Ecology
Ecology (from Greek oikos meaning "house" and logos "science") is the science of the habitat. The term was invented in 1866 by Ernst Haeckel, a German pro-darwinist biologist. Ecology is the study of the interactions between living things and the environment. The environment includes both the abiotic environment — non-living things like climate and geology — and the biotic environment — living things like plants and animals. Much of ecological research is concerned with the distribution and abundance of organisms and how distributions are influenced by characteristics of the environment. Organisms influence their environment and the environment influences organisms.
A quite frequent definition consists in defining ecology (or scientific ecology, or natural ecology) as the science of the following triangular relationship :
Definition and scope of ecology
From an ecological point of view, the Earth consists of a hydrosphere, a lithosphere, a geosphere and a biosphere. An assemblage of natural communities and species, within areas of ecological potential based on soil, climate and topography parameters are called ecoregions, and constitute a basic element in ecology.
The term ecology holds different meanings depending on who use it. For many scientists, ecology belongs to basic biological sciences. However, most ecologists would argue that ecology is a science on its own. For many, ecology is before anything "nature protection", as if there were on one side humans and on the other side a virgin Nature to protect from human activity.
Other people view ecology as more than biology as studied by science, but rather a certain vision of the world, which would consist in living in harmony with the other living beings, in not seing the other organisms which surrounds us as mere objects to be used, but rather as organisations, entities belonging to a larger coherent system. According to Serge Moscovisci for example, there are three approaches to define ecology:
Ecology includes many sub-disciplines including theoretical ecology, applied ecology, behavioral ecology, macroecology, systems ecology, ecosystems ecology, community ecology, social ecology, population ecology, landscape ecology, conservation ecology, soil ecology, paleoecology, microbial ecology, ecoevolution and agroecology. Ecology also plays important roles in the inter-disciplinary fields of ecological economics, ecological health, ecological design and ecological engineering.
An interesting, but somewhat controversial idea in ecology is the Gaia theory (science).
One of the first ecologists may have been Aristotle who was interested in many species of animals. He was followed by numerous naturalists such as Buffon and Linné, whose work is usually considered the origin of modern ecology.
Throughout the 18th and the beginning of the 19th century, the great maritime powers such as France and Germany, launched many world exploratory expeditions to develop maritime commerce with other countries, and to discover new natural resources, as well as to catalog them. At the beginning of the 18th century, about twenty thousand plant species were known, versus forty thousand at the beginning of the 19th, and almost 400,000 today.
These expeditions were joined by many scientists, including botanists, such as the German explorer Alexander von Humboldt. Humboldt is often considered the true father of ecology. He was the first to take on the study of the relationship between organisms and their environment. He exposed the existing relationships between observed plant species and climate, and described vegetation zones using latitude and altitude, a discipline now known as geobotany.
In 1804, for example, he reported an impressive number of species, particularly plants, for which he sought to explain their geographic distribution with respect to geological data. One of Humboldt's famous works was "Idea for a Plant Geography" (1805).
Other important botanists include Aimé Bonpland and Eugenius Warming.
Towards 1850 there was a breakthrough in the field with the publishing of the work of Charles Darwin on The Origin of Species: Ecology passed from a repetitive, mechanical model to a biological, organic, and hence [[evolution|
evolutionary]] model.
Alfred Russel Wallace, contemporary and competitor to Darwin, was first to propose a "geography" of animal species. Several authors recognized at the time that species were not independent of each other, and grouped them into plant species, animal species, and later into communities of living beings or biocenose. This term was coined in 1877 by Karl Möbius.
By the 19th century, ecology blossomed due to new discoveries in chemistry by Lavoisier and de Saussure, notably the nitrogen cycle. After observing the fact that life developed only within strict limits of each compartment which comprise atmosphere, hydrosphere, and lithosphere, the Austrian geologist Eduard Suess proposed the term biosphere in 1875. Suess proposed the name biosphere for the conditions promoting life, such as those found on Earth, which includes flora, fauna, minerals, matter cycles, et cetera.
In the 1920s Vladimir Ivanovitch Vernadsky, a Russian geologist who had defected to France, detailed the idea of the biosphere in his work "The biosphere" (1926), and described the fundamental principles of the great biogeochemical cycles. He thus redefined the biosphere as the sum of all ecosystems.
The first ecological damage was reported in the 18th century, as the multiplication of colonies caused deforestation. Since the 19th century, with the industrial revolution, more and more pressing concerns have grown about the impact of human activity on the environment. The term ecologist has been in use since the end of the 19th century.
Over the 19th century, botanical geography and zoogeography combined to form the basis of biogeography.
Biogeography, which deals with habitats of species, is often confused with ecology, which seeks to explain the reasons for the presence of certain species in a given location.
It was in 1935 that Arthur Tansley, the british ecologist, coined the term ecosystem, the interactive system established between the biocenose (the group of living creatures), and their biotope, the environment in which they live. Ecology thus became the science of ecosystems.
Main article: Gaia theory
Since the Second World War, the subdiscipline of human ecology, dealing with the place and role of Man in his World, has dealt with the new challenges of the nuclear menace, industrialization, the consequences of pollution, the exhaustion of natural resources by industrial countries, and the exponential population growth of the third world countries.
The vision of "Gaïa" is a sign of the times, proposed by James Lovelock, in his work The Earth is Alive comparing the Earth to a single living macro-organism. Though controversial, the Gaia Hypothesis spread a certain amount of ecological concern to the general public. Some of the public adopted the view that their Earth-mother, Gaia, was becoming sick from humans and their activities. From a scientific point of view, this hypothesis brought up the new notion of the ecology as being a global vision of the biosphere and of biodiversity.
Usage of the term
Related fields
History of ecology
Botanical geography and Alexander von Humbolt
The notion of biocenosis: Darwin and Wallace
The biosphere - Eduard Suess and Vernadsky
The ecosystem concept and Arthur Tansley
James Lovelock and the Gaia hypothesis
References
See also
