Species diversity and microhabitat characteristics of bryophytes on different types of walls in karst city

Abstract

Abstract The correlation between bryophyte community characteristics, alterations in species diversity, and microhabitat characteristics on various types of urban walls remains ambiguous. This study investigates the distribution and habitat characteristics of bryophytes on various types of urban walls in karst areas. The α and β diversity indices were employed to examine the variation of bryophytes on these walls. Additionally, a canonical correspondence analysis was conducted to analyze the relationship between bryophyte species composition and their microhabitat. The results showed that: (1) There were 14 families, 31 genera, and 80 species of wall bryophytes (including six species of liverworts) on urban walls. Brachytheciaceae, Pottiaceae, and Hypnaceae were the dominant families. Bryophyte species were most abundant on stone retaining walls, followed by concrete revetment. The highest proportion of dominant bryophyte species were found on the concrete face, in the crevasses of stone walls, and on the tops of brick walls. (2) The species distribution across the nine types of walls was highly uneven, stone retaining walls exhibited the highest species diversity, while concrete revetment and freestanding walls demonstrated strong habitat heterogeneity. (3) The species composition of wall bryophytes was intricately linked to the properties of the wall and micro-environmental factors, with wall temperature and air humidity being the key determinants. These findings can serve as a benchmark for assessing the diversity and ecosystems of urban wall bryophytes. By enhancing the conservation and restoration of various types of wall bryophytes, we can bolster the self-sustaining mechanisms of urban ecosystems.