基于地形因子的森林物种多样性与蓄积量分析

Species Diversity and Stand Volume of Forest Based on Topographical Factors

以凉水国家级自然保护区为例,在群落尺度上,基于激光雷达数据生成高精度DEM,提取主要地形因子坡度、坡向,并对其进行划分,坡度分3级、坡向分为8个,分析不同地形条件下物种多样性与蓄积量的变化。结果表明,东坡、1级坡度物种多样性最低,平均为20.5个/样方;西坡、2级坡度最高,平均为28个/样方。无坡、3级坡度的平均蓄积量最低,为11.77 m3/样方;东南坡、2级坡度最高,为20.38 m3/样方。2级坡度的物种多样性和蓄积量最高,坡向、坡度过大或过小均可引起物种多样性与蓄积量的下降,自北坡沿东坡到西坡,蓄积量呈先升后降趋势。

In community scale, LiDAR data were used to generate high resolution DEM taking Liangshui National Nature Reserve as an example. And several topographic factors, such as slope, aspect and so on, were extracted. The slope and as pects were classified into 3 classes and 8 classes, respectively. Meanwhile, the changes of stand volume and biodiversity were analyzed under different topographic factors. Results showed that the east aspect with first class slope exhibited the lowest biodiversity, with an average of 20.5 per sample; whereas, the west aspect with second class slope displayed the highest biodiversity, averaging 28.0 per sample. The highest average stand volume （20.38 m3 per sample） was observed on the southeast aspect with second class slope, while the lowest one （11.77 m3 per sample） appeared on no aspect with third class slope. The second class slope showed the highest stand volume and biodiversity, which indicates that too small or too large slope and aspect can both result in a decrease in biodiversity and stand volume. The mean stand volume first increased and then decreased from north aspect to east aspect, and then to west aspect.