关键词: 土壤表层盐分, 地理加权回归, 空间分异

Abstract: Litterfall dynamic is one of the functional strategies in plant species. Exploring litterfall dynamics of overlapping (i.e., co-occurring at three successional stages at least) and turnover (i.e., occurring at one successional stage only) species is important for understanding mechanisms underlying species replacement during forest succession.  In this study, seasonal dynamics of litterfall over 4 overlapping species and 6 turnover species were investigated in four successional stages in evergreen broadleaved forests in Tiantong National Forest Park (29.45° N, 121.97° E), Zhejiang Province. Then differences in litterfall dynamics were examined between overlapping species at different successional stages, and between overlapping and turnover species. The results showed that, in addition to Eurya japonica (P>0.05), litterfall dynamics in overlapping species of Pinus massoniana, Schima superba and Castanopsis fargesii (P<0.05) were significantly affected by forest succession. Differences in litterfall dynamics between overlapping and turnover species were successional stagedependent. Specifically, at the first successional stage, there were significant differences in litterfall dynamics among P. massoniana, S. superba, Lithocarpus glaber and Loropetalum chinense (P<0.05). At the secondary successional stage, litterfall dynamics varied significantly between S. superba and Symplocos caudata (P<0.05) and between C. fargesii and C. sclerophylla (P<0.05). At the fourth successional stage, litterfall dynamics of S. superba, C. fargesii, Eurya japonica, Cinnamomum pedunculatum and Camellia cuspidata differed significantly (P<0.05). There was no significant difference in litterfall dynamics between other species. In summary, litterfall dynamics changed partly for overlapping species during forest succession. At the same successional stage, litterfall dynamics differed significantly between overlapping and turnover species. Changes of litterfall dynamics in overlapping and turnover species indicate divergent strategies in leaf phenology for plants to adapt to the microenvironment shift with forest succession.

Key words: topsoil salinity, GWR model, spatial heterogeneity