Chapter 30

Chapter 30Chapter 30

Earth’s Diverse EcosystemsEarth’s Diverse Ecosystems

What Factors Influence Earth’s What Factors Influence Earth’s Climate?Climate?

Climate and Weather Climate and Weather Are Driven by SunAre Driven by Sun About 1/2 solar energy About 1/2 solar energy

that reaches the earth that reaches the earth actually strikes the actually strikes the surfacesurface

Most is reflected or Most is reflected or absorbed absorbed

Sunlight strikes Earth at various anglesSunlight strikes Earth at various angles Earth’s curvature and tilt helps produce seasons and Earth’s curvature and tilt helps produce seasons and

climate climate

Solar energy drives ocean currents, wind and the Solar energy drives ocean currents, wind and the water cyclewater cycle Large scale movements of air and water produce different Large scale movements of air and water produce different

climatesclimates

Mountains complicate Mountains complicate weather and climateweather and climate

Elevation effects temperatureElevation effects temperature

Mountains modify rainfall Mountains modify rainfall patternspatterns

What Conditions Does Life Require?What Conditions Does Life Require?

4 Resources necessary for life4 Resources necessary for life NutrientsNutrients EnergyEnergy Liquid waterLiquid water Appropriate temperature Appropriate temperature

How Is Life on Land Distributed?How Is Life on Land Distributed? Distribution of terrestrial biomes is determined by Distribution of terrestrial biomes is determined by

rainfall and temperaturerainfall and temperature

BiomesBiomes Large land areas with similar environmental conditions and Large land areas with similar environmental conditions and

characteristic plant communitiescharacteristic plant communities

Tropical Rain ForestsNear equatorAnnual precipitation up to 160 inchesTemp averages 77-860 with little seasonal variation

•Highest biodiversity of any ecosystem on Earth

•2/3 of the species on Earth but it only covers 6% of the surface

Human Impact – Deforestation

Savanna Annual precipitation up to 12 inchesDistinct wet and dry seasons

Grasses are dominant vegetationMost diversity of large land mammals

Human Impact- Poaching

Deserts Annual precipitation less than 10 inchesTemp varies dramatically

•Cacti have adaptations forwater conservation

•Desert plants secrete chemicals to prevent growth of competitors

•Most desert animals are nocturnal

ChaparralChaparralCoastal regions that boarder deserts Annual precipitation up to 30 inchesFog in dry season retains moisture

•Maintained by frequent fires set by summer lightning •The tops of the plants may be burned off, but the roots send up new shoots

Grasslands (prairie) Grasslands (prairie) Generally centrally located Annual precipitation up to 30 inches

Tallgrass prairie

Shortgrass Prairie

Human Impact- Overgrazing

Temperate Deciduous Forests Temperate Deciduous Forests Annual precipitation up to 60 inchesCold dry winters Trees drop their leaves during dry season

Coniferous Forest (taiga)Coniferous Forest (taiga)Long cold winters with a short growing season Diversity is lower than any most other biomes

Human Impact- Clear Cutting

Tundra Tundra Boarders the Artic Ocean Winter temp can reach -400 with 60 mph windsPermafrost – permanently frozen layer of soil