The use of 137Cs to establish longer-term soil erosion rates on footpaths in the UK

There is increasing awareness of the damage caused to valuable and often unique sensitive habitats by people pressure as degradation causes a loss of plant species, disturbance to wildlife, on-site and off-site impacts of soil movement and loss, and visual destruction of pristine environments. This research developed a new perspective on the problem of recreational induced environmental degradation by assessing the physical aspects of soil erosion using the fallout radionuclide caesium-137 (¹³⁷Cs). Temporal sampling problems have not successfully been overcome by traditional research methods monitoring footpath erosion and, to date, the ¹³⁷Cs technique has not been used to estimate longer-term soil erosion in regard to sensitive recreational habitats. The research was based on-sites within Dartmoor National Park (DNP) and the South West Coast Path (SWCP) in south-west England. ¹³⁷Cs inventories were reduced on the paths relative to the reference inventory (control), indicating loss of soil from the path areas. The Profile Distribution Model estimated longer-term erosion rates (ca. 40 years) based on the ¹³⁷Cs data and showed that the combined mean soil loss for all the sites on ‘paths’ was 1.41 kg m^?2 yr^?1 whereas the combined ‘off path’ soil loss was 0.79 kg m^?2 yr^?1, where natural (non-recreational) soil redistribution processes occur. Recreational pressure was shown to increase erosion in the long-term, as greater soil erosion occurred on the paths, especially where there was higher visitor pressure.     

Defining acceptable conditions in wilderness

The limits of acceptable change (LAC) planning framework recognizes that forest managers must decide what indicators of wilderness conditions best represent resource naturalness and high-quality visitor experiences and how much change from the pristine is acceptable for each indicator. Visitor opinions on the aspects of the wilderness that have great impact on their experience can provide valuable input to selection of indicators. Cohutta, Georgia; Caney Creek, Arkansas; Upland Island, Texas; and Rattlesnake, Montana, wilderness visitors have high shared agreement that littering and damage to trees in campsites, noise, and seeing wildlife are very important influences on wilderness experiences. Camping within sight or sound of other people influences experience quality more than do encounters on the trails. Visitors’ standards of acceptable conditions within wilderness vary considerably, suggesting a potential need to manage different zones within wilderness for different clientele groups and experiences. Standards across wildernesses, however, are remarkably similar.     

Wilderness campsite impacts: Do managers and visitors see them the same?

Human-induced impacts from recreational use of wilderness continue to be a significant management challenge, threatening the integrity of the wilderness resource and the quality of visitor experiences. Campsite impacts are of particular concern to managers. One approach to this problem is the Limits of Acceptable Change (LAC) planning system, which focuses attention on the question, “How much change in wilderness conditions is acceptable?” The research reported here compares and contrasts wilderness manager and visitor perceptions of theacceptability of different levels of campsite impacts,amount of impact, and perceptual zoning of wilderness. The results reinforce previous findings regarding differences between managers and visitors. Management implications are discussed.     

The indicator performance estimate approach to determining acceptable wilderness conditions

Using data from a study conducted in the Cranberry Wilderness Area of West Virginia, United States, this paper describes how a modified importance—performance approach can be used to prioritize wilderness indicators and determine how much change from the pristine is acceptable. The approach uses two key types of information: (1) indicator importance, or visitor opinion as to which wilderness indicators have the greatest influence on their experience, and (2) management performance, or the extent to which actual indicator conditions exceed or are within visitor expectations. Performance was represented by calculating indicator performance estimates (IPEs), as defined by standardized differences between actual conditions and visitor preferences for each indicator. The results for each indicator are then presented graphically on a four-quadrant matrix for objective interpretation. Each quadrant represents a management response: keep up the good work, concentrate here, low priority, or possible overkill. The technique allows managers to more systematically and effectively utilize information routinely collected during the limits of acceptable change wilderness planning process. This paper is submitted with the approval of the Director of the West Virginia Agricultural and Forestry Experiment Station as Scientific Article No. 541. The study was funded in part, through a grant from the USDA Forest Service, Monongahela National Forest.     

LAND USE AND AQUATIC BIOINTEGRITY IN THE BLACKFOOT RWER WATERSHED,MONTANA1

ABSTRACT: Benthic macroinvertebrate samples representing 151 taxa were collected in August 1995 to examine the linkage between land use, water quality, and aquatic biointegrity in seven tributaries of the Blackfoot River watershed, Montana. The tributaries represent silvicultural (timber harvesting), agricultural (irrigated alfalfa and hay and livestock grazing), and wilderness land uses. A 2.4 km (1.5 mile) reach of a recently restored tributary also was sampled for comparison with the other six sites. A geographic information system (GIS) was used to characterize the seven subwatersheds and estimate soil erosion, using the Modified Universal Soil Loss Equation, and sediment delivery. The wilderness stream had the highest aquatic biointegrity. Two agricultural streams had the largest estimated soil erosion and sediment delivery rates, the greatest habitat impairment from nonpoint source pollution, and the most impoverished macroinvertebrate communities. The silvicultural subwatersheds had greater rates of estimated soil erosion and sediment delivery and lower aquatic biointegrity than the wilderness reference site but evinced better conditions than the agricultural sites. A multiple-use (forestry, grazing, and wildlife management) watershed and the restored site ranked between the silvicultural and agricultural sites. This spectrum of land use and aquatic biointegrity illustrates both the challenges and opportunities that define watershed management.     

Applying knowledge-based methods to design and implement an air quality workshop

In response to protection needs in class I wilderness areas, forest land managers of the USDA Forest Service must provide input to regulatory agencies regarding air pollutant impacts on air quality-related values. Regional workshops have been convened for land managers and scientists to discuss the aspects and extent of wilderness protection needs. Previous experience with a national workshop indicated that a document summarizing workshop discussions will have little operational utility. An alternative is to create a knowledge-based analytical system, in addition to the document, to aid land managers in assessing effects of air pollutants on wilderness. Knowledge-based methods were used to design and conduct regional workshops in the western United States. Extracting knowledge from a large number of workshop participants required careful planning of workshop discussions. Knowledge elicitation methods helped with this task. This knowledge-based approach appears to be effective for focusing group discussions and collecting knowledge from large groups of specialists.     

Perceived Effects of Setting Attributes on Visitor Experiences in Wilderness: Variation with Situational Context and Visitor Characteristics

Understanding how setting attributes influence the nature of the visitor experience is crucial to effective recreation management. Highly influential attributes are useful indicators to monitor within a planning framework, such as Limits of Acceptable Change. This study sought to identify the setting attributes perceived to have the most profound effect on the ability to have “a real wilderness experience” and to assess the degree to which attribute importance varied with situational context and visitor characteristics. To this end, exiting hikers were surveyed at moderate and very high use trailheads in Alpine Lakes Wilderness, WA (USA), and Three Sisters Wilderness, OR (USA). They were asked about the degree to which encountering varying levels of different setting attributes would add to or detract from their experience. Attributes with the largest range of effect on experience, based on evaluations of different levels, were considered most important. The most influential attributes were litter and several types of campsite interaction—people walking through camp and number of other groups camping close by. The perceived importance of setting attributes did not vary much between wilderness locations with substantially different use levels, suggesting that conclusions are robust and generalizable across wilderness areas. There also was little difference in the perceptions of day and overnight visitors. In contrast, we found substantial variation in the perceived importance of setting attributes with variation in wilderness experience, knowledge, attachment, and motivation. Our results validate the emphasis of many wilderness management plans on indicators of social interaction, such as number of encounters.     

The (un)common good: diverging justifications for wilderness making in a modified landscape

ABSTRACT

Wilderness is most often conceived as comprising large remote areas where evidence of human influence is slight. Little attention has been afforded to the study of wilderness ‘making’ in smaller landscapes that have been heavily modified by human activity. This paper addresses this knowledge deficit by employing the pragmatic sociology of Boltanski and Thévenot to analyse a case study of wilderness making in the west of Ireland. The application of this framework illustrates how contending positions on ‘why’ wilderness making should occur and ‘how’ it should be conducted reflect ethical frameworks rooted in different conceptions of the ‘common good’ presented by the idea of wilderness. The paper demonstrates the difficulties with developing such a new nature-based concept in the absence of conventional (received) ideas of wilderness by revealing how the diverging justifications used suggest incommensurability in the competing notions of wilderness that are formulated and advanced.     

京津冀地区矿产资源开发的生态环境影响研究

京津冀地区位于我国北方农牧交错带前缘,坝上、燕山、太行山等地区是区域水源的主要发源地,同样是京津及华北平原的主要生态屏障。对京津冀地区矿产资源开发的生态环境影响进行评价,具有重要现实意义。本文根据京津冀地区矿产资源开发现状、规划空间布局和生态环境特点,综合运用GIS空间分析技术和生态风险理论,从矿产资源的空间布局合理性角度入手,分析京津冀地区矿产资源开发利用的生态环境影响,并以此识别区域内矿产资源开发的生态风险高发区和较高发区。结果显示,京津冀地区矿产资源开发空间布局与燕山、太行山山地水源涵养与水土保持区、坝上高原风沙防护区等生态功能区存在空间重叠,规模性的矿产开发会对区域内的水源涵养、土壤保持、生物多样性维护等生态功能构成持续性影响;高海拔地区的高强度开矿同样会加剧水土流失和荒漠化。天津市滨海区,承德市宽城满族自治县,邯郸市武安市等市县因密集分布了已有的矿产开发企业,并囊括了近期矿产资源开发的众多矿区,矿产资源开发的遗留性问题也比较突出,成为矿产资源开发的生态风险高发区。在生态影响分析基础上,本文提出了有针对性的空间差异性生态保护对策,以期为京津冀地区矿产资源开发布局优化提供技术支撑。     

Pathways Towards Sustainability: The Australian Approach

Following its rise to international prominence, sustainability has become an official principle or goal in many countries. Due to contextual differences, countries have followed different paths in the pursuit of sustainability. Approachescan be classified into three categories: green planning; institutional reform; and social mobilization. None of these courses on its own is likely to achieve sustainability. Yet, countries often appear to develop a path dominated by one of these approaches. This paper focuses on Australia, sketches the extent to which green planning, institutional reform and social mobilization have been playing a role in the pursuit of sustainability, and illustrates the difficulties of developing a pathway that combines these approaches.     

Wilderness politics: Public participation and values

This article deals with wilderness politics in relationship to values and public participation; these terms are defined for the purpose of the study. It is argued that the survival, quantity, and quality of wilderness everywhere will basically be determined by the political and governmental processes through values. Yet there is a strong tendency in these processes to avoid value exposure and emphasis.Much of governmental approach toward wilderness affairs hinges upon economic development, technoscientific facts, and short-term considerations, in contrast to the intangible noneconomic and long-term values of wilderness. By not articulating nd involving wilderness values more in public participation and the political processes, the public often misses opportunities for influencing far-reaching wilderness decisions. In short, wilderness values need to be more explicitly and implicitly stated and implemented politically.More study and emphasis need to be given to wilderness values per se. It is necessary to develop more innovative ways of educating the public on wilderness values in terms of their lives and of ensuring that their value inputs are effectively incorporated into public participation and political processes. The last section of this article is devoted to efforts by the author and others to identify and describe wilderness tropical forest values.     

西部的生态恢复与水土保持对策

水资源和土地资源的不合理开发利用是造成西部严重生态环境问题的根源。因此,西部的生态恢复,必须从解决水生态失衡和控制严重的水土流失、土地荒漠化入手,以提高植被整体覆盖度为手段,逐步达到恢复西部生态环境功能的目的。     

A Comparison of Urban-Proximate and Urban-Distant Wilderness Users on Selected Variables

/ The underlying premise of this study is that wilderness areas attract visitors desiring or expecting different wilderness experiences. In this study, wilderness areas were dichotomized according to distance from a large urban center (urban-proximate vs urban-distant). Four wilderness areas in southern California were used as the study sites. Comparisons were made on selected attributes commonly associated with the wilderness experience. Differences were observed on a number of variables such as acceptable number and type of encounters with other visitors, management preferences, and preferred group sizes. The findings of this study are congruent with those from previous studies and suggest that distance to large urban centers may be a functional variable in explaining differences among selected wilderness attributes.KEY WORDS: Expectancy theory; Normative standards; Wilderness; Wilderness experience; Urbanization     

Trail erosion patterns in Great Smoky Mountains National Park

All the maintained trails in Great Smoky Mountains National Park were surveyed for width, depth, and a variety of types of erosion. Trail erosion is related to a number of environmental variables, including vegetation type, elevation, trail slope, and section of the park. Open grass balds and spruce-fir forest are the most erosion-sensitive plant communities, and the xeric oak and pine types are the least sensitive. Trails in virgin or mature forest tend to be in poorer condition than those in successional areas. The most important physical factor is the slope of the trail.Trails in the Tennessee district are in slightly poorer condition, on the average, than those in the North Carolina district, but the Appalachian Trail is more eroded than either. A poor section of the park may have ten times the erosion of a good section. On an allpark basis, water erosion is the most important problem, with 15% of the trail surface affected.A comparison of visitation patterns with trail condition indicates that redistribution of use would help to mitigate some erosion problems. Because trail condition is correlated to physical environmental factors, however, some sites will require intensive maintenance, even if visitation is low.The data from this survey have already been used in environmental analysis of proposed developments within the park and can be applied to long-range planning for the park trail system as a whole.     

The change of European landscapes: human-nature relationships, public attitudes towards rewilding, and the implications for landscape management in Switzerland

The rewilding of landscapes is one of the most important and intensively discussed landscape changes occurring in Switzerland, as the need for agricultural and forest land is decreasing. To ensure that decisions concerning future landscape management will be supported by the public, it is crucial to take public opinion into account. Hence the present study aims to assess the public attitudes towards nature and "rewilding" processes. In order to analyze these attitudes, we sent a standardized questionnaire to 4000 randomly selected households throughout Switzerland. A cluster analysis led to a typology with four different types of human-nature relationship ("nature lovers", "nature sympathizers", "nature-connected users" and "nature controllers") that each characterize a particular attitude towards nature. These human-nature relationship types differ in their attitudes towards rewilding as well, allowing a rough classification of the sample into wilderness opponents (51.1%) and wilderness proponents (49.9%). However both groups agree with regard to their opinion concerning the rules and regulations that should apply in future wilderness areas. The parallels of the human-nature relationship typology of this survey with other typologies, and the implications for further research are discussed. We can conclude that, due to the differences concerning the attitudes towards wilderness between the human-nature relationship types, between the rural and urban dwellers, and between the language regions, a uniform strategy for the designation and management of wilderness areas in Switzerland is not possible. We recommend that, when managing landscape change, all stakeholders are included in a participatory process and we advise a thorough assessment of the attitudes of the involved persons towards nature and rewilding at the start of such processes. Such an assessment would facilitate the identification of well-defined target groups allowing specific interventions and management actions customized to the needs and characteristics of each of these groups. In addition we see the commonalities between wilderness opponents and wilderness proponents concerning the rules in wilderness areas as an ideal starting point for a successful participatory process.     

Using ecological criteria to evaluate wilderness planning options in Idaho

Legally designated wilderness areas are acknowledged to be an important element in strategies to conserve biological diversity in United States. However, because of the restrictions on consumptive uses in wilderness, their establishment is normally contentious. Criteria for establishment have typically been associated with opportunity and aesthetic and experiential values. Biological data have not normally played a major role in guiding wilderness establishment. We present four wilderness allocation options for those public lands considered suitable for wilderness designation in Idaho. These options cover the span of choices presently available to wilderness planners in the state and range from not establishing any new wilderness areas to the inclusion of all suitable lands in wilderness. All options are evaluated using spatial biological data from the National Biological Survey's Gap Analysis Project. A conservation strategy that would protect a minimum of 10% of the area occupied by each of 113 native vegetation types and at a minimum 10% of the distribution of each of 368 vertebrate species was evaluated for each option. Only the inclusion of all suitable lands in wilderness, creating a system of 5.1 million ha came close to achieving these goals, protecting 65% of the vegetation types and 56% of the vertebrate species. We feel this approach, which allows planners to evaluate the ecological merits of proposed widerness units along with other values, can provide a means to resolve the impasse over additional wilderness designation in Idaho.     

Magnitude and distribution of option value for the Washakie Wilderness,northwest Wyoming,USA

Option value is estimated for the Washakie Wilderness, northwest Wyoming, USA, using the contingent valuation technique. Consumer surplus, the traditional measure of economic value, is estimated separately and compared with option value. Several populations are tested, including Washakie visitors, Yellowstone National Park visitors, and residents from four metropolitan test markets: Salt Lake City, Utah; Portland, Oregon; Nashville, Tennessee; and Orlando, Florida, USA. The average annual preservation option value (consumer surplus) expressed by on-site wilderness visitors is $46.17 ($80.13), by urban residents is $9.70 ($8.97), and by rural residents is $8.43 ($7.80). Four selected attributes are determined to be important in motivating option demand for the Washakie, including existence value, bequest value, the desire for an on-site visit, and interest in securing the visiting privileges of others. The results suggest that option value is important in wilderness valuation and that off-site users account for a large part of the economic value of wilderness.     

Optimal Land Use Management for Soil Erosion Control by Using an Interval-Parameter Fuzzy Two-Stage Stochastic Programming Approach

Soil erosion is one of the most serious environmental and public health problems, and such land degradation can be effectively mitigated through performing land use transitions across a watershed. Optimal land use management can thus provide a way to reduce soil erosion while achieving the maximum net benefit. However, optimized land use allocation schemes are not always successful since uncertainties pertaining to soil erosion control are not well presented. This study applied an interval-parameter fuzzy two-stage stochastic programming approach to generate optimal land use planning strategies for soil erosion control based on an inexact optimization framework, in which various uncertainties were reflected. The modeling approach can incorporate predefined soil erosion control policies, and address inherent system uncertainties expressed as discrete intervals, fuzzy sets, and probability distributions. The developed model was demonstrated through a case study in the Xiangxi River watershed, China’s Three Gorges Reservoir region. Land use transformations were employed as decision variables, and based on these, the land use change dynamics were yielded for a 15-year planning horizon. Finally, the maximum net economic benefit with an interval value of [1.197, 6.311] × 10⁹ $ was obtained as well as corresponding land use allocations in the three planning periods. Also, the resulting soil erosion amount was found to be decreased and controlled at a tolerable level over the watershed. Thus, results confirm that the developed model is a useful tool for implementing land use management as not only does it allow local decision makers to optimize land use allocation, but can also help to answer how to accomplish land use changes.     

Decline of the mountain acacia, Brachystegia glaucescens in Gonarezhou National Park, southeast Zimbabwe

The objectives of the study were to investigate the role of fire and other factors in the decline of the mountain acacia, Brachystegia glaucescens Burtt Davy & Hutch. in the northern region of the Gonarezhou National Park, southeast Zimbabwe. The study site, which is a wilderness area, has suffered a succession of fires which, coupled with elephant pressure and drought, has reduced what was once woodland into scrubland. With the grass continuously burnt off, very few grazing animals can be found in the area and erosion of the unprotected slopes has left it rocky and barren. The paper attempts to analyse field observations using established ordination and statistical procedures. The conclusions that both fire and elephant damage are powerful factors leading to loss the loss of B. glaucescens woodland are established. The findings should be considered in setting management goals and monitoring their effects, particularly in measures that encourage restoration of the woodland.     

Quantifying the effects of trampling and habitat edges on forest understory vegetation – A field experiment

We investigated the effects of human trampling on boreal forest understory vegetation on, and off paths from suburban forest edges towards the interiors and on the likelihood of trampling-aided dispersal into the forests for three years by carrying out a trampling experiment. We showed that the vegetation was highly sensitive to trampling. Even low levels of trampling considerably decreased covers of the most abundant species on the paths. Cover decreased between 10 and 30% on paths which had been trampled 35 times, and at least by 50% on those trampled 70–270 times. On-path vegetation cover decreased similarly at forest edges and in the interiors. However, some open habitat plant species that occurred outside the forest patches and at forest edges dispersed into the forests, possibly through the action of trampling. A higher cover percentage of an open habitat species at the forest edge line increased its probability to disperse into the forest interior. The vegetation community on, next to, and away from lightly trampled paths remained the same throughout the trampling experiment. For heavily trampled paths, the community changed drastically on the paths, but stayed relatively similar next to and away from the paths. As boreal vegetation is highly sensitive to the effects of trampling, overall ease of access throughout the forest floor should be restricted to avoid the excessive creation of spontaneous paths. To minimize the effects of trampling, recreational use could be guided to the maintained path network in heavily used areas.