Plant Diversity And Structure Of Different Replaced Communities After The Removal Of Invasive Weed, Crofton (Eupatorium Adenophorum Spreng)

Crofton weed (Eupatorium adenophorum Spreng) is a harmful noxious weed in southwestern China. In this paper, the structure, species composition, plant diversity, soil bank and aboveground biomass of different replaced communities after removal invasive Crofton that occurred at the beginning of the 1980s was made in the Shuangbo County of Yunnan Province, with local old-growth forest of Pinus yunnanensis and unmanaged E. adenophorum community as reference. The results were as follows:1. In replaced communities, Richness index, Shannon-Wiener index, Simpson index and Pielou evenness index of the woody species were 25～28, 1.06～2.34, 0.36～0.86 and 0.32～0.73, and those of herb species were 6～8, 1.51～1.97, 0.74～0.84, 0.84～0.90, respectively. In unmanaged E. adenophorum community, the corresponding indices 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 the E. adenophorum community developed through a 20 years rehabilitation period, under which, there was a clear under storey 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 old-growth forest of P. yunnanensis, with 42, 2.88, 0.92 and 0.77 for woody species, and 8, 2.08, 0.86 and...