Application of Herbaceous plant CSR strategy responses to four kinds of habitats in the Qinling Mountain for plant community design

Context Urban habitats have been severely degenerated or destroyed due to construction activities and consequent human interference, which have threatened the urban ecosystem, especially plant species richness and diversity. The interactive relationship between plants and habitats is an outcome of long-time evolution. Exploring the relationship can provide an insight for improving the sustainability of urban greenspace. Objectives We attempted to 1) build a relationship between individual plants and the whole community based on CSR theory, and 2) explore ecological function of communities can be achieved better by a suitable combination of individual functional traits. Methods This study referred to Grime's CSR (C: competitor, S: stress tolerance, R: ruderal) theory to analyze Qinling mountain herbaceous communities in typical habitats (roadside, riverside, forest margin, and understory). Species composition in communities of different habitats was recorded. Then dominant and non-dominant species were identified and analyzed emphatically. Results (1) In four habitats, the CWMs of CSR ecological strategies showed that C-scores of riverside communities were the highest, while understory communities were the lowest. S-scores of understory communities were the highest, while roadside communities were the lowest. Lastly, R-scores of roadside communities were the highest, while those of understory communities were the lowest. (2) In terms of CWMs of leaf traits, LDMC gradually increased along the disturbance gradient, but SLA was on the contrary. (3) Dominant species were more profoundly shaped by environmental circumstances than non-dominant species, which can effectively indicate their habitat characteristics. For example, C-scores of dominant species and subdominant species in riverside were significantly higher than in other habitats; S-scores of dominant species in understory habitats were significantly higher than others; and R-scores of dominant species in roadside habitats were significantly higher than others. Conclusions This study suggested that the strategy of dominant species is the main factor that determines the effect of various habitats on plant compositions. This rule verified that the CSR model could help select the cultivated species for urban green space. Also, it can help predict the effect of climate change on herbaceous communities, which has great potential for the planting design of urban herbaceous communities.