Abstract:

52 sites were set up within typical tidal creek of Jiuduansha Nature Reserve.The ecological importance value of plant,soil moisture ,soil conductivity and water conductivity in 52 sites were measured.We figured out species diversity index,individual specie niche breadth and overlap between each other,then generated principal coordinates diagram and minimum spanning tree.The results showed 48 species in Jiuduansha Nature Reserve,belonging to 4 bryophytes,21 unicotyledon and 23 bicotyledon,of which 31 species were first reported.According to plant geographical distribution,components are most in temperate,then in world wide and less in tropical least.22 species were found in 52 sites,in which diversity index were significantly different.It can be identified six ecological groups on principal coordinates diagram with niche overlap.We conclude that Jiuduansha Nature Reserve has been interfered by the human activities and more weeds and  invasive plants develop in sites.〖