Climate and Terrestrial Biodiversity

Hoh Rainforest (140 – 170 inches rainfall per year)

CLIMATE: A BRIEF INTRODUCTION Weather is a local area’s short-term physical conditions such as temperature and precipitation. Climate is a region’s average weather conditions over a long time. –Latitude and elevation help determine climate.

Solar Energy and Global Air Circulation: Distributing Heat Global air circulation is affected by the uneven heating of the earth’s surface by solar energy, seasonal changes in temperature and precipitation.

Ocean Currents: Distributing Heat and Nutrients Ocean currents influence climate by distributing heat from place to place and mixing and distributing nutrients.

Effects of Global Warming Alter precipitation patterns Shift areas we can grow crops Raise average sea levels Change areas where some types of plants and animals can live

Topography and Local Climate: Land Matters Interactions between land and oceans and disruptions of airflows by mountains and cities affect local climates.

BIOMES: CLIMATE AND LIFE ON LAND Different climates lead to different communities of organisms, especially vegetation. –Biomes – large terrestrial regions characterized by similar climate, soil, plants, and animals. –Each biome contains many ecosystems whose communities have adapted to differences in climate, soil, and other environmental factors.

Polar ice Equator Tropic of Capricorn Tropic of Cancer High mountains Polar grassland (arctic tundra) Temperate grassland Tropical grassland (savanna) Chaparral Coniferous forest Temperate deciduous forest Tropical forest Desert

BIOMES: CLIMATE AND LIFE ON LAND Biome type is determined by precipitation, temperature and soil type

Mountain ice and snow Elevation Tundra (herbs, lichens, mosses) Coniferous Forest Deciduous Forest Tropical Forest Tropical Forest Deciduous Forest Coniferous Forest Tundra (herbs, lichens, mosses) Polar ice and snow Latitude

DESERT BIOMES Deserts are areas where evaporation exceeds precipitation. Deserts have little precipitation and little vegetation. –Found in tropical, temperate and polar regions. Desert plants have adaptations that help them stay cool and get enough water.

DESERT BIOMES Variations in annual temperature (red) and precipitation (blue) in tropical, temperate and cold deserts.

Desert Plant Adaptations Drop their leaves during hot and dry spells to survive dormant state Succulent plants – fleshy plants store water Some have deep roots to tap into groundwater Some have widely spread, shallow roots to collect water during brief rain showers Spines to guard against predators Wax coated leaves to reduce water loss Grasses and wildflowers store their biomass in seeds

Desert Animal Adaptations Small Hide in burrows during day and hunt at night Dormant during periods of extreme heat and drought Insects and reptiles thick outer coverings Insects and reptiles feces is dry and a dried concentrate of urine to minimize water loss Get water from dew Dry feces Dry urine

Saguaro (“sah-WAH-ro”)cactus No leaves Store water and synthesize food in their expandable fleshy tissue Reduce water loss by opening their stomata only at night to take up CO 2 -Grow up to 50 feet tall -Live up to 200 years -Grow a few inches a year -Branches around 50 years

Why are desert ecosystems fragile?  Soils take a long time to recover  Slow plant growth  Low species diversity  Slow nutrient cycling  Lack of water

GRASSLANDS AND CHAPARRAL BIOMES Variations in annual temperature (red) and precipitation (blue).

GRASSLANDS Grasslands occur in areas too moist for desert and too dry for forests.

Savanna Grasslands Scattered clumps of trees Animals farsighted, swift, stealthy Large herds of hoofed animals Seasonal droughts Occasional fires

Temperate Grasslands The cold winters and hot dry summers have deep and fertile soil that make them ideal for growing crops and grazing cattle.

Temperate grassland

Chaparral Chaparral has a moderate climate but its dense thickets of spiny shrubs are subject to periodic fires.

Chaparral

Arctic tundra

Why is the tundra a fragile biome?  Short growing season  Soil and vegetation recovers slowly  Human activities leave scars that persist for centuries

FOREST BIOMES Variations in annual temperature (red) and precipitation (blue) in tropical, temperate, and polar forests.

Bromeliad

buttress

Rafflesia – world’s largest flower which smells like rotting flesh Dense vegetation = little wind Rainforest depends on others to spread seeds and pollen

Tropical Rain Forest Filling such niches enables species to avoid or minimize competition and coexist Stratification of specialized plant and animal niches

Temperate Rain Forests Coastal areas support huge cone-bearing evergreen trees such as redwoods and Douglas fir in a cool moist environment.

Temperate deciduous forest

Taiga (Boreal) Forest Long winters Coniferous trees Low plant diversity High soil acidity Soil nutrient poor

Taiga

MOUNTAIN BIOMES High-elevation islands of biodiversity Often have snow- covered peaks that reflect solar radiation and gradually release water to lower- elevation streams and ecosystems.

Tree line

Ecological Role of Mountains Contain majority of world’s forest Often habitats for endemic species Sanctuaries for animal species driven from lowland Help regulate earth’s climate About 75% of world’s freshwater stored as glacial ice Critical role in hydrologic cycle

Human impact tropical rainforest

Human impact on deserts

Human impact on grasslands

Human impact on forests

Human impact on mountains

The End