Gan, Israel
| | | | - Nadav M Shnerb
- Department of Physics, Bar-Ilan University, Ramat Gan, Israel
| |
Collapse
|
11
|
Bowler CH, Weiss-Lehman C, Towers IR, Mayfield MM, Shoemaker LG. Accounting for demographic uncertainty increases predictions for species coexistence: A case study with annual plants. Ecol Lett 2022; 25:1618-1628. [PMID: 35633300 PMCID: PMC9328198 DOI: 10.1111/ele.14011] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 03/02/2022] [Accepted: 03/22/2022] [Indexed: 11/29/2022]
Abstract
Natural systems contain more complexity than is accounted for in models of modern coexistence theory. Coexistence modelling often disregards variation arising from stochasticity in biological processes, heterogeneity among individuals and plasticity in trait values. However, these unaccounted‐for sources of uncertainty are likely to be ecologically important and have the potential to impact estimates of coexistence. We applied a Bayesian modelling framework to data from an annual plant community in Western Australia to propagate uncertainty in coexistence outcomes using the invasion criterion and ratio of niche to fitness differences. We found accounting for this uncertainty altered predictions of coexistence versus competitive exclusion for 3 out of 14 species pairs and yielded a probability of priority effects for an additional species pair. The propagation of uncertainty arising from sources of biological complexity improves our ability to predict coexistence more accurately in natural systems.
Collapse
Affiliation(s)
- Catherine H Bowler
- School of Biological Sciences, University of Queensland, Brisbane, Queensland, Australia
| | | | - Isaac R Towers
- School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Margaret M Mayfield
- School of BioSciences, University of Melbourne, Parkville, Victoria, Australia
| | | |
Collapse
|
12
|
Stump SM, Song C, Saavedra S, Levine JM, Vasseur DA. Synthesizing the effects of individual‐level variation on coexistence. ECOL MONOGR 2021. [DOI: 10.1002/ecm.1493] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Simon Maccracken Stump
- Department of Ecology & Evolutionary Biology Yale University New Haven Connecticut 06511 USA
| | - Chuliang Song
- Department of Civil and Environmental Engineering Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA
| | - Serguei Saavedra
- Department of Civil and Environmental Engineering Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA
| | - Jonathan M. Levine
- Department of Ecology & Evolutionary Biology Princeton University Princeton New Jersey 08544 USA
| | - David A. Vasseur
- Department of Ecology & Evolutionary Biology Yale University New Haven Connecticut 06511 USA
| |
Collapse
|
13
|
Fung T, O'Dwyer JP, Chisholm RA. Effects of temporal environmental stochasticity on species richness: a mechanistic unification spanning weak to strong temporal correlations. OIKOS 2021. [DOI: 10.1111/oik.08667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Tak Fung
- National Univ. of Singapore, Dept of Biological Sciences Singapore Singapore
| | - James P. O'Dwyer
- Dept of Plant Biology, School of Integrative Biology, Univ. of Illinois Urbana IL USA
| | - Ryan A. Chisholm
- National Univ. of Singapore, Dept of Biological Sciences Singapore Singapore
| |
Collapse
|
14
|
Civantos-Gómez I, García-Algarra J, García-Callejas D, Galeano J, Godoy O, Bartomeus I. Fine scale prediction of ecological community composition using a two-step sequential Machine Learning ensemble. PLoS Comput Biol 2021; 17:e1008906. [PMID: 34871304 PMCID: PMC8675934 DOI: 10.1371/journal.pcbi.1008906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 12/16/2021] [Accepted: 11/12/2021] [Indexed: 11/19/2022] Open
Abstract
Prediction is one of the last frontiers in ecology. Indeed, predicting fine-scale species composition in natural systems is a complex challenge as multiple abiotic and biotic processes operate simultaneously to determine local species abundances. On the one hand, species intrinsic performance and their tolerance limits to different abiotic pressures modulate species abundances. On the other hand, there is growing recognition that species interactions play an equally important role in limiting or promoting such abundances within ecological communities. Here, we present a joint effort between ecologists and data scientists to use data-driven models to predict species abundances using reasonably easy to obtain data. We propose a sequential data-driven modeling approach that in a first step predicts the potential species abundances based on abiotic variables, and in a second step uses these predictions to model the realized abundances once accounting for species competition. Using a curated data set over five years we predict fine-scale species abundances in a highly diverse annual plant community. Our models show a remarkable spatial predictive accuracy using only easy-to-measure variables in the field, yet such predictive power is lost when temporal dynamics are taken into account. This result suggests that predicting future abundances requires longer time series analysis to capture enough variability. In addition, we show that these data-driven models can also suggest how to improve mechanistic models by adding missing variables that affect species performance such as particular soil conditions (e.g. carbonate availability in our case). Robust models for predicting fine-scale species composition informed by the mechanistic understanding of the underlying abiotic and biotic processes can be a pivotal tool for conservation, especially given the human-induced rapid environmental changes we are experiencing. This objective can be achieved by promoting the knowledge gained with classic modelling approaches in ecology and recently developed data-driven models.
Collapse
Affiliation(s)
- Icíar Civantos-Gómez
- Universidad Pontificia Comillas, Faculty of Economics and Business Administration, Madrid, Spain
- Complex Systems Group, Universidad Politécnica de Madrid, Madrid, Spain
| | | | - David García-Callejas
- Departamento de Biología, Instituto Universitario de Investigación Marina (INMAR), Universidad de Cádiz, Puerto Real, Spain
- Estación Biológica de Doñana (EBD-CSIC), Sevilla, Spain
| | - Javier Galeano
- Complex Systems Group, Universidad Politécnica de Madrid, Madrid, Spain
| | - Oscar Godoy
- Departamento de Biología, Instituto Universitario de Investigación Marina (INMAR), Universidad de Cádiz, Puerto Real, Spain
| | | |
Collapse
|
15
|
Arnoldi J, Barbier M, Kelly R, Barabás G, Jackson AL. Invasions of ecological communities: Hints of impacts in the invader's growth rate. Methods Ecol Evol 2021. [DOI: 10.1111/2041-210x.13735] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | - Ruth Kelly
- Agri‐Food and Biosciences Institute Belfast UK
| | - György Barabás
- Division of Theoretical Biology Department of IFM Linköping University Linköping Sweden
- ELTE‐MTA Theoretical Biology and Evolutionary Ecology Research Group Budapest Hungary
| | - Andrew L. Jackson
- Zoology Department School of Natural Sciences Trinity College Dublin University of Dublin Dublin Ireland
| |
Collapse
|
16
|
Spaak JW, Carpentier C, De Laender F. Species richness increases fitness differences, but does not affect niche differences. Ecol Lett 2021; 24:2611-2623. [PMID: 34532957 DOI: 10.1111/ele.13877] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 06/21/2021] [Accepted: 08/20/2021] [Indexed: 11/30/2022]
Abstract
A key question in ecology is what limits species richness. Modern coexistence theory presents the persistence of species as a balance between niche differences and fitness differences that favour and hamper coexistence, respectively. With most applications focusing on species pairs, however, we know little about if and how this balance changes with species richness. Here, we apply recently developed definitions of niche and fitness differences, based on invasion analysis, to multispecies communities. We present the first mathematical proof that, for invariant average interaction strengths, the average fitness difference among species increases with richness, while the average niche difference stays constant. Extensive simulations with more complex models and analyses of empirical data confirmed these mathematical results. Combined, our work suggests that, as species accumulate in ecosystems, ever-increasing fitness differences will at some point exceed constant niche differences, limiting species richness. Our results contribute to a better understanding of coexistence multispecies communities.
Collapse
Affiliation(s)
- Jurg W Spaak
- University of Namur, Institute of Life-Earth-Environment, Namur Center for Complex Systems, Namur, Belgium.,Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
| | - Camille Carpentier
- University of Namur, Institute of Life-Earth-Environment, Namur Center for Complex Systems, Namur, Belgium
| | - Frederik De Laender
- University of Namur, Institute of Life-Earth-Environment, Namur Center for Complex Systems, Namur, Belgium
| |
Collapse
|
17
|
Agranov T, Bunin G. Extinctions of coupled populations, and rare event dynamics under non-Gaussian noise. Phys Rev E 2021; 104:024106. [PMID: 34525629 DOI: 10.1103/physreve.104.024106] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 07/15/2021] [Indexed: 11/07/2022]
Abstract
The survival of natural populations may be greatly affected by environmental conditions that vary in space and time. We look at a population residing in two locations (patches) coupled by migration, in which the local conditions fluctuate in time. We report on two findings. First, we find that, unlike rare events in many other systems, here the histories leading to a rare extinction event are not dominated by a single path. We develop the appropriate framework, which turns out to be a hybrid of the standard saddle-point method, and the Donsker-Varadhan formalism which treats rare events of atypical averages over a long time. It provides a detailed description of the statistics of histories leading to the rare event and the mean time to extinction. The framework applies to rare events in a broad class of systems driven by non-Gaussian noise. Second, applying this framework to the population-dynamics model, we find a phase transition in its extinction behavior. Strikingly, a patch which is a sink (where individuals die more than are born) can nonetheless reduce the probability of extinction, even if it lowers the average population's size and growth rate.
Collapse
Affiliation(s)
- Tal Agranov
- Department of Physics, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Guy Bunin
- Department of Physics, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| |
Collapse
|
18
|
Spaak JW, Godoy O, De Laender F. Mapping species niche and fitness differences for communities with multiple interaction types. OIKOS 2021. [DOI: 10.1111/oik.08362] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Jürg W. Spaak
- Univ. of Namur, Inst. of Life‐Earth‐Environment, Namur Center for Complex Systems Namur Rue de Bruxelles Belgium
| | - Oscar Godoy
- Depto de Biología, Inst. Universitario de Investigación Marina (INMAR), Univ. de Cádiz Puerto Real Spain
| | - Frederik De Laender
- Univ. of Namur, Inst. of Life‐Earth‐Environment, Namur Center for Complex Systems Namur Rue de Bruxelles Belgium
| |
Collapse
|
19
|
Song C, Fukami T, Saavedra S. Untangling the complexity of priority effects in multispecies communities. Ecol Lett 2021; 24:2301-2313. [PMID: 34472694 DOI: 10.1111/ele.13870] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/23/2021] [Accepted: 08/09/2021] [Indexed: 11/28/2022]
Abstract
The history of species immigration can dictate how species interact in local communities, thereby causing historical contingency in community assembly. Since immigration history is rarely known, these historical influences, or priority effects, pose a major challenge in predicting community assembly. Here, we provide a graph-based, non-parametric, theoretical framework for understanding the predictability of community assembly as affected by priority effects. To develop this framework, we first show that the diversity of possible priority effects increases super-exponentially with the number of species. We then point out that, despite this diversity, the consequences of priority effects for multispecies communities can be classified into four basic types, each of which reduces community predictability: alternative stable states, alternative transient paths, compositional cycles and the lack of escapes from compositional cycles to stable states. Using a neural network, we show that this classification of priority effects enables accurate explanation of community predictability, particularly when each species immigrates repeatedly. We also demonstrate the empirical utility of our theoretical framework by applying it to two experimentally derived assembly graphs of algal and ciliate communities. Based on these analyses, we discuss how the framework proposed here can help guide experimental investigation of the predictability of history-dependent community assembly.
Collapse
Affiliation(s)
- Chuliang Song
- Department of Civil and Environmental Engineering, MIT, Cambridge, MA, USA.,Department of Biology, McGill University, Montreal, Canada.,Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
| | - Tadashi Fukami
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Serguei Saavedra
- Department of Civil and Environmental Engineering, MIT, Cambridge, MA, USA
| |
Collapse
|
20
|
Lyberger KP, Osmond MM, Schreiber SJ. Is Evolution in Response to Extreme Events Good for Population Persistence? Am Nat 2021; 198:44-52. [PMID: 34143724 DOI: 10.1086/714419] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractClimate change is predicted to increase the severity of environmental perturbations, including storms and droughts, which act as strong selective agents. These extreme events are often of finite duration (pulse disturbances). Hence, while evolution during an extreme event may be adaptive, the resulting phenotypic changes may become maladaptive when the event ends. Using individual-based models and analytic approximations that fuse quantitative genetics and demography, we explore how heritability and phenotypic variance affect population size and extinction risk in finite populations under an extreme event of fixed duration. Since more evolution leads to greater maladaptation and slower population recovery following an extreme event, greater heritability can increase extinction risk when the extreme event is short. Alternatively, when an extreme event is sufficiently long, heritability often helps a population persist. We also find that when events are severe, the buffering effect of phenotypic variance can outweigh the increased load it causes.
Collapse
|
21
|
Pande J, Fung T, Chisholm R, Shnerb NM. Invasion growth rate and its relevance to persistence: a response to Technical Comment by Ellner et al. Ecol Lett 2020; 23:1725-1726. [PMID: 32851799 DOI: 10.1111/ele.13585] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 07/10/2020] [Indexed: 11/26/2022]
Abstract
Ellner et al. (2020) state that identifying the mechanisms producing positive invasion growth rates (IGR) is useful in characterising species persistence. We agree about the importance of the sign of IGR as a binary indicator of persistence, but question whether its magnitude provides much information once the sign is given.
Collapse
Affiliation(s)
- Jayant Pande
- Department of Physics, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Tak Fung
- Department of Biological Sciences, National University of Singapore, Singapore, 117543, Republic of Singapore
| | - Ryan Chisholm
- Department of Biological Sciences, National University of Singapore, Singapore, 117543, Republic of Singapore
| | - Nadav M Shnerb
- Department of Physics, Bar-Ilan University, Ramat Gan 52900, Israel
| |
Collapse
|
22
|
Ellner SP, Snyder RE, Adler PB, Hooker G, Schreiber SJ. Technical Comment on Pande et al. (2020): Why invasion analysis is important for understanding coexistence. Ecol Lett 2020; 23:1721-1724. [PMID: 32851766 DOI: 10.1111/ele.13580] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 06/19/2020] [Indexed: 01/23/2023]
Abstract
Pande et al. (2020) point out that persistence time can decrease even as invader growth rates (IGRs) increase, which potentially undermines modern coexistence theory. However, because persistence time increases rapidly with system size only when IGR > 0, to understand how any real community persists, we should first identify the mechanisms producing positive IGR.
Collapse
Affiliation(s)
- Stephen P Ellner
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA
| | - Robin E Snyder
- Department of Biology, Case Western Reserve University, Cleveland, OH, USA
| | - Peter B Adler
- Department of Wildland Resources and the Ecology Center, Utah State University, Logan, UT, USA
| | - Giles Hooker
- Department of Statistics and Data Science, Cornell University, Ithaca, NY, USA
| | - Sebastian J Schreiber
- Department of Evolution and Ecology and the Center of Population Biology, University of California, Davis, CA, USA
| |
Collapse
|
23
|
Dean AM, Shnerb NM. Stochasticity‐induced stabilization in ecology and evolution: a new synthesis. Ecology 2020; 101:e03098. [DOI: 10.1002/ecy.3098] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 01/16/2020] [Accepted: 02/24/2020] [Indexed: 11/12/2022]
Affiliation(s)
- Antony M. Dean
- Department of Ecology, Evolution, and Behavior University of Minnesota St. Paul Minnesota55108USA
- BioTechnology Institute University of Minnesota St. Paul Minnesota55108USA
| | - Nadav M. Shnerb
- Department of Physics Bar‐Ilan University Ramat Gan52900Israel
| |
Collapse
|