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711.
We conducted a natural resource assessment at two national parks, New River Gorge National River and Shenandoah National Park,
to help meet the goals of the Natural Resource Challenge—a program to help strengthen natural resource management at national
parks. We met this challenge by synthesizing and interpreting natural resource information for planning purposes and we identified
information gaps and natural significance of resources. We identified a variety of natural resources at both parks as being
globally and/or nationally significant, including large expanses of unfragmented, mixed-mesophytic forests that qualify for
wilderness protection, rare plant communities, diverse assemblages of neotropical migratory birds and salamanders, and outstanding
aquatic recreational resources. In addition, these parks function, in part, as ecological reserves for plants in and wildlife.
With these significant natural resources in mind, we also developed a suite of natural resource management recommendations
in light of increasing threats from within and outside park boundaries. We hope that our approach can provide a blueprint
for natural resource conservation at publically owned lands. 相似文献
712.
It has been argued that strategies to manage natural areas important for tourism and recreation should integrate an understanding
of tourist preferences for specific natural features. However, the accuracy of tourist recalled perceptions of environmental
attributes, which are usually derived from post hoc surveys and used to establish management priorities, is currently unmeasured.
We tested the validity of the relationship between tourist-stated preferences and actual condition of coral reefs around the
Caribbean island of Bonaire. Using standardized questionnaires, we asked 200 divers to select their most and least favorite
dive sites and the attributes that contributed to that selection. We also carried out ecological surveys at 76 of the 81 dives
sites around the island to assess the actual conditions of the attributes indicated as important for site selection. Fish-
and coral-related attributes were key features affecting dive enjoyment. In general, divers appeared to be able to perceive
differences between sites in the true condition of biological attributes such as fish species richness, total number of fish
schools, live coral cover, coral species richness, and reef structural complexity, although men and women divers differed
in their ability to perceive/recall some of the attributes. Perceived differences in environmental attributes, such as surface
conditions, underwater current, and the likelihood of encountering rare fish and sea turtles, were not empirically validated.
The fact that divers perceive correctly differences in the condition of some of the key biological attributes that affect
dive enjoyment reinforces the need to maintain overall reef condition at satisfactory levels. However, variation in accuracy
of perceptions owing to demographic factors and attribute type suggests the need for caution when using public perceptions
to develop environmental management strategies, particularly for coral reefs. 相似文献
713.
In this article we present a framework for assessing climate change impacts on water and watershed systems to support management
decision-making. The framework addresses three issues complicating assessments of climate change impacts—linkages across spatial
scales, linkages across temporal scales, and linkages across scientific and management disciplines. A major theme underlying
the framework is that, due to current limitations in modeling capabilities, assessing and responding to climate change should
be approached from the perspective of risk assessment and management rather than as a prediction problem. The framework is
based generally on ecological risk assessment and similar approaches. A second theme underlying the framework is the need
for close collaboration among climate scientists, scientists interested in assessing impacts, and resource managers and decision
makers. A case study illustrating an application of the framework is also presented that provides a specific, practical example
of how the framework was used to assess the impacts of climate change on water quality in a mid-Atlantic, U.S., watershed. 相似文献
714.
The paper applies the Contingent Valuation Method using a visitor survey to determine trip values to three rivers in northeastern Puerto Rico. Sample data were obtained from 984 interviews conducted in 13 sites during the summer months. The trip value is statistically decomposed into components representing natural features and recreation activities. The median net economic value of a river visit without waterfalls or foot trails is $96. Recreation at rivers with both waterfalls and foot trails has a median value of $138 per trip. The presence of waterfalls accounts for $23 and foot trails $19 per trip. This information can be pertinent for managers in selecting recreation site locations and protecting them from competing uses. 相似文献
715.
In order to effectively conserve the non-renewable resource phosphorus (P), flows and stocks of P must be known at national, regional and global scales. P is a key non-renewable resource because its use as fertilizer cannot be substituted posing a constraint on the global food production in the long-term. This paper presents a methodology to establish country-wide P balances that emphasises resource use. We develop a material flow analysis (MFA) model that comprises all relevant flows and stocks of P in five subsystems, seven processes and 36 material flows. For quantification, statistical data from economic and agricultural sources as well as available information about P partitioning in natural and anthropogenic processes are used. Special attention is paid to data gaps and uncertainties. The model was tested in two case studies on P management in Turkey and Austria. MFA appears to be a tool well suited for establishing country-wide P balances, provided that national statistics are well-structured and accessible. If a common approach is used for modelling P-flows and stocks, regional and national balances can be compared and linked towards larger scale P balances for an improved management of the resource. 相似文献
716.
Andreas Koenig Jan Beise Mukesh K. Chalise Jörg U. Ganzhorn 《Behavioral ecology and sociobiology》1998,42(4):225-237
Predictions of ecological models on female social relationships (van Schaik 1989) and their links with food distribution
and the potential competitive regime are used to analyze the feeding and spatial behavior, and resource density, size, distribution,
and quality in a forest population of Hanuman langurs (Presbytis entellus). In contrast to other populations, and assumptions on folivorous primates, the females of this population exhibit a linear
dominance hierarchy. The langurs concentrated their feeding on three key resources with a low density and clumped distribution.
Two out of the three key resources contained significantly higher levels of extractable protein and soluble sugar than other
food plants, indicating high spatial variability of food quality. Even the mature leaves of the most preferred food plant
were about twice as nutritious as those from other food plants. Group spread was small and only a single high-quality resource
was used at a time. Finally, even rich resources could accommodate only a subset of a group. These findings fit predictions
made for the prevalence of within-group contest competition. Given the observed food distribution and phytochemical heterogeneity
of mature foliage, even females of folivorous species should contest for food. The effect of female dominance rank on size
and composition of feeding parties also agrees with this prediction. A comparison with data from another forest population,
where female dominance relations are weakly developed, revealed a clear-cut difference in the use and abundance of resources.
It is argued that between-population differences in female social relationships within a species may be viewed as adaptive
responses to local habitat conditions.
Received: 1 August 1997 / Accepted after revision: 7 December 1997 相似文献
717.
Birth sex ratios in toque macaques and other mammals: integrating the effects of maternal condition and competition 总被引:2,自引:0,他引:2
Wolfgang P. J. Dittus 《Behavioral ecology and sociobiology》1998,44(3):149-160
Mammalian life histories suggest that maternal body condition and social dominance (a measure of resource-holding potential)
influence the physical and social development of offspring, and thereby their reproductive success. Predictably, a mother
should produce that sex of offspring which contributes most to her fitness (as measured by the number of her grandchildren)
and that she is best able to raise within the constraints imposed by her condition, social rank, and environment. Such combined
effects were investigated by monitoring variations in body condition (weight) and behavior of female toque macaques, Macaca sinica of Sri Lanka, in a changing forest environment over 18 years. Maternal rank, by itself, had no influence on offspring sex,
but did affect maternal body condition. The combined effects of rank and condition indicated the following: mothers in robust
condition bore more sons, whereas those in moderate condition bore more daughters, but both effects were expressed most strongly
among mothers of high rank. Where the consequences of low rank were felt most acutely, as shown by poor condition, mothers
underproduced daughters. Environmental quality directly influenced rank and condition interactions, and thus sex ratios. These
relationships, and data from other mammals suggest an empirically and theoretically consistent pattern of sex allocation in
mammals. New predictions integrate effects, proposed by Trivers and Willard, that are rooted in male mate competition, which
is universal among polygynous mammals, with those of local resource competition (and/or female reproductive competition),
which are not universal and differ in intensity between the socioecologies and local environments of different species.
Received: 30 May 1998 / Accepted after revision: 29 August 1998 相似文献
718.
J. H. M. de Ruig 《Journal of Coastal Conservation》1998,4(1):71-78
In The Netherlands shoreline retreat is actively counteracted, mostly by means of beach nourishment in which some allowance
is made for natural fluctuations.
For some parts of the coast, however, a more active socalled ‘seaward coastal defence strategy’ might be more profitable.
This applies to coasts with a small dune ridge subject to severe erosion. According to this strategy the morphological system
is influenced in such a way that erosion is prevented, which will result in a stable or even an accretion coastline.
The effectiveness of the seaward coastal defence strategy has to be compared with maintenance by beach nourishment. The effects
on the morphological system, the environment and other interests must also be analysed. Several seaward solutions are possible.
In order to gain more insight into the behaviour of these solutions, comparative pilot studies have been executed for the
most vulnerable locations.
This paper gives an overview of the main conclusions of the pilot studies in comparison with sand nourishment, the main coastal
defence measure. 相似文献
719.
Systems of Knowledge: Dialogue, Relationships and Process 总被引:1,自引:0,他引:1
Kenneth Ruddle 《Environment, Development and Sustainability》2000,2(3-4):277-304
During the last 20 years, the existence of rich systems of local knowledge, and their vital support to resource use and management regimes, has been demonstrated in a wide range of biological, physical and geographical domains, such as agriculture, animal husbandry, forestry and agroforestry, medicine, and marine science and fisheries.Local knowledge includes empirical and practical components that are fundamental to sustainable resource management. Among coastal-marine fishers, for example, regular catches and, often, long-term resource sustainment are ensured through the application of knowledge that encompasses empirical information on fish behaviour, marine physical environments, fish habitats and the interactions among ecosystem components, as well as complex fish taxonomies. Local knowledge is therefore an important cultural resource that guides and sustains the operation of customary management systems. The sets of rules that compose a fisheries management system derive directly from local concepts and knowledge of the resources on which the fishery is based.Beyond the practical and the empirical, it is essential to recognise the fundamental socio-cultural importance of local knowledge to any society. It is through knowledge transmission and socialisation that worldviews are constructed, social institutions perpetuated, customary practices established, and social roles defined. In this manner, local knowledge and its transmission, shape society and culture, and culture and society shape knowledge.Local knowledge is of great potential practical value. It can provide an important information base for local resources management, especially in the tropics, where conventionally-used data are usually scarce to non-existent, as well as providing a shortcut to pinpoint essential scientific research needs. To be useful for resources management, however, it must be systematically collected and scientifically verified, before being blended with complementary information derived from Western-based sciences.But local knowledge should not be looked on with only a short-term utilitarian eye. Arguments widely accepted for conserving biodiversity, for example, are also applicable to the intellectual cultural diversity encompassed in local knowledge systems: they should be conserved because their utility may only be revealed at some later date or owing to their intrinsic value as part of the world's global heritage.At least in cultures with a Western liberal tradition, more than lip-service is now being paid to alternative systems of knowledge. The denigration of alternative knowledge systems as backward, inefficient, inferior, and founded on myth and ignorance has recently begun to change. Many such practices are a logical, sophisticated and often still-evolving adaptation to risk, based on generations of empirical experience and arranged according to principles, philosophies and institutions that are radically different from those prevailing in Western scientific circles, and hence all-but incomprehensible to them. But steadfastly held prejudices remain powerful.In this presentation I describe the 'design principles' of local knowledge systems, with particular reference to coastal-marine fishing communities, and their social and practical usefulness. I then examine the economic, ideological and institutional factors that combine to perpetuate the marginalisation and neglect of local knowledge, and discuss some of the requirements for applying local knowledge in modern management. 相似文献
720.
Natural environment has endured fast economic growth population explosion sine the th century which has soil erosion land desertification ozone layer depletion bio-diversity reduction persistent toxic harmful pollutants are among the major environmental challenges.…… 《环境科学学报(英文版)》2007,19(4):469
Natural environment has endured fast economic growth and population explosion sine the 20th century,which has soil erosion,land desertification,ozone layer depletion,bio-diversity reduction and persistent toxic and harmful pollutants are among the major environmental challenges. 相似文献