Transcript biomes1
Biomes Specific Divisions of Biosphere Ecosystems • So almost every corner of this planet, from the highest to the lowest, the warmest to the coldest, above water and below, has acquired its population of interdependant plants and animals. It is the nature of these adaptations that has enabled living organisms to spread so widely through our varied planet. – David Attenborough Biome Definition • Large, distinct, terrestrial ecosystem characterized by particular climate, soil, plants and animals. • Boundaries determined mostly by climate • Precipitation next limiting factor • Altitude next Tundra • Cold north!!! Why not south? • Long, harsh winters; dark 20 hrs/day • Very short summers • Due to tilt of earth, sunshine is “watery” and weak • However, days are long; light 20 hrs/day • Sun might not even set for a few days in midsummer!!!! • Cold limits precipitation; very little available • Tundra soils young. Why? – Only since last ice age • Consequences? – Poor organic load – Poor nutrients • Permafrost – – – – – Never thaws Only a few feet down Limits roots; no plants over a foot tall!!! In summer when upper layer melts; water sits there “Boggy” • Low species diversity – Plant • “Lots of a little” • Monotonous landscape – Animal • Small herbivores – Rodents, hares • Low species diversity – Plant • “Lots of a little” • Monotonous landscape – Animal • Small herbivores – Rodents, hares • Larger herbivores – moose, caribou, musk-oxen www.smouse.force9.co.uk/index.htm (moosecall) Caribou Notice the monotonous plant life • Low species diversity – Plant • “Lots of a little” • Monotonous landscape – Animal • Small herbivores – Rodents, hares • Larger herbivores – moose, caribou, musk-oxen • Carnivores – Weasels, owls, hawks • No reptiles!!!!! • No amphibians!!!! • Lots of insects • parkscanada.pch.gc.ca/parks/nwtw/nahanni/ • tqjunior.thinkquest.org/3500/animals.htm Taiga: Evergreen Forests of North • Large stretches of North America and Europe • ~11% of earth’s surface!! • Again not found in Southern Hemisphere • Winters long and cold, but not as severe as tundra • Little precipitation (rain; there is lots of snow) • Consequently poor soils • Lots of ponds and lakes, depressions left from previous ice ages • Layer of decomposed conifer detritus • Predominant vegetation; conifers - the cone bearers • Consequently poor soils • Lots of ponds and lakes, depressions left from previous ice ages • Consequently poor soils • Lots of ponds and lakes, depressions left from previous ice ages • Layer of decomposed conifer detritus • Predominant vegetation; conifers - the cone bearers • Animals = all sorts of consumers – Migrators; bear, moose, wolves, etc Brown Bear Grizzly Black Bear Wolves Foxes • Consequently poor soils • Lots of ponds and lakes, depressions left from previous ice ages • Layer of decomposed conifer detritus • Predominant vegetation; conifers - the cone bearers • Animals = all sorts of consumers – Migrators; bear, moose, wolves, etc – Most mammals small; rodents, rabbits, fur covered predators (lynx, mink, etc) – Birds seasonal • Lots of insects (due to standing water) • Some reptiles; but low species diversity • Not good for agriculture; but huge in forestry • 1 in 6 Canadians works in forestry • www.taiga.org/photo/image.php3?pic=1047