NJAS Opinion: Spring, 1994

In today's envirospeak, a key word is indicator used to describe a measure of the state of the environment, whether healthy or damaged, whether better or worse than before. Partly because of economics, indicators of environmental health or damage are regarded as useful if they can chart progress in environmental programs such as clean-ups or regulatory schemes and thus justify the costs of improvement or protection. What are these indicators that are used to measure our progress or lack of it?

When the issue is water, the indicators are such things as the amount of dissolved oxygen, or parts per million (ppm) of chemicals. The ppm can be used to define a level of acceptable risk so that the public water supply is not contaminated and the public health is not threatened. Likewise, when the issue is habitat, the talk turns to indicator species, whose presence or absence may define habitat quality. A forest with floor species (ovenbird), shrub layer species (wood thrush) and canopy species (yellow-throated vireo or cerulean warbler) is one with a flourishing, intact community. Conversely, the absence of one of those elements may indicate an environmental problem.

There is another set of indicators that come close to the heart of New Jersey Audubon's concerns about habitat and wildlife, and these are worth more consideration than they are now getting. They include things like the percent of forest cover in a watershed; the rate of subdivision (parcelization); the percent of forest loss at buildout according to current zoning in a watershed's communities; the rate of forest loss per year in a watershed; and the percent of impervious surface cover (roof, pavement, etc.) in a watershed. Those indicators say a great deal about what the prospects are for future habitat, future wildlife, future water quality, and future clean air - all of which are provided for at no cost by forests.

For example, recent studies in Maryland showed that when the impervious cover reached 12 percent of the watershed area, there were already impacts on the invertebrates in the streams, and major impacts at 30 percent. That has implications for the aquatic food chain. A review of watershed protection by the Environmental Defense Fund (EDF) points out very clearly that limited buffers and stormwater management practices (BMP's) such as detention basins by themselves do not assure water quality. Literature abounds on the subject of birds and forest size; some species may drop out of a tract as large as 4000 acres if it becomes isolated. A recent study in Wilson Bulletin reported declines in both bird density and species richness at six forest tracts which had become isolated by forest loss; it noted that some of the species, reported declining, include some of our most common birds such as red-eyed vireo, American redstart, and hooded warbler. Our own work in New Jersey in several watersheds (Arthur Kill, Delaware tributaries, Great Swamp) clearly indicates the importance of forest protection for many species both aquatic and terrestrial, as well as for water quality protection and recreational interests.

The current trend toward viewing land-use questions on a watershed-wide basis is a very good one because it unifies the conservation issues. Water quality, wildlife, clean air, and recreation are not separate in the real world; you don't have one without the other. The cheapest water quality protection and by far the best BMP is forest conservation, to handle erosion, non-point pollution, and sediment control. In the process of protecting water, habitat, air, and recreation also benefit. In short, the watershed is a natural conservation unit, whereas the municipality, where land use decisions are usually made, is not. We commend the New Jersey Department of Environmental Protection and Energy (NJDEPE) for moving in the direction of watershed analysis of secondary and cumulative impacts of development.

We believe that managing growth and land use problems on a watershed basis makes sense because forests and streams and wildlife cross municipal boundaries. Upstream forest loss has an impact on downstream communities of wildlife as well as on the upstream communities at the point of loss. Water quality standards across state lines may be different on the same stream (e.g., Ringwood Creek in the NY-NJ Highlands). Forests cross municipal, county, and state lines and have no protection as wetlands do. Governments, whether state, federal or county, can't possibly buy all the land that needs to be protected. So there needs to be some stewardship by private property owners and some by regional regulation. New Jersey has a history of regional regulation which includes CAFRA, the Pinelands Commission, the Hackensack Meadowlands Development Commission, and the D & R Canal Commission - all of which have been operating with varying levels of success to deal with land use on a regional level.

Watershed management by commission has been proposed for the Great Swamp Watershed as well as for the Highlands, two other regions of New Jersey which have high habitat value. The rate of forest loss and the percent of impervious cover are important issues for both the Highlands watersheds on a large scale, and for the Great Swamp on a smaller scale. A prediction has been made that by the year 2003, the Great Swamp Watershed will have sustained a loss of 50 percent of its forest cover if current zoning reaches buildout. Likewise, the rate of parcelization of forest lands in the Highlands threatens large forest wildlife communities such as Neotropical birds, water quality for four million people dependent on Highlands water, and recreational opportunities of many kinds. It is a logical step to move ahead and link watershed-based conservation with regional growth management in these key sensitive areas.

Richard Kane
Director of Conservation