Theoretical Ecology - Principles and Applications - Robert May & Angela McLean (2025)

Dispersal-mediated coexistence of competing predators

Theoretical population biology, 2004

Models of metapopulations have often ignored local community dynamics and spatial heterogeneity among patches. However, persistence of a community as a whole depends both on the local interactions and the rates of dispersal between patches. We study a mathematical model of a metacommunity with two consumers exploiting a resource in a habitat of two different patches. They are the exploitative competitors or the competing predators indirectly competing through depletion of the shared resource. We show that they can potentially coexist, even if one species is sufficiently inferior to be driven extinct in both patches in isolation, when these patches are connected through diffusive dispersal. Thus, dispersal can mediate coexistence of competitors, even if both patches are local sinks for one species because of the interactions with the other species. The spatial asynchrony and the competitioncolonization trade-off are usual mechanisms to facilitate regional coexistence. However, in our case, two consumers can coexist either in synchronous oscillation between patches or in equilibrium. The higher dispersal rate of the superior prompts rather than suppresses the inferior. Since differences in the carrying capacity between two patches generate flows from the more productive patch to the less productive, loss of the superior by emigration relaxes competition in the former, and depletion of the resource by subsidized consumers decouples the local community in the latter.

Why don't all species overexploit?

Oikos, 2021

Overexploitation of natural resources is often viewed as a problem characteristic of only the human species. However, any species could evolve a capacity to overexploit its essential resources through natural selection and competition, even to the point of resource collapse. Here, we describe the processes that potentially lead to overexploitation and synthesize what is known about overexploitation limiters in other species. We propose that there are five pathways that counteract the evolutionary drive towards overexploitation and/or mitigate its consequences: top-down trophic control, interference, cost-efficiency tradeoffs, resource trait evolution, and spatial heterogeneity. These mechanisms constrain the number of exploiters and/or lower the rate of the resource usage at the individual level. We hypothesize that in ecosystems with reasonable functional diversity, coevolution strengthens this limiter network, preventing overexploitation, and thus argue that diversity begets stability via evolution. Violent population cycles in species-poor northern ecosystems and eruptions of invading alien species are exceptions that confirm this rule, because these ecosystems either lack functional diversity or there has not been enough time for coevolution to play out its stabilizing role. We propose that the overexploitation by our own species could be prevented via a network of socio-economical limiters that act in an analogous way.

Big questions, small worlds: microbial model systems in ecology

Trends in Ecology & Evolution, 2004

Although many biologists have embraced microbial model systems as tools to address genetic and physiological questions, the explicit use of microbial communities as model systems in ecology has traditionally been more restricted. Here, we highlight recent studies that use laboratory-based microbial model systems to address ecological questions. Such studies have significantly advanced our understanding of processes that have proven difficult to study in field systems, including the genetic and biochemical underpinnings of ...

FOUNDATIONS OF RESTORATION ECOLOGY SOCIETY FOR ECOLOGICAL RESTORATION INTERNATIONAL THE SCIENCE AND PRACTICE OF ECOLOGICAL RESTORATION

Advance praise for Foundations of Restoration Ecology " Restoration is a keystone strategy for conserving biodiversity, and ecology has matured into a central discipline of the biological sciences. This important work shows us that their synergy offers new hope for the future of life on Earth. " —Edward O. Wilson, author of two Pulitzer Prize–winning books, University Research Professor Emeritus, Harvard University " Humanity has damaged more than half the land surface on Earth, making restoration an essential tool to preserve biodiversity. It is also the ultimate test of whether we scientists know enough to do the job. There is no better place to find out than inside this book. " —Stuart Pimm, Doris Duke Professor of Conservation Ecology, Duke University " The publication of this book is an important event, a coming-of-age of restoration—it's an indispensable key to the survival and well-being of classic ecosystems, setting the context for basic ecological research. A rich trove of ecological theory in productive and provocative dialogue with restoration practice. " —William R. Jordan III, director, New Academy and DePaul University Institute for Nature and Culture " This volume explores classical ecological theory from a perspective that identifies optimal strategies behind the practical application of restoration ecology in the near future. The editors and authors have produced a paragon of sustainability science. " —Jelte van Andel, professor of plant ecology, University of Gronigen, The Netherlands " This is a comprehensive synthesis of the conceptual basis of the field of restoration ecology. With contributions by leading theoretical ecologists as well as by recognized restoration ecologists, it covers the range of hierarchies from population genetics to macroecology. " —Edith B. Allen, professor,

Interaction networks in agricultural landscape mosaics

Advances in Ecological Research, 2013

The organisation of human-populated landscapes results from many interacting processes tied to the historical development of societies and human activities. Agriculture, in particular, has dramatically altered much of the Earth's surface over many millennia. Landscape mosaics can be used to understand these impacts, which are increasing at an accelerating rate on a global scale. On a local-to-regional scale, mosaic concepts are also of practical interest for designing natural enemy-based pest control strategies as an alternative to intensive pesticide use.

Review of theoretical community ecology: implications for marine communities

2007

1. SUMMARY The mechanistic link between variation in fishing pressure and changes in species diversity is unclear with respect to marine fish and benthic invertebrate communities. If an EAM is to successfully address biodiversity issues then the mechanisms relating diversity and fishing activity need to be clearly understood. This requires an understanding of the processes that structure and organise marine communities.

Food web structure and habitat loss

Ecology Letters, 2002

In this paper we explore simple food web models to study how metacommunity structure affects species response to habitat loss. We ®nd that patch abundances and extinction thresholds vary according to the kind of food web. Second, for intermediate species, a slight decrease in the exploration cost of the better competitor has a strong effect on the extinction threshold of the poorer competitor. When predicting extinction risk one should consider not only the amount of habitat destroyed, but also the structure of the food web in which species are embedded. Both direct and indirect interactions are critical for predicting the consequences of habitat destruction.

Habitat fragmentation and large-scale conservation: what do we know for sure?

Ecography, 1999

We review the ecological effects of habitat fragmentation, comparing the theoretical approaches that have been taken to understanding it with the existing evidence from empirical studies. Theory has emphasized the spatial aspects of fragmentation and the role of dispersal among patches, and has generated interesting predictions such as a nonlinear relationship between the amount of remaining habitat and the probability of species persistence. However, while the few available large-scale empirical studies of fragmentation all tend to show that it has major effects, these documented effects tend to be relatively simple ones such as the degradation of habitat quality within fragments. There is good reason to be cautious of any claim that corridors or the spatial configuration of remaining habitat can compensate for the overall loss of habitat.This is an invited Minireview on the occasion of the 50th anniversary of the Nordic Ecological Society Oikos.

Evolutionary ecology of carnivorous plants

ADVANCES IN ECOLOGICAL RESEARCH, 2003

Summary: This review synthesizes published data and new results concerning the evolutionary ecology of carnivorous plants. These diverse taxa occur in many angiosperm clades, but are united by a common ecological "niche" - botanical carnivory. Aspects of their life-history, including developmental preformation and rapid responses to nutrient additions, make some carnivorous plants well-suited for addressing basic questions in population biology, including cost-benefit analysis of resource use and allocation, demographic trends, and population forecasting. These cost-benefit analyses also suggest ways to test hypotheses regarding coexistence of plant species in resource-limited environments. Most carnivorous plants are pollinated by insects, and the conflict between using insects as pollination vectors and as prey provides new insights into ecological and evolutionary dynamics of plant-pollinator assemblages. A subset of the carnivorous plants, the pitcher plants, host distinctive communities of invertebrates in their modified leaves. These "inquiline" communities have been developed as model systems for experimental studies of interspecific competition, food web dynamics, metapopulations and metacommunities, and species co- occurrence patterns and assembly rules. The rapid generation times of the inquilines allows for the explicit incorporation of evolutionary dynamics into experimental studies of ecological communities. These research foci suggest that carnivorous plants are model systems for a broad range of basic questions in evolutionary ecology. Aspects of their autecology and synecology permit investigations of fundamental ecological processes across the full range of spatial, temporal, and biological organization.

Eco-evolutionary feedbacks - theoretical models and perspectives

arXiv (Cornell University), 2018

1. Theoretical models pertaining to feedbacks between ecological and evolutionary processes are prevalent in multiple biological fields. An integrative overview is currently lacking, due to little crosstalk between the fields and the use of different methodological approaches. 2. Here we review a wide range of models of eco-evolutionary feedbacks and highlight their underlying assumptions. We discuss models where feedbacks occur both within and between hierarchical levels of ecosystems, including populations, communities, and abiotic environments, and consider feedbacks across spatial scales. 3. Identifying the commonalities among feedback models, and the underlying assumptions, helps us better understand the mechanistic basis of eco-evolutionary feedbacks. Eco-evolutionary feedbacks can be readily modelled by coupling demographic and evolutionary formalisms. We provide an overview of these approaches and suggest future integrative modelling avenues. 4. Our overview highlights that eco-evolutionary feedbacks have been incorporated in theoretical work for nearly a century. Yet, this work does not always include the notion of rapid evolution or concurrent ecological and evolutionary time scales. We discuss the importance of density-and frequency-dependent selection for feedbacks, as well as the importance of dispersal as a central linking trait between ecology and evolution in a spatial context.