Biodiversity
Biodiversity, a portmanteau of biological (life) and diversity, generally refers to the variety and variability of life on Earth. According to the United Nations Environment Programme (UNEP), biodiversity typically measures variation at the genetic, the species, and the ecosystem level. Terrestrial biodiversity tends to be greater near the equator, which seems to be the result of the warm climate and high primary productivity. Biodiversity is not distributed evenly on Earth, and is richest in the tropics. These tropical forest ecosystems cover less than 10 percent of earth's surface, and contain about 90 percent of the world's species. Marine biodiversity tends to be highest along coasts in the Western Pacific, where sea surface temperature is highest, and in the mid-latitudinal band in all oceans. There are latitudinal gradients in species diversity. Biodiversity generally tends to cluster in hotspots, and has been increasing through time, but will be likely to slow in the future.
Ecology
Ecology (from Greek: οἶκος, "house", or "environment"; -λογία, "study of") is the branch of biology which studies the interactions among organisms and their environment. Objects of study include interactions of organisms with each other and with abiotic components of their environment. 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. Biodiversity means the varieties of species, genes, and ecosystems, enhances certain ecosystem services.
Ecology
If we have been slow to develop the general concepts of ecology and conservation, we have been even more tardy in recognizing the facts of the ecology and conservation of man himself. We may hope that this will be the next major phase in the development of biology. Here and there awareness is growing that man, far from being the overlord of all creation, is himself part of nature, subject to the same cosmic forces that control all other life. Man's future welfare and probably even his survival depend upon his learning to live in harmony, rather than in combat, with these forces.
Rachel Carson, "Essay on the Biological Sciences" in Good Reading (1958).
Ecology
The study of public administration must include its ecology. "Ecology," states the Webster Dictionary, "is the mutual relations, collectively, between organisms and their environment." J. W. Bews points out that "the word itself is derived from the Greek oikos a house or home, the same root word as occurs in economy and economics. Economics is a subject with which ecology has much in common, but ecology is much wider. It deals with all the inter-relationships of living organisms and their environment." Some social scientists have been returning to the use of the term, chiefly employed by the biologist and botanist, especially under the stimulus of studies of anthropologists, sociologists, and pioneers who defy easy classification, such as the late Sir Patrick Geddes in Britain.
John M. Gaus, Reflections on public administration, 1947, p. 6