John Lander Harper(27 May 1925 – 22 March 2009) was a British biologist, specializing in ecology and plant population biology.
He was born in 1925 and educated at Lawrence Sheriff School, Rugby. He obtained his degree in Botany in (1946) and his MA and DPhil (1950) from Oxford with his doctoral thesis An investigation of the interaction of soil micro-organisms with special reference to the study of the bacterial population of plant root systems. Dr Harper spent a further nine years conducting research at the Department of Agriculture, Oxford, and a sabbatical as Rockefeller Foundation Fellow at the University of California, Davis, he was in 1967 appointed head of the newly formed School of Plant Biology at Bangor University North Wales.
He served as president of the British Ecological Society (BES) (1966–1968) and of the European Society for Evolutionary Biology (1993-1995).
He was elected a Fellow of the Royal Society in 1978 and was their Darwin Medal recipient for 1990.He received the Millennium Botany Award in 1999 and the Marsh Ecology Award from the BES the same year. He was awarded CBE in 1989.
He has authored several textbooks on ecology and population biology.
The British Ecological Society awards the John L. Harper Young Investigator's prize annually to the best paper in Journal of Ecology by a young author.He was a member of the British Humanist Association.
He died on 22 March 2009.
Ecology is a branch of biology concerning interactions among organisms and their biophysical environment, which includes both biotic and abiotic components. Topics of interest include the biodiversity, distribution, biomass, and populations of organisms, as well as cooperation and competition within and between species. Ecosystems are dynamically interacting systems of organisms, the communities they make up, and the non-living components of their environment. Ecosystem processes, such as primary production, pedogenesis, nutrient cycling, and niche construction, regulate the flux of energy and matter through an environment. These processes are sustained by organisms with specific life history traits.
Theoretical ecology is the scientific discipline devoted to the study of ecological systems using theoretical methods such as simple conceptual models, mathematical models, computational simulations, and advanced data analysis. Effective models improve understanding of the natural world by revealing how the dynamics of species populations are often based on fundamental biological conditions and processes. Further, the field aims to unify a diverse range of empirical observations by assuming that common, mechanistic processes generate observable phenomena across species and ecological environments. Based on biologically realistic assumptions, theoretical ecologists are able to uncover novel, non-intuitive insights about natural processes. Theoretical results are often verified by empirical and observational studies, revealing the power of theoretical methods in both predicting and understanding the noisy, diverse biological world.
In ecology, a biological interaction is the effect that a pair of organisms living together in a community have on each other. They can be either of the same species, or of different species. These effects may be short-term, like pollination and predation, or long-term; both often strongly influence the evolution of the species involved. A long-term interaction is called a symbiosis. Symbioses range from mutualism, beneficial to both partners, to competition, harmful to both partners. Interactions can be indirect, through intermediaries such as shared resources or common enemies. This type of relationship can be shown by net effect based on individual effects on both organisms arising out of relationship.
Sir Arthur George Tansley FLS, FRS was an English botanist and a pioneer in the science of ecology.
Sir Edward James Salisbury CBE FRS was an English botanist and ecologist. He was born in Harpenden, Hertfordshire and graduated in botany from University College London in 1905. In 1913, he obtained a D.Sc. with a thesis on fossil seeds and was appointed a senior lecturer at East London College. He returned to University College London as a senior lecturer, from 1924 as a reader in plant ecology and from 1929 as Quain Professor of botany.
In evolutionary ecology, an ecotype, sometimes called ecospecies, describes a genetically distinct geographic variety, population or race within a species, which is genotypically adapted to specific environmental conditions.
The development of population ecology owes much to demography and actuarial life tables. Population ecology is important in conservation biology, especially in the development of population viability analysis (PVA) which makes it possible to predict the long-term probability of a species persisting in a given habitat patch. Although population ecology is a subfield of biology, it provides interesting problems for mathematicians and statisticians who work in population dynamics.
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. Its history stems all the way back to the 4th century. One of the first ecologists whose writings survive may have been Aristotle or perhaps his student, Theophrastus, both of whom had interest in many species of animals and plants. Theophrastus described interrelationships between animals and their environment as early as the 4th century BC. Ecology developed substantially in the 18th and 19th century. It began with Carl Linnaeus and his work with the economy of nature. Soon after came Alexander von Humboldt and his work with botanical geography. Alexander von Humboldt and Karl Möbius then contributed with the notion of biocoenosis. Eugenius Warming’s work with ecological plant geography led to the founding of ecology as a discipline. Charles Darwin’s work also contributed to the science of ecology, and Darwin is often attributed with progressing the discipline more than anyone else in its young history. Ecological thought expanded even more in the early 20th century. Major contributions included: Eduard Suess’ and Vladimir Vernadsky’s work with the biosphere, Arthur Tansley’s ecosystem, Charles Elton's Animal Ecology, and Henry Cowles ecological succession. Ecology influenced the social sciences and humanities. Human ecology began in the early 20th century and it recognized humans as an ecological factor. Later James Lovelock advanced views on earth as a macro-organism with the Gaia hypothesis. Conservation stemmed from the science of ecology. Important figures and movements include Shelford and the ESA, National Environmental Policy act, George Perkins Marsh, Theodore Roosevelt, Stephen A. Forbes, and post-Dust Bowl conservation. Later in the 20th century world governments collaborated on man’s effects on the biosphere and Earth’s environment.
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 intervention and action.
Fire ecology is a scientific discipline concerned with natural processes involving fire in an ecosystem and the ecological effects, the interactions between fire and the abiotic and biotic components of an ecosystem, and the role as an ecosystem process. Many ecosystems, particularly prairie, savanna, chaparral and coniferous forests, have evolved with fire as an essential contributor to habitat vitality and renewal. Many plant species in fire-affected environments require fire to germinate, establish, or to reproduce. Wildfire suppression not only eliminates these species, but also the animals that depend upon them.
A generalist species is able to thrive in a wide variety of environmental conditions and can make use of a variety of different resources. A specialist species can thrive only in a narrow range of environmental conditions or has a limited diet. Most organisms do not all fit neatly into either group, however. Some species are highly specialized, others less so, and some can tolerate many different environments. In other words, there is a continuum from highly-specialized to broadly-generalist species.
Competition is an interaction between organisms or species in which both the organisms or species are harmed. Limited supply of at least one resource used by both can be a factor. Competition both within and between species is an important topic in ecology, especially community ecology. Competition is one of many interacting biotic and abiotic factors that affect community structure. Competition among members of the same species is known as intraspecific competition, while competition between individuals of different species is known as interspecific competition. Competition is not always straightforward, and can occur in both a direct and indirect fashion.
Charles Henry Gimingham was a British botanist at the University of Aberdeen, patron of the Institute of Ecology and Environmental Management, former president of the British Ecological Society, and one of the leading researchers of heathlands and heathers.
A standing crop is the total dried biomass of the living organisms present in a given environment.
Alexander Stuart Watt FRS(21 June 1892 – 2 March 1985) was a Scottish botanist and plant ecologist.
Ecology: From Individuals to Ecosystems is a 2006 higher education textbook on general ecology written by Michael Begon, Colin R. Townsend and John L. Harper. Published by Blackwell Publishing, it is now in its fourth edition. The first three editions were published by Blackwell Science under the title Ecology: Individuals, Populations and Communities. Since it first became available it has had a positive reception, and has long been one of the leading textbooks on ecology.
Threshold host density (NT), in the context of wildlife disease ecology, refers to the concentration of a population of a particular organism as it relates to disease. Specifically, the threshold host density (NT) of a species refers to the minimum concentration of individuals necessary to sustain a given disease within a population.
Erling Christophersen was a Norwegian botanist, geographer and diplomat. He participated in and led several notable scientific expeditions in the 20th century, including the fifth Tanager Expedition (1924) to Nihoa and Necker Island and the Norwegian Scientific Expedition to Tristan da Cunha (1937–1938).
Moshe Shachak is an ecologist at the Ben Gurion University. Shachak’s research focuses on ecosystem engineers, organisms that modulate the abiotic environment. Most of his studies were conducted in arid and semi arid ecosystems.
Grazing is a method of feeding in which a herbivore feeds on plants such as grasses or other multicellular organisms such as algae. Many species of animals can be said to be grazers, from large animals such as hippopotamuses to small aquatic snails. Grazing behaviour is a type of feeding strategy within the ecology of a species. Specific grazing strategies include graminivory ; coprophagy ; pseudoruminant ; and grazing on plants other than grass, such as on marine algae.