Macroinvertebrate Community Structure Along the Longitudinal Gradient of an Agriculturally Impacted Stream

/ Lapwai Creek, an agriculturally impacted stream in northern Idaho, was sampled seasonally over a two-year period to determine if macroinvertebrate community composition changed along the longitudinal gradient and if changes followed predictions of the river continuum concept. Possible relationships between changes in food resource availability and community structure were also examined. Benthic invertebrates were collected at eight locations along the longitudinal gradient of Lapwai Creek using a Hess sampler. Random skewer analysis suggested there was no longitudinal gradient for either number of individuals or functional feeding group composition. Cluster analysis revealed that all locations, excluding a site receiving outflow from a small, eutrophic reservoir, had a similar community structure, further suggesting that invertebrate community composition remained consistent along the longitudinal gradient of the stream. The community was dominated at all sites, excluding the site below the reservoir, by functionalgrazers. Shredders were rare throughout Lapwai Creek, even in areas where healthy riparian vegetation still remained. Studies of other streams within the drainage basin show that many species found in the upper reaches of these streams, where agricultural impacts are low, were absent throughout the length of Lapwai Creek. Data collected concurrently with macroinvertebrates indicated that the input, storage, and transport of particulate organic matter was low throughout the stream, whereas periphyton abundance was high. The absence of longitudinal changes, despite flowing through three distinct geomorphological regions, and the grouping of all sites except one by cluster analysis for both dominant taxa and functional feeding groups suggest that agricultural alteration has influenced community structure of Lapwai Creek, resulting in a relatively homogeneous assemblage of macroinvertebrates capable of tolerating agricultural nonpoint source pollution. Additional support for this hypothesis is the high abundance of one food source, periphyton, and the small quantities of terrestrially derived organic matter. The abundance of the former and the rarity of the latter can be attributed to alteration of the drainage basin resulting from agricultural activities through inputs of fertilizers that generated high nutrient concentrations and the removal of riparian vegetation to clear more land for agriculture and provide increase access to the stream.KEY WORDS: Agriculture; Longitudinal patterns; Macroinvertebrates; Nonpoint source; River continuum     

Sources of Deforestation in Tropical Developing Countries

/ Key causes of tropical deforestation are investigated using cross-sectional data for 90 developing countries for the period 1981-1990. Regression results reveal that deforestation is associated with both development and scarcity. Deforestation accelerates with expanding infrastructure, trade, debt, investment in the human capital base, and resource-based economic expansion. On the other hand, absolute and relative scarcities-manifested by growing population pressures, food and land shortages, fuelwood dependency, and inequalities in access to land-are also key factors explaining forest loss. Thus, results point to a fundamental environmental conundrum: Development is required if countries are to alleviate scarcity-driven forms of forest exploitation but is itself a major cause of deforestation. Can countries balance development goals with forest protection? Setting aside the issue of its practical realization, the paper concludes that forest sustainable development cannot be achieved by implementing simple technical improvements in land-use practices alone. Securing the foundations for the sustainability of the forest base will require that countries address the underlying social processes driving tropical forest loss as well.KEY WORDS: Tropical deforestation; Developing countries; Rural land-use practices; Development; Scarcity.     

Environmental Values and Popular Conflict over Environmental Management: A Comparative Analysis of Public Comments on the Clinton Forest Plan

/ Public participation in environmental management decisions has frequently led to conflict. This paper examines the role of environmental values in fueling these conflicts, based on a data base and sample content analysis of written public comments solicited in 1994 regarding the highly contentious Clinton Forest Plan (also known as Option 9) proposed for management of federal forests in the US Pacific Northwest. The analysis considered whether those respondents favoring more versus less environmental protection than was offered in Option 9 held entirely different values, identifying which antagonistic values appeared to be most fundamental and where (if at all) values consensus occurred. It also compared values emanating from respondents within and outside the affected region, although few major differences were detected in this regard. Results suggest that strong values differences did exist among those preferring greater versus less environmental protection, in particular as concerned the extent, form, and spatial and temporal scope of justification of their positions, their ideas of forests, and the appropriate role of people in forest management. Disagreement concerned far more than purely environmental values: a major point of difference involved human benefits and harms of the proposed forest plan. Indeed, both sides' positions were overridingly anthropocentric and consequentialist-a values orientation that almost inevitably spells conflict in light of the commonly differentiated social impacts of environmental management decisions. Although public involvement in environmental management thus cannot be expected to lead to a clear and consensual social directive, the Pacific Northwest case suggests that viable environmental management solutions that take this range of values into account can still be crafted.KEY WORDS: Environmental values; Public participation; Clinton Forest Plan; Pacific Northwest     

Indicators Assessment for Habitat Conservation Plan of Yolo County, California, USA

/ Whereas habitat conservation plans (HCPs) have been intended to provide comprehensive environmental mitigation for multiple species, they often narrow in focus to one species and either one mitigation site or unspecified sites. We developed an indicators framework from which to rate land units for their ecological integrity, collateral values (nonbiological qualities that can improve conservation), and restoration and conservation opportunities. The ratings of land units were guided by the tenets of conservation biology and principles of landscape and ecosystem ecology, and they were made using existing physical and floral information managed on a GIS. As an example of how the indicators approach can be used for HCPs, the 29 legally rare species targeted by the Yolo County HCP were each associated with vegetation complexes and agricultural crops, the maps of which were used for rating some of the landscape indices. The ratings were mapped so that mitigation can be directed to the places on the landscape where the legally rare species should benefit most from conservation practices. The most highly rated land units for conservation opportunity occurred along streams and sloughs, especially where they emerged from the foothills and entered the Central Valley and where the two largest creeks intersected the Sacramento River flood basin. We recommend that priority be given to mitigation or conservation at the most highly rated land units. The indices were easy to measure and can be used with other tools to monitor the mitigation success. The indicators framework can be applied to other large-area planning efforts with some modifications.KEY WORDS: Ecosystem; Indicators; Landscape; Mitigation; Planning; Yolo County; California     

Norms for Behavior and Conditions in Two National Park Campgrounds in Korea

/ This study was conducted to examine norm prevalence, norm agreement, and norm stability in an international setting. Data were collected at two campgrounds in Chiri-Mountain National Park, Korea, in 1993 and 1994. Results showed that a high proportion of users could specify norms for various types of campground impacts. Users who rated high importance on impacts tended to show a higher level of norm prevalence. Generally there were differences in social norms and norm agreement across locations. Among those impacts that showed differences, social norms in a less developed area were more restrictive and norm agreement was higher. The results of this study are consistent with normative studies conducted in North America, suggesting that a normative approach can be applied in a variety of settings. Social norms for selected impact indicators were also stable over a one-year time period. Implications are discussed.KEY WORDS: Norms; Norm prevalence; Norm agreement; Norm stability     

Assessment of Nonpoint Source Pollution from Inactive Mines Using a Watershed-Based Approach

/ A watershed-based approach for screening-level assessment of nonpoint source pollution from inactive and abandoned metal mines was developed and illustrated. The methodology was designed to use limited stream discharge and chemical data from synoptic surveys to derive key information required for targeting impaired waterbodies and critical source areas for detailed investigation and remediation. The approach was formulated based on the required attributes of an assessment methodology, information goals for targeting, attributes of data that are typical of basins with inactive mines, and data analysis methods that were useful for the case study. The methodology is presented as steps in a framework including evaluation of existing data/information and identification of data gaps; definition of assessment information goals for targeting and monitoring design; data collection, management, and analysis; and information reporting and use for targeting. Information generated includes the type and extent of and critical conditions for water-quality impairment, concentrations in and loadings to streams, differences between concentrations in and loadings to streams, and risks of exceeding target concentrations and loadings. Data from the Cement Creek Basin, located in the San Juan Mountains of southwestern Colorado, USA, were used to help develop and illustrate application of the methodology. The required information was derived for Cement Creek and used for preliminary targeting of locations for detailed investigation and remediation. Application of the approach to Cement Creek was successful in terms of cost-effective generation of information and use for targeting.KEY WORDS: Water quality assessment; Nonpoint source pollution; Inactive mines; Watershed     

Visitor Response to Management Regulations—A Study Among Recreationists in Southern Norway

/ The objectives of nature area management are often twofold: To protect the natural environment and to facilitate recreational use. In order to maintain the natural setting, it is sometimes necessary to regulate the recreational use of an area. In deciding on a management action, one problem can be the lack of knowledge about the effects of management actions on visitors. In order to enhance the knowledge base for future management practices, this study empirically evaluates the effects of management regulations in a Norwegian nature area. In this area camping outside commercial campgrounds was restricted in 1992. The management regulations seems to have influenced the use of Sjodalen for camping in several ways. The number of campers using the area has decreased. The user composition seems to have changed, with new campers in the area after the regulation being more tolerant of human influence on the natural environment than the campers before the regulations. In addition, a considerable proportion of the existing users ceased to stay overnight in Sjodalen, totally or partly due to the regulations. The behavioral response among existing users is related both to environmental preferences and place attachment. Implications for management and future research studies on impact assessment in general, and displacement specifically, are discussed.KEY WORDS: Outdoor recreation; Management regulations; Behavioral response; Displacement, Place attachment     

Simulating Spatial and Temporal Context of Forest Management Using Hypothetical Landscapes

/ Spatially explicit models that combine remote sensing with geographic information systems (GIS) offer great promise to land managers because they consider the arrangement of landscape elements in time and space. Their visual and geographic nature facilitate the comparison of alternative landscape designs. Among various activities associated with forest management, none cause greater concern than the impacts of timber harvesting on the composition, structure, and function of landscape ecosystems. A timber harvest allocation model (HARVEST) was used to simulate different intensities of timber harvest on 23,592-ha hypothetical landscapes with varying sizes of timber production areas and different initial stand age distributions. Our objectives were to: (1) determine the relative effects of the size of timber production areas, harvest intensity, method used to extract timber, and past timber harvest activity on the production of forest interior and edge; and (2) evaluate how past management (in the form of different initial stand age distributions) constrains future timber production options. Our simulations indicated that the total area of forest interior and the amount of forest edge were primarily influenced by the intensity of timber harvest and the size of openings created by harvest. The size of the largest block of interior forest was influenced most by the size of timber harvests, but the intensity of harvest was also significant, and the size of nontimber production areas was important when harvests were numerous and widely dispersed within timber management areas, as is often the case in managed forests. Stand age-class distributions produced by past harvest activity limited the amount of timber production primarily when group selection was used, but also limited clear-cutting when recent harvest levels were high.KEY WORDS: Simulation modeling; Timber harvest; Historical context; Spatial context; Landscape pattern; Forest interior; Forest edge     

Sailing the Shoals of Adaptive Management: The Case of Salmon in the Pacific Northwest

/ Emerging ecosystem science builds on adaptive management as an approach to dealing with salmon problems in the Pacific Northwest. Adaptive management brings scientific and democratic processes together. However, managers, the public, resource users, and scientists differ in their views on the causes of salmon decline. Managers emphasize habitat loss and over-harvest as the primary causes; commercial fishers point to habitat loss, management practices, and predators; and the public gives greatest weight to water pollution and ocean drift nets. Scientific studies of salmon often produce results that seem contradictory or unclear to the public. For adaptive management to be effective, scientists' and the public need to better understand one another's perspectives.KEY WORDS: Perception; Fishery management; Salmon; Pacific Northwest; Science     

Effects of Tracking by Armored Vehicles on Townsend's Ground Squirrels in the Orchard Training Area, Idaho, USA

Spermophilus townsendii ) prey. These changes could occur directly or as a result of changes in the vegetation available as food and cover for the ground squirrels. We assessed the effects of long-term tracking by armored vehicles by comparing 9-ha areas in sagebrush (Artemisia tridentata) -dominated shrubsteppe and bluegrass (Poa secunda) -dominated grasslands subjected to low-intensity tracking for ∼50 years with others that had not been tracked. We did not detect any effect on ground squirrel population dynamics associated with long-term tracking. Although densities of adults and juveniles tended to be higher in the areas exposed to such tracking, we attribute this difference to other factors that varied spatially. To determine short-term (two-year) effects, we experimentally tracked two sagebrush and two grassland sites with an M-1 tank after animals had begun their inactive season. In the following two active seasons we monitored squirrel demography and behavior and vegetative characteristics on the experimentally tracked sites and compared the results with control sites. Although we experimentally tracked ∼33% of the surface of each of four sites where ground squirrel densities were assessed, the tracking had a detectable effect only on some herbaceous perennials and did not influence ground squirrel densities or behavior significantly during the subsequent two active seasons. We conclude that tracking after the start of the inactive season is likely to influence ground squirrel demography or behavior only if vegetation cover is substantially changed by decreasing coverage of preferred food plants or increasing the coverage of annual grasses and forbs that are succulent for only a short time each year.