Ecological niche and interspecific relationship of dominant bryophyte communities in stone walls of cities at different elevations, Guizhou, China

Abstract

To investigate the utilization characteristics and distribution patterns of major bryophyte communities on urban walls, we examined the bryophyte communities in stone walls at varying elevations. This study employed niche width and niche overlap indices, Chi-square Statistic Test, and association coefficient to analyze the species composition, niche characteristics, and interspecific associations within the bryophyte communities. The results showed that the stone walls across the four elevation gradients supported a total of 65 bryophyte species, including six liverwort species, but the dominant species varied from elevation to elevation E1 ~ E4 (989-1398m). Didymodon rufidulus, Didymodon ditrichoides, and Bryum argenteum had larger niche widths and were primarily distributed in the E3 elevation. In each elevation gradient, there was low niche overlap among the dominant bryophyte species. Interspecific association analysis revealed a significant negative association among bryophytes, suggesting the early stage of community succession. Among the elevation gradients, E4 displayed the weakest degree of bryophyte association, while E3 exhibited the strongest negative association and relative stability. The 16 dominant species of stonewall bryophytes could be categorized into three groups. These findings provide insights into the competition mechanism of wall bryophyte communities at different elevations and offer guidance for ecological restoration of wall vegetation.