Biogeochemical Cycles

Need to consider interactions between abiotic (non living) and biotic (living) factors. Also consider energy flow and chemical cycling.

Carbon, nitrogen and oxygen can be recycled between living and non- living things in an ecosystem and the biosphere.

Even though energy flow and chemical cycling are different in nature, they are related to feeding patterns within ecosystems…

Chemical Cycling Producers incorporate chemicals from non- living environment into organic compounds. Consumers feed on producers, incorporating some chemicals into their bodies and release some as waste. As organisms die, decomposers break them down to supply chemicals in the inorganic form for soil, water and air. Three types of cycling: ◦ Carbon and Oxygen Cycle ◦ Nitrogen Cycle ◦ Water Cycle

Carbon and Oxygen Cycle In the atmosphere carbon is found in its inorganic form CO 2. Producers use the CO 2 to form organic compounds during photosynthesis. During cellular respiration, both producers and consumers break down organic compounds and release CO 2 as a waste product. Non-living processes contribute to CO 2 production:

◦ Burning of fossil fuels  Oil  Coal  Natural gas ◦ Burning of wood ◦ Forest fires ◦ Human activities ◦ Volcanic eruptions

Carbon and Oxygen Cycle

Nitrogen Cycle Nitrogen ◦ Found in all living organisms ◦ An element of Amino Acids  Produce proteins ◦ Makes up 80% of the Earth’s atmosphere ◦ Producers can use it in the form of ammonium or nitrate  Nitrogen fixation ◦ Nitrogen gas to ammonia  Nitrification ◦ Ammonium to nitrates

Nitrogen Cycle

Water Cycle Solar energy evaporates water from land and water surfaces adding gaseous water vapor into the atmosphere. Water vapor cools and condenses falling to the ground as precipitation. ◦Rain ◦Snow ◦Hail ◦Sleet Plants get water from soil, consumers by eating and drinking.

Some water can be lost by plants through the process called transpiration, which is then evaporated into the atmosphere. Water not retained by plants or soil will run off into rivers and streams, or restore ground waters.

Water Cycle