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101.
景观演变对野生动物栖息地质量和连接度造成的影响,一直是威胁全球生物多样性保护的关键问题,开展扎龙湿地丹顶鹤(Grus japonensis)繁殖栖息地选择及繁殖期生境间的扩散研究,对野生丹顶鹤的保护具有重要的意义。首先利用需要“出现点”的生态位MAXENT模型,进行适宜栖息地选择研究。从水源、食物、干扰、隐蔽物四个方面选择明水面距离、土壤湿度、NDVI、道路距离和居民地距离五个环境变量作为丹顶鹤繁殖栖息地选择的影响因子,预测扎龙保护区可供丹顶鹤进行营巢繁殖的栖息地分布,并分析各影响因子的反应曲线。结果显示:丹顶鹤易于选择远离道路和居民地干扰且靠近明水面的区域作为营巢栖息地,栖息地土壤湿度较高并且植被覆盖较多。从MAXENT模型中提取了38个适宜栖息地斑块,基于电路理论模拟丹顶鹤繁殖期失去飞行能力时的多路径扩散,最大电流密度图突出了可能的“夹点”,模拟出具有一定宽度范围的连接区域,可供丹顶鹤在繁殖期间进行扩散。累积电流密度图突出了在维持网络连通性方面起到积极作用的斑块,并进行面积加权来评估适宜栖息地斑块的综合重要性。结果表明,在MAXENT模型预测出的适宜栖息地斑块基础上,考虑丹顶鹤繁殖期的迁移扩散行为,利用累积电流密度面积加权来评估适宜栖息地斑块的综合重要性,得到的适宜性等级更符合丹顶鹤真实巢址的分布。研究成果可为保护区丹顶鹤栖息繁殖生境的恢复和保护提供科学依据。 相似文献
102.
Fensham RJ Low Choy SJ Fairfax RJ Cavallaro PC 《Journal of environmental management》2003,68(4):421-436
Accounting of carbon stocks in woody vegetation for greenhouse purposes requires definition of medium term trends with accurate error assessment. Tree and shrub cover was sampled through time at randomly located sites over a large area of central Queensland, Australia using aerial photography from 1945 to 1999. Calibration models developed from field data for the same land types as those represented within the study area allowed for the extrapolation of overstorey and understorey cover, basal area and biomass values and these were modelled as trends over the latter half of the 20th century. These structural attributes have declined over the region because of land clearing with values for biomass changing from a mean of 58.0(+/-1.2)t/ha in 1953 to 41.1(+/-1.0)t/ha in 1991. The biomass of Acacia on clay and Eucalypt on texture contrast soils land types has declined most dramatically. Within uncleared vegetation there was an overall trend of increase from 56.1(+/-1.2)t/ha in 1951 to 67.6(+/-1.3)t/ha in 1995. The increase in structural attributes within uncleared vegetation was most pronounced for the Eucalypt on texture contrast soils and Eucalypt on clay land types. It was demonstrated that the sites sampled were representative of their land types and that spatial bias of the photography, undetected tree-killing, sampling error, inherent variability of structural attributes and measurement error should not have impacted greatly on bias or precision of trend estimates for well-sampled land types. Certainly the errors are not likely to be substantial for trends averaged over all land types and they provide an accurate assessment of the magnitude and direction of change. The technique presented here would appear to be a robust means of accounting for the above-ground woody component of woodlands and open forests and will also contribute to a broader understanding of savanna dynamics. 相似文献
103.
Linnell JD Andersen R Kvam T Andrén H Liberg O Odden J Moa PF 《Environmental management》2001,27(6):869-879
Annual and seasonal home ranges were calculated for 47 Eurasian lynx in four Scandinavian study sites (two in Sweden and two
in Norway). The observed home ranges were the largest reported for the species, with study site averages ranging from 600
to 1400 km2 for resident males and from 300 to 800 km2 for resident females. When home range sizes were compared to the size of protected areas (national parks and nature reserves)
in Scandinavia, it was concluded that very few protected areas contained sufficient forest to provide space for more than
a few individuals. As a direct consequence of this, most lynx need to be conserved in the multiuse seminatural forest habitats
that cover large areas in Scandinavia. This conservation strategy leads to a number of conflicts with some land uses (sheep
and semidomestic reindeer herding, and roe deer hunters), but not all (forestry and moose harvest). Accordingly research must
be aimed at understanding the ecology of these conflicts, and finding solutions. 相似文献
104.
Managers need measurements and resource managers need the length/width of a variety of items including that of animals, logs,
streams, plant canopies, man-made objects, riparian habitat, vegetation patches and other things important in resource monitoring
and land inspection. These types of measurements can now be easily and accurately obtained from very large scale aerial (VLSA)
imagery having spatial resolutions as fine as 1 millimeter per pixel by using the three new software programs described here.
VLSA images have small fields of view and are used for intermittent sampling across extensive landscapes. Pixel-coverage among
images is influenced by small changes in airplane altitude above ground level (AGL) and orientation relative to the ground,
as well as by changes in topography. These factors affect the object-to-camera distance used for image-resolution calculations.
‘ImageMeasurement’ offers a user-friendly interface for accounting for pixel-coverage variation among images by utilizing
a database. ‘LaserLOG’ records and displays airplane altitude AGL measured from a high frequency laser rangefinder, and displays
the vertical velocity. ‘Merge’ sorts through large amounts of data generated by LaserLOG and matches precise airplane altitudes
with camera trigger times for input to the ImageMeasurement database. We discuss application of these tools, including error
estimates. We found measurements from aerial images (collection resolution: 5–26 mm/pixel as projected on the ground) using
ImageMeasurement, LaserLOG, and Merge, were accurate to centimeters with an error less than 10%. We recommend these software packages as a means for expanding
the utility of aerial image data. 相似文献
105.
由于受人类活动干扰的加强以及受与长江干流之间"江湖关系"变化的影响,近年来鄱阳湖水生生态系统的状况及变化受到较多关注。对底栖动物群落结构的研究将有助于了解鄱阳湖生态系统结构现状及影响因子,对鄱阳湖保护对策的制定形成有效支撑。2016年7月,对鄱阳湖湖区(分别于鄱阳湖保护区和南矶山保护区)的底栖动物群落结构及相关环境因子进行了调查。调查共发现大型底栖动物27种,隶属于5门8纲,平均密度为48.40 ind.·m-2,其中主要以软体动物门为主;平均生物量为28.12 g·m-2,亦主要由软体动物门贡献。湖区主要优势种为河蚬(Corbicula fluminea)(优势度y=0.0655)、铜锈环棱螺(Bellamya aeruginosa)(y=0.0336)、霍甫水丝蚓(Limnodrilus hoffmeisteri)(y=0.0268)。底栖动物密度、生物量及多样性指数均呈现出鄱阳湖保护区高于南矶山保护区的格局,且二者在群落组成上有明显差异,鄱阳湖自然保护区主要以腹足纲和寡毛纲为主,南矶山自然保护区主要以瓣鳃纲和腹足纲为主。典范对应分析的结果显示,鄱阳湖保护区主要受到高水深、低浊度及高溶氧的影响;南矶山保护区各样点之间群落相似性较差,分别受不同因子的影响,这表明在各区域内部,局域微生境在局域群落结构的塑造上起主要作用,因此该区域内生态系统的保护应适当考虑空间尺度。 相似文献
106.
Ecotourism in protected areas plays an important role in establishing mutually beneficial relationships among local people, the protected area, and tourism that are essential in protected area management. However, to properly manage protected areas, local people should be major stakeholders in order to maximize local economic benefits and obtain support for conservation efforts. This study assesses the current status of local people's economic participation in tourism in the Wolong Nature Reserve using a questionnaire survey. Through evaluation of geographic origin, income, and occupational distribution of operators engaged in tourism-related business, we identified and discussed constraints and opportunities for economic participation of local people. Economic inequity was found among local people, as well as between locals and non-locals, due to limited startup capital and operational skills. At present, only a small percentage of local people receive revenue directly from tourism. In addition, economic leakage and local dependence on natural resources still exist in the study area. To promote ecotourism and sustainable development, the relationships among tourism, local people, and biodiversity conservation in the study area must be strengthened. According to the findings, some suggestions are offered to protected area managers to foster better relationships. 相似文献
107.
江苏泗洪洪泽湖湿地自然保护区生态服务功能价值评估 总被引:8,自引:0,他引:8
在野外实际调查基础上,运用市场价值、影子工程、旅行费用等方法对江苏泗洪洪泽湖湿地自然保护区生态服务功能进行价值评估.结果显示,该保护区生态服务功能年均总价值约为13.97亿元,占泗洪县2005年国民生产总值的20.82%.重要物种栖息地、水分调节以及大气调节生态服务功能价值分别占总价值的27.49%、25.27%、19.33%,是该保护区的主要核心服务功能.泗洪湿地单位面积生态服务功能价值为28 299元·hm-2·a-1,分别为全球和中国湿地平均单位价值的4.09倍、4.85倍.在发展当地经济过程中,必须从该保护区湿地生态系统的基本特征出发,科学合理地保护、开发湿地资源. 相似文献
108.
应用浮游植物对扎龙自然保护区水质的初步评价 总被引:3,自引:0,他引:3
通过对扎龙自然保护区水体中浮游植物调查及运用几种评价公式分析,评价结论为:扎龙水体浮游植物由8门60个属组成,数量在19 515×10~2~23 755×10~3个/升之间;水质属中污染型,同一年度污染情况为:8月>6月,北区>南区。 相似文献
109.
110.
着重介绍了美国国家海洋自然保护区的监测目标、理论基础、监测内容。监测是掌握海洋自然保护区状况与发展趋势的重要手段,是海洋自然保护区建设与管理的重要工作内容。美国国家海洋自然保护区的保护目的和所保护的资源类型同我国的海洋自然保护区相似。且监测水平与管理机制处于世界领先水平。了解研究美国的先进经验,对促进我国海洋自然保护区的监测工作具有很好的借鉴作用。 相似文献