关于景观的保护问题

景观作为自然与人类相互作用的一个基本单位，目前正在发生剧烈的变化。许多传统的文化建筑和土地利用方式和格局正在走向衰亡，景观的多样性和丰富性受到前所未有的威胁，常常被千篇一律的大片单调的景色所代替。本文主要讨论下列三个问题：景观的基本含义及其保护，景观保护的主要任务；景观保护是区域发展的基础。     

A Spatially Explicit Decision Support Model for Restoration of Forest Bird Habitat

Abstract:  The historical area of bottomland hardwood forest in the Mississippi Alluvial Valley has been reduced by >75%. Agricultural production was the primary motivator for deforestation; hence, clearing deliberately targeted higher and drier sites. Remaining forests are highly fragmented and hydrologically altered, with larger forest fragments subject to greater inundation, which has negatively affected many forest bird populations. We developed a spatially explicit decision support model, based on a Partners in Flight plan for forest bird conservation, that prioritizes forest restoration to reduce forest fragmentation and increase the area of forest core (interior forest >1 km from "hostile" edge). Our primary objective was to increase the number of forest patches that harbor >2000 ha of forest core, but we also sought to increase the number and area of forest cores >5000 ha. Concurrently, we targeted restoration within local (320 km²) landscapes to achieve ≥60% forest cover. Finally, we emphasized restoration of higher-elevation bottomland hardwood forests in areas where restoration would not increase forest fragmentation. Reforestation of 10% of restorable land in the Mississippi Alluvial Valley (approximately 880,000 ha) targeted at priorities established by this decision support model resulted in approximately 824,000 ha of new forest core. This is more than 32 times the amount of core forest added through reforestation of randomly located fields (approximately 25,000 ha). The total area of forest core (1.6 million ha) that resulted from targeted restoration exceeded habitat objectives identified in the Partners in Flight Bird Conservation Plan and approached the area of forest core present in the 1950s.     

Conservation Easements: Biodiversity Protection and Private Use

Abstract:  Conservation easements are one of the primary tools for conserving biodiversity on private land. Despite their increasing use, little quantitative data are available on what species and habitats conservation easements aim to protect, how much structural development they allow, or what types of land use they commonly permit. To address these knowledge gaps, we surveyed staff responsible for 119 conservation easements established by the largest nonprofit easement holder, The Nature Conservancy, between 1985 and 2004. Most easements (80%) aimed to provide core habitat to protect species or communities on-site, and nearly all were designed to reduce development. Conservation easements also allowed for a wide range of private uses, which may result in additional fragmentation and habitat disturbance. Some residential or commercial use, new structures, or subdivision of the property were permitted on 85% of sampled conservation easements. Over half (56%) allowed some additional buildings, of which 60% restricted structure size or building area. Working landscape easements with ranching, forestry, or farming made up nearly half (46%) of the easement properties sampled and were more likely than easements without these uses to be designated as buffers to enhance biodiversity in the surrounding area. Our results demonstrate the need for clear restrictions on building and subdivision in easements, research on the compatibility of private uses on easement land, and greater public understanding of the trade-offs implicit in the use of conservation easements for biodiversity conservation.     

Range-Wide Selection of Catchments for Pacific Salmon Conservation

Abstract:  Freshwater ecosystems are declining in quality globally, but a lack of data inhibits identification of areas valuable for conservation across national borders. We developed a biological measure of conservation value for six species of Pacific salmon ( Oncorhynchus spp.) in catchments of the northern Pacific across Canada, China, Japan, Russia, and the United States. We based the measure on abundance and life-history richness and a model-based method that filled data gaps. Catchments with high conservation value ranged from California to northern Russia and included catchments in regions that are strongly affected by human development (e.g., Puget Sound). Catchments with high conservation value were less affected by agriculture and dams than other catchments, although only 1% were within biodiversity reserves. Our set of high-value areas was largely insensitive to simulated error, although classification remained uncertain for 3% of catchments. Although salmon face many threats, we propose they will be most likely to exhibit resilience into the future if a complementary mosaic of conservation strategies can be proactively adopted in catchments with healthy salmon populations. Our analysis provides an initial map of where these catchments are likely to be located.     

Quantifying forest fragmentation spatial process in the developing State of Selangor,peninsular Malaysia

Forest fragmentation has several phases; thus, the ecological significance of each phase during a particular period of time must be interpreted. To interpret, this study quantifies the magnitude of forest loss and the changes in the temporal pattern of fragmentation in the State of Selangor, peninsular Malaysia. Using the decision tree model of land transformation, five phases of forest fragmentation were identified: perforation, dissection, dissipation, shrinkage and attrition. This analysis showed that the magnitude of forest loss was the highest during the dissipation phase. The patchiness analysis showed that dissipation contributes to the highest environmental uncertainty found for the forest patches. This study can be considered a first step in the exploration of the properties and the behavioural pattern shown by the spatial process of forest fragmentation.     

Modeling Opportunity Costs of Conservation in Transitional Landscapes

Abstract:  Conservation scientists recognize the urgency of incorporating opportunity costs into conservation planning. Despite this, applications to date have been limited, perhaps partly because of the difficulty in determining costs in regions with limited data on land prices and ownership. We present methods for estimating opportunity costs of land preservation in landscapes or ecoregions that are a changing mix of agriculture and natural habitat. Our approach derives from the literature on estimating land values as opportunity costs of alternate land uses and takes advantage of general availability of necessary data, even in relatively data-poor regions. The methods integrate probabilities of habitat conversion with region-wide estimates of economic benefits from agricultural land uses and estimate land values with a discount rate to convert annual values into net present values. We applied our method in a landscape undergoing agricultural conversion in Paraguay. Our model of opportunity costs predicted an independent data set of land values and was consistent with implicit discount rates of 15–25%. Model-generated land values were strongly correlated with actual land values even after correcting for the effect of property size and proportion of property that was forested. We used the model to produce a map of opportunity costs and to estimate the costs of conserving forest within two proposed corridors in the landscape. This method can be applied to conservation planning in situations where natural habitat is currently being converted to market-oriented land uses. Incorporating not only biological attributes but also socioeconomic data can help in the design of efficient networks of protected areas that represent biodiversity at minimum costs.     

Importance of Reserve Size and Landscape Context to Urban Bird Conservation

Abstract:  We tested whether reserve size, landscape surrounding the reserve, and their interaction affect forest songbirds in the metropolitan area of Seattle, Washington (U.S.A.), by studying 29 reserves of varying size (small, medium, large) and surrounding urbanization intensity (urban, suburban, exurban). Larger reserves contained richer and less even bird communities than smaller reserves. These size effects disappeared when we removed the positive correlation of shrub diversity with reserve size, suggesting that greater habitat diversity in large reserves supported additional species, some of which were rare. Standardizing the number of individuals detected among all reserve size classes reversed the effect of size on richness in exurban landscapes and reduced the magnitude of the effect in suburban or urban landscapes. The latter change suggested that richness increased with reserve size in most landscapes because larger areas also supported larger samples from the regional bird species pool. Most bird species associated with native forest habitat (native forest species) and with human activity (synanthropic species) were present in reserves larger than 42 ha and surrounded by >40% urban land cover, respectively. Thus, we recommend these thresholds as means for conserving the composition of native bird communities in this mostly forested region. Native forest species were least abundant and synanthropic species most abundant in urban landscapes, where exotic ground and shrub vegetation was most common. Therefore, control of exotic vegetation may benefit native songbird populations. Bird nests in shrubs were most dense in medium (suburban) and large reserves (urban) and tended to be most successful in medium (suburban) and large reserves (exurban), potentially supplying another mechanism by which reserve size increased retention of native forest species.     

Conserving Biodiversity and Ecosystem Function through Limited Development: an Empirical Evaluation

Abstract:  Suburban, exurban, and rural development in the United States consumes nearly 1 million hectares of land per year and is a leading threat to biodiversity. In response to this threat, conservation development has been advanced as a way to combine land development and land conservation while providing functional protection for natural resources. Yet, although conservation development techniques have been in use for decades, there have been few critical evaluations of their conservation effectiveness. We addressed this deficiency by assessing the conservation outcomes of one type of conservation development project: conservation and limited development projects (CLDPs). Conducted by land trusts, landowners, and developers, CLDPs use revenue from limited development to finance the protection of land and natural resources. We compared a sample of 10 CLDPs from the eastern United States with their respective baseline scenarios (conventional development) and with a sample of conservation subdivisions—a different conservation development technique characterized by higher-density development. To measure conservation success, we created an evaluation method containing eight indicators that quantify project impacts to terrestrial and aquatic ecosystems at the site and in the surrounding landscape. The CLDPs protected and managed threatened natural resources including rare species and ecological communities. In terms of conservation benefits, the CLDPs significantly outperformed their respective baseline scenarios and the conservation subdivisions. These results imply that CLDPs can offer a low-impact alternative to conventional development and a low-cost method for protecting land when conventional conservation techniques are too expensive. In addition, our evaluation method demonstrates how planners and developers can incorporate appropriate ecological considerations when designing, reviewing, and evaluating conservation development projects.     

城市景观生态分类——以深圳市为例

从我国传统城市景观分类出发，在分析城市景观生态特征的基础上，指出理想的城市景观生态分类应当从人地关系出发，充分反映景观中的人类活动方式、人类活动对景观的“干扰”程度以及景观的抗“干扰”能力，并以此为依据，在理论和实践(以深圳为例)上提出了新的分类办法。     

Gaps and Mismatches between Global Conservation Priorities and Spending

Abstract:  Several international conservation organizations have recently produced global priority maps to guide conservation activities and spending in their own and other conservation organizations. Surprisingly, it is not possible to directly evaluate the relationship between priorities and spending within a given organization because none of the organizations with global priority models tracks how they spend their money relative to their priorities. We were able, however, to evaluate the spending patterns of five other large biodiversity conservation organizations without their own published global priority models and investigate the potential influence of priority models on this spending. On average, countries with priority areas received greater conservation investment; global prioritization systems, however, explained between only 2 and 32% of the US$1.5 billion spent in 2002, depending on whether the United States was removed from analyses and whether conservation spending was adjusted by the per capita gross domestic product within each country. We also found little overlap in the spending patterns of the five conservation organizations evaluated, suggesting that informal coordination or segregation of effort may be occurring. Our results also highlight a number of potential gaps and mismatches in how limited conservation funds are spent and provide the first audit of global conservation spending patterns. More explicit presentation of conservation priorities by organizations currently without priority models and better tracking of spending by those with published priorities are clearly needed to help make future conservation activities as efficient as possible.     

乡村景观规划的发展历史及其在我国的发展前景

介绍了国内外乡村景观规划的发展历史 ,阐述了乡村景观规划的内容和特点 ,并简要分析了我国开展乡村景观规划的基础研究和应用的发展趋势 ,指出了应继续完善系统性的理论和方法论上的探讨 ,并对一些重点区域进一步开展典型研究和实践应用 ,以此作为今后研究发展的重点领域。     

城市的景观生态学探讨

城市是一种人为活动影响比较强烈的景观，建筑物和道路组成其比较均质的外观，但其内部的物质流、能量流、人口流及信息流等却非常活跃。本文主要对城市景观的特征、结构和功能进行了分析探讨。     

景观规划与管理及其相关领域研究的新进展

景观规划与管理是景观生态学应用研究的热点,是以景观异质性和景观功能的定量研究为基础,以3S和模型模拟方法为技术支撑的综合性应用领域,它是沟通景观生态学理论研究和实践运用的桥梁。景观规划与管理和景观结构、景观功能与景观动态以及景观尺度、景观过程及景观格局等具有密切的联系,上述方面的相关理论与方法,共同支撑着景观规划与管理的客观实践。景观异质性是景观规划与管理的重要理论基础,景观功能是景观规划与管理的现实目标,景观生态研究方法是景观规划与景观管理的技术保障。20世纪90年代以来,随着学科的交叉与融合,景观规划与管理领域取得了一系列新进展,主要表现在理论、方法和应用方面的研究愈加广泛和深入,景观规划与管理方式也越来越智能化与人性化;景观规划管理的发展也在一定程度上推动了景观异质性、景观功能和景观研究方法的发展。目前,相关学科方法和技术的交叉融合成为研究景观规划与管理的重要趋势,3S和模型交叉融合促进景观规划与管理方法向着多元化、数字化和可视化发展。随着景观规划管理现实应用领域的拓展,景观异质性和景观功能在理论、方法、应用方面的研究进一步深化。     

南宁市景观生态格局现状与改善途径

应用景观生态规划设计原理，通过南宁市景观现状进行分析，提出了改善南宁市景观的基本途径，包括保护自然生态空间，保持地方特色，维持景观生态过程与格局的连续性，建立城市中具有生态功能的廊道等。     

景观生态学在公路景观环境评价中的应用

公路景观环境评价研究是我国公路建设中的新课题，景观生态学的发展为公路景观环境评价研究提供了新理论、方法和技术手段。分析了景观生态学研究内容、方法特点，提出了从景观生态价值、美学质量、视觉容量和景观安全格局4个方面对公路景观环境进行评价，并探讨了具体评价过程，该思想对公路战略环境评价和环境影响后评价也具有启示意义。     

National Responsibilities in European Species Conservation: a Methodological Review

Abstract: One particular challenge in reducing the loss of biodiversity by 2010, as agreed on at the Earth Summit in 2002, is to assign conservation tasks to geographic or administrative entities (e.g., countries or regions) on different geographical scales. To identify conservation tasks, it is imperative to determine the importance of a specific area for the global survival of a species. So far, these national or subnational responsibilities for the conservation of species have been included differently in methods prioritizing conservation. We reviewed how 12 European and 3 non‐European methods determined national conservation responsibilities and evaluated the international importance of a biological population. Different countries used different methodologies, which made a direct comparison of assessments of national responsibilities among countries extremely difficult. Differences existed in the importance criteria used. Criteria included population decline, range reduction, rarity status, degree of isolation of a population, endemism, proportional distribution, and geographic location. To increase comparability, it is imperative to develop criteria for which data are generally available and to standardize the methodology among countries. A standardized method would allow conservation decisions to be based on the conservation status of a species and on the responsibility of a geographic or administrative entity for the survival of a species. We suggest that such a method should use a scalable index of proportional distribution, taxonomic status, and the distribution pattern of a taxon or species as key elements. Such a method would allow for the creation of hierarchical lists and would be highly relevant for parts of the world with multiple political jurisdictions or state unions and for nations with regional governmental structures. Conservation priorities could then be reasonably set by combining national responsibility assessments with the international conservation status of a species.     

广州城市绿地系统景观生态学分析

绿地是城市这个人工景观中最重要的自然要素。以往对绿地的研究主要集中于能量流动等功能方面，很少涉及空间结构，在本文中，将利用景观生态学中的原理和方法，分析广州市绿地景观的异质性，并提出一些建议。     

Conservation Science and Forest Service Policy for Roadless Areas

Abstract:  Questions persist regarding whether the science of conservation biology can successfully affect environmental decision making. One of the most prominent fields of intersection between conservation science and environmental policy is public-lands debates in the United States. I reviewed the role of conservation science in the roadless-area policies of the U.S. Forest Service. Since 1971, the Forest Service has systematically evaluated roadless areas on national forests three times, most recently during the Clinton administration's Roadless Area Conservation Review (1998–2000) ( U.S. Department of Agriculture Forest Service 2000b ). Drawing on the agency's environmental impact statements and supporting documents and the internal records of conservation organizations, I examined the changing goals, methodology, and outcome of roadless-area advocacy and policy. Since the 1970s, conservation science has successfully informed public and administrative concern for roadless-area protection. Conservation science has transformed public discourse regarding roadless areas and has changed the scope and rationale of national conservation organizations' goals for roadless-area policy from protecting some to protecting all remaining national forest roadless areas. The Forest Service has increasingly drawn on the lessons of conservation biology to justify its methodology and its administrative recommendations to protect roadless areas. The 2000 Roadless Area Conservation Review resulted in a recommendation to protect all remaining national forest roadless areas, up from 22% of roadless areas in the first roadless review. Despite the scientific merits of recent roadless-area advocacy and policy, however, such initiatives have faced political difficulties. The emphasis on large-scale, top-down, national approaches to conservation policy has rendered such policies politically problematic.