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Food habits of white-tailed deer (Odocoileus virginianus) were examined from January to November 1984 via fecal-pellet analysis at Valley Forge National Historical Park (VFNHP), which represents an island habitat for deer surrounded by extensive urbanization, in southeastern Pennsylvania. In addition, use of fields by deer was compared to food habits. Herbaceous vegetation (forbs, leaves of woody plants, and conifer needles) was the predominant food type in all seasons except fall. Acorns and graminoids (grasses and sedges) were important food resources in fall and spring, respectively. Use of woody browse (twigs) was similar among seasons. Field use was relatively high during fall, winter without snow cover (<20 cm), and spring when food resources in fields were readily available. In contrast, use of fields was lowest in summer when preferred woodland foods were available and in winter with snow cover when food in fields was not readily accessible. Patterns of food-type use by deer at VFNHP indicate the year-round importance of nonwoody foods and field habitats to deer populations on public lands such as national parks in the northeastern United States.  相似文献   

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Recent appearance of cattail (Typha domingensis) within a southern Everglades slough—Upper Taylor Slough (Everglades National Park)—suggests ecosystem eutrophication. We analyze water quality, nutrient enrichment, and water management operations as potential drivers of eutrophication in Upper Taylor Slough. Further, we attempt to determine why surface water phosphorus, a parameter used commonly to monitor ecosystem health in the Everglades, did not serve as an early warning for eutrophication, which has broader implication for other restoration efforts. We found that surface water total phosphorus concentrations generally were below a 0.01 mg L−1 threshold determined to cause imbalances in flora and fauna, suggesting no ecosystem eutrophication. However, assessment of nutrient loads and loading rates suggest Upper Taylor Slough has experienced eutrophication and that continued total phosphorus loading through a point-source discharge was a major driver. These nutrient loads, combined with increases in hydroperiods, led to the expansion of cattail in Upper Taylor Slough. We recommend other metrics, such as nutrient loads, periphyton and arthropod community shifts, and sediment core analyses, for assessing ecosystem health. Monitoring surface water alone is not enough to indicate ecosystem stress.  相似文献   

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/ Heavy visitor use in many areas of the world have necessitated development of ways to assess visitation impacts. Arches National Park recently completed a Visitor Experience and Resource Protection (VERP) plan. Integral to this plan was developing a method to identify biological indicators that would both measure visitor impacts and response to management actions. The process used in Arches for indicator selection is outlined here as a model applicableto many areas facing similar challenges. The steps were: (1) Vegetation types most used by visitors were identified. Impacted and unimpacted areas in these types were sampled, comparing vegetation and soil factors. (2) Variables found to differ significantly between compared sites were used as potential indicators. (3) Site-specific criteria for indicators were developed, and potential indicators evaluated using these criteria. (4) Chosen indicators were further researched for ecological relevancy. (5) Final indicators were chosen, field tested, and monitoring sites designated. In Arches, indicators were chosen for monitoring annually (soil crust index, soil compaction, number of used social trails and soil aggregate stability) and every five years (vegetation cover and frequency; ground cover; soil chemistry; and plant tissue chemistry).KEY WORDS: Biological indicators; Recreation impacts; Recreation management; Desert soils; Trampling  相似文献   

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The paper gives an account of the development and implementation of a stakeholder management framework at Ream National Park, Cambodia. Firstly, the concept of stakeholder is reviewed in management and in conservation literatures. Secondly, the context in which the stakeholder framework was implemented is described. Thirdly, a five-step methodological framework is suggested: (1) stakeholder analysis, (2) stakeholder mapping, (3) development of generic strategies and workplan, (4) presentation of the workplan to stakeholders, and (5) implementation of the workplan. This framework classifies stakeholders according to their level of influence on the project and their potential for the conservation of natural resources. In a situation characterized by conflicting claims on natural resources, park authorities were able to successfully develop specific strategies for the management of stakeholders. The conclusion discusses the implications of the Ream experience and the generalization of the framework to other protected areas.  相似文献   

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The Terai-Duar savanna and grasslands, which once extended along most of the Himalayan foothills, now only remain in a number of protected areas. Within these localities, grassland burning is a major issue, but data on frequency and distribution of fires are limited. Here, we analysed the incidence of active fires, which only occur during the dry season (Nov.–Mar.), within a significant area of Terai grasslands: the Manas National Park (MNP), India. We obtained locations of 781 fires during the 2000–2008 dry seasons, from the Fire Information for Resource Management System (FIRMS) that delivers global MODIS hotspot/fire locations using remote sensing and GIS technologies. Annual number of fires rose significantly from around 20 at the start of the study period to over 90 after 2002, with most (85%) detected between December and January. Over half of the fires occurred in tall grasslands, but fire density was highest in wetland and riverine vegetation, dry at the time. Most burning took place near rivers, roads and the park boundary, suggesting anthropogenic origins. A kernel density map of all recorded fires indicated three heavily burnt areas in the MNP, all within the tall grasslands. Our study demonstrates, despite some technical caveats linked to fire detection technology, which is improving, that remote fire data can be a practical tool in understanding fire concentration and burning temporal patterns in highly vulnerable habitats, useful in guiding management.  相似文献   

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The United States Congress established Grand Canyon National Park in 1919 to preserve for posterity the outstanding natural attributes of the canyon cut by the Colorado River. In some cases National Park Service attempts to maintain Grand Canyon's natural environment have been thwarted by activities outside the park. One of the most obvious external threats is Glen Canyon Dam, only 26 km upstream from the park boundary. Constructed in 1963, this gigantic dam has greatly altered the physicochemical and biological characteristics of 446 km of the Colorado River in Grand Canyon National Park. The river's aquatic ecosystem has been greatly modified through the loss of indigenous species and the addition of numerous exotics. We consider this anexotic ecosystem. The riparian ecosystem has been less modified, with addition of a few exotics and no loss of natives—this we consider anaturalized ecosystem.The great dilemma now faced by park managers is that, after 20 years of managing resources along a river controlled by Glen Canyon Dam, the Bureau of Reclamation has proposed major changes in operational procedures for the dam. Scientists and managers from the National Park Service, Bureau of Reclamation, and cooperating federal and state resource management agencies are using a systems analysis approach to examine the impacts of various Colorado River flow regimes on aquatic, riparian, and recreational parameters in the park. This approach will help in the development of management alternatives designed to permit the most efficient use of that river's natural resources without their destruction.  相似文献   

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Available information on the socioeconomic implications of marine protected areas (MPAs) for the socioculturally diverse Mediterranean region is scant. The National Marine Park of Alonissos, Northern Sporades (NMPANS), Greece was established in 1992 as a foundation for the conservation of the endangered Mediterranean monk seal Monachus monachus. The evolution of the degree of acceptance of and satisfaction from the NMPANS by involved stakeholder groups (fishermen, tourism operators, hoteliers and owners of rooms to let, governmental bodies, nongovernmental bodies, students, domestic and foreign tourists) were investigated 13 years after its establishment using written questionnaires delivered during personal interviews. The initial positive attitude of local professionals for the NMPANS has eroded due to the unsatisfactory fulfillment of expectations for socioeconomic development. Fishermen expressed dissatisfaction with, mistrust toward, and a reluctancy to communicate with the NMPANS’s management body. They believe that the fishery areas have decreased in actual geographic area because of the prohibitive measures; fish stocks are declining; compensation for damage to fishery equipment by the Mediterranean monk seal and for the prohibitive measures should be provided; and stricter enforcement of regulations should take place. On the other hand, tourism operators, who organize trips for tourists to the NMPANS, unanimously reported direct economic benefits. Furthermore, there was a disparity in the perception of socioeconomic benefits derived from the NMPANS between governmental bodies and local stakeholders. The governmental bodies and the nongovernmental organization MOm-Hellenic Society for the Study and Protection of the Monk Seal postulated that there had been considerable socioeconomic benefits for the local community of Alonissos due to the establishment of the NMPANS, whereas the local nongovernmental organization Ecological and Cultural Movement of Alonissos claimed benefits were scant. Tourists (domestic and foreign) believe that the NMPANS is not the main attraction to Alonissos Island but is part of a composite, including serenity, aesthetic beauty, and small-scale tourism development, which can turn Alonissos Island into an ideal eco-tourism destination; a common aspiration for both the tourists and the local community by general consensus. The aim of the NMPANS to integrate conservation and development lies in (1) the effectiveness of the NMPANS management body in formulating a strategic management plan that would accommodate stakeholders’ interests and aspirations and (2) a national policy of conservation and enhancement of natural resources with consistency and continuity. Quantitative assessment of the socioeconomic effectiveness of the Mediterranean MPAs using a common methodology would facilitate the identification of intraregional variation and better planning for the network of MPAs in the Mediterranean.  相似文献   

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The Jamaica Bay portion of Gateway National Recreation Area, located next to highly urbanized New York City, faces many challenges to preserve and protect its natural, cultural, and recreational resources. To aid in the management of the park resources, detailed estuarine shoreline analyses of Jamaica Bay were undertaken using imagery taken in 1951, 1974, and 2006. A 15-class land use/land cover (LULC) classification scheme was created after doing an initial examination of the types of LULC in the 2006 orthoimagery and then applied in the analyses of the previous years. By quantifying how and where the shoreline has changed over the past 60 years, park managers can better assess the impact of management practices by comparing LULC of the shoreline within the park boundary to the LULC of the shoreline outside the park boundary before and after the park was created in 1972. Despite the heavy development of New York City and the trend for shoreline modification, the overall shoreline of Jamaica Bay has maintained large percentages of undeveloped vegetation and sandy beaches. Much of the LULC change has occurred in the creeks as a result of dredging and shape modification for residential and commercial uses. Park management has been effective in limiting the alteration of undeveloped shoreline although there have been significant changes in the relative percentages of sand and vegetated beaches between 1974 and 2006.  相似文献   

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