Cycles of Matter Recycling in the Biosphere n

Cycles of Matter

Recycling in the Biosphere n n Unlike the one way flow of energy, matter is recycled within and between ecosystems Elements, chemicals and all other forms of matter are passed from one organism to another and from one part of the biosphere to another, this is known as the Biogeochemical cycles.

The Water Cycle All living things need water to survive! n Water is recycled, it moves between the ocean, atmosphere, and land. n Evaporation = water changes from water to atmospheric gas. n Water can also enter the atmosphere in by evaporating from the leaves of plants in the process of transpiration. n

The Water Cycle Water once in the atmosphere as water vapor condenses into droplets. n Once these droplets become to large they fall to the earths surface as precipitation. n Once on the ground, water runs along the surface of the ground until it enters a river or stream that carries it back to an ocean or lake. n

The Water Cycle

Nutrient Cycles Every living organism needs nutrients to grow and carry out essential life functions. n Just like water nutrients are passed between organisms and the environment through biogeochemical cycles. n Nutrient = all the chemical substances that an organism need to live. n

The Carbon Cycle n Carbon is especially important to living systems because it is the key ingredient in all living organisms.

The Nitrogen Cycle Organisms require nitrogen to make amino acids, which build proteins n Nitrogen fixation = converting nitrogen gas into ammonia, usually done by bacteria that live in the soil n Some bacteria convert ammonia into nitrates and nitrites n Denitrification = when bacteria convert nitrates into nitrogen gas n

The Nitrogen Cycle

The Phosphorus Cycle n Phosphorus is essential to living organisms because it forms part of important molecules such as DNA and RNA.

Nutrient Limitations Primary Productivity = the rate at which organic matter is create by producers n When an ecosystem is limited by a single nutrient that is scarce or cycles very slowly, this substance is called a limiting nutrient. n Example fertilizers; they usually contain nitrogen, phosphorus and potassium. n