On modelling temporal patterns in stressed ecosystems — Recreation in a coniferous forest

A system of ordinary differential equations is presented as being appropriate for modelling the impact of stress on the temporal behaviour of certain components within an ecosystem. The modelling problem is fist discussed in general terms and then in terms specifically relating to the impact of recreational activities (hunting, fishing, sightseeing, etc.) on a coniferous forest ecosystem.Using crude data, the model is used to simulate over a 3-year period the biomass levels of four compartments of the ecosystem (viz, timber, deer, fish and forage) in the absence of recreational activities. These results are then contrasted with simulation results obtained by introducing a “moderate” and then “high” degree of recreational activity, as well as the response of the system under moderate recreation to management strategies involving the construction of dams and the harvesting of timber.     

Effects of Rock Climbing on Populations of Presettlement Eastern White Cedar (Thuja occidentalis) on Cliffs of the Niagara Escarpment, Canada

Cliffs of the Niagara Escarpment support a self-sustaining presettlement forest of eastern white cedar (  Thuja occidentalis L.) in which some trees are over 1000 years old. Many of the cliffs are also popular locations for recreational rock climbing. Our study employed a stratified random sampling design to assess the impact of rock climbing on populations of cliff-face and cliff-edge trees. Tree density and age structure were compared between four climbed and three unclimbed sites in the vicinity of Milton, Ontario. Signs of physical damage were also recorded for the trees sampled at each site. The results showed that living tree density on the cliff face was lower in climbed areas. The age structures of these forests showed that the numbers of older and younger age classes have been reduced on climbed cliff faces compared with unclimbed areas. A high percentage of trees on climbed cliff faces showed evidence of damage by humans. These trends were not as apparent on cliff edges where other disturbances have affected age structure. We recommend that cliff faces be explored for the presence of presettlement forest and that recreation managers of lands with exposed cliff faces incorporate rock climbing considerations into their management plans. Monitoring programs would help track levels of disturbance. Education of the climbing community would be the most effective long-term solution to limiting disturbance in sensitive areas.     

Moral Hazard, Externalities, and Compensation for Crop Damages from Wildlife

A principal–multiple agent model is used to examine wildlife damage abatement and compensation programs in a setting in which farmers suffer damages and hunters use the wildlife for recreational purposes. In addition to externalities inherent in abatement, abatement/compensation policy confronts the issue of moral hazard. By representing the principal as a wildlife management authority who acts on behalf of hunters, we investigate contracts in which transfers of more or less severe hunting regulations, a public good that aids in dispersing wildlife, and monetary payments from hunting license fees can be used to overcome moral hazard.     

Social values and biodiversity conservation in a dynamic world

Understanding what shape values (which ultimately shape human behavior) will help improve the effectiveness of conservation solutions that depend on public support. To contribute to this understanding, we investigated the influence of societal‐level changes, such as modernization, on values in a multilevel framework. We collected survey responses (n = 4183) to questionnaires mailed to a random selection of households within each county in Washington (U.S.A.) (response rate 32%). We used multilevel modeling to determine the relationship between modernization (e.g., county‐level urbanization, wealth, and education) and wildlife value orientations (values that shape thought about wildlife) while controlling for individual‐level sociodemographics. We then explored how values influence conservation support at different levels (e.g., individual and county) and how values explain conservation support in a case study of public responses to wolf (Canis lupis) recovery. We found positive associations between county‐level examples of modernization and mutualism (a wildlife value orientation that prioritizes the perceived needs of wildlife) independent of a respondent's sociodemographics, and negative associations between modernization and domination (a wildlife value orientation that prioritizes human needs). Our results suggest that context has an additive impact on one's values; certain locations exhibited domination values, whereas others exhibited a mix of value types. This finding is important because actions that restrict human interests to promote biodiversity were negatively associated with domination and positively associated with mutualism. In the wolf case study, mutualism was strongly correlated with less social conflict over wolf recovery in many, but not all, counties (e.g., Pearson's r correlation = 0.59 in one county and a nonsignificant correlation in another). Our findings suggest that modernization operates on values within a state with implications for biodiversity, but other factors in addition to values must be investigated to fully understand what leads to proconservation behavior.     

Use of a seagrass residency index to apportion commercial fishery landing values and recreation fisheries expenditure to seagrass habitat service

Where they dominate coastlines, seagrass beds are thought to have a fundamental role in maintaining populations of exploited species. Thus, Mediterranean seagrass beds are afforded protection, yet no attempt to determine the contribution of these areas to both commercial fisheries landings and recreational fisheries expenditure has been made. There is evidence that seagrass extent continues to decline, but there is little understanding of the potential impacts of this decline. We used a seagrass residency index, that was trait and evidence based, to estimate the proportion of Mediterranean commercial fishery landings values and recreation fisheries total expenditure that can be attributed to seagrass during different life stages. The index was calculated as a weighted sum of the averages of the estimated residence time in seagrass (compared with other habitats) at each life stage of the fishery species found in seagrass. Seagrass‐associated species were estimated to contribute 30%–40% to the value of commercial fisheries landings and approximately 29% to recreational fisheries expenditure. These species predominantly rely on seagrass to survive juvenile stages. Seagrass beds had an estimated direct annual contribution during residency of €58–91 million (4% of commercial landing values) and €112 million (6% of recreation expenditure) to commercial and recreational fisheries, respectively, despite covering <2% of the area. These results suggest there is a clear cost of seagrass degradation associated with ineffective management of seagrass beds and that policy to manage both fisheries and seagrass beds should take into account the socioeconomic implications of seagrass loss to recreational and commercial fisheries.     

Evaluation of Selective Culling of Infected Individuals to Control Tasmanian Devil Facial Tumor Disease

Abstract: Sustainable strategies to manage infectious diseases in threatened wildlife are still lacking despite considerable concern over the global increase in emerging infectious diseases of wildlife and their potential to drive populations to extinction. Selective culling of infected individuals will often be the most feasible option to control infectious disease in a threatened wildlife host, but has seldom been implemented or evaluated as a management tool for the conservation of threatened species. The Tasmanian devil (Sarcophilus harrisii) is threatened with extinction by an infectious cancer, devil facial tumor disease (DFTD). We assess the success of an adaptive management trial involving selective culling of infected Tasmanian devils to control DFTD. Demographic and epidemiological parameters indicative of disease progression and impact were compared between the management site and a comparable unmanaged control site. Selective culling of infected individuals neither slowed rate of disease progression nor reduced population‐level impacts of this debilitating disease. Culling mortality simply compensated for disease mortality in this system. Failure of selective culling to impede DFTD progress and reduce its impacts in the managed population was attributed to DFTD's frequency‐dependent nature, its long latent period and high degree of infectivity, and the presence of a cryptic hidden disease reservoir or continual immigration of diseased individuals. We suggest that increasing the current removal rate and focusing removal efforts prior to the breeding season are options worth pursuing for future management of DFTD in this population. On the basis of our experience, we suggest that disease‐management programs for threatened wildlife populations be developed on the principles of adaptive management and utilize a wide variety of strategies with regular reviews and adaptation of strategies undertaken as new information is obtained.     

Extraction,reclamation and after use at gravel quarries near Canterbury,Kent

A study of the extraction, reclamation and after use of flood plain gravel quarries between Bagham and Thannington, south west of Canterbury in Kent, South-east England, was made, based on a review of the literature and field work. The area represents a linear extension of the urban fringe of Canterbury. Gravel production has been the most significant industry in terms of environmental impact over the last thirty years, and the result of such activity has been the creation of an extensive area of lakes and wetland habitats. Present and future gravel production will more than double the existing lakes and wetlands areas. It is suggested that, in terms of land use, this man-made environment is best suited for water-based recreation and that three zones should be recognised for an amenity park, angling and wildlife respectively. Further mineral production between Ashford and Bagham may mean a reappraisal of the proposed water resource use, particularly for wildlife. As a result of this study, attention is drawn to the spatial relationships between recreational demand groups and flood plain location with respect to the urban centre and to each other.     

Effects of Management of Domestic Dogs and Recreation on Carnivores in Protected Areas in Northern California

Abstract: In developed countries dogs (Canis lupus familiaris) are permitted to accompany human visitors to many protected areas (e.g., >96% of protected lands in California, U.S.A.), and protected‐area management often focuses on regulating dogs due to concerns about predation, competition, or transmission of disease and conflicts with human visitors. In 2004 and 2005, we investigated whether carnivore species richness and abundance were associated with management of domestic dogs and recreational visitation in protected areas in northern California. We surveyed for mammalian carnivores and human visitors in 21 recreation areas in which dogs were allowed offleash or onleash or were excluded, and we compared our observations in the recreation areas with observations in seven reference sites that were not open to the public. Carnivore abundance and species richness did not differ among the three types of recreation areas, but native carnivore species richness was 1.7 times greater (p < 0.01) and the relative abundances of native coyotes (Canis latrans) and bobcats (Lynx rufus) were over four times greater (p < 0.01) in the reference sites. Abundances of bobcats and all carnivores declined as the number of visitors increased. The policy on domestic dogs did not appear to affect species richness and abundance of mammalian carnivores. But the number of dogs we observed was strongly associated with human visitation (R²= 0.54), so the key factors associated with recreational effects on carnivores appear to be the presence and number of human visitors to protected areas.     

Relevance of crowding effects in a coastal National Park in Germany: results from a case study on Hamburger Hallig

Coastal environments are popular sites for tourism and faced with an increasing recreational demand. Most of European coastal areas attract numerous visitors annually. In recreation research this management problem can be described in terms of carrying capacity which expresses the ability of a site or region to absorb recreational use without deterioration of natural resources and the quality of the visitor experience. As social aspects of recreation in Europe still have received little attention, the purpose of this study is to examine the applicability of the concept of social carrying capacity in a German coastal national park. The article addresses if the relationship between perceived visitor encounters, crowding perception and visitor characteristics is applicable by using data from an on-site survey (N?=?509) of visitors conducted on Hamburger Hallig, Germany. It examines whether effects of overcrowding are measurable on a popular daytrip destination with established approaches. Results demonstrate that visitors to Hamburger Hallig are characterised by a heterogeneous visitor composition of local residents and domestic tourists with different motivations and who mainly visited the area for hiking or cycling. Study findings show that valuation for reported encounters and perceived crowding differed substantially among origin of visitors and sampling dates. All in all, respondents report a high level of encounter with others and in contrast a very low level of perceived crowding.     

Conserving and managing the subnivium

In regions where snowfall historically has been a defining seasonal characteristic of the landscape, warming winters have reduced the depth, duration, and extent of snowpack. However, most management and conservation has focused on how aboveground wildlife will be affected by altered snow conditions, even though the majority of species that persist through the winter do so under the snowpack in a thermally stable refugium: the subnivium. Shortened winters, forest management practices, and winter recreation can alter subnivium conditions by increasing snow compaction and compromising thermal stability at the soil–snow interface. To help slow the loss of the subnivium in the face of rapidly changing winter conditions, we suggest managers adopt regional conservation plans for identifying threatened snow‐covered environments; measure and predict the effects land cover and habitat management has on local subnivium conditions; and control the timing and distribution of activities that disturb and compact snow cover (e.g., silvicultural practices, snow recreation, and road and trail maintenance). As a case study, we developed a spatially explicit model of subnivium presence in a working landscape of the Chequamegon National Forest, Wisconsin. We identified landscapes where winter recreation and management practices could threaten potentially important areas for subnivium persistence. Similar modeling approaches could inform management decisions related to subnivium conservation. Current climate projections predict that snow seasons will change rapidly in many regions, and as result, we advocate for the immediate recognition, conservation, and management of the subnivium and its dependent species.     

Recreational Portage Trails as Corridors Facilitating Non-Native Plant Invasions of the Boundary Waters Canoe Area Wilderness (U.S.A.)

Abstract:  Wilderness areas are protected and valued in part for recreation; recreational use, however, can negatively impact these areas. In particular, recreational use can facilitate transport of non-native propagules and create open sites for establishment of non-native species. We examined the role of recreational portage trails in the introduction and establishment of non-native plants into the Boundary Waters Canoe Area Wilderness of northern Minnesota (U.S.A.). On 20 portages, we sampled non-native plant richness and cover at four distances (0, 10, 25, and 50 m) from trails. Non-native richness and cover were not related to distance from wilderness entry point. Non-native richness and cover were, however, negatively related to distance from trails. All six non-native species we observed were either directly on or within 1 m of trails. These results suggest that recreational trails act as corridors facilitating invasions of non-native plants into wilderness areas. It remains unclear, however, whether these effects are caused by dispersal of propagules, creation of bare ground, or changes in the native plant community.     

Benefits of Studies of Overwintering Birds for Understanding Resident Bird Ecology and Promoting Development of Conservation Capacity

Abstract:  Funding of ecological research and monitoring of Neotropical migratory birds on their overwintering grounds has benefited both migratory and permanent-resident species. Using examples from our work in Puerto Rico and the Dominican Republic, we demonstrate that ecological research of overwintering migrants often provides information about the ecology and demography of little-known tropical resident birds. Critically important long-term monitoring in Puerto Rico with a focus on winter residents has provided information on the relationships between annual rainfall and fluctuations in resident bird populations and survival rates. It also has alerted local biologists to declines in resident bird populations, including a decline apparently driven by the entry of a brood parasite. But migrant-focused research may also have had an underappreciated effect on the development of conservation capacity and conservation efforts in host countries. Investments in research on Neotropical migrants overwintering on Hispaniola have resulted in a huge increase in field training of students and wildlife professionals, promoted conservation awareness at local and national levels, played an important role in the growth and professionalization of key environmental organizations, spawned a growing ecotourism industry for bird-watching, and driven national park management planning and conservation efforts for all bird species. We encourage funding organizations and agencies to consider the broader impacts of funding migratory-bird research and monitoring efforts, and we encourage researchers in the tropics to use protocols that provide the most information about all the birds that use the study areas involved and to be aware of important opportunities that they may have to build capacity in host countries.     

A simulation model for the management of low density recreational areas

In order to take account of the congestion externalities associated with increased use intensity during a given period at a low density recreational resource, it is necessary to determine the effects of alternative use levels on the expected quality of each individual's experience. This paper describes a simulation model for wilderness recreation designed to provide such measures. In order to illustrate the model it is applied to the Spanish Peaks Areas in Montana.     

Effects of Tourists on Behavior and Demography of Olympic Marmots

Abstract:  If changes in animal behavior resulting from direct human disturbance negatively affect the persistence of a given species or population, then these behavioral changes must necessarily lead to reduced demographic performance. We tested for the effects of human disturbance on Olympic marmots ( Marmota olympus ), a large ground-dwelling squirrel that has disappeared from several areas where recreation levels are high. We assessed the degree to which antipredator and foraging behavior and demographic rates (survival and reproduction) differed between sites with high recreation levels (high use) and those with little or no recreation (low use). Compared with the marmots at low-use sites, marmots at high-use sites displayed significantly reduced responses to human approach, which could be construed as successful accommodation of disturbance or as a decrease in predator awareness. The marmots at high-use sites also looked up more often while foraging, which suggests an increased wariness. Marmots at both types of sites had comparable reproductive and survival rates and were in similar body condition. Until now, the supposition that marmots can adjust their behavior to avoid negative demographic consequences when confronted with heavy tourism has been based on potentially ambiguous behavioral data. Our results support this hypothesis in the case of Olympic marmots and demonstrate the importance of considering demographic data when evaluating the impacts of recreation on animal populations.     

Estimating net benefits of recreation under conditions of excess demand

The public provision of outdoor recreation necessitates the development of nonmarket measures of the value of resources in recreational use. Such values can be used as surrogates for market values in the decision-making process. Another aspect of recreation as a publicly provided good is the absence of a mechanism to eliminate automatically excess demand. The absence of such a mechanism has resulted in conditions of excess demand at many recreation sites.This paper deduces the implications of excess demand for the travel cost method of benefit estimation. We show that when excess demand results in rationing at a particular site, the travel cost method will underestimate the true benefits of the site. The results are important because they help identify the direction of bias of one measure of the benefits from the use of a natural resource.     

Effects of Knowledge of an Endangered Species on Recreationists’ Attitudes and Stated Behaviors and the Significance of Management Compliance for Ohlone Tiger Beetle Conservation

Recreation is a leading cause of species decline on public lands, yet sometimes it can be used as a tool for conservation. Engagement in recreational activities, such as hiking and biking, in endangered species habitats may even enhance public support for conservation efforts. We used the case of the endangered Ohlone tiger beetle (Cicindela ohlone) to investigate the effect of biking and hiking on the beetle's behavior and the role of recreationists’ knowledge of and attitudes toward Ohlone tiger beetle in conservation of the species. In Inclusion Area A on the University of California Santa Cruz (U.S.A.) campus, adult Ohlone tiger beetles mate and forage in areas with bare ground, particularly on recreational trails; however, recreation disrupts these activities. We tested the effect of recreation on Ohlone tiger beetles by observing beetle behavior on trails as people walked and road bikes at slow and fast speed and on trails with no recreation. We also surveyed recreationists to investigate how their knowledge of the beetle affected their attitudes toward conservation of the beetle and stated compliance with regulations aimed at beetle conservation. Fast cycling caused the beetles to fly off the trail more often and to fly farther than slow cycling or hiking. Slow cycling and hiking did not differ in their effect on the number of times and distance the beetles flew off the trail. Recreationists’ knowledge of the beetle led to increased stated compliance with regulations, and this stated compliance is likely to have tangible conservation outcomes for the beetle. Our results suggest management and education can mitigate the negative effect of recreation and promote conservation of endangered species. Efectos del Conocimiento de una Especie en Peligro sobre las Actitudes y Comportamientos Declarados de los Recreacionistas y el Significado del Manejo de la Conformidad para la Conservación del Escarabajo Tigre de Ohlone     

Wildlife Connectivity Approaches and Best Practices in U.S. State Wildlife Action Plans

As habitat loss and fragmentation threaten biodiversity on large geographic scales, creating and maintaining connectivity of wildlife populations is an increasingly common conservation objective. To assess the progress and success of large‐scale connectivity planning, conservation researchers need a set of plans that cover large geographic areas and can be analyzed as a single data set. The state wildlife action plans (SWAPs) fulfill these requirements. We examined 50 SWAPs to determine the extent to which wildlife connectivity planning, via linkages, is emphasized nationally. We defined linkage as connective land that enables wildlife movement. For our content analysis, we identified and quantified 6 keywords and 7 content criteria that ranged in specificity and were related to linkages for wide‐ranging terrestrial vertebrates and examined relations between content criteria and statewide data on focal wide‐ranging species, spending, revenue, and conserved land. Our results reflect nationwide disparities in linkage conservation priorities and highlight the continued need for wildlife linkage planning. Only 30% or less of the 50 SWAPs fulfilled highly specific content criteria (e.g., identifying geographic areas for linkage placement or management). We found positive correlations between our content criteria and statewide data on percent conserved land, total focal species, and spending on parks and recreation. We supplemented our content analysis with interviews with 17 conservation professionals to gain specific information about state‐specific context and future directions of linkage conservation. Based on our results, relevant literature, and interview responses, we suggest the following best practices for wildlife linkage conservation plans: collect ecologically meaningful background data; be specific; establish community‐wide partnerships; and incorporate sociopolitical and socioeconomic information. Acercamientos a la Conectividad de Vida Silvestre y las Mejores Prácticas en los Planes de Acción de Vida Silvestre Estatales en los Estados Unidos     

Implications of human value shift and persistence for biodiversity conservation

Large‐scale change in human values and associated behavior change is believed by some to be the ultimate solution to achieve global biodiversity conservation. Yet little is known about the dynamics of values. We contribute to this area of inquiry by examining the trajectory of values affecting views of wildlife in North America. Using data from a 19‐state study in the United States and global data from the Schwartz Value Survey, we explored questions of value persistence and change and the nature of attitudinal responses regarding wildlife conservation issues. We found support, based on subjects’ ancestry, for the supposition that domination is a prevalent American value orientation toward wildlife that has origins in European Judeo‐Christian traditions. Independent of that effect, we also found indications of change. Modernization is contributing to a shift from domination to mutualism value orientations, which is fostering attitudes less centered on human interests and seemingly more consistent with a biocentric philosophy. Our findings suggest that if value shift could be achieved in a purposeful way, then significant and widespread behavior change believed necessary for long‐term conservation success may indeed be possible. In particular, greater emphasis on mutualism values may help provide the context for more collaborative approaches to support future conservation efforts. However, given the societal forces at play, it is not at all clear that human‐engineered value shift is tenable. Instead of developing strategies aimed at altering values, it may be more productive to create strategies that recognize and work within the boundaries of existing values. Whereas values appear to be in a period of flux, it will be difficult to predict future trends without a better understanding of value formation and shift, particularly under conditions of rapid social‐ecological change.     

Estimating the influence of overhead transmission power lines and landscape context on the density of little bustard Tetrax tetrax breeding populations

Collision with conductors and earth cables is a known impact generated by transmission power lines, however there is virtually no information on how these infrastructures might affect bird distribution in a landscape context. With this work we specifically hypothesise that transmission power lines may affect the occurrence of a threatened bird, the little bustard (Tetrax tetrax). To test this hypothesis we used a Stochastic Dynamic Methodology (StDM), analysing the effects of power lines in a landscape perspective and simulating population trends as a response to power line installation and habitat changes induced by agricultural shifts in southern Portugal. The data used in the dynamic model construction included relevant gradients of environmental conditions and was sampled during the breeding seasons of 2003-2006. Transmission power lines were significantly avoided by the little bustard and the developed StDM model showed that the distance to these utility structures is the most important factor determining breeding densities in sites with suitable habitat for the species, which possibly leads to displacement of populations and habitat fragmentation. The model simulations also provided the base to analyse the cumulative effects caused by the habitat degradation that can ultimately lead to the extinction of local populations. Within priority conservation sites, the dismantling of existing transmission lines should be considered whenever possible, in order to ensure adequate breeding habitat. The model is considered useful as an auxiliary tool to be used in environmental impact assessments, management and conservation studies.     

Evaluating and managing wildlife impacts of climate change under uncertainty

Wildlife managers face the daunting task of managing wildlife in light of uncertainty about the nature and extent of future climate change and variability and its potential adverse impacts on wildlife. A conceptual framework is developed for managing wildlife under such uncertainty. The framework uses fuzzy logic to test hypotheses about the extent of the wildlife impacts of past climate change and variability, and fuzzy multiple attribute evaluation to determine best compensatory management actions for adaptively managing the potential adverse impacts of future climate change and variability on wildlife. A compensatory management action is one that can offset some of the potential adverse impacts of climate change and variability on wildlife. Implementation of the proposed framework requires wildlife managers to: (1) select climate impact states, hypotheses about climate impact states, possible management actions for alleviating adverse wildlife impacts of climate change and variability, and future climate change scenarios; (2) choose biological attributes or indicators of species integrity; (3) adjust those attributes for changes in non-climatic variables; (4) define linguistic variables and associated triangular fuzzy numbers for rating both the acceptability of biological conditions under alternative management actions and the relative importance of biological attributes; (5) select minimum or maximum acceptable levels of the attributes and reliability levels for chance constraints on the biological attributes; and (6) define fuzzy sets on the extent of species integrity and biological conditions and select a fuzzy relation between species integrity and biological conditions. A constructed example is used to illustrate a hypothetical application of the framework by a wildlife management team. An overall best compensatory management action across all climate change scenarios is determined using the minimax regret criterion, which is appropriate when the management team cannot assign or is unwilling to assign probabilities to the future climate change scenarios. Application of the framework can be simplified and expedited by incorporating it in a web-based, interactive, decision support tool.