Concern for protecting the clean water that originates in American forests has been part of the forestry profession since its inception. During Gifford Pinchot’s – the first American forester’s – training in France, he met with the head of the government agency in charge of public forests. The name of that agency was the Department of Forests and Waters. Although the linkage between forests and clean water was known anecdotally prior to that, it has certainly not been forgotten since.
“Next to the earth itself the forest is the most useful servant of man. Not only does it sustain and regulate the streams, moderate the winds, and beautify the land, but it also supplies wood, the most widely used of all materials.” – Gifford Pinchot, 1905
Public knowledge of the connection between forests and water quality, albeit anecdotal, predates the establishment of scientific forestry in America. The unsustainable and heavy-handed exploitation of the forest resource in the latter part of the 19th century was pronounced and unmistakable. In New Jersey (as well as Pennsylvania, southern New York, Maryland, and Delaware), demand from sawmills and for charcoal resulted in dramatic cutting. Erosion, particularly after forest fires had swept through harvest areas, had a severe impact on water resources. That impact on drinking water and, to a lesser extent, scenery, helped to drive forest protection legislation on federal and state levels, particularly in the decade between 1892 and 1911.
Beginning with the emigration of professionally-trained German foresters in the 1880’s, and gaining momentum with the return of Gifford Pinchot from the French National School of Forestry, scientific forestry began to take root in America. With the establishment of the USDA Forest Service and the initial and subsequent cadre of foresters interested in the relationships between forests and water, came watershed research. These scientific experiments began in Colorado in 1911. For the eastern US, the lion’s share of scientific data has come from the USDA Forest Service’s Forest Experiment Stations in Hubbard Brook, NH; Fernow, WV; and Coweeta, NC. The USDA Forest Service’s studies in the east have been conducted more or less continuously since 1940.
Regarding the effects of forestry on water quality, the scientific literature can be divided into two separate and distinct periods: before and after the establishment of Best Management Practices (hereafter referred to as “BMP’s”).
According to a 1975 report published by the U.S. Environmental Protection Agency, sediment was identified as the most significant pollutant resulting from timber harvesting and that logging roads were the primary source. Such erosion caused increases in turbidity and nutrient loads. While this was generally known at the time, this study placed logging roads front-and-center in policy discussions regarding forest management. Soon after, a number of studies were published that focused on buffers left above the stream channel and water temperature, and also showing that the cutting of trees (exclusive of forest roads and skidding) has had no significant effect on turbidity.
The Federal Clean Water Act of 1987 prompted states to develop BMP guidelines to control non-point source pollution caused by silvicultural activities. In New Jersey, as with most other states, clear emphasis has been placed on the transport element (including stream crossings and road design and maintenance) as well as protection of forest canopy above the stream channel and above jurisdictional wetlands (referred to as “Streamside Management Zones”). The New Jersey BMP’s draw heavily from a 1993 EPA technical guide. Given the remarkable public attention that forestry activities receive in New Jersey, it is a testament to the authors of the BMP’s, and to the foresters and the loggers involved that forestry activities following BMP’s have been able to be carried out successfully and without adverse environmental impact.
However, anecdotal evidence only carries so far. Now that most states have had BMP’s for more than twenty years, important work is proceeding on two fronts: an analysis of their effectiveness, and an analysis of their successful implementation across individual logging operations and regional landscapes. Many states have conducted studies on the effectiveness of their BMP’s, and some states go so far as to review their BMP’s annually. As a result, over the past ten to fifteen years, there have been a large number of studies published that evaluate BMP effectiveness on any number of issues from sediment capture to nitrogen cycling, and from preventing pesticide leaching to the effects of coarse woody debris on macroinvertebrates.
In brief, although certain in-stream characteristics may change in a manner that is statistically significant, such changes are not significant when compared to legal thresholds (e.g. nitrate) or the natural variation that would be expected in any given year (e.g. changes in groundwater levels). BMP research continues to focus on prevention of non-point pollution from forest roads and stream crossings through better design, use of riparian areas by imperiled wildlife, and other issues.
Given the concern for clean water shown by foresters, and knowledge of BMP’s, compliance rates nationwide are very high, although methods of measuring and reporting compliance vary state-to-state making reporting a single statistic impossible.