VOCABULARY: system; equilibrium; response time; ecology; cycle; food chain; food web; trophic level; ecosystem; biome; ecotone; biomass; habitat; ecological niche; photosynthesis; photoperiodism; hygrophytic; xerophytic; wind chill; monoculture; exotics; plant succession; extinction; extirpation; climax community; evergreen; deciduous; vertical zonation; zoogeographic region; tropical rainforest; selva; epiphytes; lianas; tropical deciduous forest; jungle; tropical scrub; tropical savanna; desert; mediterranean woodland and shrub; chaparral; midlatitude grassland; prairie; steppe; midlatitude deciduous forest; boreal forest; taiga; timberline; tundra; permafrost
system--any collection of interacting objects; the earth as a whole is a system
systems on earth are closely related
equilibrium--balance which needs to be maintained within systems
response time--time it takes a system to recover its equilibrium after it has been disturbed

ecology--science which studies the interactions between organisms and their environment

cycle--repetitive exchange

rock cycle; energy cycle; hydrologic cycle; carbon cycle; oxygen cycle; nitrogen cycle; mineral cycles

most are powered by sun, particularly the biological ones

food chain--one organism eats another, absorbs energy and nutrients
food web--food chains interrelated within a community

higher up, more complex, higher trophic level

ecosystem--ecological system--totality of interactions among organisms and the environment in an area
biome--assemblage of plants and animals in functional interaction with its environment
ecotones--transition zones of competition between species of different biomes
biomass--total weight of all organisms in an area
habitat--location in ecosystem occupied by an organism; satisfies needs of organism
ecological niche--combination of role and habitat in ecosystem of an organism

generalists--eats wide variety of foods
specialists--have narrow variety of foods

environmental influences on organisms


soil--(edaphic influence)--soil nutrients, permeability, etc.

topographic influence--slope steepness, slope aspect, drainage, erosion, sunlight, permeability

accessibility--isolation, influences to migration
wildfire--destroy or aid


among man's most successful skills is the elimination of other living things

other natural disasters

climate and vegetation--particularly close relationship
vegetation is important geographically:

plant succession--one type of vegetation naturally replaces another, simpler to complex
climax community--stable, complex vegetation at end of succession
evergreen--no seasonal leaf fall; deciduous--leaf fall; broadleaf; needleleaf
major floristic associations vertical zonation--altitude makes a change in the vegetation as the climatic conditions differ

animals--less prominent (more secretive); less clear environmental relations; not inconsequential; may be more sensitive;

are motile (capable of spontaneous self-generated movement)

zoogeographic regions
The Zoogeographic Region Map

richest faunal assemblages in humid tropics; desert or cold fewest

based on terrestrial vertebrates (Wallace and Sclater); six major and three lesser regions

11 Major Biomes--dominant vegetation association; encompasses fauna and interrelationships with soil, climate, and topography
The world biome map

The hypothetical continent biome map

1) Tropical Rainforest--(selva)--most complex of all terrestrial ecosystems; broadleaf evergreens; shallow roots; fig, mahogany; floor shaded; layered structure; sparse undergrowth because of lack of light; epiphytes--perched plants; lianas--tree climbing vines; soil infertile (rapid decomposition); fauna is mainly arboreal (tree-dwelling); lots of invertebrates; monkeys, birds, tree snakes and lizards; climate--hot, wet
northern Brazil; west central Africa; Thailand, Burma, Indonesia
2) Tropical Deciduous Forests [monsoon rain forest, tropical semideciduous]--less dense canopy; less layered; pronounced dry period, trees shed their leaves so light penetrates; jungle growth; fewer tree species; more shrubs and lesser plants; more ground-level vertebrates
north coast South America, central Brazil, around tropical rainforest in Africa, Vietnam, northeastern Australia, southwestern India
3) Tropical Scrub [tropical thornbush and scrub, tropical scrub woodland, and other]--low growing,scraggly trees and tall bushes; grasses below; fewer species; wetter to drier change from evergreen to deciduous; thorny shrubs; rich assemblage of ground-dwelling mammals and reptiles, birds, insects
southern Brazil, southern Africa, India, south central Australia
4) Tropical Savanna [tropical savanna grasslands, tropical grassland]--tall grasses; some bunchgrass; some without shrubs or trees (with--parkland or park savanna); pronounced seasonal rhythm; wet-dry seasons; wildfires; African big game; ungulates and carnivores; Latin America sparse; Asian and Australian intermediate
around tropical deciduous forest in central Africa; northeastern interior Australia
5) Desert--variable; sparse; drought-resisting plants which conserve moisture or drought-evading ones with hasty reproduction; shrubs, sporadic trees; sagebrush; conifers; inconspicuous animals; limited large mammals; burrowing and nocturnal; oases; fertile soils if not saline
southwestern United States; Sahara, Arabia; Australia
6) Mediterranean Woodland and Shrub [Mediterranean sclerophyllous woodland or Mediterranean mid-latitude forest]--dry summer/wet winter; dense growth of woody shrubs--chaparral; open grassy woodland with scattered trees; oaks; shrubs are broadleaf evergreens with waxy leaves; deep roots; summer fires; floods; burrowing rodents, birds, reptiles
California, mediterranean
7) Midlatitude Grassland--lack dependable precipitation for bigger vegetation; fires; prairie--wetter;steppe--drier; [savanna has grasses and scattered trees and scrubs, the parkland or park savanna] perennial grasses (unless disturbed); between forests and deserts; rich soils; grazing animals, burrowing; bison; antelopes, wolves, mice, ground birds
western United States, central Asia, eastern Argentina
8) Midlatitude Deciduous Forest [broad-leaf deciduous forest, broadleaf and mixed mid-latitude forest and broad-leaf evergreen forest and mixed forest, mid-latitude deciduous and mixed forest (includes mid latitude evergreen forest)]--broadleaf deciduous; little natural original left; dense growth tall trees; canopy complete; lower levels shrubs or barren; seasonal fall; to north grade to needle-leaf evergreen; richest fauna of mid-latitudes; birds, mammals, reptiles, amphibians, insects, deer, cottontail; red fox; quail squirrel; oak maple hickory; precipitation year round, warm summer
eastern United States, Europe to Asia; eastern China
9) Boreal Forest [northern coniferous forest]--taiga--coniferous; needle-leaf evergreens and tamarack or larch (drops needles); pines, firs, spruces, acid leached soils; migratory birds, insects, moose, caribou, snowshoe hare, wolverine; fur bearers; fauna limited--timberline
Canada, most of Russia, Scandinavia
10) tundra [arctic and alpine tundra, tundra and alpine meadow]--cold desert, long winter, short summer, permafrost--permanently frozen ground; mixture of species dwarf form; grasses, mosses, lichens, flowering herbs, low shrubs; ground hugging arrangement; hasty annual cycles; birds, insects, few mammals, caribou, wolf, polar bear
northern Canada and Alaska, northern Asia, northernmost Russia
(11) oceans (aquatic)--70% of earth's surface; life concentrated near the shore; shallow water; light penetrates; intertidal zone

Go to the biome map

Go to the hypothetical continent biome map

 Go to the Biogeography Partial Test Bank.
Dr. M. H. Hill's Homepage