In ecology, the competitive exclusion principle, sometimes referred to as Gause's law, is a proposition that two species which compete for the same limited resource cannot coexist at constant population values. When one species has even the slightest advantage over another, the one with the advantage will dominate in the long term. This leads either to the extinction of the weaker competitor or to an evolutionary or behavioral shift toward a different ecological niche. The principle has been paraphrased in the maxim "complete competitors can not coexist".
Restoration ecology is the scientific study supporting the practice of ecological restoration, which is the practice of renewing and restoring degraded, damaged, or destroyed ecosystems and habitats in the environment by active human interruption and action. Effective restoration requires an explicit goal or policy, preferably an unambiguous one that is articulated, accepted, and codified. Restoration goals reflect societal choices from among competing policy priorities, but extracting such goals is typically contentious and politically challenging.
In ecology, an ecosystem is said to possess ecological stability if it is capable of returning to its equilibrium state after a perturbation or does not experience unexpected large changes in its characteristics across time. Although the terms community stability and ecological stability are sometimes used interchangeably, community stability refers only to the characteristics of communities. It is possible for an ecosystem or a community to be stable in some of their properties and unstable in others. For example, a vegetation community in response to a drought might conserve biomass but lose biodiversity.
Daniel Simberloff is an American biologist and ecologist. He earned his Ph.D. from Harvard University in 1969. He is currently Gore Hunger Professor of Environmental Science at the University of Tennessee, editor-in-chief of the journal Biological Invasions, and a member of the National Academy of Sciences.
Intertidal ecology is the study of intertidal ecosystems, where organisms live between the low and high tide lines. At low tide, the intertidal is exposed whereas at high tide, the intertidal is underwater. Intertidal ecologists therefore study the interactions between intertidal organisms and their environment, as well as between different species of intertidal organisms within a particular intertidal community. The most important environmental and species interactions may vary based on the type of intertidal community being studied, the broadest of classifications being based on substrates—rocky shore and soft bottom communities.
The mesopredator release hypothesis is an ecological theory used to describe the interrelated population dynamics between apex predators and mesopredators within an ecosystem, such that a collapsing population of the former results in dramatically increased populations of the latter. This hypothesis describes the phenomenon of trophic cascade in specific terrestrial communities.
In ecology, the theory of alternative stable states predicts that ecosystems can exist under multiple "states". These alternative states are non-transitory and therefore considered stable over ecologically-relevant timescales. Ecosystems may transition from one stable state to another, in what is known as a state shift, when perturbed. Due to ecological feedbacks, ecosystems display resistance to state shifts and therefore tend to remain in one state unless perturbations are large enough. Multiple states may persist under equal environmental conditions, a phenomenon known as hysteresis. Alternative stable state theory suggests that discrete states are separated by ecological thresholds, in contrast to ecosystems which change smoothly and continuously along an environmental gradient.
In ecology, a priority effect refers to the impact that a particular species can have on community development as a result of its prior arrival at a site. There are two basic types of priority effects: inhibitory and facilitative. An inhibitory priority effect occurs when a species that arrives first at a site negatively affects a species that arrives later by reducing the availability of space or resources. In contrast, a facilitative priority effect occurs when a species that arrives first at a site alters abiotic or biotic conditions in ways that positively affect a species that arrives later. Priority effects are a central and pervasive element of ecological community development that have significant implications for natural systems and ecological restoration efforts.
Ecological fitting is "the process whereby organisms colonize and persist in novel environments, use novel resources or form novel associations with other species as a result of the suites of traits that they carry at the time they encounter the novel condition". It can be understood as a situation in which a species' interactions with its biotic and abiotic environment seem to indicate a history of coevolution, when in actuality the relevant traits evolved in response to a different set of biotic and abiotic conditions.
The term phylogenetic niche conservatism has seen increasing use in recent years in the scientific literature, though the exact definition has been a matter of some contention. Fundamentally, phylogenetic niche conservatism refers to the tendency of species to retain their ancestral traits. When defined as such, phylogenetic niche conservatism is therefore nearly synonymous with phylogenetic signal. The point of contention is whether or not "conservatism" refers simply to the tendency of species to resemble their ancestors, or implies that "closely related species are more similar than expected based on phylogenetic relationships". If the latter interpretation is employed, then phylogenetic niche conservatism can be seen as an extreme case of phylogenetic signal, and implies that the processes which prevent divergence are in operation in the lineage under consideration. Despite efforts by Jonathan Losos to end this habit, however, the former interpretation appears to frequently motivate scientific research. In this case, phylogenetic niche conservatism might best be considered a form of phylogenetic signal reserved for traits with broad-scale ecological ramifications. Thus, phylogenetic niche conservatism is usually invoked with regards to closely related species occurring in similar environments.
Catherine H. Graham is an American team leader and senior scientist working on the Biodiversity & Conservation Biology, and the Spatial Evolutionary Ecology research units at the Swiss Federal Institute for Forest, Snow and Landscape Research WSL. From 2003 to 2017 she was an Assistant, Associate, or Full Professor of Ecology and Evolution at the Stony Brook University, and since her appointment at the WSL in 2017 she has maintained adjunct status there. She received both her M.S. degree (1995) and her Ph.D. (2000) from the University of Missouri at St. Louis, and did post-doctoral training at the Jet Propulsion Laboratory and the University of California, Berkeley. She studies biogeography, conservation biology, and ecology. Catherine H. Graham is most noted for her analysis of statistical models to describe species' distributions. This work with Jane Elith is useful in determining changes in biodiversity resulting from human activities. Her paper on niche conservatism with John J. Wiens is also highly cited. They focused on how species' retention of ancestral traits may limit geographic range expansion. In many of her papers, she has sought to unite ecology and evolutionary biology to derive a better understanding of the processes driving species diversity patterns. In particular, she and Paul Fine laid out a framework for interpreting community assembly processes from a phylogenetic approach to quantifying beta diversity.
Pedro Diego Jordano Barbudo is an ecologist, conservationist, researcher, focused on evolutionary ecology and ecological interactions. He is an honorary professor and associate professor at University of Sevilla, Spain. Most of his fieldwork is done in Parque Natural de las Sierras de Cazorla, Segura y Las Villas, in the eastern side of Andalucia, and in Doñana National Park, where he holds the title of Research Professor for the Estación Biológica Doñana, Spanish Council for Scientific Research (CSIC). Since 2000 he has been actively doing research in Brazil, with fieldwork in the SE Atlantic rainforest.
Erika S. Zavaleta is an American professor of ecology and evolutionary biology at the University of California, Santa Cruz. Zavaleta is recognized for her research focusing on topics including plant community ecology, conservation practices for terrestrial ecosystems, and impacts of community dynamics on ecosystem functions.
Jeannine Cavender-Bares is a Distinguished McKnight University Professor at the University of Minnesota in the Department of Ecology, Evolution & Behavior. Her research integrates evolutionary biology, ecology, and physiology by studying the functional traits of plants, with a particular focus on oaks.
Stephanie M. Carlson is the A.S. Leopold Chair in Wildlife Biology at the University of California Berkeley. Her research considers fish ecology, freshwater ecology, and evolutionary ecology.
Priyanga Amarasekare is a Professor of Ecology and Evolutionary Biology at the University of California, Los Angeles (UCLA) and distinguished Fellow of the Ecological Society of America (ESA). Her research is in the fields of mathematical biology and trophic ecology, with a focus on understanding patterns of biodiversity, species dispersal and the impacts of climate change. She received a 2021 Guggenheim Fellowship and received ESA's Robert H. MacArthur Award in 2022.
Tadashi Fukami is an associate Professor of Biology and community ecologist at Stanford University. He is currently the head of Fukami Lab which is a community ecology research group that focuses on "historical contingency in the assembly of ecological communities." Fukami is an elected Fellow of the Ecological Society of America.
Eco-evolutionary dynamics refers to the reciprocal effects that ecology and evolution have on each other. The effects of ecology on evolutionary processes are commonly observed in studies, but the realization that evolutionary changes can be rapid led to the emergence of eco-evolutionary dynamics. The idea that evolutionary processes can occur quickly and on one timescale with ecological processes led scientists to begin studying the influence evolution has on ecology along with the affects ecology has on evolution. Recent studies have documented eco-evolutionary dynamics and feedback, which is the cyclic interaction between evolution and ecology, in natural and laboratory systems at different levels of biological organization, such as populations, communities, and ecosystems.
Jessica Gurevitch is a plant ecologist known for meta-analysis in the fields of ecology and evolution.
Jennifer Dunne is an American ecologist whose research focuses on the network structure of food webs. One of 14 scientists who led critical advances in food web research over the last century, according to the journal Food Webs, Dunne uses ecological network research to compare the varying ways humans interact with other species through space and time, providing a quantitative perspective on sustainability of socio-ecological systems.
