Restoration ecology through the lens of coexistence theory

Abstract

Ecological restoration success can depend on environmental conditions and species interactions, and initial trajectories may not reflect long-term outcomes.Coexistence theory can help diagnose restoration outcomes early by assessing whether focal species can increase when at low density.Partitioning the effect of the environment and competition on the low-density growth rates of focal species can help guide restoration efforts. As human influence over Earth’s ecosystems increases and the amount of land available for traditional conservation dwindles, ecological restoration is gaining traction as an essential tool for biodiversity conservation [1.Gann G.D. et al.International principles and standards for the practice of ecological restoration.Restor. Ecol. 2019; 27: S1-S46Crossref Scopus (571) Google Scholar]. Despite enthusiasm, the discipline of restoration ecology has struggled to become a predictive science capable of consistently improving restoration outcomes [2.Hobbs R.J. Norton D.A. Towards a conceptual framework for restoration ecology.Restor. Ecol. 1996; 4: 93-110Crossref Google Scholar,3.Suding K. Toward an era of restoration in ecology: successes, failures, and opportunities ahead.Annu. Rev. Ecol. Evol. Syst. 2011; 42: 465-487Crossref Scopus (233) Google Scholar]. Over the history of restoration ecology, frameworks often assumed a monotonic recovery trajectory [4.Brudvig L.A. The restoration of biodiversity: where has research been and where does it need to go?.Am. J. Bot. 2011; 98: 549-558Crossref PubMed Scopus (202) Google Scholar] or aimed for a ‘carbon copy’ of a past site [5.Hilderbrand R.H. et al.The myths of restoration ecology.Ecol. Soc. 2005; 10: 19Crossref Scopus (311) Google Scholar], drawing largely from theories of ecological succession and community assembly [6.Wainwright C.E. et al.Links between community ecology theory and ecological restoration are on the rise.J. Appl. Ecol. 2017; 55: 570-581Crossref Scopus (55) Google Scholar]. At the same time, there is long-standing appreciation that restoration trajectories are often nonlinear [7.Young T.P. et al.Community succession and assembly comparing, contrasting and combining paradigms in the context of ecological restoration.Ecol. Restor. 2001; 19: 5-18Crossref Google Scholar,8.Suding K.N. Hobbs R.J. Threshold models in restoration and conservation: a developing framework.Trends Ecol. Evol. 2009; 24: 271-279Abstract Full Text Full Text PDF PubMed Scopus (495) Google Scholar] and outcomes can diverge due to conditions specific to the site and time period of project implementation [9.Choi Y.D. Theories for ecological restoration in changing environment: toward ‘futuristic’ restoration.Ecol. Res. 2004; 19: 75-81Crossref Scopus (0) Google Scholar,10.Vaughn K.J. Young T.P. Contingent conclusions: year of initiation influences ecological field experiments, but temporal replication is rare.Restor. Ecol. 2010; 18: 59-64Crossref Scopus (65) Google Scholar]. Explicitly incorporating the role of variability in restoration frameworks is important to guide and assess efforts in a variable and changing world [6.Wainwright C.E. et al.Links between community ecology theory and ecological restoration are on the rise.J. Appl. Ecol. 2017; 55: 570-581Crossref Scopus (55) Google Scholar,9.Choi Y.D. Theories for ecological restoration in changing environment: toward ‘futuristic’ restoration.Ecol. Res. 2004; 19: 75-81Crossref Scopus (0) Google Scholar]. Within the broader field of ecology, Modern Coexistence Theory (hereafter ‘coexistence theory’) [11.Chesson P. Mechanisms of maintenance of species diversity.Annu. Rev. Ecol. Syst. 2000; 31: 343-366Crossref Scopus (4341) Google Scholar,12.Barabás G. et al.Chesson’s coexistence theory.Ecol. Monogr. 2018; 88: 277-303Crossref Scopus (152) Google Scholar] has emerged as a framework to delineate the effect of environment and species interactions on whether and how species coexist, ultimately influencing community composition and diversity. Coexistence theory emphasizes the importance of spatial and temporal variability for community dynamics and provides analytical metrics to assess species success in relation to average and variable conditions. Coexistence theory has led to advances in numerous ecological subfields, such as community ecology [13.Bowler C.H. et al.Accounting for demographic uncertainty increases predictions for species coexistence: a case study with annual plants.Ecol. Lett. 2022; 25: 1618-1628Crossref PubMed Scopus (5) Google Scholar, 14.Hallett L.M. et al.Rainfall variability maintains grass-forb species coexistence.Ecol. Lett. 2019; 22: 1658-1667Crossref PubMed Scopus (52) Google Scholar, 15.Grainger T.N. et al.The Invasion Criterion: a common currency for ecological research.Trends Ecol. Evol. 2019; 34: 925-935Abstract Full Text Full Text PDF PubMed Scopus (69) Google Scholar], invasion biology [16.MacDougall A.S. et al.Plant invasions and the niche.J. Ecol. 2009; 97: 609-615Crossref Scopus (332) Google Scholar,17.Godoy O. Coexistence theory as a tool to understand biological invasions in species interaction networks: Implications for the study of novel ecosystems.Funct. Ecol. 2019; 33: 1190-1201Crossref Scopus (26) Google Scholar], and trait-based ecology [18.Adler P.B. et al.Trait-based tests of coexistence mechanisms.Ecol. Lett. 2013; 16: 1294-1306Crossref PubMed Scopus (367) Google Scholar, 19.Kraft N.J. et al.Plant functional traits and the multidimensional nature of species coexistence.Proc. Natl. Acad. Sci. U. S. A. 2015; 112: 797-802Crossref PubMed Google Scholar, 20.Yu W. Li S. Modern coexistence theory as a framework for invasion ecology.Biodivers. Sci. 2020; 28: 1362Crossref Scopus (6) Google Scholar]. Here, we unify coexistence theory and restoration ecology to improve restoration goals, strategies, and assessment in an variable world on biodiversity in are a of ecological restoration and a for in coexistence and principles are to Coexistence theory is a framework for and common coexistence that species coexistence [11.Chesson P. Mechanisms of maintenance of species diversity.Annu. Rev. Ecol. Syst. 2000; 31: 343-366Crossref Scopus (4341) Google Scholar]. as as that depend on environmental coexistence theory has that in the of species to environmental can to temporal when species are to such as or a of the G. et al.Chesson’s coexistence theory.Ecol. Monogr. 2018; 88: 277-303Crossref Scopus (152) Google P. for the spatial an with 88: PubMed Scopus Google Scholar]. temporal in the environment or interactions that to in to to species P. and coexistence from PubMed Scopus (0) Google Scholar, et coexistence Natl. Acad. Sci. U. S. A. 2018; PubMed Scopus Google Scholar, et the of community 2020; PubMed Scopus Google Scholar]. is that coexistence theory provides analytical to coexistence and the role of environmental can we assess whether a species or over is the invasion species can can increase from low species interactions from the community [11.Chesson P. Mechanisms of maintenance of species diversity.Annu. Rev. Ecol. Syst. 2000; 31: 343-366Crossref Scopus (4341) Google P. on of maintenance of species Ecol. 2018; Scopus Google Scholar]. The invasion is by the low-density growth of focal a that the focal species can a a species is to [11.Chesson P. Mechanisms of maintenance of species diversity.Annu. Rev. Ecol. Syst. 2000; 31: 343-366Crossref Scopus (4341) Google Scholar,12.Barabás G. et al.Chesson’s coexistence theory.Ecol. Monogr. 2018; 88: 277-303Crossref Scopus (152) Google Scholar]. As the the influence of the growth of the focal species in the of interactions, and the of interactions with the community G. et al.Chesson’s coexistence theory.Ecol. Monogr. 2018; 88: 277-303Crossref Scopus (152) Google Scholar]. is by the over that the of environmental variability that the species L.M. et al.Rainfall variability maintains grass-forb species coexistence.Ecol. Lett. 2019; 22: 1658-1667Crossref PubMed Scopus (52) Google Scholar]. The of to assess coexistence is but as it to in the growth of a species on the of G. et al.Chesson’s coexistence theory.Ecol. Monogr. 2018; 88: 277-303Crossref Scopus (152) Google Scholar]. a on low-density growth field of restoration in community 2000; Scopus Google Scholar]. environmental variability help species or increase of Coexistence theory growth for the that in time P. competition in variable Scopus Google Scholar] or P. theory of coexistence in 2000; PubMed Scopus Google Scholar]. been to dynamics P. and coexistence from PubMed Scopus (0) Google P. competition in variable Scopus Google Scholar, P. theory of coexistence in 2000; PubMed Scopus Google Scholar, P.B. et for Lett. 10: PubMed Scopus Google Scholar, et coexistence theory for Lett. 2019; 22: PubMed Scopus Google Scholar], but the common is that the is as a of a by variability in a by et et coexistence theory for Lett. 2019; 22: PubMed Scopus Google Scholar], are in variability is or for of the of a species as growth and competition and in to assess the importance of variability in for the of the species L.M. et al.Rainfall variability maintains grass-forb species coexistence.Ecol. Lett. 2019; 22: 1658-1667Crossref PubMed Scopus (52) Google et coexistence Natl. Acad. Sci. U. S. A. 2018; PubMed Scopus Google Scholar]. is for restoration it the effect of environmental variability on the growth of a species the competition a can to the of restoration as the environment the on the and of focal species coexistence models to restoration models can to assess restoration success and predictions the outcomes of restoration models the of a species over the of environmental and conditions it long-term and can the of conditions to common is to a for the focal species environmental can by environmental conditions and the of focal and species and that a of environmental and The of the focal species or as as the of the the functional of the may by the growth of the focal and the effect of species to for environmental models are the can a in the focal species is at low to the variable long-term can by the average with environmental by the with the role of variability on average can in with the environment or is and in The role of restoration can by the of environmental conditions to the average of the focal species reflect restoration that site or by the of the community average reflect restoration that the long-term of the focal species can in growth at time is with or environmental conditions. a of the is that it the focal predictions are by the when the focal species Coexistence models can to assess restoration success and predictions the outcomes of restoration models the of a species over the of environmental and conditions it long-term and can the of conditions to common is to a for the focal species environmental can by environmental conditions and the of focal and species and that a of environmental and The of the focal species or as as the of the the functional of the may by the growth of the focal and the effect of species to for environmental models are the can a in the focal species is at low to the variable long-term can by the average with environmental by the with the role of variability on average can in with the environment or is and in The role of restoration can by the of environmental conditions to the average of the focal species reflect restoration that site or by the of the community average reflect restoration that the long-term of the focal species can in growth at time is with or environmental conditions. a of the is that it the focal predictions are by the when the focal species are often on a community and success has been by the of species in species are in dynamics that are not of long-term The and of as a conservation tool for 2013; Scopus Google dynamics restoration and may Lett. 2019; 22: PubMed Scopus Google Scholar] but et from succession for the restoration of and and Ecological Google Scholar] or restoration such as or et of coexistence theory to restoration provides early of restoration Appl. 2022; PubMed Scopus Google Scholar]. with the of K. 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The invasion provides a restoration a for focal the on long-term not metrics of biodiversity as of restoration success is when the focal species has effect on the community or when effect is with restoration goals, such as a effect on an the restoration of species of conservation can et of history and on time in of 2019; 33: PubMed Scopus Google P. et of on the annual 2009; Scopus Google Scholar]. from traditional coexistence theory in that the is on the of the species of on the of species in the in the case of delineate how species are to with the of species C.H. et of species by 2022; PubMed Scopus (0) Google Scholar], as the is how the focal species with the community with N.J. et al.Plant functional traits and the multidimensional nature of species coexistence.Proc. Natl. Acad. Sci. U. S. 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