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531.
Radioactive contamination of agricultural land may necessitate long-term changes in food production systems, through application
of selected countermeasures, in order to reduce the accumulation of radionuclides in food. We quantified the impact of selected
countermeasures on habitat diversity, using the hypothetical case of two agricultural areas in Finland. The management scenarios
studied were conversions from grassland to cereal production and from grassland and crop production to afforestation. The
two study sites differed with respect to present agricultural production: one being predominantly cereal production and seminatural
grasslands, while the other was dominated by intensive grass and dairy production. Some of the management scenarios are expected
to affect landscape structures and habitat diversity. These potential changes were assessed using a spatial pattern analysis
program in connection with geographic information systems. The studied landscape changes resulted in a more monotonous landscape
structure compared to the present management, by increasing the mean habitat patch size, reducing the total habitat edge length
and reducing the overall habitat diversity calculated by the Shannon diversity index. The degree of change was dependent on
the present agricultural management practice in the case study sites. Where dairy production was predominant, the landscape
structure changes were mostly due to conversion of intensive pastures and grasslands to cereal production. In the area dominated
by cereal production and seminatural grasslands, the greatest predicted impacts resulted from afforestation of meadows and
pastures. The studied management changes are predicted to reduce biodiversity at the species level as well as diminishing
species-rich habitats. This study has predicted prominent side effects in habitat diversity resulting from application of
management scenarios. These potential long-term impacts should be considered by decision-makers when planning future strategies
in the event of radionuclide deposition. 相似文献
532.
Assessing Landscape Health: A Case Study from Northeastern Italy 总被引:17,自引:0,他引:17
Bertollo P 《Environmental management》2001,27(3):349-365
This article investigates the concept of biophysical landscape health for what are termed “highly governed landscapes.” It
proposes a definition of landscape health along with a preliminary diagnostic model and methods. The idea of landscape health
derives from the emerging integrative science of ecosystem health, which seeks to diagnose ecosystem condition as humans diagnose
human health. Highly governed landscapes, such as the reclaimed areas of coastal northeastern Italy, are landscapes that have
been subject to even greater degrees of human manipulation than normal cultural landscapes. These highly altered landscapes
are not easily served by existing environmental paradigms and concepts of health are seen to have numerous advantages. This
paper condenses a broader investigation of landscape health into three main sections. A brief review of the literature is
followed by a case study, which details two different phases of landscape transformation in the Lower Piave area of northeastern
Italy. A definition and general parameters of biophysical landscape health are then presented after this background stage.
Some key parameters of biophysical health include absence of distress and risk factors, sustainability, biodiversity, resilience,
and balance. For certain parameters, a preliminary landscape health diagnostic framework is presented that includes potential
diagnostic methods and thresholds based on findings from this case study. At the paper's conclusion, a summary diagnostic
model is presented, which suggests a process needed to implement landscape health assessment into practice. 相似文献
533.
Gerard McMahon Thomas F. Cuffney 《Journal of the American Water Resources Association》2000,36(6):1247-1261
ABSTRACT: Three investigations are underway, as part of the U.S. Geological Survey's National Water‐Quality Assessment (NAWQA) Program, to study the relation between varying levels of urban intensity in drainage basins and in‐stream water quality, measured by physical, chemical, and biological factors. These studies are being conducted in the vicinities of Boston (Massachusetts), Salt Lake City (Utah), and Birmingham (Alabama), areas where rapid urbanization is occurring. For each study, water quality will be sampled in approximately 30 drainage basins that represent a gradient of urban intensity. This paper focuses on the methods used to characterize and select the basins used in the studies. It presents a methodology for limiting the variability of natural landscape characteristics in the potential study drainage basins and for ranking the magnitude of human influence, or urbanization, based on land cover, infrastructure, and socioeconomic data in potential study basins. Basin characterization efforts associated with the Boston study are described for illustrative purposes. 相似文献
534.
河北省可持续农业发展中上土地生态环境约束及对策 总被引:3,自引:0,他引:3
钱金平 《中国人口.资源与环境》2001,11(2):94-96
本文论述了河北省土地生态环境存在的水土流失、土地沙化、土地盐碱化、土地干旱化、土地污染等主要问题及其对农业生产的影响,提出了保护和整治土地生态环境,保证可持续农业发展相应对策。 相似文献
535.
A. Begossi 《Regional Environmental Change》2001,2(1):1-12
This study analyzes the fishing areas or spots used by artisanal fishers of the Atlantic Forest coast. Fishers include inhabitants
of islands of the SE Atlantic Forest in Brazil. Data on fish landings were collected for different islands, in 1986 and 1989–1990,
for species caught, technology used and fishing time. Fishing spots were marked or rechecked using GPS in 1997–1999. Fishing
is performed in paddled, motorized canoes or in small boats with set gillnets or hook and line. Marine animals caught vary
from place to place and include fish, shrimp, squid and crab. Spots used are very stable in time, since they did not change
for about 10 years. Among other factors, technology limits the range of access of the fishers to the spots. An informal division
of fishing areas or spots is observed, based on the locality of residence of the fishers. The mapping and observed division
of fishing spots may be used in local management, helping to control the intrusion of industrial fishers in artisanal areas.
Local rules and discrimination of spot users may be helpful for artisanal fishers, especially in areas where conflicts with
trawlers occur. The observed long-term stability of the use of fishing spots by artisanal fishers and conflicts with other
users indicate the urgency of considering local rules for conservation purposes in Atlantic Forest coastal areas.
Electronic Publication 相似文献
536.
E. A. Platonova 《Russian Journal of Ecology》2001,32(6):375-381
The distribution of tree species in the landscape was studied using the approach based on the comparison of the ecological requirements of species and the properties of ecotopes distinguished by their position in the relief and peculiarities of basement rocks. The types and specificity of ecological regimes were determined for the typical ecotopes of the southern Karelian ridge landscape. The main environmental and successional factors determining the distribution of seven forest-forming tree species in the ecotopes of this landscape were identified. The results of this work can provide a basis for the prognosis of forest vegetation in the landscape studied. 相似文献
537.
The state of gonads was analyzed in sea urchins Strongylocentrotus intermediuscollected in Amur Bay (Peter the Great Bay, the Sea of Japan) in August 1984, 1985, 1989, and 1997 at five stations: Skrebtsov Island (1), Sportivnaya Harbor (2), Cape Tokarevskii (3), Alekseev Bay on Popov Island (4), and Verkhovskii Islands (5). The first three stations were in the polluted inshore zone of Vladivostok; stations 4 and 5 were in the open (insular) part of the bay, remote from the main sources of pollution. The state of gonads of sea urchins collected in different years and areas strongly varied with respect to gonad index (GI), gonad maturity index, and indices of pathological changes in gonads. As compared with the data obtained in 1984, 1985, and 1989, the values of GI increased in sea urchins from stations 1–3 and decreased in sea urchins from stations 4 and 5. Although GI values were high, the indices of gonad maturity in animals from the coastal zone were very low. In general gonad maturity in sea urchins from the Amur Bay was lower in 1997 than in the previous years. The correlation analysis of long-term data revealed no positive correlation between the values of GI and gonad maturity index in sea urchins from stations 1–4. Histopathological changes were more serious in sea urchins from stations 1–3. In 1997, the indices of pathological changes in the gonads of sea urchins from the insular zone (stations 4 and 5) were higher than in the previous period (1984–1989). The influence of various ecological factors—temperature, salinity, environmental pollution, and food supply—on gametogenesis in sea urchins is discussed. 相似文献
538.
国外生态工业研究概况 总被引:16,自引:0,他引:16
生态工业园是人类探索经济发展新途径的产物,它可使社会经济,环境和人类的需求三之间达到平衡,是工业生态学的一个重要研究领域。本对丹麦卡隆堡工业共生体,生态工园的定义,生态工业的发展模式,国外一些生态工业园的特征及研究情况等作了简要的介绍。 相似文献
539.
初论新疆环境域类型特征及对策 总被引:1,自引:0,他引:1
在进行环境保护时,首先必须对环境进行域类型划分,然后对划分的环境域特征以及它们之间的相互制约、影响的关系进行研究,并确定对不同的环境域采用不同的措施和对策,以达到环境保护的目的。本文初次对新疆的环境域进行了划分,在此基础上,对其特征及其相互关系进行了初步研究,最后提出了防治和保护不同环境域的措施及对策。 相似文献
540.
Joan Iverson Nassauer Sandra E. Kosek Robert C. Corry 《Journal of the American Water Resources Association》2001,37(6):1439-1443
ABSTRACT: Appearances matter for managing riparian landscapes because the appearance of landscapes affects public willingness to accept plans and designs that improve ecological quality. Riparian landscape design and planning should respect and strategically incorporate characteristics that the public values and expects to see. Such design can be quite novel in its ecological effects, but it also should be sufficiently familiar in appearance to correspond with cultural values. This paper describes some influential cultural values for riparian landscapes and demonstrates how attention to such values supports public acceptance of ecologically innovative design in rural and urban watersheds. 相似文献