Response of interspecific relationships in Artemisia scoparia community to precipitation gradient in tempe-rate steppe region.

We investigated Artemisia scoparia community across a natural precipitation gradient in the temperate steppe region, including desert (mean annual precipitation was 220.18 mm), desert steppe (287.71 mm), and typical steppe (399.11 mm) habitats, and analyzed interspecific relationships and community stability. The results showed that a total of 15 herbaceous species were recorded across three types of habitats, dominated by species from Poaceae and Asteraceae. A. scoparia had relatively high importance values at all sites, indicating its dominance in the plant communities. However, its importance value in the typical steppe (6.5) was lower than that in areas with less precipitation, being 13.9 in the desert and 21.0 in the desert steppe. The niche overlap among most plant species in the community was low, with the proportion of niche overlap indices (Oik) <0.5 being 86.7%, 89.3%, and 97.8% in desert, desert steppe, and typical steppe, respectively, indicating significant differentiation of resource utilization among species. The niche breadth of A. scoparia in desert steppe (Levins's niche breadth index of 7.70 and Shannon's niche breadth index of 2.22) was higher than that in desert and typical steppe. Plant species in the study area were mainly negatively associated, and the community structure was relatively loose. A. scoparia communities in desert, desert steppe, and typical steppe did not reach a stable state and were in a non-stable dynamic succession stage, with the A. scoparia community in desert steppe exhibiting relatively higher stability.