Transcript GRASSLANDS
GRASSLANDS GRASSLANDS, TUNDRA AND CHAPARRAL BIOMES GRASSLANDS REGIONS WITH ENOUGH AVERAGE ANNUAL PRECIPITATION TO ALLOW GRASS (AND IN SOME AREAS, A FEW TREES) TO PROSPER BUT WITH PRECIPITATION SO ERRATIC THAT DROUGHT AND FIRE PREVENT LARGE STANDS OF TREES FROM GROWING GRASSLANDS MOST GRASSLANDS ARE FOUND IN THE INTERIORS OF CONTINENTS GRASSLANDS PERSIST BECAUSE OF A COMBINATION OF SEASONAL DROUGHT GRAZING BY LARGE HERBIVORES PERIODIC FIRES GRASSLANDS THESE 3 FACTORS KEEP LARGE TREES AND SHRUBS FROM GROWING MANY GRASSES ARE PERENNIALS STEMS GROW OUT FROM BOTTOM, ALLOWING PLANT TO GROW AFTER TOP IS EATEN TROPICAL GRASSLANDS FOUND IN AREAS WITH HIGH AVERAGE TEMPERATURES LOW TO MODERATE PRECIPITATION PRLONGED DRY SEASON OCCUR IN A WIDE BELT ON EITHER SIDE OF THE EQUATOR TROPICAL GRASSLANDS SAVANNAS WARM TEMPEATURES YEAR ROUND TWO PRLONGED DRY SEASONS ABUNDANT RAIN THE REST OF THE YEAR LARGEST SAVANNAS IN CENTRAL AND SOUTHERN AFRICA ALSO IN CENTRAL SOUTH AMERICA, AUSTRALIA AND S.E. ASIA SAVANNAS PREDOMINANT VEGETATION: AFRICAN SAVANNA- ACACIA TREE AUSTRALIA SAVANNA-EUCALYPTUS TREE AFRICAN SAVANNAS CONTAIN ENORMOUS HERDS OF GRAZING AND BROWSING HOOFED ANIMALS (WILDEBEESTS, GAZELLES, ZEBRAS, GIRAFFES, ANTELOPES) HERBIVORES HAVE SPECIALIZED FEEDING HABITS THAT MINIMIZE COMPETITION AFRICAN SAVANNAS GIRAFFES EAT LEAVES AND SHOOTS FROM THE TOPS OF TREES ELEPHANTS EAT LEAVES AND BRANCHES LOWER DOWN THOMPSON’S GAZELLES AND WILDEBEESTS PREFER SHORT GRASS ZEBRAS GRAZE ON LONGER GRASS AND STEMS TEMPERATE GRASSLANDS COVERS VAST EXPANSES OF PLAINS AND GENTLY ROLLING HILLS IN THE INTERIORS OF N. AND S. AMERICA, EUROPE AND ASIA. NO TREES SEASONAL EXTREMES OF HOT AND COLD WINTERS BITTERLY COLD SUMMERS ARE HOT AND DRY TEMPERATE GRASSLANDS ANNUAL PRECIPITATION AVERAGES 10-39 INCHES RECURRENT FIRES – PLANTS HAVE ADAPTED THE ABILITY TO GROW BACK RAPIDLY AFTER A FIRE DEEP, FERTILE SOIL FROM GRASSES DYING AND DECOMPOSING TYPES OF TEMPERATE GRASSLANDS TALL GRASS PRAIRIES & SHORT GRASS PRAIRIES OF THE MIDWESTERN AND WESTERN U.S. & CANADA SOUTH AMERICAN PAMPAS AFRICAN VELDT STEPPS OF CENTRAL EUROPE AND ASIA POLAR GRASSLANDS ARCTIC TUNDRA – COVERS 10% OF EARTH’S SURFACE; OCCURS JUST SOUTH OF THE POLAR ICE CAP BITTERLY COLD, COVERED WITH ICE AND SNOW WINTERS ARE LONG AND DARK MOST PRECIPITATION FALLS AS SNOW TUNDRA PLANTS GROW CLOSE TO GROUND LEATHERY EVERGREEN LEAVES COATED BY WAXES THAT REDUCE HEAT LOSS OTHER PLANTS SURVIVE AS ROOTS, STEMS, BULBS SOME DEHYDRATE TO AVOID FROST DAMAGE(LICHENS) PERMAFROST A PERENNIALLY FROZEN LAYER OF THE SOIL THAT FORMS WHEN THE WATER THERE FREEZES. IN SUMMER SOIL IS WATERLOGGED, FORMING SHALLOW LAKES, MARSHES, BOGS, PONDS ANIMAL ADAPTATIONS THICK FUR COATS FEATHERS COMPACT BODIES TO EXPOSE AS LITTLE SURFACE AS POSSIBLE LIVING UNDERGROUND TUNDRA DECOMPOSITION IS SLOW DUE TO THE COLD PARTIALLY DECOMPOSED ORGANIC MATTER FORMS SOGGY PEAT BOGS ALPINE TUNDRA OCCURS ABOVE THE LIMIT OF TREE GROWTH BUT BELOW THE PERMANENT SNOW LINE ON HIGH MOUNTAINS NO PERMAFROST MORE SUNLIGHT IMPACT OF HUMAN ACTIVITIES ON GRASSLANDS CONVERTING SOME AREAS OF SAVANNA INTO CROPLAND RELEASES LARGE AMOUNTS OF CO2 INTO ATMOSPHERE OVERGRAZING BY LIVESTOCK – TURNS GRASSLANDS INTO DESERTS AND SEMIDESERT CULTIVATING TEMPERATE GRASSLANDS CAN CAUSE SOIL EROSION DRILLING IN THE ARCTIC TUNDRA CHAPARRAL TEMPERATE SHRUBLAND OCCURS ALONG COASTAL AREAS WITH A MEDITERRANEAN CLIMATE LOCATED IN: PARTS OF PACIFIC COAST OF N.A. S. TEXAS AND N.E. MEXICO COASTAL HILLS OF CHILE, S.W. AFRICA, S.W. AUSTRALIA & THE MED. CHAPARRAL FIRES A YEARLY PROBLEM CHAPARRAL IS ADAPTED TO AND MAINTAINED BY PERIODIC FIRES