Ecosystem Recycling

Biogeochemical Cycle Biogeochemical cycle – water and minerals (carbon, nitrogen, and phosphorous) are recycled and reused

Water Cycle Most of life’s chemical reactions occur in aqueous environments Key processes in water cycle are evaporation, transpiration, and precipitation

Carbon Cycle Photosynthesis and cellular respiration are the two main steps in the carbon cycle Carbon dioxide is used to make sugars and break down sugars

Human Influences on Carbon Cycle CO2 in atmosphere has risen nearly 30% in the last 150 years Humans release CO2 by burning fossil fuels CO2 is released by decay of organisms

Nitrogen Cycle Nitrogen-fixing bacteria are important in nitrogen cycle They change nitrogen gas into usable form of nitrogen for plants

Phosphorous Cycle Phosphorous moves from phosphate deposited in rock, to the soil, to living organisms, and finally to the ocean Phosphorous is needed to make DNA, RNA, and Proteins

Biomes Biomes – large terrestrial ecosystems that contain smaller ecosystems within

Tundra Cold and largely treeless biome and characterized by permafrost Plants: Grass, sedges, conifers, etc. Animals: Caribou, Snowy Owls, bear, etc.

Deciduous Forests Characterized by trees that loose their leaves in fall Plants: Maple trees, oak trees, grasses, wild flowers, etc. Animals: Deer, rabbits, foxes, etc.

Temperate Grasslands Low rainfall and dominated by grasses (A.K.A. prairie) Plants: Grasses and some trees Animals: Grazing animals (bison, moose, etc.)

Other Deserts = low rainfall Savannas = tropical grasslands (Africa) Rain Forests = abundant rainfall