Cycles Water Carbon Nitrogen The Water Cycle Evaporation

Cycles Water, Carbon, Nitrogen

The Water Cycle § Evaporation – Adds water as vapor to the atmosphere § Transpiration – Plants take in water through their roots, and release it through their leaves § Precipitation – The atmosphere becomes saturated with water vapor

Carbon Cycle § Photosynthesis – Autotrophs use carbon dioxide to make oxygen § Cellular Respiration – Heterotrophs use oxygen to make carbon dioxide – Decomposers release carbon dioxide when they break down organic material

Human Influence on Carbon Cycle § § § CO 2 levels up by 30% in last 150 years ½ has occurred in last 40 years Human activities are responsible… – Burning fossil fuels, tropical rainforests… § The consequences of this increase are still being studied and under debate in the scientific community…we know there will be repercussions, we don’t know exactly what yet…

Nitrogen Cycle § Plants cannot use nitrogen in the air § Plants use nitrogen in soil (fertilizers) – Bacteria convert nitrogen in the air to useable nitrogen in the soil – Plants use nitrogen to make important molecules (proteins) for animals § Animals return nitrogen to the environment (urine & animal waste)

Phosphorus Cycle § moves from phosphate deposited in rock, to the soil, to living organisms, and finally to the ocean