Exploring how food web complexity emerges and evolves in island ecosystems remains a major challenge in ecology.Food webs assembled from multiple islands are commonly recognized as highly complex trophic networks that...Exploring how food web complexity emerges and evolves in island ecosystems remains a major challenge in ecology.Food webs assembled from multiple islands are commonly recognized as highly complex trophic networks that are dynamic in both space and time.In the context of global climate change,it remains unclear whether food web complexity will decrease in a monotonic fashion when undergoing habitat destruction(e.g.,the inundation of islands due to sea-level rise).Here,we develop a simple yet comprehensive patch-dynamic framework for complex food web metacommunities subject to the competition-colonization tradeof between basal species.We found that oscillations in food web topological complexity(characterized by species diversity,mean food chain length and the degree of omnivory)emerge along the habitat destruction gradient.This outcome is robust to changing parameters or relaxing the assumption of a strict competitive hierarchy.Having oscillations in food web complexity indicates that small habitat changes could have disproportionate negative efects on species diversity,thus the success of conservation actions should be evaluated not only on changes in biodiversity,but also on system robustness to habitat alteration.Overall,this study provides a parsimonious mechanistic explanation for the emergence of food web complexity in island ecosystems,further enriching our understanding of metacommunity assembly.展开更多
A formal policy development framework, based on a system of systems （SOS） approach, is synthesized to systematically address, in an integrative and adaptive fashion, major global challenges, such as the current food...A formal policy development framework, based on a system of systems （SOS） approach, is synthesized to systematically address, in an integrative and adaptive fashion, major global challenges, such as the current food and fjnancial crises, and their interactions with other key natural, societal, and technological systems. A SoS approach seeks to respect the different value systems of multiple participants, to harness complexity through effective integration, and to engage the world of uncertainty and unpredictability with an adaptive response. Faced with the present global challenges, what is needed are strategic and operational methods which lead to ethical policies, enhance integrative and adaptive management practices, and are able to direct conflict resolution in a positive direction. Policy makers need tools to model and analyze complex systems which they are trying to responsibly govern, taking into account values and risks to design and evaluate different policies. A preliminary investigation into the global food system is undertaken to understand the SoS and to provide insights on how to carry out policy development using the proposed framework.展开更多
基金J.L.is supported by the Natural Science Foundation of China(No.32271548&31901175).
文摘Exploring how food web complexity emerges and evolves in island ecosystems remains a major challenge in ecology.Food webs assembled from multiple islands are commonly recognized as highly complex trophic networks that are dynamic in both space and time.In the context of global climate change,it remains unclear whether food web complexity will decrease in a monotonic fashion when undergoing habitat destruction(e.g.,the inundation of islands due to sea-level rise).Here,we develop a simple yet comprehensive patch-dynamic framework for complex food web metacommunities subject to the competition-colonization tradeof between basal species.We found that oscillations in food web topological complexity(characterized by species diversity,mean food chain length and the degree of omnivory)emerge along the habitat destruction gradient.This outcome is robust to changing parameters or relaxing the assumption of a strict competitive hierarchy.Having oscillations in food web complexity indicates that small habitat changes could have disproportionate negative efects on species diversity,thus the success of conservation actions should be evaluated not only on changes in biodiversity,but also on system robustness to habitat alteration.Overall,this study provides a parsimonious mechanistic explanation for the emergence of food web complexity in island ecosystems,further enriching our understanding of metacommunity assembly.
基金support received from a strategic grant entitled"Systems Engineering Approaches for Brownfield Redevelopment"from the Natural Sciences and Engineering Research Council(NSERC) of Canada,from the Centre for International Governance Innovation (CIGI),and from the Social Sciences and Humanities Research Council(SSHRC) of Canada
文摘A formal policy development framework, based on a system of systems （SOS） approach, is synthesized to systematically address, in an integrative and adaptive fashion, major global challenges, such as the current food and fjnancial crises, and their interactions with other key natural, societal, and technological systems. A SoS approach seeks to respect the different value systems of multiple participants, to harness complexity through effective integration, and to engage the world of uncertainty and unpredictability with an adaptive response. Faced with the present global challenges, what is needed are strategic and operational methods which lead to ethical policies, enhance integrative and adaptive management practices, and are able to direct conflict resolution in a positive direction. Policy makers need tools to model and analyze complex systems which they are trying to responsibly govern, taking into account values and risks to design and evaluate different policies. A preliminary investigation into the global food system is undertaken to understand the SoS and to provide insights on how to carry out policy development using the proposed framework.
