Climate and Terrestrial Biodiversity Chapter 6 (Biomes: Sections 3-7)

Key Concept 1: How Does Climate Affect the Nature and Locations of Biomes?  Differences in average annual precipitation and temperature lead to the formation of tropical, temperate, and cold deserts, grasslands, and forests, and largely determine their locations.

Climate Affects Where Organisms Can Live  Major biomes Similar climate, soil, plants, animals throughout world Ecotone  Latitude and elevation  Annual precipitation Deserts, grasslands, forests  Temperature Tropical, temperate, polar

The Earth’s Major Biomes

Generalized Effects of Elevation and Latitude on Climate and Biomes

Fig. 7-10, p. 147 Cold Polar Tundra Subpolar Temperate Coniferous forest Desert Deciduous forest Grassland Chaparral Tropical Hot Desert Wet Rain forest Savanna Tropical seasonal forest Dry Scrubland

There Are Three Major Types of Deserts  Tropical deserts  Temperate deserts  Cold deserts  Fragile ecosystems Hundreds of years for soil to recover from disturbances Slow plant growth Low species diversity Slow nutrient recycling (Why?) Lack of water

Climatographs of 3 Types of Deserts

Staying Alive in the Desert  Plant adaptations Drop leaves or no leaves Storage of water and food in fleshy tissue Take in CO 2 only at night Deep roots to tap into ground water Waxy coating on leaves  Animal strategies and adaptations Small, hide during the day Dormant Camel – stores massive amounts of water, doesn’t sweat Don’t drink – water from break down of fats in seeds Think coverings Dry feces and urine

There Are Three Major Types of Grasslands  Tropical Savanna Grazing animals Browsing animals  Temperate Tall-grass prairies Short-grass prairies

There Are Three Major Types of Grasslands  Cold (arctic tundra) – treeless plains Can be referred to as desert Fragile biome Nutrient poor soil Melting of permafrost Release CH 4 and CO 2 into the atmosphere  Adaptations of plants and animals Thick fur or feathers Living underground Low growing plants  Alpine tundra – below permafrost snow line on mountains, more sunlight, more flowers

Climatographs of Tropical, Temperate, and Cold Grasslands

Temperate Shrubland: Nice Climate, Risky Place to Live  Chaparral  Near the sea: nice climate Significant human impact  Prone to fires in the dry season  Maintained by fire, plants adapt with fire-resistant roots, produce seeds that sprout after fire, use nutrients released by the fire  Soil thin and not very fertile

Chaparral Vegetation in Utah, U.S.

There Are Three Major Types of Forests (Dominated by Trees)  TROPICAL  Tropical rain forests Warm temperatures, high humidity, heavy rainfall Dominated by broadleaf evergreen plants Stratification of specialized plant and animal niches Emergent layer, canopy (most life forms), understory, shrub layer, ground level Little wind to spread seeds, depend on pollinators Rapid recycling of scarce soil nutrients due to warm, moist conditions Immediately taken up by trees, poor soil Impact of human activities?

There Are Three Major Types of Forests  TEMPERATE  Temperate deciduous forests Moderate temperatures, abundant precipitation Dominated by few species of broad-leaf trees Drop leaves and become dormant in winter Slow rate of decomposition: storehouse of nutrients Impact of human activities more than any other biome

There Are Three Major Types of Forests  COLD  Evergreen/Northern coniferous forests: boreal and taigas Long extremely cold and dry winters Few species of cone-bearing evergreen trees Low plant diversity Slow decomposition: waxy coating on needles, acidic soil, nutrient poor  Coastal coniferous forest/Temperate rain forests Ample rainfall or moisture from dense ocean fog

Climatographs of Tropical, Temperate, and Cold Forests

Stratification of Specialized Plant and Animal Niches in a Tropical Rain Forest

Mountains Play Important Ecological Roles  Dramatic changes in altitude, slope, climate, soil, and vegetation  Majority of the world’s forests Majority of world’s terrestrial biodiversity  Habitats for endemic species  Sanctuaries for migrating animals (low to high)  Help regulate the earth’s climate Ice and snow reflect solar radiation back into space Opposite – dark exposed rock absorbs energy?  Can affect sea levels  Major storehouses of water - role in hydrologic cycle

Key Concept 2: How Have We Affected the Word’s Terrestrial Ecosystems?  In many areas, human activities are impairing ecological and economic services provided by the earth’s deserts, grasslands, forests, and mountains.

Fig. 7-20, p. 158 NATURAL CAPITAL DEGRADATION Major Human Impacts on Terrestrial Ecosystems Deserts Grasslands Forests Mountains Large desert citiesConversion to cropland Clearing for agriculture, livestock grazing, timber, and urban development Agriculture Soil destruction by off-road vehicles Timber extraction Release of CO 2 to atmosphere from burning grassland Conversion of diverse forests to tree plantations Hydroelectric dams and reservoirs Mineral extraction Soil salinization from irrigation Increasing tourism Overgrazing by livestock Depletion of groundwater Damage from off- road vehicles Urban air pollution Increased ultraviolet radiation from ozone depletion Land disturbance and pollution from mineral extraction Oil production and off-road vehicles in arctic tundra Pollution of forest streams Soil damage from off-road vehicles