Xu X.-H.,Urban Administration Bureau of Shenzhen |
Wang X.-Q.,Sun Yat Sen University |
Sun Y.-J.,Urban Administration Bureau of Shenzhen |
Lai Y.-L.,Urban Administration Bureau of Shenzhen |
And 2 more authors.
Journal of Plant Resources and Environment
The composition, population vertical structure and population age structure of three communities of Brainea insignis (Hook.) J. Sm. in Maluanshan Country Park, Tiantou Mountain Nature Reserve and Paiyashan Mountain Nature Reserve in Shenzhen were investigated and analyzed, and frequency, diversity and evenness of species in three communities were compared. According to important value of dominant species and layer of arbor and shrub, B. insignis community in three regions above mentioned are named on Comm. Schefflera octophylla-Litsea rotundifolia var. oblongifolia-B. insignis, Comm. Sapium discolor-Rhododendron moulmainense-B. insignis and Comm. Syzygium hancei + S. octophylla-L. rotundifolia var. oblongifolia-B. insignis, respectively. Among the three communities, individual number in middle-low layer (height less than 10 m) is more than 90% of total individual number of communities, and with increasing of height, individual number decreases sharply. Taking DBH to reflect age structure of dominant population, except B. insignis population, dominant populations of three communities almost have a certain proportion of I class (DBH<2. 5 cm) saplings, II class (2. 5 cm≤DBH<7. 5 cm) arborets and III class (7. 5 cm≤DBH<22. 5 cm) adult trees, and a small proportion of IV class (DBH≥22. 5 cm) big trees, showing that three communities have a trend of constant renewing. Species with frequency rank ( FR) A (0% ≤FR < 20%) take an dominating advantage in the three communities above mentioned with a percentage of 57. 50%, 63. 16% and 61. 70%, respectively, but species with frequency rank E (80% ≤FR ≤100%) take a lower percentage. While the percentage of frequency rank E species is higher than that of frequency rank D (60%≤FR<80%) species in B. insignis community in Maluanshan Country Park, it is accorded with Raunkiaer's law. Simpson's and Shannon-Wiener's diversity indexes and evenness index are all the highest in B. insignis community of Tiantou Mountain Nature Reserve in the three communities, while those are the lowest in Maluanshan Country Park. It is sugggested that three B. insignis communities all are in the middle stage of succession and don't up to status of climax or sub-climax communities. Source