Responses of plant species diversity and niche breadth of dominant species to human disturbance in Baili Rhododendron National Forest Park
We explored plant species diversity and niche breadth of dominant species and their coupling relation-ships with human disturbance in Baili Rhododendron National Forest Park,aiming to provide theoretical basis for sustainable use of landscape resources and biological conservation.We analyzed the relationship between species composition of plant community and dominant species under different human disturbances.Results showed that:(1)A total of 109 species from 80 genera and 49 families were recorded in the 15 plots.(2)The species diversity at different structural layers showed significant differences in response to human disturbance,and species diversity index of tree layer and shrub layer was the highest under moderate disturbance.The Margalef index of shrub layer and herb layer was significantly negatively correlated with the intensity of human disturbance(P<0.01).(3)Niche breadth was the highest in tree layer and shrub layer under different disturbance levels.In shrub layer,niche breadth of Rhododendron agastum was positively correlated with disturbance intensity(P<0.05),while that of Quercus fabri was negatively correlated with disturbance intensity(P<0.01).In herb layer,niche breadth of Hedera nepalensis var.sinensis was positively correlated with human disturbance(P<0.01),while that of Smilax riparia was negatively correlated with human disturbance(P<0.01).Species diversity of each layer in plant community showed significant differences in response to human disturbance.Meanwhile,human disturbance would change community composition,directly or indirectly affect the structure and function of plant populations,and thus destroy community habitat,which are unfavorable to community development.