Transpiration is when water from plants is evaporated into the atmosphere. It usually happens when, during photosynthesis, the plant's stomata is open so that Carbon Dioxide and Oxygen can pass through. When transpiration occurs, not only is the water cycle being executed, but also it pulls water up from the roots into the plant leaves, supplies needed materials for photosynthesis and even cools the leaf (rcn.com).

Some factors in to environment that effect how quickly or slowly transpiration occurs are light, temperature, humidity, wind, and soil water. Light affects the process because the light stimulates plants. Temperature effects because water evaporates more quickly when the temperature are higher. Humidity is a factor because when the air is dryer, more water is needed in the atmosphere. Then when there is a breeze, it circulates the air around the leaf and causes transpiration in occur more. The amount of water in the soil is important because when there is no water in the soil, the stomatas close and decrease the rate of transpiration (rcn.com).

Transpiration begins with the roots of the plant collect water from the soil. The water is then pumped through the plant to the leaves' stomatas (uiuc.edu). The stomatas are found on the underside of the leaf and are attached to vascular plant tissue. Also, as a result of transpiration, nutrients from the soil are brought into the plant to assist its growth and development (www.physicalgeography.net).

Bibliography

http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/T/Transpiration.html

http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/hyd/trsp.rxml

http://www.physicalgeography.net/fundamentals/8i.html