Pub. date: 2008 | Online Pub. Date: May 28, 2008 | DOI: 10.4135/9781412963930 | Print ISBN: 9781412941655 | Online ISBN: 9781412963930| Publisher:SAGE Publications, Inc.About this encyclopedia
Michael J. Sebetich
The science of ecology is the study of organisms, their relationship with the physical environment, and the interactions among organisms. Ecosystem is a concept in ecology. An ecosystem consists of both nonliving and living components. The abiotic parts include the atmospheric gases, all forms of water, and sediment. The 28 chemical elements required by living organisms are contained in these three interconnected physical spheres. The biotic segments of an ecosystem are the living organisms in five biological kingdoms: Monera (bacteria and blue-green cyanobacteria), Protista (algae and protozoa), Fungi (mushrooms, molds), Plantae (green plants), and Animalia (animals). The living organisms in an ecosystem may be divided into two functional groups: producers, which are the photo synthetic plants and algae, and consumers, which are the heterotrophs. Heterotrophs are macro consumers and micro consumers. Macro consumers are herbivores and carnivores. Micro consumers are bacteria and fungi; together they are the decomposers of the ...