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31.
Private landowners play a pivotal role in determining whether or not rare species persist in regions where privately owned
land is extensive. The range of the gopher tortoise (Gopherus polyphemus) is confined to the Southeastern U.S., a region predominantly under private ownership, and thus the status of this species
is largely dependent upon land management decisions made by private landowners. We sent an anonymous mail survey to 2,584
individuals to examine factors affecting gopher tortoise occurrence on private lands in Mississippi (adjusted response rate
of 23%). Few respondents (19%) reported currently having tortoises on their property, although many had them in the past (30%).
Tortoises were persisting primarily on larger properties with longleaf pine that were not managed chiefly for timber production.
In general, respondents were largely unaware of habitat requirements of tortoises or effects of various land management practices
on them, and few reported using management techniques that benefit tortoises, such as prescribed burning. Most respondents
(57%) knew of wildlife incentive programs, but were hesitant to enroll because they did not want to commit to managing their
property in a particular manner (34%). We suggest actions that could improve the likelihood of tortoise persistence in this
region, as well as changes that could be made to incentive programs to increase landowner participation. These suggestions
should be relevant to the conservation of other rare species on private lands in other regions. 相似文献
32.
Coral lipids and environmental stress 总被引:1,自引:0,他引:1
Vicki J. Harriott 《Environmental monitoring and assessment》1993,25(2):131-139
Environmental monitoring of coral reefs is presently limited by difficulties in recognising coral stress, other than by monitoring coral mortality over time. A recent report described an experiment demonstrating that a measured lipid index declined in shaded corals. The technique described might have application in monitoring coral health, with a decline in coral lipid index as an indicator of coral stress. The application of the technique as a practical monitoring tool was tested for two coral species from the Great Barrier Reef. Consistent with the previous results, lipid index for Pocillopora damicornis initially declined over a period of three weeks in corals maintained in filtered seawater in the dark, indicating possible utilization of lipid stored as energy reserves. However, lipid index subsequently rose to near normal levels. In contrast, lipid index of Acropora formosa increased after four weeks in the dark in filtered seawater. The results showed considerable variability in lipid content between samples from the same colony. Results were also found to be dependent on fixation times and sample weight, introducing potential error into the practical application of the technique. The method as described would be unsuitable for monitoring environmental stress in corals, but the search for a practical method to monitor coral health should continue, given its importance in coral reef management. 相似文献
33.
The contingent rewards subscale of the Multifactor Leadership Questionnaire (MLQ) was examined in an attempt to theoretically explain recent empirical results linking contingent rewards to transformational rather than transactional leadership. In Study 1, we supported the proposal that the items in the contingent rewards subscale represented two separate factors, an explicit and an implicit psychological contract. In addition, the implicit factor loaded with other transformational subscales and the explicit factor loaded with other transactional subscales. We confirmed these results in Study 2, and supported other hypotheses from transformational leadership theory using the contingent rewards revision. Implications for the transformational leadership construct are discussed. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
34.
Harriott VJ 《Ambio》2003,32(2):130-133
The international trade in corals has been identified as a potential cause of localized depletion of coral populations in the major coral-exporting countries. The international coral trade is regulated by the Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES) agreement, which requires that export of corals is not detrimental to the species. The primary coral importing regions (USA and Europe) have threatened to limit or ban coral imports unless sustainable practices can be demonstrated. The spatial and temporal scale at which sustainability is defined is important in evaluating sustainability, e.g. at geological, regional or local scales. Other major issues are: the ecology of the target species; management options including provision of no-take areas; and the potential for coral culture. Implementation of practices that enhance ecological sustainability in the coral harvest fishery is possible, but may be difficult in some developing countries because of limited natural-resource management capacity. 相似文献