唐家河自然保护区植被景观梯度变化及其成因

Spatial Variation of Vegetation Landscape of the Tangjiahe Nature Reserve and Its Causes.

以ETM+影像数据为基础,利用景观分析软件Fragstats对唐家河自然保护区植被景观分别从东西、南北、西北至东南3个方向进行空间梯度分析。结果表明,沿东西方向,景观多样性呈现"升—降—升"的波动变化趋势,破碎化程度与复杂度降低;沿北南方向,景观多样性、复杂度以及连接度逐渐下降,但破碎度增加,形状趋于复杂;沿西北至东南方向,景观多样性与复杂度均表现出"降—升—降—升"的波动变化趋势;在西北部至中部斑块邻近度相对较高,变化较为明显;而东南部相对较低,变化幅度小。唐家河自然保护区所处的自然条件是其景观格局梯度变化形成的主要原因和先决条件,植物群落的空间格局明显受水文地貌特征的控制。

Based on ETM＋ remote sensing images,spatial variation of the vegetation landscape of the Tangjiahe nature reserve was analyzed along the gradients from east to west,north to south,and northwest to southeast with the aid of a software,Fragstats.Results show that along the gradient from east to west,diversity of the landscape varies in a saddle pattern,＂up-down-up＂,while its fragmentation degree and complexity decrease.Along the gradient from north to south,diversity,complexity and connectivity of the landscape all decrease,while the landscape becomes more fragmented and more complicated in shape.And along the gradient from northwest to southeast,diversity and complexity of the landscape showed an undulated fluctuation,＂down-up-down-up＂.In the northwest and central parts,plaque neighboring degree is relatively high and varies quite significantly,while in the southeast part,it is low and relatively stable.The natural factors of the Tangjiahe nature reserve are the major causes and prerequisites of the gradient variations of its landscape.The distribution of vegetation communities was obviously governed by its hydrogeological conditions.