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State Forest
Energy Extraction Schemes
Endanger Our Natural Heritage
By JVAS Conservation Chair Dr. Stan Kotala
The Department of Conservation and Natural Resources’ decision to open 75,000 acres of Pennsylvania’s State Forests to gas drilling combined with that agency’s proposal to open 45,000 acres of State Forest land to industrial windplant development indicate that the department’s decision-makers have a poor understanding of the adverse effects of forest fragmentation. It is impossible to construct miles of roadway associated with gas wells or miles of roads and transmission lines associated with industrial windplants and not cause severe forest fragmentation.
These adverse effects of forest fragmentation include reduced habitat area, habitat isolation and loss of species from an area, disruption of dispersal, increased edge effects and loss of core habitat, and the facilitation of alien invasive species. Due to their linearity, roads and transmission lines have particularly pronounced fragmentation effects.
Noted conservation biologist Dr. Reed Noss writes: “Edge effects, once considered favorable for wildlife because many game species (e.g., white-tailed deer, eastern cottontail) are edge-adapted, are now seen as one of the most harmful consequences of habitat fragmentation. Especially when it cuts through an intact forest, a road introduces a long swath of edge habitat. Forest edge is not a line, but rather a zone of influence that varies in width depending on what is measured. Changes in microclimate, increased blowdowns, and other impacts on vegetation may extend two-to-three tree-heights into a closed-canopy forest. Shade-intolerant plants, many of them exotic weeds, colonize the edge and gradually invade openings in the forest interior. Dan Janzen found weedy plant species invading treefall gaps in a Costa Rican forest up to 5 kilometers from the forest edge. Changes in vegetation structure and composition from edge effects can be more persistent than effects of clear-cutting, from which at least some forest types will eventually recover, if left alone.”
Dr. Noss goes on to say:
“The net, cumulative effect of roads is to
diminish the native diversity of ecosystems everywhere.
Habitats in many different places around the world are
invaded by virtually the same set of cosmopolitan weeds.
Regions gradually are homogenized — they lose their
‘character.’ Every place of similar climate
begins to look the same and most ecosystems are incomplete
and missing the apex of the food chain. The end result is
an impoverishment of global biodiversity.”
See http://www.eco-action.org/dt/roads.html.
Even narrow open corridors through forests, such as roads and rights-of-way, degrade the forest by creating unfavorable habitat for many species of migratory birds because of high rates of nest predation by ecotonal meso-predators such as foxes, skunks, and raccoons and nest parasitism by brown-headed cowbirds. Furthermore, the effects of such openings extend 300 feet into the forest from the edge. Interior forest, therefore, is defined as forest occurring more than 300 feet from an edge. Interior forest is required for successful breeding by species such as the black-throated blue warbler, the black-throated green warbler, the wood thrush, the ovenbird, and the scarlet tanager.
In addition to decimating interior forest habitat, roads produce edge effects conducive to the spread of alien invasive plants such as multiflora rose, Japanese stiltgrass, Russian olive, Japanese barberry, tree-of-heaven, and Japanese knotweed. Once established on roadsides, these alien invaders infiltrate adjacent habitats, further degrading our forests.
The construction of forest roads associated with gas wells and industrial windplants constitutes a relatively permanent change in habitat structure. Because the construction of forest roads involves a major investment, the incentive for long-term maintenance to provide future access is high. The longer such roads are in place, the greater the chance that forest degradation will occur.
There are already 2,600 miles of roads on our state forests, as well as 600 miles of natural gas line rights-of-way, and 600 miles of electric utility rights-of-way. As a matter of fact, Pennsylvania’s state forests now have an average of 3.13 miles of roads and rights-of-way for every square mile. Instead of promoting energy extraction and the roads associated with such development, the DCNR should be designing a series of large roadless areas to safeguard our natural heritage.
Because natural resource agency lands are among the last remaining large blocks of unfragmented land in Pennsylvania, these lands are particularly in need of protection. Ironically, a publication produced by the Pennsylvania Department of Conservation and Natural Resources (Moyer 2003) emphasizes the importance of preserving these last remaining large blocks of unfragmented habitat in the state.
Forest conservation — not energy extraction — should be the overarching purpose of our state forests.