Abstract:

Spatial patterns of species richness and mechanism are vital to biodiversity conservation. Based on the distribution of beetles and combined the climate and habitat heterogeneity, we explored the distribution patterns and effect factors of beetle species richness of overall and six dominant families in Helan Mountain of northern China. The results showed that species richness and fauna differentiation intensity of beetles were the highest in the middle of Helan Mountain, the southern section was higher than the northern section, and the western section was higher than the eastern section. After clustering analysis of species distributed in 183 grids, the distribution of beetles could be classified into three groups (xerophilic landscape beetle groups in the northern section, semi-hygric landscape beetle groups in the middle-western section, and semi-xerophytic beetle groups in the middle-east and south section). The mean annual temperature and precipitation were the most significant factors on beetle distribution by analyzing of RDA. Meanwhile, water and energy factors together explained 57.1% of the spatial variation in overall beetle species richness, only 5.9% and 7.1% separately, followed by habitat heterogeneity (35.2%) and only 1.8% separately. The relative effect of dominant species richness were inconsistent with climatic and habitat heterogeneity, but water and habitat heterogeneity have significant effect on beetle species richness in southern and northern of Helan Mountain. Water and energy factors dominantly impacted beetle spatial distribution, and habitat heterogeneity increased the species richness. Therefore, we suggested that topographic and soil factors may also have an important influence on beetle species richness in Helan Mountain according to the unexplained proportion.

Key words: beetle, species richness, distribution pattern, water factors, energy factors, habitat heterogeneity, Helan Mountain