Cycles of Matter

MATTER is recycled in an ecosystem. ENERGY flows in and out and cannot be recycled.

WHAT IS A BIOGEOCHEMICAL CYCLE? • A biogeochemical cycle is the movement of a

particular chemical through the biotic and abiotic parts of an ecosystem.

• Cycles are driven directly or indirectly by solar energy and gravity.

HOW DOES CARBON CYCLE?

• The carbon cycle moves CO2 from the atmosphere, through the food web, and returns to the atmosphere.

• CO2 is taken up via photosynthesis and released via respiration.

• Volcanoes and the burning of fossil fuels contribute CO2 to the atmosphere.

Carbon-based organic molecules are essential to all organisms.

HOW DOES CARBON CYCLE?

HOW DOES WATER CYCLE?

•The hydrologic, or water, cycle is the circular pathway of water on Earth.

•Water moves by the processes of evaporation, transpiration, condensation, precipitation, and movement through surface and groundwater.

Water is essential to all organisms. Organisms all have bodies made mostly of water.

• 97% of the biosphere’s water is contained in the oceans, 2% is in glaciers and polar ice caps, and 1% is in lakes, rivers, and groundwater.

HOW DOES WATER CYCLE?

HOW DOES NITROGEN CYCLE?

•The nitrogen cycle mostly takes place underground.

•Nitrogen Fixation: bacteria (in soil or plant roots) convert N2 gas into ammonia.

•Ammonia released into soil is transformed into ammonium.

•Nitrifying bacteria change the ammonium into nitrate.

Nitrogen is a component of amino acids, proteins, and nucleic acids.

•Decomposition returns Nitrogen back to the soil.

HOW DOES NITROGEN CYCLE?

HOW DOES PHOSPHORUS CYCLE?

•The phosphorus cycle takes place at and below ground level.

•Phosphate is released by the weathering of rocks.

•Decomposition returns phosphorus to the soil.

• Phosphorus leaches into groundwater from the soil and is locked in sediments.

• Mining and agriculture add phosphorus into the environment.

Phosphorus is required by all organisms (in nucleic acids, membranes, ATP).

HOW DOES PHOSPHORUS CYCLE?

HOW DO HUMANS INFLUENCE CYCLES OF MATTER? • Water withdraw from lakes and streams

• Clear vegetation (forests and other plants)

• Fill wetlands

• Burning fossil fuels and wood

• Agriculture

• Runoff of animal wastes, fertilizer, sewage treatment

• Etc.

Finish your Cornell Notes…

• Complete:

– Study Questions

– Summary

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