Influence of topographic factors on plant diversity and spatial distribution of karst around FAST

Abstract

To explore the influence of topographic factors on the diversity and spatial distribution of plant species around FAST (Five-hundred-meter Aperture Spherical radio Telescope), three typical plant communities (tree layer, shrub layer, vine layer) in the karst peak-cluster depression around FAST were selected as the study objects, and ANOVA and canonical correspondence analysis (CCA) were used to investigate the species diversity and spatial distribution of plant communities under different topographic factors (altitude, slope, aspect, and gradient). The results were as follows: (1) The α-diversity index of plant communities around FAST showed a trend of shrub layer > tree layer > vine layer, and the α-diversity index of plants in the tree layer and vine layer increased with the increase of altitude (P<0.05), while the topographic factor had no significant effect on the α-diversity of plants in shrub layer. (2) The spatial distribution of plant community species around FAST was most influenced by the altitude, followed by the slope (P<0.05). (3) The Jaccard similarity index above 70% was extremely dissimilar and moderately dissimilar at altitude and slope gradients. The Jaccard similarity index of the three plant communities tended to increase with the increase of altitude and then decrease along the increase of the slope around FAST. In summary, species differed in their habitat selection, and altitude and slope are key factors affecting the spatial distribution of plant communities in the karst depressions around FAST. Species diversity can better reflect the differences in plant communities in terms of species composition. Species diversity is not only influenced by topographic factors, but also related to biotic and abiotic factors, such as temperature, precipitation, human activities, and functional plant traits. Therefore, corresponding environmental factors need to be added in future studies to further investigate the intrinsic mechanisms of plant species diversity and species spatial distribution at the regional scale and to strengthen the ecological protection of the surrounding area, improve the forest composition, and provide a good natural environment around FAST and in the karst peak-cluster depression.

Keywords

• karst peak-cluster depression
• topographical factor
• species diversity
• spatial distribution
• fast