Human Disturbances

Human impacts have the greatest potential to degrade forest health and balance. In many instances, humans needlessly degrade forests and contaminate water and soil without realizing it or considering the consequences.

One of the most harmful impacts of improper forestry practices is contamination to water resources resulting from erosion and sediments it produces. This is an example of what’s known as non point-source pollution. Land cleared of trees and vegetation loses its ability to store water, hold sediment in place, and retain soil nutrients such as phosphorous and nitrogen. Since the tree canopy has been removed, this land also loses its ability to help regulate temperature of the forest floor and surrounding streams.

Key Indicators of Past
Human Disturbances:

• Structures — foundations, old road beds, fences, rock piles or ponds
• Agriculture — orchard, fence, pine forest mixed with eastern redcedar
• Forestry — stumps (alone they indicate logging in the past 15 years, if tree tops are also present logging occurred within the past three years), planted tree rows, trees are all the same height and age
• Other — cemetery, burial mound

Surface runoff, erosion and sedimentation (think mud) pollute waterways by

  • removing shade, which increases stream temperatures,
  • increasing the amount of precipitation runoff and sediment runoff. This can alter stream flow and lead to increased flooding, bank erosion and bank failure,
  • covering stream gravel with sediment that smothers habitat for fish and other aquatic organisms
  • encouraging algae blooms by providing excessive amounts of sunlight and nutrients. This can inhibit the growth of beneficial plants and may lead to severe oxygen depletion.
  • Promoting the growth of harmful bacteria may release toxic chemicals into the water. These bacterium live in the mud and silt that accumulate and their presence is known by a rotten egg smell.

Non point-source pollution is an even greater problem when it occurs in steep topography such as that found throughout Kentucky’s Appalachian region. The land’s steep topography accelerates the speed at which surface run-off occurs making erosion and sedimentation and even greater challenge. Cumulative effects of sedimentation and erosion are rarely isolated to a single stream. More than likely, the activities of one landowner will also be felt downstream and can potentially degrade the quality of neighboring water resources. See the Land and Water Protection Measures section for specific information about how to conduct forestry activities without polluting your water.

Pesticides

Pesticides are occasionally used in forest management to reduce mortality of desired tree species, improve forest production, and favor particular plant species. Even with limited applications, watersheds accumulate pesticides and fertilizers in the soil and waterbodies. These chemicals, which are often toxic, can enter surface water through drift, direct application, overland flow, leaching through the soil and transport through ephemeral streams. Pesticides and fertilizers actually alter the ecosystem and need to be used with extreme caution.

photo: KY State Nature Preserves Commission

This is a photo of what not to do. The erosion and rutting of this logging site are only the most obvious disturbances. A cut and run like this can permanently alter the entire forest ecosystem.

Poor Land Management Practices

Often people think of forestry activities in terms of what is being taken out of the forest. But, if you’re interested in maintaining or improving the quality of your forest, the more important question is, "What are you leaving in the forest and in what condition?"

One of the most common forms of timber harvesting is called high-grading. This practice removes the most commercially valuable species leaving a residual stand of trees that are either in poor condition or considered undesirable from a commercial standpoint. This practice results in untold, prolonged damage to the forest that often takes decades to repair naturally. It’s also a practice virtually guaranteed to decrease future property values and greatly reduce management options for multiple use.

 

 

 

 

 

 

 

 

 

 

 

 

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