Biology, 9th ed, Sylvia Mader Chapter 49 Chapter 49 The Biosphere The Biosphere

Outline Climate and the Biosphere Terrestrial Ecosystems Solar Radiation Global Wind Circulation Terrestrial Ecosystems Tundra Forests Shrublands Grasslands Deserts Aquatic Ecosystems Life Zones Lakes Estuaries Seashores Oceans

Climate and the Biosphere Prevailing weather conditions in a region Determined primarily by temperature and precipitation Influenced by a multitude of factors including latitude, tilt of the earth’s axis, and topography Effects of solar radiation Spherical earth Rotation and path of the earth around the sun

Distribution of Solar Energy

Global Wind Circulation

Consider a coastal mountain range Rain Shadow Consider a coastal mountain range Windward side of the mountain Winds rise Release moisture Leeward side Dry winds subside Evaporates existing water and rarely rains Rain shadow

Formation of a Rain Shadow

Terrestrial Communities Biomes A particular mix of plants and animals adapted to living under certain environmental conditions Often delineated by climate Tend to repeat wherever temperature and precipitation are the same

Pattern of Biome Distribution

Climate and Biomes

Tundra Arctic tundra Encircles Earth just south of ice-covered polar seas in Northern Hemisphere Covers 20% of Earth’s land surface Trees are not found in the tundra because growing season is too short Roots cannot penetrate permafrost

The Tundra

Taiga typifies coniferous forest with cone-bearing trees Coniferous Forests Taiga typifies coniferous forest with cone-bearing trees Trees well adapted to cold Leaves and bark have thick covering Needle-like leaves can withstand weight of heavy snowfall Temperate Rainforest (Old-Growth Forests) of Pacific Northwest Evergreen forest

The Taiga

Temperate Deciduous Forests Found south of taiga in eastern North America, eastern Asia, and much of Europe Four well-defined seasons with long growing seasons Tallest trees form a canopy Ground-life is plentiful

Temperate Deciduous Forest

Found in equatorial regions Tropical Forests Found in equatorial regions Plentiful rainfall Most animals live in trees Abundant insect life Epiphytes grow in many areas Soils are nutrient-poor Rapid recycling of nutrients Swidden agriculture successful but destructive

Levels of Life in a Tropical Rain Forest

Representative Animals of the Tropical Rain Forests of the World

Shrublands Tend to occur along coasts that have hot, dry summers and cool, wet winters Shrubs adapted to withstand arid conditions Dense shrubland in California known as chaparral

Shrubland

Grasslands Occur where annual rainfall is greater than 25 cm, but generally insufficient to support trees Grasses well adapted to changing environment Temperate Grasslands Savannas

Temperate Grassland

The Savanna

Deserts Usually found at latitudes of about 30o in both north and south hemispheres Descending winds lack moisture Annual rainfall less than 25 cm Large temperature differential between day and night

The Desert

Aquatic Ecosystems Lakes Bodies of water classified by nutrient status Oligotrophic - Nutrient-poor Eutrophic - Nutrient-rich Lake Stratification In temperate zones, deep lakes are stratified in the summer and winter

Freshwater and Saltwater Ecosystems

Types of Lakes

Lake Stratification in a Temperate Region

Aquatic Life Zones Plankton Life Zones Important community in fresh water and salt water Phytoplankton - Algae Zooplankton - Animals Life Zones Littoral zone - Closest to shore Limnetic zone - Sunlit areas Profundal zone - Below light penetration Benthic zone - Soil-Water interface

Zones of a Lake

Coastal Communities Estuaries Partially enclosed bodies of water where fresh water and seawater meet and mix Organisms must be able to adapt to changing salinity Estimated over half of all marine fishes require development in estuaries

Estuary Structure and Function

Types of Estuaries

Littoral zone lies between high and low water marks Seashores Littoral zone lies between high and low water marks Rocky Shores Many attached organisms Littoral zone of rocky beach divided into subzones Sandy beach No attachment sites available Nearly all permanent residents dwell underground

Seacoasts

Biology, 9th ed, Sylvia Mader Oceans Chapter 49 The Biosphere Major ocean currents move heat from the equator to cooler parts of the biosphere Gulf Stream warms east coast of North America and parts of Europe El Nino Southern Oscillation Cold upwelling off west coast of South America subsides 4.B.4: El Niño

Ocean Currents

Oceans Pelagic Division Neritic Province Oceanic Province High concentration of organisms due to sunlight penetration and supply of inorganic nutrients Coral Reefs Oceanic Province Lacks inorganic nutrients Does not have high concentration of phytoplankton

Oceans Benthic Division Includes organisms that live on or in: Continental Shelf (sublittoral zone) Continental Slope (bathyal zone) Abyssal Plain (Abyssal zone) Interrupted by hydrothermal vents Organisms are dependent on debris sinking down from above

Marine Environment

Ocean Inhabitants

Biology, 9th ed, Sylvia Mader Chapter 49 Ending Slide Chapter 49 The Biosphere The Biosphere