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31.
Changes in forest and agricultural land management practices have the potential to increase carbon (C) storage by terrestrial
systems, thus offsetting C emissions to the atmosphere from energy production. This study assesses that potential for three
terrestrial management practices within the state of Virginia, USA: afforestation of marginal agricultural lands; afforestation
of riparian agricultural lands; and changing tillage practices for row crops; each was evaluated on a statewide basis and
for seven regions within the state. Lands eligible for each practice were identified, and the C storage potential of each
practice on those lands was estimated through a modeling procedure that utilized land-resource characteristics represented
in Geographic Information System databases. Marginal agricultural lands’ afforestation was found to have the greatest potential
(1.4 Tg C yr−1, on average, over the first 20 years) if applied on all eligible lands, followed by riparian afforestation (0.2 Tg C yr−1 over 20 years) and tillage conversion (0.1 Tg C yr−1 over 14 years). The regions with the largest potentials are the Ridge and Valley of western Virginia (due to extensive areas
of steep, shallow soils) and in the Mid-Atlantic Coastal Plain in eastern Virginia (wet soils). Although widespread and rapid
implementation of the three modeled practices could be expected to offset only about 3.4% of Virginia’s energy-related CO2 emissions over the following 20 years (equivalent to about 8.5% of a Kyoto Treaty–based target), they could contribute to
achievement of C-management goals if implemented along with other mitigation measures. 相似文献
32.
MATTHEW A. BOWKER MARK E. MILLER JAYNE BELNAP THOMAS D. SISK NANCY C. JOHNSON 《Conservation biology》2008,22(6):1533-1543
Abstract: Conservation prioritization usually focuses on conservation of rare species or biodiversity, rather than ecological processes. This is partially due to a lack of informative indicators of ecosystem function. Biological soil crusts (BSCs) trap and retain soil and water resources in arid ecosystems and function as major carbon and nitrogen fixers; thus, they may be informative indicators of ecosystem function. We created spatial models of multiple indicators of the diversity and function of BSCs (species richness, evenness, functional diversity, functional redundancy, number of rare species, number of habitat specialists, nitrogen and carbon fixation indices, soil stabilization, and surface roughening) for the 800,000‐ha Grand Staircase‐Escalante National Monument (Utah, U.S.A.). We then combined the indicators into a single BSC function map and a single BSC biodiversity map (2 alternative types of conservation value) with an unweighted averaging procedure and a weighted procedure derived from validations performance. We also modeled potential degradation with data from a rangeland assessment survey. To determine which areas on the landscape were the highest conservation priorities, we overlaid the function‐ and diversity‐based conservation‐value layers on the potential degradation layer. Different methods for ascribing conservation‐value and conservation‐priority layers all yielded strikingly similar results (r= 0.89–0.99), which suggests that in this case biodiversity and function can be conserved simultaneously. We believe BSCs can be used as indicators of ecosystem function in concert with other indicators (such as plant‐community properties) and that such information can be used to prioritize conservation effort in drylands. 相似文献
33.
Prioritizing Abandoned Coal Mine Reclamation Projects Within the Contiguous United States Using Geographic Information System Extrapolation 总被引:4,自引:0,他引:4
Coal mine reclamation projects are very expensive and require coordination of local and federal agencies to identify resources for the most economic way of reclaiming mined land. Location of resources for mine reclamation is a spatial problem. This article presents a methodology that allows the combination of spatial data on resources for the coal mine reclamation and uses GIS analysis to develop a priority list of potential mine reclamation sites within contiguous United States using the method of extrapolation. The extrapolation method in this study was based on the Bark Camp reclamation project. The mine reclamation project at Bark Camp, Pennsylvania, USA, provided an example of the beneficial use of fly ash and dredged material to reclaim 402,600 sq mi of a mine abandoned in the 1980s. Railroads provided transportation of dredged material and fly ash to the site. Therefore, four spatial elements contributed to the reclamation project at Bark Camp: dredged material, abandoned mines, fly ash sources, and railroads. Using spatial distribution of these data in the contiguous United States, it was possible to utilize GIS analysis to prioritize areas where reclamation projects similar to Bark Camp are feasible. GIS analysis identified unique occurrences of all four spatial elements used in the Bark Camp case for each 1 km of the United States territory within 20, 40, 60, 80, and 100 km radii from abandoned mines. The results showed the number of abandoned mines for each state and identified their locations. The federal or state governments can use these results in mine reclamation planning. 相似文献
34.
荒山荒地是我省农业的重要后备,本文将主要探讨这部分资源的开发利用及其原则和方向,为发展农业寻求新的途径与措施。 相似文献
35.
Donald W. Floyd 《Environmental management》1988,12(4):457-462
Implementation of a consensus-based management and planning process on three pilot areas has reduced conflicts among interest groups. There are insufficient data to demonstrate biological improvement in range condition on the pilot areas at this time. Economic analysis indicates that recreation values exceed all other resource values in all three pilot areas. 相似文献
36.
Roger B. Hammer Susan I. Stewart Todd J. Hawbaker Volker C. Radeloff 《Journal of environmental management》2009
Rural, forested areas throughout the United States are experiencing strong housing growth with potentially detrimental impacts on the environment. In this paper, we quantify housing growth in Northern Wisconsin over the last sixty years to determine if growth rates were higher near public lands, which may represent an important recreational amenity. We used data from the U.S. Census to produce decadal housing density estimates, “backcasts,” from 1940 to 2000 for northern Wisconsin to examine “rural sprawl” in northern Wisconsin and its relationship to forested areas and public lands. We integrated housing density estimates with the 1992/1993 National Land Cover Dataset to examine the relationship between rural sprawl and land cover, especially forests. Between 1940 and 2000, private land with <2 housing units/km2 decreased from 47% to 21% of the total landscape. Most importantly, housing growth was concentrated along the boundaries of public lands. In 14 of the 19 counties that we studied, housing growth rates within 1 km of a public land boundary exceeded growth rates in the remainder of the county, and three of the five counties that did not exhibit this pattern, were the ones with the least amount of public land. Future growth can be expected in areas with abundant natural amenities, highlighting the critical need for additional research and effective natural resource management and regional planning to address these challenges. 相似文献
37.
Many “natural” areas are exposed to military or recreational off-road vehicles. The interactive effects of different types
of vehicular disturbance on vegetation have rarely been examined, and it has been proposed that some vegetation types are
less susceptible to vehicular disturbance than others. At Fort Riley, Kansas, we experimentally tested how different plant
community types changed after disturbance from an M1A1 Abrams tank driven at different speeds and turning angles during different
seasons. The greatest vegetation change was observed because of driving in the spring in wet soils and the interaction of
turning while driving fast (vegetation change was measured with Bray-Curtis dissimilarity). We found that less vegetation
change occurred in communities with high amounts of native prairie vegetation than in communities with high amounts of introduced
C3 grasses, which is the first experimental evidence we are aware of that suggests plant communities dominated by introduced
C3 grasses changed more because of vehicular disturbance than communities dominated by native prairie grasses. We also found
that vegetation changed linearly with vehicular disturbance intensity, suggesting that at least initially there was no catastrophic
shift in vegetation beyond a certain disturbance intensity threshold. Overall, the intensity of vehicular disturbance appeared
to play the greatest role in vegetation change, but the plant community type also played a strong role and this should be
considered in land use planning. The reasons for greater vegetation change in introduced C3 grass dominated areas deserve further study. 相似文献
38.
Willem Odendaal 《Journal of Land Use Science》2020,15(2-3):457-476
ABSTRACT This paper is about mining under communal ownership which makes this kind of mining a new mining frontier. The newness of the frontier is that it has introduced a series of institutional complexities that is uncommon to artisanal and large-scale mining. Mining companies have to negotiate deals with communities and their leaders to be able to prospect for mineral resources. We also argue that the state’s environmental legislation is poorly harmonised with the prevalent conditions in communal areas where mining is gaining greater importance. Legislation remains silent on the rights of those living on communal land. These rights remain in a state of confusion with often negative effects on the local communities who are exposed to a number of duplicating development programmes and legislative structures. The aim of this paper is to explore the dynamics communal mining in the Kunene Region in north-western Namibia. 相似文献
39.
Matthew Wagner Ronald Kaiser Urs Kreuter Neal Wilkins 《Journal of the American Water Resources Association》2007,43(3):698-711
Abstract: As nearly all of Texas’ rural lands are privately owned, landowner associations for the management of white‐tailed deer and ground‐water have become increasingly popular. Deer are a common‐pool resource with transboundary characteristics, requiring landowner cooperation for effective management. Ground‐water reserves are economically important to landowners, but are governed by the “rule of capture” whereby property rights are not defined. One ground‐water association and four wildlife management associations (WMAs) were surveyed to characterize their member demographics, land use priorities, attitudes, and social capital. Members of the ground‐water cooperative were part of a much larger, more heterogeneous, and more recently formed group than members of WMAs. They also placed greater importance on utilitarian aspects of their properties, as opposed to land stewardship for conservation as practiced by members of WMAs. If ground‐water association members could be more locally organized with more frequent meetings, social capital and information sharing may be enhanced and lead to land stewardship practices for improved hydrologic functions and sustained ground‐water supply. This, coupled with pumping rules assigned by the local ground‐water district, could yield an effective strategy that is ecologically and hydrologicaly sound, and that allows rural provision of water supply to urban consumers. 相似文献
40.
双季稻区冬种覆盖作物对土壤微生物量的影响 总被引:7,自引:1,他引:6
利用氯仿熏蒸浸提法研究了南方双季稻区4种冬季覆盖作物对土壤微生物量碳、氮周年动态的影响.结果表明:冬季种植紫云英(Astragalus sinicus L.)、黑麦草(Lolium multiflroum Lam.)和马铃薯(Solanum tuberosum L.)土壤微生物量碳含量分别为:248.8mg·kg-1、256.7mg·kg-1和238.9mg·kg-1均显著高于冬闲田的218.3 mg·kg-1(P<0.05),增幅为9.43%~17.59%;冬季种植油菜(Brassica campestris L.)土壤微生物量碳比冬闲田提高了0.63%,没有显著性差异.4种覆盖作物土壤微生物量氮含量分别为:紫云英,100.3 mg·kg-1、黑麦草,153.8 mg·kg-1、马铃薯,99.9 mg·kg-1和油菜,86.2 mg·kg-1,均显著高于冬闲田,73.5 mg·kg-1(P<0.05).对比冬闲田,各个覆盖作物均显著提高土壤有机质含量(P<0.05).说明种植冬季覆盖作物可以提高土壤有机质含量和有效养分含量,促进了土壤微生物的活动,有利于保持土壤肥力. 相似文献