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1.
Using Wildlife as Receptor Species: A Landscape Approach to Ecological Risk Assessment 总被引:4,自引:0,他引:4
Gaines KF Porter DE Dyer SA Wein GR Pinder JE Brisbin IL 《Environmental management》2004,34(4):528-545
To assist risk assessors at the Department of Energy’s Savannah River Site (SRS), a Geographic Information System (GIS) application was developed to provide relevant information about specific receptor species of resident wildlife that can be used for ecological risk assessment. Information was obtained from an extensive literature review of publications and reports on vertebrate- and contaminant-related research since 1954 and linked to a GIS. Although this GIS is a useful tool for risk assessors because the data quality is high, it does not describe the species’ site-wide spatial distribution or life history, which may be crucial when developing a risk assessment. Specific receptor species on the SRS were modeled to provide an estimate of an overall distribution (probability of being in an area). Each model is a stand-alone tool consisting of algorithms independent of the GIS data layers to which it is applied and therefore is dynamic and will respond to changes such as habitat disturbances and natural succession. This paper describes this modeling process and demonstrates how these resource selection models can then be used to produce spatially explicit exposure estimates. This approach is a template for other large federal facilities to establish a framework for site-specific risk assessments that use wildlife species as endpoints.Current address: Biology Department, University of South Dakota, Vermillion, SD 57069 相似文献
2.
Simulating Spatial and Temporal Context of Forest Management Using Hypothetical Landscapes 总被引:1,自引:0,他引:1
/ 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 相似文献
3.
介绍了当今世界上机动车燃料无铅化的各种方法,重点介绍了汽油添加剂甲基叔丁基醚(MTBE)和甲基环戊二羰基锰(MMT),以及天然气等。 相似文献
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Edvardsson K 《Environmental management》2004,34(2):170-180
In Sweden, environmental policy is essentially carried out through a system of environmental objectives adopted by Parliament in the late 1990s. This system contains principles, objectives, interim targets, strategies, and follow-up mechanisms, which together provide a solid ground for increased efficiency and improved prioritization in environmental policies. Despite the ambitious approach of the Swedish Parliament, the system of environmental objectives suffers from certain shortcomings. Some of the objectives are imprecise and difficult to evaluate, and there are no rules or principles that may be used to solve goal conflicts and to prioritize between different objectives. As a consequence, the environmental objectives tend to differ in their degrees of operationalizability, and the priority-setting between different objectives is often unclear.*Rskr. denotes a written communication (from the Swedish Parliament to the Swedish Government) of a Parliamentary decision.
Note: This version was published online in June 2005 with the cover date of August 2004. 相似文献
6.
The Hponkanrazi Wildlife Sanctuary, North Myanmar and three contiguous protected areas, comprise some of the largest expanses
of natural forest remaining in the region. Demand for wildlife products has resulted in unsustainable exploitation of commercially
valuable species resulting in local extirpation of vulnerable species. Camera trap, track and sign, and questionnaire-based
surveys were used to examine (a) wildlife species targeted by hunters, (b) the importance of wild meat for household consumption,
and (c) the significance of hunting as a livelihood activity for resident villages. Certain commercially valuable species
highly preferred by hunters were either completely absent from hunt records (tiger, musk deer and otter) or infrequently obtained
during actual hunts (bear, pangolin). Species obtained by hunters were commonly occurring species such as muntjacs with low
commercial value and not highly preferred by hunters. Fifty eight percent of respondents (n = 84) indicated trade, 27% listed subsistence use and 14% listed human-wildlife conflict as the main reason for hunting (n = 84). Average amount of wild meat consumed per month is not significantly higher during the hunting season compared to the
planting season (paired t-test, P > 0.05). Throughout the year, the average amount of fish consumed per month was higher than livestock or wild meat (Friedman
test, P < 0.0001). Hunting is driven largely by trade and wild meat, while not a critical source of food for a large number of families
could potentially be an important, indirect source of access to food for hunting families. Findings and trends from this study
are potentially useful in helping design effective conservation strategies to address globally prevalent problems of declining
wildlife populations and dependent human communities. The study provides recommendations to reduce illegal hunting and protect
vulnerable species by strengthening park management through enforcement, increasing the opportunity costs of poaching, establishing
no-take zones and research to determine the economic significance of hunting for livelihoods. 相似文献
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For the last 20 years, human–wildlife conflicts have been rapidly increasing in towns. Although people want “greener” cities,
the expansion of disliked species causes problems that are difficult to manage and to reduce. The complexity of the numerous
factors involved in these human–wildlife relations needs the development of a comprehensive tool for urban planners. Today,
with the development of computers and geographical information systems, it is easier to analyze and combine different spatial
data as methods used for the management of risks in studies of natural hazards. Here we present a method for assessing and
mapping the risk in cases of human–wildlife conflict. An application to starling management in a town in western France will
show the efficiency of our methods to combine information given by a network of experts and to highlight higher risk sites.
The map of risk provides a spatial result useful for comprehension, communication between people and agencies, and public
education. 相似文献
9.
P. A. Anadu 《The Environmentalist》1987,7(3):211-220
Summary This paper draws the attention to the major threats to nature conservation in Nigeria, and reviews critically the measures adopted for the protection of wildlife. The major problems include habitat degradation (through uncontrolled logging, agricultural projects, industrial plantations, highway and urban development, and exploitation for fuelwood), over-hunting and poachingSteps taken so far to protect wildlife include the creation of one national park and eighteen game reserves, enactment of wildlife laws, signing of international treaties, and manpower development. These measures have however failed to produce the desired effect owing largely to public apathy, low level of funding, inadequate game laws and weak enforcement of existing legal provisions.It is suggested that the Federal Government should intervene more positively in favour of conservation by creating more national parks and assuming joint responsibility with the states for formulating wildlife laws. Furthermore, the role of non-governmental organizations in influencing conservation policies and mobilizing public opinion will be crucial in the difficult years ahead.Dr. P. A. Anadu, although recently on secondment to the Department of Zoology, University of Oxford, UK; is currently on the staff of the Department of Forestry and Wildlife in the Faculty of Agriculture at the University of Benin. 相似文献
10.
Non-point-source pollution of surface and groundwater is a prominent environmental issue in rural catchments, with major consequences on water supply and aquatic ecosystem quality. Among surface-water protection measures, environmental or landscape management policies support the implementation and the management of buffer zones. Although a great number of studies have focused on buffer zones, quantification of the buffer effect is still a recurring question.The purpose of this article is a critical review of the assessment of buffer-zone functioning. Our objective is to provide land planners and managers with a set of variables to assess the limits and possibilities for quantifying buffer impact at the catchment scale. We first consider the scale of the local landscape feature. The most commonly used empirical method for assessing buffers is to calculate water/nutrient budgets from inflow–outflow monitoring at the level of landscape structures. We show that several other parameters apart from mean depletion of flux can be used to describe buffer functions. Such parameters include variability, with major implication for water management. We develop a theoretical framework to clarify the assessment of the buffer effect and propose a systematic analysis taking account of temporal variability. Second, we review the current assessment of buffer effects at the catchment scale according to the theoretical framework established at the local scale. Finally, we stress the limits of direct empirical assessment at the catchment scale and, in particular, we emphasize the hierarchy in hydrological processes involved at the catchment scale: The landscape feature function is constrained by other factors (climate and geology) that are of importance at a broader spatial and temporal scale.Published on line 相似文献
11.
An Object-Based Image Analysis of Pinyon and Juniper Woodlands Treated to Reduce Fuels 总被引:1,自引:0,他引:1
April Hulet Bruce A. Roundy Steven L. Petersen Ryan R. Jensen Stephen C. Bunting 《Environmental management》2014,53(3):660-671
Mechanical and prescribed fire treatments are commonly used to reduce fuel loads and maintain or restore sagebrush steppe rangelands across the Great Basin where pinyon (Pinus) and juniper (Juniperus) trees are encroaching and infilling. Geospatial technologies, particularly remote sensing, could potentially be used in these ecosystems to (1) evaluate the longevity of fuel reduction treatments, (2) provide data for planning and designing future fuel-reduction treatments, and (3) assess the spatial distribution of horizontal fuel structure following fuel-reduction treatments. High-spatial resolution color-infrared imagery (0.06-m pixels) was acquired for pinyon and juniper woodland plots where fuels were reduced by either prescribed fire, tree cutting, or mastication at five sites in Oregon, California, Nevada, and Utah. Imagery was taken with a Vexcel UltraCam X digital camera in June 2009. Within each treatment plot, ground cover was measured as part of the Sagebrush Steppe Treatment Evaluation Project. Trimble eCognition Developer was used to classify land cover classes using object-based image analysis (OBIA) techniques. Differences between cover estimates using OBIA and ground-measurements were not consistently higher or lower for any land cover class and when evaluated for individual sites, were within ±5 % of each other. The overall accuracy and the K hat statistic for classified thematic maps for each treatment were: prescribed burn 85 % and 0.81; cut and fell 82 % and 0.77, and mastication 84 % and 0.80. Although cover assessments from OBIA differed somewhat from ground measurements, they are sufficiently accurate to evaluate treatment success and for supporting a broad range of management concerns. 相似文献
12.
Some believe that provision of private property rights in wildlife on private land provides a powerful economic incentive for nature conservation because it enables property owners to market such wildlife or its attributes. If such marketing is profitable, private landholders will conserve the wildlife concerned and its required habitat. But land is not always most profitably used for exploitation of wildlife, and many economic values of wildlife (such as non-use economic values) cannot be marketed. The mobility of some wildlife adds to the limitations of the private-property approach. While some species may be conserved by this approach, it is suboptimal as a single policy approach to nature conservation. Nevertheless, it is being experimented with, in the Northern Territory of Australia where landholders had a possibility of harvesting on their properties a quota of eggs and chicks of red-tailed black cockatoos for commercial sale. This scheme was expected to provide an incentive to private landholders to retain hollow trees essential for the nesting of these birds but failed. This case and others are analysed. Despite private-property failures, the long-term survival of some wildlife species depends on their ability to use private lands without severe harassment, either for their migration or to supplement their available resources, for example, the Asian elephant. Nature conservation on private land is often a useful, if not essential, supplement to conservation on public lands. Community and public incentives for such conservation are outlined. 相似文献
13.
Much can be learned about adaptation by applying structures and methodologies already used in other research fields. This study employs a public economic policy approach to investigate how – or if at all – adaptation should be supported by the public sector. Three different fields of adaptation activity are identified which are especially relevant for government intervention and the study proposes ways in which government intervention could be conducted. The analysis takes into account that developing regions are particularly vulnerable and they have insufficient funds to adequately adapt to climate change. 相似文献
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Karl F. Nordstrom Ulrike Gamper Giorgio Fontolan Annelore Bezzi Nancy L. Jackson 《Environmental management》2009,44(6):1121-1135
Human actions can contribute to degradation of coastal environments or they can increase the likelihood that these environments
will be restored. Beach nourishment provides a basis for restoration, but ways must be found to add habitat improvement to
projects designed for shore protection. This study examines how beach nourishment projects can help reinstate dune landscapes
in locations where beaches and dunes had been replaced by static shore protection structures. Dune topography and vegetation
on three nourished sites on the northern Adriatic Coast of Italy are compared to a reference site to evaluate changes after
beach fill was emplaced. Results reveal how nourishment projects used for shore protection can restore the space available
for dunes to form, increase the likelihood of sediment transfers inland and increase the diversity of topography and vegetation.
Beach raking prevents formation and growth of hummocky, incipient backshore dunes that would otherwise evolve into a naturally
functioning foredune. Sand-trapping fences can speed the process of foredune development but can be counterproductive if they
interfere with transport to beach grass (Ammophila littoralis) planted landward of them. Shore protection structures can provide stability and more time for dune evolution on eroding
shores, resulting in greater species richness and longer retention of ecological niches. These structures need not be required
if re-nourishment occurs frequently enough to provide a beach wide enough to protect against storm wave uprush. 相似文献
16.
Gunavant M. Oza 《The Environmentalist》2003,23(2):189-192
Much of the forest wealth on the plains and in the hilly areas of India has been foolishly destroyed, and the rich heritage of wildlife has been slaughtered mostly for only temporary gain. The wanton axing of the larger indigenous trees and the uprooting of other floristic elements in the hills and on the lower slopes of the mountains, gradually impoverishes them, and may be followed by erosion that ultimately leaves the slopes barren. These alarming threats to the chir (Pinus roxburghii) and fir (Abies pindrow) forests of Kashmir will have disastrous consequences. Once densely-forested, the mountain slopes in Kashmir have become largely naked through too-heavy tapping and cutting of the trees; with concomitant landslides, frequent floods, and loss of fertile topsoil. Unfortunately, the people living in the areas of the chir and fir trees, do not play a proper part in their protection, and the last two decades have witnessed, year by year, the rapid march of urbanization and manifold destructive activities which have taken a heavy toll on these precious species. Urgent conservation measures are essential to preserve these endangered trees in Kashmir. 相似文献
17.
Hunting is a threat to wildlife within the Hkakaborazi National Park in north Myanmar. We used questionnaire surveys to obtain
data on variables such as commonly targeted species, prices of traded wildlife, reasons for hunting and the relative importance
of livelihood sources. We examine (a) the significance of hunting and trade for livelihoods and explore (b) the impacts of
hunting on targeted species. Ninety per cent of trade records (n = 803) was constituted by seven species commonly targeted by hunters (serow, red goral, muntjac, bear, Assamese macaque,
black musk deer and takin). Commercially valuable species previously targeted by hunters (tiger, otter, pangolin) appear to
be completely absent from current harvest records and potentially in decline. Although farming is the predominant occupation,
hunting (driven by trade) represents a significantly higher source of income than other livelihood activities. Management
recommendations include increased investment in enforcement, education and outreach, small livestock development, improved
crop productivity, demarcation of no-take areas for wildlife and biological monitoring of targeted species. 相似文献
18.
R. Gerald Wright 《Environmental management》1984,8(2):121-124
Legislation settling the Alaska Native Lands Claims also resulted in the establishment of ten new parks and preserves in Alaska. This settlement was the result of a long and often bitter legislative struggle between pro- and antidevelopment groups. The planning history of the Wrangell-St. Elias National Park and Preserve is used as a case example of this debate. One particular source of conflict was the curtailment of sport hunting that would result under national park classification. A preserve classification was introduced to resolve this conflict. Data on wildlife resources and sport hunting were instrumental in defining the areas so classified. 相似文献
19.
Determining Relative Contributions of Vegetation and Topography to Burn Severity from LANDSAT Imagery 总被引:2,自引:0,他引:2
Zhiwei Wu Hong S. He Yu Liang Longyan Cai Bernard J. Lewis 《Environmental management》2013,52(4):821-836
Fire is a dominant process in boreal forest landscapes and creates a spatial patch mosaic with different burn severities and age classes. Quantifying effects of vegetation and topography on burn severity provides a scientific basis on which forest fire management plans are developed to reduce catastrophic fires. However, the relative contribution of vegetation and topography to burn severity is highly debated especially under extreme weather conditions. In this study, we hypothesized that relationships of vegetation and topography to burn severity vary with fire size. We examined this hypothesis in a boreal forest landscape of northeastern China by computing the burn severity of 24 fire patches as the difference between the pre- and post-fire Normalized Difference Vegetation Index obtained from two Landsat TM images. The vegetation and topography to burn severity relationships were evaluated at three fire-size levels of small (<100 ha, n = 12), moderate (100–1,000 ha, n = 9), and large (>1,000 ha, n = 3). Our results showed that vegetation and topography to burn severity relationships were fire-size-dependent. The burn severity of small fires was primary controlled by vegetation conditions (e.g., understory cover), and the burn severity of large fires was strongly influenced by topographic conditions (e.g., elevation). For moderate fires, the relationships were complex and indistinguishable. Our results also indicated that the pattern trends of relative importance for both vegetation and topography factors were not dependent on fire size. Our study can help managers to design fire management plans according to vegetation characteristics that are found important in controlling burn severity and prioritize management locations based on the relative importance of vegetation and topography. 相似文献