ENVIRONMENTAL CONSEQUENCES INTRODUCTION Environmental consequences are the estimated physical, biological, social, and economic effects that would result from implementing each of the alternatives described in Chapter II. The analysis of these effects provides a basis for comparing the alternatives. This chapter describes the projected direct, indirect, and cumulative effects of the alternatives and summarizes the planned mitigation measures. It also describes conflicts between the effects of the alternatives and other plans and policies. Tables, figures, and text often refer to the 1st decade and several subsequent decades. The 1st decade is the period to be covered by the Forest Plan. Estimates for subsequent decades represent effects if activities and outputs of the alternatives were continued beyond the 1st decade. Comparison of plan alternatives to existing condition refer to the average condition during the period from 1979 to 1988, unless otherwise noted. The average annual timber harvest during 1979-1988 was 302 MMBF. The environment (e.g., vegetation) can be directly changed by the activities (e.g., timber harvest) promoted by an alternative. These changes may trigger indirect effects on other facets of the environment (e.g., changing vegetation species composition or age distribution by harvesting timber indirectly alters the conditions in wildlife habitat). Cumulative effects are total actions on Forest lands and neighboring lands for the foreseeable future. Mitigation measures are activities planned to prevent, rectify, or reduce projected adverse effects on the environment. Some effects are described quantitatively while others are described in qualitative terms. Timber harvesting, regeneration of vegetation after harvest, protection from fire and pests, and development of areas for recreation, wildlife and fish habitat broadly affect the environment. Directly or indirectly, changes in vegetation, and construction and maintenance of roads would cause most of the effects described in Chapter IV. All management activities will conform to the standards and guidelines detailed in Forest Plan, Chapter IV. Treatment of vegetation and construction of access roads most affect the Forest's visual and recreational characteristics; the quantity, quality, and distribution of wildlife and fish habitat; the size, age, health and vigor of the vegetation; the susceptibility of the trees to insects and disease; soil erosion; and the quality of the water flowing from the treated area. Other effects on the environment result from constructing facilities such as recreation sites, trails, and in-stream structures for improving fish habitat; law enforcement; and activities of recreationists, permittees, and agents. All activities with an environmental effect can be grouped under one or more of the following: construction of roads, trails, and structures (e.g., campsites, leachfields, shelters, fish habitat structures); cutting and transportation of vegetation; burning of vegetation or organic materials; application of chemicals to alter soil productivity, vegetation, or animals (e.g., insects); and the planting of vegetation. These activities always create changes in their vicinity and may have effects far from where they occur. The management activities and their associated effects are referred to later in this chapter in discussions of consequences on specific components of the environment. These components include vegetation, soil, water, fish, wildlife (including threatened and endangered species and critical habitat), recreation and research opportunities, scenery, Wilderness, undeveloped areas, research opportunities, air, cultural resources, communities, farmland, wetland, floodplains, minerals, range land, consumers, civil rights, and minority groups. Other environmental effects considered include energy requirements and conservation potential of the alternatives and mitigation measures. Management Activities and Effects The following is a general description of management activities, and the major effects they have on the environment. Road and Landing Construction Road and landing construction require heavy equipment (tractors, trucks, earth movers) to develop stable surfaces capable of supporting log trucks and log yarding equipment across mountain slopes. The construction and maintenance of roads and landings... displace, compact, or remove topsoil and vegetation from the roadway. may increase the probability of erosion. Surface and ground water flow may be redirected when the subsoil on cutbanks and fill slopes is exposed and these areas are not properly treated. may divide wildlife ranges and degrade or destroy habitats. ... provide passage for wildlife or interrupt travel routes. ... make remote areas, and their resources (recreation, fish, timber and so forth) accessible to visitors and commercial or non-commercial users. Trail Construction Trail construction requires light equipment and manual labor to develop stable surfaces (on a small scale) capable of supporting pedestrians, and, where allowed, horses or ORVs, across many terrain types. Trails... may increase soil erosion where steep trails aren't designed to prevent interruption or redirection of water flow. ... make remote and scenic areas accessible to hikers. ... provide passage for wildlife. Construction of Waste Water Structures Construction of waste water structures involves the construction of leachfields and vault toilets in the soil. Waste water structures... ... may increase the risk of contaminating the soil and groundwater in the immediate area of the structure. Any contamination noted will be short term. No long term degradation of water or soil quality will be allowed. ... reduce contamination from human waste and grey water in heavily used areas. increase comfort and convenience for Forest visitors. Construction of Other Recreation Facilities Construction of recreation facilities such as parking lots, shelters, signs, campgrounds and so forth, involve the construction of various buildings, concrete footings, signposts, or pavement to make the use of recreation areas more pleasurable. Recreation facilities... ... concentrate people in certain areas. This may result in soil compaction, disturbance to vegetation and wildlife, and an increase in the level of noise. ... allow the Forest Service to make visitors safer and more comfortable. reduce the quality of small areas of wildlife habitat. Construction of Fish Habitat Structures Construction of fish habitat structures involves blasting bedrock, or placing logs, gabions (cobble-filled wire baskets), concrete, or boulders, in stream channels. Fish structures... change stream flow and alter the movement and distribution of stream gravel and sediment. ... increase the quantity and quality of fish habitat. Cutting Vegetation This activity includes cutting down and removing trees and shrubs for a variety of reasons, mostly timber production and wildlife habitat management. Cutting vegetation... ... changes species composition of the cutover area and of the basin(s) in which the cutting occurs. changes age distribution of the vegetation in the cutover area and in the basin(s) in which the cutting occurs. changes amount and arrangement of organic debris such as logs, branches, and twigs. ... kills roots, temporarily reducing resistance to landslides on unstable slopes. ... changes habitats in the cutover area, and changes the distribution of these habitats in the basin(s) in which the cutting occurs. ... when done along streams, changes the type and timing of organic debris deposits in stream systems. ... when done along streams, may increase the temperature of streams and lakes. ... influences dependence of communities on timber revenues. ... in the case of cutting commercial timber, generates revenues locally through returns to the counties, generates jobs and influences local economy. ... increases growth rates of remaining vegetation. ... may alter microclimate by increasing daily temperature fluctuations; and increases surface winds. ... alters the scenery of the area. eliminates the natural condition of areas not previously cut. Burning Vegetation or Organic Debris Burning vegetation and debris involves broadcast burning in cutover areas or in meadows. The objective is to: 1) lower the hazard of wildfire by reducing fuel; 2) reduce undesirable competing vegetation to increase sunlight and nutrients for desired trees or forage; 3) facilitate tree planting by reducing low growing vegetation and logging slash. Burning vegetation... alters the soil by changing the amount and availability of certain nutrients (especially Nitrogen), lowers the soil's resistance to erosion, and reduces reservoirs of soil microorganisms and mycorrhizal fungi. ... may reduce the cost of subsequent cultural activities for trees and wildlife habitats. ... alters the scenery of the area. ... reduces the risk of wildfire and the difficulty of suppressing wildfire. ... creates smoke in local airsheds. ... alters the microclimate by increasing surface temperatures as long as black color remains. Application of Chemicals Application of chemicals involves applying fertilizer, pesticides, and other materials. The objective is to improve vegetation growth and selectively reduce plants or animals which compete with or damage desired Forest resources. Application of chemicals... Planting vegetation introduces desired species into areas where the vegetation has been cut, or cut and burned. The objective is to enhance economic, ecological, or aesthetic values. Planting vegetation... ... increases soil strength and resistance to erosion by promoting root growth, and ground cover. ... may change forage and habitat for some wildlife. ... initiates future timber crops. Incomplete or Unavailable Information Some information used to predict environmental effects in this chapter is incomplete, while other information is unavailable at this time. Incomplete or unavailable information is noted later in this chapter for each major resource. The Forest has used the most current information available and state-of-the-art analytical tools to evaluate activities and to estimate effects. The Council on Environmental Quality's NEPA regulations relating to incomplete or unavailable information have been amended [40 CFR 1502.22, amended at 51 Fed. Reg. 15618 (April 25, 1986)]. The discussion below complies with the amended regulations. In the FEIS and Forest Plan: • The discussions of the management of resources on the Siuslaw National Forest have involved an evaluation of reasonably foreseeable significant adverse effects on the human environment. • The evaluation of those effects sometimes has been based upon information that is incomplete or is only partially available. • The incomplete or unavailable information cannot be obtained because the overall time and money costs to obtain the information would be exorbitant, and in some cases the means to obtain the information are not known. Consequently, pursuant to 40 CFR 1502.22(b), as amended, the following discussions of management impacts on vegetation, watersheds, fish, wildlife, recreation, scenery, Wildernesses, undeveloped areas, research, communities and other resources include a description of the incomplete or unavailable information which is relevant to the evaluation of reasonably foreseeable significant adverse impacts associated with the alternatives. In many cases, the incomplete or unavailable information is not necessary for an evaluation of the reasonably foreseeable significant adverse impacts on the human environment. In other cases, notably the effectiveness of the headwall leave area technique in preventing landslides and the habitat requirements for wildlife indicator species, the incomplete or unavailable information |