Ecological Gradient Analysis and Environmental Interpretation of Cyclocarya paliurus Communities

Cyclocarya paliurus (Batal.) Iljinsk. is mainly distributed in the subtropical areas of China. The leaves of this species are rich in beneficial secondary metabolites exhibiting bioactivity against human diseases, including hyperlipemia, diabetes, and hypertension. To explore the adaptability and distribution characteristics along the environmental gradient of this species, investigation of the characteristics of C. paliurus communities is necessary. In this study, we established 31 sample plots, each 20 m × 20 m, and comparatively analyzed the species composition, species importance value, and tree species diversity of different C. paliurus communities in 2 years. Canonical correspondence analyses were carried out: the first between tree-species importance value and 12 environmental factors, and the second between C. paliurus population-related indices and the 12 environmental factors. On the basis of these analyses, we identified tree species varying markedly in abundance in the studied C. paliurus communities. Several tree species showed adaptive characteristics similar to those of C. paliurus. We also observed that the C. paliurus importance value varied along elevational, longitudinal, and temperature gradients. Our findings should be valuable for prediction of C. paliurus adaptive areas and mixed forest afforestation in different distribution areas.