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101.
以神农架林区木鱼镇茶山上生长的8种不同类型植物为试验材料,于晴天选择其植株上东南朝向的顶部成长叶,采用LI—COR6400便携式光合测定系统、调制叶绿素荧光成像系统(IMAGING-PAMM-Series)及双通道PAM—100测量系统(Dual-PAM-100)和常规方法研究了其叶片特征、光合性能及相互间的关系,将有助于了解神农架植物的光合生产力及其植被管理。结果表明,不同类型植物叶片的叶片特征和光合性能存在明显的物种差异。比叶重(SLW)为乔木〉灌木〉草本;气孔参数以气孔导度(Cond)差异最大;草本植物的光合能力明显高于灌木和乔木,而灌木和乔木间的差异不大;叶绿素含量(Chl)及其组分的差异较小,类胡萝卜素(Car)和花青素含量(Ant)及其与Chl的比值差异极大。不同类型植物叶片特征和光合性能指标的变异系数在7.3%~73.0%间,Chla/Chlb最小,Car/Ant最大;Chla/Chlb、基于叶温的蒸汽压亏缺(VpdL)和胞间C02浓度(Ci)dx于15%,Cond、单位鲜重Car、PSII实际量子产量和PsI非光化学能量耗散的量子产量为40%~50%,单位干重Car、Ant、Chl/Ant和Car/Ant则大于60%,其他指标在20%-40%。相关分析显示,Jpn受Cond、叶片含水量和单位干重Chl的正向调控,Ant和Car对两无决定性作用;PSII和PSI的实际量子产量依赖于ci和Chl,Car过高导致其降低;PSI的光保护受SLW的负调控及单位鲜重Chl和单位干重Car的正调控;光合机构的光损伤受Ci的负调控和Chl/Car的正调控。  相似文献   
102.
Given the increasing expansion of human dominated landscapes it often becomes necessary to relocate endangered and at-risk species from existing habitat areas. Further, there is growing research stating that climatic and atmospheric changes attributed to climate change are already affecting species distributions and geographic ranges, requiring endangered species to be relocated. Existing reserve design models mostly focus on choosing the optimal land area given existing species distributions and have not incorporated species relocation as a criterion. This paper introduces linear integer programming formulations for the relocation of multiple populations of a species at risk to clustered conservation areas. We present a basic clustered relocation model and extend the model to minimize the distances of relocation. We apply the models to a dataset related to Gopher Tortoise (GT), a keystone species currently considered ‘at risk’, at Ft. Benning Georgia where expanding military training needs require the relocation of GTs. We present the results and discuss the trade-off between compactness and relocation considerations using an efficiency frontier.  相似文献   
103.
通过对湖南省绥宁县黄桑坪自然保护区长苞铁杉的种群结构、特定时间生命表、生殖价分析、分布数量与环境因子的关系进行分析.结果表明:(1)种群结构数量具有"中间大,两头小"的特点,为衰退型种群,虽然种群有一定的幼龄个体,但死亡率高,35 a内长苞铁杉的年龄结构模型为:Age(a)=0.002 765(DBH)3-0.128 756(DBH)2+4.120 978(DBH)+13.439 846(R=0.991 2,F=2 654.48);(2)长苞铁杉种群既有r对策特征,又有K对策特征,该种群处于r对策→K对策的过渡阶段;(3)长苞铁杉的累积剩余生殖价(SRRV)和整个生活史的总生殖价(TRV)呈现出逐渐递减的趋势,而生殖投资策略(OREx)在整个生长过程中具有"n"型变化特征,说明长苞铁杉种群有实现生殖与恢复的可能,但能力有限.  相似文献   
104.
Conservation planning is the process of locating and designing conservation areas to promote the persistence of biodiversity in situ. To do this, conservation areas must be able to mitigate at least some of the proximate threats to biodiversity. Information on threatening processes and the relative vulnerability of areas and natural features to these processes is therefore crucial for effective conservation planning. However, measuring and incorporating vulnerability into conservation planning have been problematic. We develop a conceptual framework of the role of vulnerability assessments in conservation planning and propose a definition of vulnerability that incorporates three dimensions: exposure, intensity, and impact. We review and categorize methods for assessing the vulnerability of areas and the features they contain and identify the relative strengths and weaknesses of each broad approach. Our review highlights the need for further development and evaluation of approaches to assess vulnerability and for comparisons of their relative effectiveness.  相似文献   
105.
In 1979, the Pinelands Commission was established as a regional land-use planning and regulatory agency charged with the implementation of a Comprehensive Management Plan (CMP) for the Pinelands National Reserve (New Jersey, USA). The CMP was created to balance land preservation and development interests in the Reserve. Because water-quality degradation from developed and agricultural landscapes is associated with changes in the composition of biological communities, monitoring landscape changes provides one of the most direct measures of the impact of land-use policies on the Pinelands ecosystem. In this study, we prepared detailed, land-cover maps within randomly selected aerial-photograph plots for a major watershed in the Reserve. We used these land-cover maps to quantify changes in landscape composition and structure (i.e., patch size, patch area, and number of patches) and characterize land-cover transitions in the basin between 1979 and 1991. Because the study period represented the first 12 years of the regional-planning effort in the Reserve, we evaluated the relationship between land-cover transitions and Commission management-area designations which permit different land-use intensities. Although the landscape composition was similar in 1979 and 1991, we found an increase in the total area and number of developed-land, managed-grassland, and barren-land patches. An increase in the number of patches and a decrease in the total area and median and third-quartile patch sizes for forest land and for all patches regardless of cover type indicated that fragmentation of forest land and the landscape as a whole occurred during the study period. The major land-cover transitions that occurred during the period were the loss of forest land to development and associated cover types and the conversion of one agricultural type to another. Overall, land-cover transitions during the period were found to be consistent with the Commission management-area designations, which indicated that the regional-planning effort has been successful in directing human activities to appropriate areas of the basin.  相似文献   
106.
Fuzzy assessment of land suitability for scientific research reserves   总被引:1,自引:0,他引:1  
Evaluating the characteristics of a set of sites as potential scientific research reserves is an example of land suitability assessment. Suitability in this case is based upon multiple criteria, many of which can be linguistically imprecise and often incompatible. Fuzzy logic is a useful method for characterizing imprecise suitability criteria and for combining criteria into an overall suitability rating. The Ecosystem Management Decision Support software combined a fuzzy logic knowledge base we developed to represent the assessment problem with a GIS database providing site-specific data for the assessment. Assessment of sites as a potential natural reserve for the new University of California campus at Merced demonstrates the benefits of fuzzy suitability assessment. The study was conducted in three stages of successively smaller assessment regions with increasingly fine spatial resolution and specificity of criteria. Several sites were identified that best satisfy the suitability criteria for a reserve to represent vernal pool habitat.  相似文献   
107.
袁涛  刘胜祥  徐海洋  卢少飞 《四川环境》2006,25(3):31-34,54
基于梁子湖自然保护区1987年和2004年Landsat-TM影像遥感数据,在Erdas Imagine 8.5图像处理软件的支持下,结合野外实地考察,获得了土地利用现状图,通过对数据的统计分析,研究了保护区近20年来土地利用/土地覆盖的动态变化。研究表明:耕地和水域是保护区内的主要土地利用类型;近20年来,耕地、园地、林地、草地的面积都有减少,其中耕地面积减少了2320.816hm^2,减少比例达到11.78%,是面积减少最多的土地利用类型;居民点、交通、水域用地有所增加,其中池塘面积变化最大,增幅达到213.4%,是面积增加最多的土地利用类型,居民点用地增加了551.18hm^2,增幅达到59.07%,是增长幅度较大的土地利用类型。变化的原因主要是经济的发展、人口数量的增长和旅游业的发展。  相似文献   
108.
Economic theory asserts that to achieve maximum conservation benefits land acquisition needs to be cost effective. Yet the most common planning technique used by land conservation organizations is ‘benefit-targeting’ that focuses only on acquiring parcels with the highest benefits and ignores costs. Unlike most of the literature which focuses on covering problems, this research applies optimization techniques to achieve maximum aggregate conservation benefits for an ongoing land acquisition effort in the Catoctin Mountain Region in central Maryland. For this case study, optimization yields additional conservation benefits worth an estimated $3.1–$3.9 million or achieves the same level of conservation benefits but at a cost savings ranging from $0.9 to $3.5 million, depending on the initial budget size. Finally, the highest efficiencies are achieved in low budget scenarios, like those most prevalent in conservation efforts.  相似文献   
109.
辉河湿地国家自然保护区生态系统健康评价   总被引:5,自引:2,他引:3  
在RS和GIS技术的支持下,以1975和2006年两期遥感影像为信息源,从生态系统空间范围和服务功能价值变化的角度对呼伦贝尔辉河草原湿地国家级自然保护区的生态系统健康状况进行了分析.结果表明,1975~2006年间辉河湿地自然保护区的草原和湖泊面积分别减少了7346和2731hm2,湿地和干涸湖面积分别增加了6877和2953 hm2.从自然保护区的核心——湿地生态系统的斑块格局变化来看,1975~2006年间斑块密度增加了74.48个.hm-2,斑块连通度在100~300m的阈限值范围内呈减少的趋势,平均减少0.069±0.038.基于生态系统服务价值的评价结果表明,1975~2006年间辉河湿地国家自然保护区生态系统达到健康水平以上的区域面积为323215 hm2,占保护区面积的93.31%,生态系统较差和恶劣区的面积为23177 hm2,占总面积的6.69%.研究区的总生态价值盈余为8.8×107元,其盈余主要来源于草原向湿地的转化、水体向湿地的转化及干涸湖向草原的转化.  相似文献   
110.
云南西双版纳纳板河自然保护区药用苔藓植物调查研究   总被引:1,自引:0,他引:1  
对纳板河流域国家级自然保护区药用苔藓植物资源进行了初步调查研究,结果表明:纳板河流域自然保护区共有药用苔藓植物18种,隶属11科15属,约占全国药用苔藓植物总数的31%;记述了纳板河保护区药用苔藓植物的分布及药用功能,提出了合理性开发利用的思路。  相似文献   
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