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381.
基于3S技术,利用2011和2015年2期不同时相高分辨率QuickBird影像和DEM数据,研究了广东石门台国家级自然保护区及毗邻区域“假林线”的时空变化特征。结果表明:1)该区域“假林线”分布的海拔介于317~1 569 m,其中80%集中分布在700~1 200 m的范围内。2)与2011年相比,2015年“假林线”在不同坡度和坡向上分布的平均海拔总体呈上升趋势,但变化不显著(P>0.1)。3)“假林线”主要分布在5°~35°的坡度,极少出现在<2°的平地或>55°的垂直坡上。不同坡向“假林线”海拔分布存在很大差异(P<0.001),呈现出北坡高于南坡,东坡略高于西坡的特点。各坡向上“假林线”海拔分布的最大值出现在西北坡,最小值出现在南坡。 相似文献
382.
To explore the characteristics of plant calcium(Ca) fraction, we analyzed 91 plant species in the Ningxia Habahu National Nature Reserve in Yanchi County of Ningxia and 84 plant species in Zhenglan Banner of Inner Mongolia. Results show that, for the two regions, there is no significant difference between Ca fraction for the same growth type, and between water soluble Ca content or between hydrochloric acid soluble Ca content for plants of the same ecosystem and between hydrochloric acid soluble Ca content for plants of the same family. In similar vegetation zones, there is a significant difference among hydrochloric acid soluble Ca content for different growth types in Yanchi County and Zhenglan Banner,which was the highest for annual herbs and the lowest for perennial herbs. There is a significant difference between acetic acid soluble Ca content and between hydrochloric acid soluble Ca content for sandy land and grassland ecosystems in Yanchi County. There is a significant difference among the same Ca fraction of different families in the same region. Thus, the characteristics of plant Ca fraction are results of long-term adaptation to the environment. 相似文献
383.
中国自然保护区建设已有近60年的历史,并成为我国最有效的保护生物多样性网络。如何对已建自然保护区,特别是快速演变的湿地类型自然保护区的保护成效进行评估已成为我们面临的最紧迫任务之一。中国人与生物圈国家委员会对其认定的保护区开展评估已有多年,但政府部门和学术界对此知之甚少。以中国人与生物圈国家委员会对以盐城世界生物圈保护区十年评估为案例,介绍了该组织对自然保护区保护成效评估方式与过程、特点,提出了我国湿地自然保护区今后如何开展保护成效评估的3点启示:1我国自然保护区事业必需转型到重建设和保护成效的新阶段;2对保护对象的科学研究和长期监测是提高保护成效的重要基础;3要特别重视滨海湿地的保护。 相似文献
384.
Mangrove species compositions and distributions are essential for conservation and restoration efforts. In this study, hyperspectral data of EO-1 HYPERION sensor and high spatial resolution data of SPOT-5 sensor were used in Mai Po mangrove species mapping. Objected-oriented method was used in mangrove species classification processing. Firstly, mangrove objects were obtained via segmenting high spatial resolution data of SPOT-5. Then the objects were classified into different mangrove species based on the spectral differences of HYPERION image. The classification result showed that in the top canopy, Kandelia obovata and Avicennia marina dominated Mai Po Marshes Natural Reserve, with area of 196.8 ha and 110.8 ha, respectively, Acanthus ilicifolius and Aegiceras corniculatum were mixed together and living at the edge of channels with an area of 11.7 ha. Additionally, mangrove species shows clearly zonations and associations in the Mai Po Core Zone. The overall accuracy of our mangrove map was 88% and the Kappa confidence was 0.83, which indicated great potential of using hyperspectral and high-resolution data for distinguishing and mapping mangrove species. 相似文献
385.
In this paper, we propose a decision tree algorithm to characterize spatial extent and spectral features of invasive plant species (i.e., guava, Madagascar cardamom, and Molucca raspberry) in tropical rainforests by integrating datasets from passive and active remote sensing sensors. The decision tree algorithm is based on a number of input variables including matching score and infeasibility images from Mixture Tuned Matched Filtering (MTMF), land-cover maps, tree height information derived from high resolution stereo imagery, polarimetric feature images, Radar Forest Degradation Index (RFDI), polarimetric and InSAR coherence and phase difference images. Spatial distributions of the study organisms are mapped using pixel-based Winner-Takes-All (WTA) algorithm, object oriented feature extraction, spectral unmixing, and compared with the newly developed decision tree approach. Our results show that the InSAR phase difference and PolInSAR HH–VV coherence images of L-band PALSAR data are the most important variables following the MTMF outputs in mapping subcanopy invasive plant species in tropical rainforest. We also show that the three types of invasive plants alone occupy about 17.6% of the Betampona Nature Reserve (BNR) while mixed forest, shrubland and grassland areas are summed to 11.9% of the reserve. This work presents the first systematic attempt to evaluate forest degradation, habitat quality and invasive plant statistics in the BNR, and provides significant insights as to management strategies for the control of invasive plants and conversation in the reserve. 相似文献
386.
387.
防潮堤坝对山东昌邑滨海湿地植物及土壤性质的影响分析 总被引:2,自引:2,他引:0
为研究防潮堤坝对滨海湿地植物及土壤性质的影响,本研究在昌邑国家级海洋生态特别保护区内,通过样线法进行野外调查采样,进行防潮堤坝内外土壤、植被以及两者之间联系的分析,研究了堤坝内外植被及土壤性质差异。结果表明:堤坝内外土壤、植被有一定的差异;堤坝外部土壤C、N、P含量小于堤坝内部,堤坝外部土壤盐度大于堤坝内部;堤坝外部是以盐地碱蓬(Suaeda salsa)和獐毛(Aeluropus sinensis)为主滨海湿地景观,堤坝内部则是以柽柳(Tamarix chinensis)为主的灌草丛景观;保护区内物种丰富度与土壤盐度值呈负相关关系,随着盐度的升高,堤坝外部物种丰富度低于堤坝内部;芦苇(Phragmites australis)体内TC、TN、TP及C︰N︰P与土壤C、N、P含量及C︰N︰P没有明显相关性,而柽柳体内N含量与土壤P含量呈明显负相关关系,说明木本植物比草本植物更加依赖土壤中营养元素的供给。 相似文献
388.
对连古城自然保护区不同降雨梯度(不截留和分别截留30%、50%、80%)下荒漠典型植被土壤无机氮和原位净氮矿化的凋落物分解和养分释放进行了连续的观测分析.结果表明:(1)随着水分输入减少,凋落物的分解速率减小,凋落物分解速率与年降水量正相关.与此相反,净氮矿化与降水量无关.(2)土壤NO3-浓度随着降水输入的增加而显著... 相似文献