[Plant diversity of different replaced communities after Eupatorium adenophorum removal]

Plant diversity of different replaced communities after Eupatorium adenophorum removal. WANG In this paper, an investigation on the structure, species composition and plant diversity of replaced communities after the removal of invasive E. adenophorum at the beginning of 1980s was made in the Shuangbo County of Yunnan Province, with local aged Pinus yunnanensis and unmanaged E. adenophorum forests as the reference. The results showed that in replaced communities, the richness, Shannon-Wiener, Simpson, and Pielou evenness indices values of woody species were 25 to approximately 28, 1.06 to approximately 2.34, 0.36 to approximately 0.86 and 0.32 to approximately 0.73, and those of herb species were 6 to approximately 8, 1.51 to approximately 1.97, 0.74 to approximately 0.84 and 0.84 to approximately 0.90, respectively. In unmanaged E. adenophorum community, the corresponding indices values of woody species were 3, 0.14, 0.10 and 0.13, and those of herb species were 3, 0.09, 0.03 and 0.08, respectively, being much lower than those of the replaced communities. The replaced communities dominated by fast-growing tree species in E. adenophorum forest developed through a 20 years rehabilitation period, under which, there was a clear understory layer dominated by native species. The density and growth rate of E. adenophorum was inhibited in the replaced communities. In comparison with the E. adenophorum community, the plant diversity of replaced communities was greatly increased. Among the replaced communities, P. yunnanensis + Schima wallichii + Eucalyptus globules community had the greatest plant diversity, but the replaced communities had lower plant diversity than the aged P. yunnanensis, with 42, 2.88, 0.92 and 0.77 for woody species, and 8, 2.08, 0.86 and 0.90 for herb species, respectively. It was suggested that more attention should be paid to conserve the rehabilitated communities, especially the P. yunnanensis plantation built on the degraded lands invaded by E. adenophorum. In addition, the introduction of local broad-leaved species and some shade-loving herb plants into these plantations and its follow-up management were also important for the sustainable development of the revegetation.