. Principles of modern biology. Biology. 588 - Heredity and Evolution grades accumulations of organic matter, re- storing the abiotic base of inorganic nu- trients. In short, each ecosystem represents a microcosm, governed by the same inexorable laws that determine the economy of life upon our terrestrial planet as a whole (Chap. 10). A pond (Fig. 30-13) will serve to exemplify the economy of a small but definitive eco- system. Such a system may endure for only a century or two, because an invasion of rooted plants (cattails, water lilies, etc.) will gradu- ally tend to fill the pond, converti
. Principles of modern biology. Biology. 588 - Heredity and Evolution grades accumulations of organic matter, re- storing the abiotic base of inorganic nu- trients. In short, each ecosystem represents a microcosm, governed by the same inexorable laws that determine the economy of life upon our terrestrial planet as a whole (Chap. 10). A pond (Fig. 30-13) will serve to exemplify the economy of a small but definitive eco- system. Such a system may endure for only a century or two, because an invasion of rooted plants (cattails, water lilies, etc.) will gradu- ally tend to fill the pond, converting it to marshland and finally to "terra ; But while the pond endures, interactions within the communities of inhabitants can be ana- lyzed with some precision. The abiotic base in a small pond ecosys- tem is provided partly by the nitrates, phos-. DEC0MP0SERS ABIOTIC BASE MATERIAL WATER, SALTS, ORGANIC DETRITUS, ETC. Fig. 30-13. Ecosystem of a small pond. The system operates upon solar energy and the producers are a com- munity of green plants of which the free-floating phytoplankton is of greatest importance. Abiotic base material, for supporting the producers, is provided by the water, salts, and carbon dioxide of the pond and by the organic detritus that sediments to the bottom. Primary consumers are small crustaceans and other herbivores that feed directly upon the producers; the secondary and tertiary consumers, respectively, are the smaller and larger carnivorous species. The decomposers, which prevent an unduly large accumula- tion of organic matter, are constituted by the community of fungi—bacteria and molds—that mainly inhabit the bottom sediment. (After E. P. Odum.). Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Marsland, Douglas, 1899-. New York, Holt, Rinehart and Winston
Size: 1731px × 1444px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionbiodiversity, booksubjectbiology
