Ecology is the natural science of the relationships among living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere levels. Ecology overlaps with the closely related sciences of biogeography, evolutionary biology, genetics, ethology, and natural history.
In ecology, a niche is the match of a species to a specific environmental condition. It describes how an organism or population responds to the distribution of resources and competitors and how it in turn alters those same factors. "The type and number of variables comprising the dimensions of an environmental niche vary from one species to another [and] the relative importance of particular environmental variables for a species may vary according to the geographic and biotic contexts".
A food web is the natural interconnection of food chains and a graphical representation of what-eats-what in an ecological community. Ecologists can broadly define all life forms as either autotrophs or heterotrophs, based on their trophic levels, the position that they occupy in the food web. To maintain their bodies, grow, develop, and to reproduce, autotrophs produce organic matter from inorganic substances, including both minerals and gases such as carbon dioxide. These chemical reactions require energy, which mainly comes from the Sun and largely by photosynthesis, although a very small amount comes from bioelectrogenesis in wetlands, and mineral electron donors in hydrothermal vents and hot springs. These trophic levels are not binary, but form a gradient that includes complete autotrophs, which obtain their sole source of carbon from the atmosphere, mixotrophs, which are autotrophic organisms that partially obtain organic matter from sources other than the atmosphere, and complete heterotrophs that must feed to obtain organic matter.
Human ecology is an interdisciplinary and transdisciplinary study of the relationship between humans and their natural, social, and built environments. The philosophy and study of human ecology has a diffuse history with advancements in ecology, geography, sociology, psychology, anthropology, zoology, epidemiology, public health, and home economics, among others.
Agroecology is an academic discipline that studies ecological processes applied to agricultural production systems. Bringing ecological principles to bear can suggest new management approaches in agroecosystems. The term can refer to a science, a movement, or an agricultural practice. Agroecologists study a variety of agroecosystems. The field of agroecology is not associated with any one particular method of farming, whether it be organic, regenerative, integrated, or industrial, intensive or extensive, although some use the name specifically for alternative agriculture.
Howard Thomas Odum, usually cited as H. T. Odum, was an American ecologist. He is known for his pioneering work on ecosystem ecology, and for his provocative proposals for additional laws of thermodynamics, informed by his work on general systems theory.
Charles Sutherland Elton was an English zoologist and animal ecologist. He is associated with the development of population and community ecology, including studies of invasive organisms.
Ecology is a new science and considered as an important branch of biological science, having only become prominent during the second half of the 20th century. Ecological thought is derivative of established currents in philosophy, particularly from ethics and politics.
The intermediate disturbance hypothesis (IDH) suggests that local species diversity is maximized when ecological disturbance is neither too rare nor too frequent. At low levels of disturbance, more competitive organisms will push subordinate species to extinction and dominate the ecosystem. At high levels of disturbance, due to frequent forest fires or human impacts like deforestation, all species are at risk of going extinct. According to IDH theory, at intermediate levels of disturbance, diversity is thus maximized because species that thrive at both early and late successional stages can coexist. IDH is a nonequilibrium model used to describe the relationship between disturbance and species diversity. IDH is based on the following premises: First, ecological disturbances have major effects on species richness within the area of disturbance. Second, interspecific competition results in one species driving a competitor to extinction and becoming dominant in the ecosystem. Third, moderate ecological scale disturbances prevent interspecific competition.
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.
John Philip Grime was an ecologist and emeritus professor at the University of Sheffield. He is best known for the universal adaptive strategy theory (UAST) and the twin filter model of community assembly with Simon Pierce, eco-evolutionary dynamics, the unimodal relationship between species richness and site productivity, the intermediate disturbance hypothesis, and DST classification.
Ecological traps are scenarios in which rapid environmental change leads organisms to prefer to settle in poor-quality habitats. The concept stems from the idea that organisms that are actively selecting habitat must rely on environmental cues to help them identify high-quality habitat. If either the habitat quality or the cue changes so that one does not reliably indicate the other, organisms may be lured into poor-quality habitat.
The Robert H. MacArthur Award is a biennial prize given by the Ecological Society of America to ecologists for their pivotal contributions to their field. The acceptance speeches of many recipients have been given at the annual meeting of the society and subsequently published in the ESA's journal, Ecology.
The Eminent Ecologist Award is prize awarded annually to a senior ecologist in recognition of an outstanding contribution to the science of ecology. The prize is awarded by the Ecological Society of America. According to the statutes, the recipient may be from any country in the world. However, in practice very few non-U.S. citizens have received the award. The awardee receives lifetime membership in the society.
John Thomas Curtis was an American botanist and plant ecologist. He is particularly known for his lasting contribution to the development of numerical methods in ecology. Together with J. Roger Bray, he developed the method of polar ordination with its inherent distance measure, the Bray-Curtis dissimilarity.
William J. Ripple is a professor of ecology at Oregon State University in the Department of Forest Ecosystems and Society. He is best known for his research on terrestrial trophic cascades, particularly the role of the gray wolf in North America as an apex predator and a keystone species that shapes food webs and landscape structures via “top-down” pressures.
Professor Fakhri Al-Bazzaz was an Iraqi-American plant ecologist specializing in the study of plant community ecological succession. A professor and prolific author, he was ranked amongst the top ten "Most Cited Scientists in Environment/Ecology, 1992–2002".
Stephen Terrence Buckland is a British statistician and professor at the University of St Andrews. He is best known for his work on distance sampling, a widely used technique for estimating the size of animal populations. He has also made significant contributions in the following areas: bootstrap resampling methods; modelling the dynamics of wild animal populations and measuring biodiversity.
Jianguo Liu is a Chinese American ecologist and sustainability scientist specializing in the human-environment and sustainability studies. He is University Distinguished Professor at Michigan State University.
Steward T. A. Pickett is an American plant ecologist and a distinguished senior scientist at the Cary Institute of Ecosystem Studies. Pickett is the recipient of the 2021 BBVA Foundation Frontiers of Knowledge Award in Ecology and Conservation Biology for "incorporating the spatial dimension into ecosystem research, in the sense of landscape and its multiple scales, and bringing it to bear in the management of coupled human-natural systems", as well the Ecologist Society of America's 2021 Eminent Ecologist Award.
