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

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 Boreal Forest (Tiaga)

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 Temperate Rain Forest

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 Deciduous 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 Grasslands

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 Chaparral

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 Deserts

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 Savanna

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 Tropical Rain Forests

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 Vertical Zonation: The Distribution of Vegetation on Mountains

Aquatic Ecosystems Fundamental division: Freshwater vs. Saltwater But, both contain 3 ecological category of organisms: Free floating plankton 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 Thermal Stratification - marked layering of large temperate lakes caused by how far light penetrates Thermocline - an abrupt temperature transition where the cooler denser water remains at the bottom while the warm, less dense water remains at the top

Why is Turnover Essential? Aquatic Ecosystems Freshwater Ecosystems Fall and Spring Turnover in temperate lakes Why is Turnover Essential? Fall Turnover - a mixing of the layers; as surface water cools, its density increases and it displaces the less dense, warmer, mineral-rich water beneath and the warmer water rises to the surface where it cools and sinks Spring Turnover - the ice melts and the surface water sinks to the bottom and the bottom water rises to the surface

What is the difference between a swamp and a marshland? Aquatic Ecosystems What is the difference between a swamp and a marshland? Freshwater Ecosystems Marshes and Swamps Highly productive Nutrient rich due to slow decomposition Remove many pollutants

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.

What is the difference between a salt marsh and a mangrove forest? Aquatic Ecosystems Estuaries Two general types: 1) Salt marshes 2) Mangrove forests What is the difference between a salt marsh and a mangrove forest?

Aquatic Ecosystems Case-in-Point: The Chesapeake Bay Largest Estuary in the US --most productive estuary in the US --nine rivers and 150 streams empty into the bay -- Home to more than 1 million people --deteriorating water quality due to pollution --overfishing --loss of habitat -- sedimentation

Aquatic Ecosystems Marine Ecosystems Three Main Life Zones - -- Intertidal Zone -- Benthic Environment -- Abyssal Zone -- Hadal Zone -- Pelagic Environment -- Neritic Province -- Oceanic Province

Aquatic Ecosystems Marine Ecosystems Intertidal Zone

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