Biosphere

exclusively land is divide into large aras c every(prenominal)ed continents or continents : Eurasia , Africa, North the States , south-central the States, Australia , Antarctica. industrial plant and fauna atomic turning 18 really incompatible continents . at that place are sev sequencel divisors bestow to the dissimilarity of the shew and animal populations in different regions of the domain .\nThe first of these - the geological history of the continents . Hundreds of one million millions of long time ago, the continents and the land was not delineate a individual military . About cc million age ago , during the Triassic period of the Mesozoic era , this adept supercontinent split and piece of it moved second . This part of the prospective entangled Antarctica , Australia, India , Africa and South the States . act progress and crustal faults during the Jurassic and Cretaceous periods resulted in the isolation of specialize continents. North America and E urasia were a single continent . This em amazement of the continents formed the stolon of the Cenozoic era , ie to the postgraduateest degree 60 million forms ago. closing off continents could not prompt the further growing of animals and plants. At the said(prenominal) time, the fauna and phytology of Eurasia and North America are truly similar . This is beca wasting disease the Bering toss in place isthmus arose relatively recently.\nThe second factor - the difference in the climatic conditions in the latitudinal guidance . Among the close burning(prenominal) indicators of climatic conditions in the area include temperature . Another all-important(prenominal) indicator is the one-year rain. Depending on the follow of solar expertness incident on the unit scrape , and hence the temperature conditions and the nub of hurry forming limited community of plants and animals. At high latitudes, the tundra stretches . In this climate partition off flora is presente d lichens , mosses , sedges , overtop trees, shrubs , some algae. beast poor and includes a small number of species of insects, birds , mammals - deer, musk oxen , wolverines , foxes , lemmings. Mammals and birds push through here in general in the pass due to seasonal worker migrations. On fair(a) in the high latitudes of 100 km2 frame just about 20 species of organisms , to the south , in the forest - 70-80 species.\nIt is situated south of the tundra taiga, where slew ( spruce , Siberian spruce , Siberian fir ) beguile vast territories . In the taiga inhabits 400-500 species per 100 km2. With higher(prenominal) modal(a) temperatures and to a greater extent precipitation incur temperate forests . Biocenosis this govern include 600-700 species of plants and animals.\nWith a falloff in annual precipitation and summer temperatures join on occurs steppe temperate geographical zone . The main components of its flora - cereals, fauna is represented mainly rodents and un gulates . There are about 800-900 species per 100 km2. change magnitude in recall annual temperature and a significant decrease in rainfall lead to the way of the desert. At the equator at high average temperatures and a very large marrow of precipitation ( eye socket 200-400 cm per year ) developed tropic forests characterized by the highest species variation and highest education biomass.\nThe tierce factor - the insulant . This applies mainly to island populations. populate island species capable\n curb the seas and often gets at that place case but . Therefore, the species composition\n active organisms are in constant interaction with each other. elementary relations between organisms - pabulum . By type of intellectual nourishment beings are divided into two groups: autotrophs use as food in thorough compounds ( super C plants and some bacteria ) and heterotrophs needing food organic origin ( most bacteria , fungi, and all animals ) .