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Wildlife NRES Ecology and Management
Chapter 2: Biomes
The earth as a planet, or biosphere, is the single largest ecological unit that we can consider. Trying to study the entire earth lacks convenience. As a species that naturally tends to organize things, we have developed hierarchies of landform classication. The biome is the largest landscape classication unit that we can use to subset the biosphere.
Biomes
Biomes are regions of similar with similar ecological characteristics. Flora - plants Fauna - animals
Ecosytems
Within biomes there are other smaller ecological units that make up the abiotic environment for a denable area. Ecosystems are the main functional units of the biosphere.
Plants and animals of similar composition in a landscape comprised of a relatively uniform environment. E.g., watersheds, mountain ranges, valleys, etc.
Communities
Within ecosystems, the biotic groupings of plants and animals are called communities. The interactions of the populations of plants and animals dene a community uniquely. The way in which these animals are adapted to their surroundings, and the control exerted on those populations by the environment are what we need to understand as wildlife managers.
Habitat
Habitat is the resources and environmental conditions that determine the presence, survival and reproduction of a population.
Classifying Biomes
Biomes are summarized by the abiotic components of mean annual rainfall and temperature. Based on this, six major terrestrial biomes exist: 1. Forests 2. Woodlands 3. Shrublands 4. Grasslands 5. Semi-desert 6. Desert
Forest biomes
Taiga/boreal forest
Taiga in Eurasia. Boreal forest in North America. >10C mean daily temperature for >30 days. Boreal is dominated by Pinus, Picea, Abies, and Larix. Soils are low in nutrients and acidic with a thick humus that decomposes slowly. Habitat for lynx, snowshoe hares, goshawks.
Temperate deciduos Forest
Deciduous forest is common in the eastern US, western Europe and eastern Asia. Deciduous forest needs a long growing season for annual leaf replacement. Deciduous forests are dominated by Quercus, Acer, Ulmus, and Fagus trees. Voles, mice, shrews, deer, bison, thrushes, and warblers are common inhabitants.
Temperate rainforest
Western coasts of North America, Chile, New Zealand, and southern Australia. Dominated by large trees such as Sequoia sempervirens (US), Podocarpus (NZ) and Eucalyptus (Australia). Generally low diversity in both plant and animals.
Temperate evergreen forest
Scattered worldwide: e.g., sclerophyll forest of eastern Australia (Eucalyptus spp.), dry pine forest of Western US (Pinus spp., Sierra Nevada Range). Various rodent species are common in western US examples, including chipmunks and squirrels.
Tropical forest
Daily temperatures and day length are relatively constant year-round due to proximity to equator. Seasons dened by rainfall (wet/dry). High endemic diversity of plants and animals. Amazon basin of South Amer., central and west Africa, southeast Asia, Indonesia, and northern Aus. Trees make up 70% of plants. Primates, sloths, tropical birds.
Woodland
Tropical broadleaf plants extending into drier and more seasonal climates; plants often shed leaves. Dense herbaceous layer promotes re adaptation. Southern and west Africa, India and Asia. Patches of woodland in Mediterranean and Mex. Roan, sable antelope, Bos spp.,
Shrubland
Typied by Mediterranean vegetation types, including much of California, with dry, hot summers and cool, wet winters. Where theres wine... Italy, Australia, Chili, etc. Often re-adapted plant species that root-sprout. Quercus, Ilex, Juniperus, Olea, Ceanothus... Hard, leathery leaves with stomata that close. Many of these areas are characterized high by levels of endemic biodiversity.
Grassland
Typied by ungulate species that can migrate with seasonal changes in climate and vegetation. The movement of these ungulates also benets them by escaping predators that are not as capable of moving great distances.
Tropical savanna grassland
Grasslands with scattered trees, such as that found in on the plains of eastern Africa or the Acacia savannas of central Africa and Australia. Relatively constant temp with seasonal precip. Perennial grasslands that frequently burn. Lion, giraffe, kangaroos, water buffalo, nches, parrots, capybara, coypus, etc.
Temperate grassland
Seasonal temperature and precipitation. Often in continental centers and in rain shadow of major mountain ranges, such as the Rockies in US. Fairly low plant and animal diversity, including redependent grasses and large-ranging ungulates. Bison, pronghorn, wolves (historically), horses (Asia), grouse/prairie chickens, hawks, falcons.
Tundra (grassland)
Arctic cold areas with exceptionally short growing seasons, extreme shifts in seasonal daylight, <189 with mean temp >0C! Soils are typically frozen as permafrost except for a thin layer near the surface in summer. Dwarf shrubs, sedges, grasses, lichens, and mosses. Ptarmigan, geese, lemmings, mosquitos, shorebirds, passerines, muskoxen, carribou, arctic hare, wolves, arctic fox, and snowy owl.
Alpine (grassland)
Typied by high precipitation in well-draining soils, often granitic, and daily extremes in temperature. Patchily distributed (sky islands) and cannot generally support many species. Marmots, pikas, voles, elk, moose, caribou, bears, Asian goats and sheep, snow leopard.
Semi-Desert scrub
This biome covers an incredible diversity of landscapes across the globe with many specialized species, especially rodents. The Great Basin can be partially considered as semi-desert scrub (high valleys that are sagebrush dominated). Ground squirrels, gerbils (Africa), kangaroo rats, Acacia, Artemisia
Deserts
Found often in mid-latitudes, including the Sahara in Africa, Gobi in Asia, Mojave in southern California and Nevada, and Sonoran of Arizona and Mexico. Receive !250mm annually that is episodic. Plants adapted to rapid owering and seedin...