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Frederic O. Sargent Philip R. Berke E. Bennette Henson 《Journal of the American Water Resources Association》1979,15(2):496-505
ABSTRACT: Six new techniques have been developed for lake watershed analysis and water resource management. The techniques are for determining: (1) watershed land use intensity with reference to water quality, (2) lake vulnerability, (3) water quality, (4) watershed carrying capacity, (5) the economic value of the lake, and (6) the potential of undeveloped lake-shore. These analyses are designed for use by rural planning commissions with guidance and assistance from state agencies and the state university. The comprehensive rural watershed land and water use plan developed by this procedure is inexpensive in time and money, understandable by the layman, and scientificially sound. It is based on presently available information. This water resource planning procedure has been demonstrated in several town planning projects. It is suggested that this method, or modification of it, could be adopted in all rural states by action by a few administrators and without any new enabling or appropriations legislation. 相似文献
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Philip D. Gardner Hanna J. Cortner Keith F. Widaman Kathryn J. Stenberg 《Environmental management》1985,9(4):303-311
The formulation and implementation of new fire policies in the national forests depend upon public acceptance. A national survey of organized groups of forest users indicates that, contrary to the concern of many forest managers, considerable support exists for flexible fire suppression policies. Forest users are also willing to accept the risk associated with the manager's use of prescribed fire. However, important intergroup differences do exist. Such variation is discussed in relation to a number of socioeconomic variables, general fire knowledge, specific knowledge about the effects of low-intensity fires, and risk preference levels. 相似文献
878.
Philip M. Fearnside 《Mitigation and Adaptation Strategies for Global Change》2009,14(6):557-567
Amazonian forest reserves have significant carbon benefits, but the methodology used for accounting for these benefits will
be critical in determining whether the powerful economic force represented by mitigation efforts to slow global warming will
be applied to creating these reserves. Opportunities for reserve creation are quickly being lost as new areas are opened to
deforestation though highway construction and other developments. Leakage, or the effects that a reserve or other mitigation
project provokes outside of the project boundaries, is critical to a proper accounting of net carbon benefits. Protected areas
in the Amazon have particularly great potential mitigation benefits over an extended time horizon. Over a 100-year time frame,
virtually no unprotected forest is likely to remain, meaning that potential leakages (both leakage to the vicinity of the
reserves and that displaced by removing protected areas from the land-grabbing market) should not matter much because any
short-term leakage would be “recovered” eventually. The effect of the value attributed to time greatly influences the impact
of leakage on benefits credited to reserves. Simple assumptions regarding leakage scenarios illustrate the benefits of reserves
and the critical areas where agreement is necessary to make this option a practical component of mitigation efforts. The stakes
are too high to allow further delays in reaching agreement on these issues. 相似文献
879.
On the value of temporary carbon: a comment on Kirschbaum 总被引:1,自引:1,他引:0
Philip M. Fearnside 《Mitigation and Adaptation Strategies for Global Change》2008,13(3):207-210
A recent paper by Miko Kirschbaum (Mitigat Adapt Strategies Glob Change 11(5–6):1151–1164, 2006) argues that temporary carbon (C) storage has “virtually no climate-change mitigation value.” However, temporary carbon has
value in delaying global warming that needs to be recognized in carbon accounting methodologies. The conclusions reached are
very sensitive to any value that is attached to time. Basing analysis exclusively on the maximum temperature reached within
a 100-year time frame ignores other important impacts of global warming that also need to be included when mitigation strategies
are assessed. The relative weightings for long-term versus short-term impacts represent policy choices that result in a greater
or a lesser value being attributed to temporary carbon, but that value should not be zero. Global warming is too formidable
an enemy to allow us the luxury of discarding part of our arsenal in fighting against it. Both reducing fossil-fuel combustion
and increasing biosphere carbon stocks are needed. 相似文献
880.
Living in a “stethoscope”: burrow-acoustics promote auditory specializations in subterranean rodents
Subterranean mammals rely to a great extent on audition for communication and to be alerted to danger. The only hitherto published
report on burrow acoustics revealed that in tunnels of blind mole-rats (Spalax ehrenbergi), airborne sounds of 440 Hz propagated best whereas lower and higher frequencies were effectively attenuated. Morpho-functional
analyses classify the ear of subterranean mammals as a low-sensitivity and low-frequency device. Concordantly, hearing is
characterized by low sensitivity and a restricted frequency range tuned to low frequencies (0.5–4 kHz). Some authors considered
the restricted hearing in subterranean mammals vestigial and degenerate due to under-stimulation. In contrast to this view
stand a rich (mostly low-frequency) vocal repertoire and progressive structural specializations of the middle and inner ear.
Thus, other authors considered these hearing characteristics adaptive. To test the hypothesis that acoustical environment
in burrows of different species of subterranean mammals is similar, we measured sound attenuation in burrows of Fukomys mole-rats (formerly known as Cryptomys, cf. Kock et al. 2006) of two differently sized species at different locations in Zambia. We show that in these burrows, low-frequency sounds (200–800 Hz)
are not only least attenuated but also their amplitude may be amplified like in a stethoscope (up to two times over 1 m).
We suggest that hearing sensitivity has decreased during evolution of subterranean mammals to avoid over-stimulation of the
ear in their natural environment.
We dedicate this work to Mathias Kawalika, who died in March 2006. 相似文献