1. Nutrient Loss Accelerated by Clear-Cutting of a Forest Ecosystem Reviewed by Michele Dixon and Ryan Lenet

2. Purpose This was an experiment that was designed to: 1. Determine the effect of clear cutting on stramflow 2. Examine some of the chemical relations of the forest ecosystem 3. Evaluate the effects of forest manipulation on nutrient relations and on eutrophication of stream water

3. Background The importance of the article is that it was the first controlled experiment in a forest ecosystem using small watersheds in the Central New Hampshire Forest.

4. Small WaterShed Concept

5. Some Important Terms 1. Eutrophication is the increase in additions of nutrients (especially nitrogen and phosphorus) to fresh water systems, which lead to increase in plant growth and often to undesirable changes in ecosystem structure and function.

6. Eutrophication Process

7. One more Important Term Nitrification is the biological oxidation of ammonia with oxygen into nitrite followed by the oxidation of these nitrites into nitrates. Nitrification is an important step in the nitrogen cycle in soil.

8. Nitrogen Cycle

9. Procedure Samples of stream water were collected and analyzed weekly for two years prior to the experiement. Then in the winter of 1965-1966, the forest was leveled. No products removed and care was taken to minimize erosion of surface. Samples of stream water were collected and analyzed weekly. Similar measurements were taken by nearby watersheds.

10. Clear Cut Forest Picture

11. Added Variables The Herbicidal Bromacil was added to the clear-cut forest to inhibit growth. ( According to the article Bromacil had little effect on nutrient loss - about a 5% effect)

12. Data

13. Conclusion 1 Clear cutting tends to deplete the nutrients of a forest ecosystem by reducing transpiration and so increasing the amount of water passing through the system.

14. Conclusion 2 Management of forest ecosystems can significantly contribute to eutrophication of ecosystem water.

15. Conclusion 3 Clear cutting of a forest ecosystem accelerated nutrient loss Example- increase loss of cations correlate with the loss of nitrate which inhibits the process of nitrification.

16. How to Integrate this model in your Classroom http://tiee.ecoed.net/index.html References 1.www.wikopedia.com 2.www.agiweb.org/geotimes/aug03/ feature_hubbard.html