基于样带的唐古特白刺灌丛沙包空间格局尺度研究

Spatial pattern of Nitraria Tangutorum shrub islands based on transect

黄河河岸与库布齐沙漠之间生态过渡带上的唐古特白刺(Nitraria Tangutorum)灌丛沙包由于遭受到不同程度的破坏而表现出一定程度的退化,空间格局尺度从一定程度上表征了其破碎化程度。我们分别应用样方方差法,小波分析,分维,谱分析以及空隙度分析等方法对鄂尔多斯高原北缘唐古特白刺灌丛沙包的空间格局尺度进行了比较研究,旨在选出适合分析干旱半干旱区白刺灌丛沙包空间格局尺度的方法,并确定研究区内唐古特白刺灌丛沙包的空间格局尺度,为保护唐古特白刺灌丛沙包提供科学依据。结果表明:(1)TTLQV法得到的格局尺度过大,而小波分析得到的格局尺度过小,分维分析得到的格局尺度除了相对较小之外,趋势也不明显,因此都不适合分析干旱半干旱区白刺灌丛沙包的空间格局尺度;(2)而3TLQV,tQV,谱分析和空隙度分析所得到的结果则相对容易接受,其大小顺序是:3TLQV>tQV>空隙度分析>谱分析;(3)独贵塔拉、呼和木独和巴拉贡唐古特白刺灌丛沙包的空间格局尺度分别为16.7～27.1 m,10.2～25.0 m和8.8～17.0 m,这一结果将有助于在今后的研究中合理地确定研究范围和尺度。

The Nitraria tangutorum shrub islands, which locate on the ecotone between the bank of Yellow River and the Kubuqi Desert, were degraded to a certain extent because of various damages. The degree of this fragmentation can be indicated by their spatial pattern. We used TTLQV, 3TLQV, tQV, wavelets, fractal dimension, spectral analysis and lacunarity analysis to analyze the spatial pattern of the Nitraria tangutorum shrub islands in north of Ordos Pleateu. Our goal was to choose the best method to analyze the spatial pattern of Nitraria tangutorum shrub islands in arid and simi-arid region and to determine the scale of the Nitraria tangutorum shrub islands in our study area, and then to provide scientific information for protection of Nitraria tangutorum shrub islands. After analyzing the continuous quadrat data by different methods, we can get the following results： 1） The scale value analyzed by TTLQV was too big and was too small by wavelets analysis, and the trend of the results analyzed by fractal dimension was not clear except too small. So TTLQV, wavelets and fractal dimension were not fit to analyze the spatial pattern of the shrub islands in arid and semi-arid region. 2） The results analyzed by 3TLQV, tQV, spectral analysis and lacunarity analysis were ideal, and the order of the scale value from these methods was： 3TLQV〉 tQV〉 lacunarity analysis 〉 spectral analysis. 3） Integrating the valid analysis methods, the scale of the spatial pattern of the Nitraria tangutorum shrub islands in Duguitala, Huhemudu and Balagong were about 16.7-27.1 m, 10.2-25.0 m and 8.8-17.0 m respectively. The results will help to determine the study range and the scale of the Nitraria tangutorum shrub islands in future.