Major Ecosystems of the World Chapter 6 Major Ecosystems of the World

Earth’s Major Biomes

Earth’s Major Biomes Type of biome controlled by temperature and precipitation

Earth’s Major Biomes Tundra Characterized by: Very short growing season Little precipitation (10-25 cm / yr) Permafrost Low species diversity

Earth’s Major Biomes Tundra

Earth’s Major Biomes Boreal Forest (Tiaga) Characterized by: Short growing season Low precipitation (~50 cm / yr) Dominated by conifers (spruce, fir), but also has aspen, birch

Earth’s Major Biomes Boreal Forest (Tiaga)

Earth’s Major Biomes Temperate Rain Forest Characterized by: Cool; high precipitation (~127 cm / yr) Dominated by evergreens (hemlock, spruce, cedar) Heavily logged

Earth’s Major Biomes Temperate Rain Forest

Earth’s Major Biomes Temperate Deciduous Forest Characterized by: Hot summers, cold winters Moderate precipitation (75-150 cm / yr) Dominated by oaks, hickory, maple Commonly converted to agriculture

Earth’s Major Biomes Temperate Deciduous Forest

Earth’s Major Biomes Grasslands Characterized by: Hot summers, cold winters Low to moderate precipitation (25-75 cm / yr) Dominated tallgrass or shortgrass prairies Heavily converted to agriculture

Earth’s Major Biomes Grasslands

Earth’s Major Biomes Chaparral Characterized by: Dry summers, mild winters Frequent fires Dominated by short pines, evergreen shrubs, scrub oak (but varies worldwide)

Earth’s Major Biomes Chaparral

Earth’s Major Biomes Deserts Characterized by: Wide daily variations in temperature Very dry (<25 cm precipitation / yr) Sparse plant coverage

Earth’s Major Biomes Deserts

Earth’s Major Biomes Savanna Characterized by: Precipitation 76-150 cm / yr, but very seasonal with extended dry periods Dominated by grasses, with occasional trees African most famous for herds of wildebeest, antelope, zebra

Earth’s Major Biomes Savanna

Earth’s Major Biomes Tropical Rain Forests Characterized by: Very high precipitation 200-450 cm / yr Very nutrient-poor soil Extremely high primary productivity Extremely high species richness

Earth’s Major Biomes Tropical Rain Forests

Earth’s Major Biomes Vertical Zonation: The Distribution of Vegetation on Mountains

Earth’s Major Biomes

Aquatic Ecosystems Fundamental division: Freshwater vs. Saltwater But, both contain 3 ecological category of organisms: Free floating plankton (Phyto- & Zoo- ) Strongly swimming nekton Bottom-dwelling benthos

Aquatic Ecosystems Freshwater Ecosystems Rivers and Streams Tend to be narrow, swift, clear, cold, nutrient poor, and highly oxygenated Tend to be wide, slow, cloudy, warm, nutrient rich, and less oxygenated

Aquatic Ecosystems Freshwater Ecosystems Lakes and Ponds Photosynthetically productive; large fish Highly productive, high species richness

Aquatic Ecosystems Freshwater Ecosystems Lakes and Ponds Not always present; anaerobic, dominated by decomposers

Aquatic Ecosystems Freshwater Ecosystems Thermal stratification in temperate lakes

Aquatic Ecosystems Freshwater Ecosystems Turnover in temperate lakes

Aquatic Ecosystems Freshwater Ecosystems Marshes and Swamps Highly productive Nutrient rich due to slow decomposition Remove many pollutants Provides flood control Habitat & Food Nesting sites Groundwater Recharge

Aquatic Ecosystems Estuaries: Where freshwater and saltwater meet. Highly variable environment (salinity, temperature, light penetration rapidly changes). Many fishes and shellfish spend larval stages here.

Aquatic Ecosystems Estuaries Two general types: 1) Salt marshes 2) Mangrove forests

Aquatic Ecosystems Case-in-Point: The Chesapeake Bay

Aquatic Ecosystems Marine Ecosystems

Marine Ecosystems Intertidal Zone Aquatic Ecosystems

Aquatic Ecosystems Marine Ecosystems Benthic Environment Photic benthic environments include: 1) Sea grasses

Aquatic Ecosystems Marine Ecosystems Benthic Environment Photic benthic environments include: 1) Sea grasses 2) Kelp forests

Aquatic Ecosystems Marine Ecosystems Benthic Environment Photic benthic environments include: 1) Sea grasses 2) Kelp forests 3) Coral reefs

Aquatic Ecosystems Types of Coral Reefs (a) Fringing reef

Aquatic Ecosystems Types of Coral Reefs (b) Atoll

Aquatic Ecosystems Types of Coral Reefs (c) Barrier reef

Aquatic Ecosystems Human Impacts on Coral Reefs Sedimentation / siltation Pollution Overfishing Direct disturbance (anchor dragging, divers damaging / collecting specimens)

Aquatic Ecosystems Marine Ecosystems The Neritic Province Dominated by floating and swimming organisms. Such as many large fishes, sea jellies, various plankton.

Aquatic Ecosystems Marine Ecosystems The Oceanic Province Largest area of ocean Least explored area

Aquatic Ecosystems Human Impacts on the Ocean

Aquatic Ecosystems Human Impacts on the Ocean

Interaction of Life Zones Case-in-Point: The Everglades