by Alison Cole

What are conservation buffers? Conservation buffers are small areas or strips of land in permanent vegetation, designed to intercept pollutants and manage other environmental concerns. Buffers include: riparian buffers, filter strips, grassed waterways, shelterbelts, windbreaks, living snow fences, contour grass strips, cross-wind trap strips, shallow water areas for wildlife, field borders, alley cropping, herbaceous wind barriers, and vegetative barriers (USDA-NRCS, 2009).

Why are we discussing them? Understanding different types of conservation buffers and various ways to construct them is crucial to attempt any type of land restoration. Whether you are working to reduce runoff from human settlements and agriculture, or you are trying to revive the soil and water flow to degraded land, using buffers and barriers aids in restoration. 

Here are a few examples taken from Bentrup, 2008 in the syllabus:

What are some other types of conservation buffers and what is their purpose? Can a forest act as a large scale conservation buffer? What types of buffers could be used to restore soil retention and water flow to a deforested site?

Resources

• Bentrup, G. 2008. Conservation buffers: design guidelines for buffers, corridors, and greenways. Gen. Tech. Rep. SRS-109. Asheville, NC: USDA, Forest Service, Southern Research Station.

by Alison Cole

What is the rhizospere? It is the area where root hairs of trees and other plants interact with the soil. “This is a special place because hair roots bring food and oxygen, enabling the micro organisms to work faster than anywhere else. A continuous flow of water is caused, as water is absorbed by these roots, drawing with it dissolved substances”, such as nutrients, salts and occasionally toxins (Anthoni, 2000). 

Although the rhizoshpere is a much smaller ecosystem than that above ground, its functions are crucial to life under and above the soil. This “micro” habitat is home to a large community of microorganisms, fungi, and bacteria.

The removal of trees has a drastic effect on soil composition. While the tree roots physically hold the soil in place and draw water to the surface, the diagram above shows that these root systems support a diverse, but fragile ecosystem (the rhizospere). 

The figure above shows soil and carbon (organic/decayed matter which the main ingedient of soil) degradation in New Zealand after forest clearance for agriculture. In your readings and research, what are some examples of deforestation and soil degredation? How about reforestation, and the renewal of soil? 

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by Alison Cole

This week and next we will be focusing on the fundamentals of hydrological processes (water cycles) that occur in the presence of forest.  Below is a figure taken from Schoenholtz (2004) in our syllabus describing the basic water cycle in forested areas. 

In this discussion we want to identify the role of forest in preserving the water cycle, and what happens to the cyle when land is deforested. Also, there are many examples in our syllabus of how the water cycle changes once land is reforested. 

Here is an awesome video tutorial on the role of forests in watersheds. A watershed is the geographical area drained by a river and its tributaries. A great example would be the Amazon basin. 

Forests and Watershed Video Tutorial (~8 min)

References

• Schoenholtz, S.H. 2004. Impacts of forest management on water quality. pp. 377-388 in Burley, J., J. Evans, and J. Youngquist, eds. Encyclopedia of Forest Sciences. Elsevier Ltd., Oxford, U.K.