Relationship Between Plant Diversity and Soil Environment in Karst Urban Remnant Mountains: A Comparative Analysis of Two Types

Understanding the characteristics of plant diversity and its relationship with the soil environment in urban remnant habitats before and after their transformation into parks is of great significance for strengthening urban biodiversity conservation. To investigate the changes in plant diversity characteristics and their relationship with the soil environment following the transformation of urban remnant natural mountains (URNM) into urban remnant mountain parks (URMP), we conducted a study in the urban area of Guiyang City, China. We sampled 90 plots across five typical URNM and five typical URMP. Plant diversity and its relationship with soil properties were evaluated using four taxonomic diversity indices and 9 soil physicochemical properties. The results showed that URNM exhibited higher plant diversity and richer species richness compared to URMP. In URNM, plant survival conditions deteriorate with the elevation of slope position, resulting in the highest plant diversity at lower slopes and the lowest at upper slopes. However, intense human disturbances lead to the opposite pattern in URMP. Additionally, soil bulk density, total phosphorus, and total potassium (TK) were found to be higher in URMP than in URNM. C/N, C/P, and soil organic carbon were identified as the main factors influencing plant diversity in URNM, with explanatory rates of 20.1%, 15.4%, and 8.6%, respectively. In URMP, TK was the most significant factor, explaining over 55.9% of plant diversity. These findings indicate that the transformation of karst urban remnant mountains into parks leads to a simplification of plant species composition and a reduction in plant diversity. This process also alters the characteristics of soil environmental factors and their relationship with plant diversity. These changes highlight the need for careful management strategies in urban park development to mitigate biodiversity loss and maintain soil health, which are crucial for the sustainability of urban ecosystems.