Communities & Biomes What determines what lives in a specific area?

Limiting factors  Def: any environmental factor (whether abiotic or biotic) that restricts the existence, numbers, reproduction, or distribution of organisms in an ecosystem. (Ex. Amount of food, predators, temperature)  Factors that limit one population may also have an indirect effect on another population.

Biomes A large group of ecosystems that share the same type of climax community

Types of biomes Aquatic 1. marine biomes (saltwater) 2. freshwater biomes Terrestrial 3. tundra 4. taiga (coniferous forest) 5. desert 6. grassland 7. temperate forest (deciduous forest) 8. tropical rain forest

Marine Biomes  Oceans contain the largest amount of living material (biomass) of all of the biomes – but most of them are microscopic orgs!!!  Photic Zone – Light  Aphotic Zone – No Light

Freshwater Biomes  EX. Lakes, ponds, rivers, streams  Light penetration affects productivity (amount of life present)  But, bottoms of lakes and ponds have decay taking place (dead orgs drift to bottom, bacteria break them down and form detritus), …

Figure The distribution of major terrestrial biomes

Figure 20.25h Tundra

Tundra: Abiotic Factors –strong winds; low precipitation; –short and soggy summer season, but long days (Short Growing Season) –long, cold, dark winters with short periods of winter sunlight –Permafrost – permanently frozen ground under the topsoil –poorly developed soil with very little nutrients (Slow Decay Process) - Cycle of freezing and thawing rips and crushes plant roots, so plants are small and stunted

Tundra  Geographic distribution: northern N.A., Asia and Europe, One of two biomes that circle poles, closest one to poles  Dominant Plants: TREELESS LAND mosses, lichens, sedges, short grasses (ground-hugging)  Dominant wildlife: birds and mammals that can withstand harshness; migratory waterfowl, shore birds, musk ox, Arctic fox, caribou; small rodents

Figure 20.25g Coniferous forests

Taiga/Boreal/Coniferous Forests  Abiotic factors: long, cold winters; short, mild summers long, cold winters; short, mild summers moderate precipitation; high humidity moderate precipitation; high humidity acidic, mineral-poor soil acidic, mineral-poor soil  Geographic distribution: N.A., Asia, Northern Europe (Circles the poles)

Tiaga, Boreal or Coniferous Forest  Dominant Plants: –needleleaf coniferous trees, broadleaf deciduous trees; small, berry-bearing shrubs  Dominant Wildlife: –predators like lynx and timberwolves; weasel family; herbivorous mammals (large and small); beavers; migratory songbirds

Figure 20.25f Temperate deciduous forest

Temperate/Deciduous forest  Abiotic factors:  cm annual precipitation (Year Round)  cold to moderate winters, warm summers,  Soil has top layer that is rich in humus, deeper layer of clay. If minerals are not taken up by plants roots, the minerals get into clay and are trapped  Geographic distribution: eastern U.S., southeastern Canada, most of Europe, parts of Japan, China, and Australia

Temperate/Deciduous Forests  Dominant plants: broadleaf deciduous trees, some conifers, flowering shrubs, herbs, mosses and ferns  Dominant wildlife: deer, black bears, bobcats, nut and acorn feeders, omnivores (raccoons and skunks), songbirds, turkeys –Many animals live here year round

Figure 50.25b Savanna

Figure 50.25bx Savanna

Savanna  Abiotic factors: warm temps, seasonal rainfall, compact soil, frequent fires due to lightning  Dominant plants: tall, perennial grasses, drought- and fire-resistant shrubs and trees  Dominant wildlife: predators (lions, leopards, cheetahs, hyenas, jackals), herbivores (elephants, giraffes, antelopes, zebras), birds (eagles, ostriches, weaver birds, storks), insects (termites)  Geographic distribution: large parts of eastern Africa, southern Brazil, northern Australia

Figure 50.25e Temperate grassland

Grasslands  Abiotic factors: –warm to hot summers, cold winters –moderate, seasonal prec (25 and 75 cm ) –fertile soils (Good humus content in soil) –fires  Geographic distribution: central Asia, N.A., Australia, central Europe, upland plateaus of S.A.  Other names: prairies, steppes, savannas, pampas  Occupies more area than any other terrestrial biome

Grasslands  Dominant plants: lush, perennial grasses and herbs, resistant to drought and fire.  Dominant wildlife: predators (coyotes, badgers, wolves, grizzly bear); herbivores (deer, antelope, rabbits, prairie dogs, bison); birds (hawks, owls, bobwhite), insects (ants and grasshoppers)

Figure 50.25c Deserts

Deserts  Abiotic factors: –Hot days and cold nights –Soil rich in minerals BUT poor in organic material –Driest of all biomes -- < 25 cm rainfall per year; but, other than this, deserts vary greatly…  Geographic distribution: Africa, Asia, Middle East, U.S., Mexico, S.A., Australia

Deserts Dominant plants: –Little to no plant life; Adapted for holding on in shifting sand and with little water available has a short life cycle –Cacti and succulents, creosote bush Dominant wildlife: –predators (mtn lions, fox, bobcats, coyote, hawk, scorpion, snake, lizard, bats, insects) –herbivores (deer, antelope, sheep, rats) –Rodents are present, but these small herbivores stay hidden in day, come out at night – nocturnal

Figure 50.25a Tropical forests

Tropical Rain Forests Abiotic factors:  Hot and wet year-round, thin, nutrient-poor soil  Nutrients are tied up in living material – very few nutrients are held in the soil because decomposers break down dead stuff very quickly Geographic distribution: Near the Equator  Parts of South and Central America, Southeast Asia, parts of Africa, southern India, northeastern Australia

Tropical Rain Forests  Home to more species than any other biome on earth (lots of different habitat possibilities…)  Dominant plants: –Broad-leaved evergreen trees, ferns, large woody vines, climbing plants, orchids and bromeliads  Dominant wildlife: –Mammals (jaguars, sloth, monkeys) –lots of birds (parrots, toucans) –insects (butterflies, ants, beetles) –piranhas and other freshwater fishes, reptiles, and snakes