子午岭天然油松林乔木层种内与种间竞争关系研究

摘要

采用改进的竞争指数模型研究了甘肃省子午岭天然油松林乔木层种内和种间竞争强度.结果发现:(1)随对象木胸径的增大,油松种群因自疏作用使植株距离增加,种内竞争强度降低.(2)油松群落内其它物种虽较多,但个体普遍较小,种间竞争相对较弱,种内与种间竞争关系顺序为:油松种内＞辽东栎＞漆树＞春榆.(3)竞争强度与对象木胸径的关系服从幂函数关系,当油松胸径达25 cm以上时,竞争强度变化不大,所得的预测模型能很好地预测油松种内和种间的竞争强度.(4)改进的竞争指数模型能很好地度量油松的种内和种间竞争强度.%By using the improved competition index model, the intraspecific and interspecific competitions of Pinus tabulae formis from Ziwuling Mountains in Qingyang City of Gansu Province were quantitatively analyzed. The results show that with the increase of the size of objective tree and the distance between plants, the intraspecific competition intensity decrease, because of the population density regulation during self-thinning. In the community, there are many other species, but their diameter at breast height is less than that of P. tabulae formis, as a result, the competition intensity of intraspecific was more excessive than that of interspecific. The order of competition intensity is intra.specific＞Quercus liaotungensis＞Toxicodendron vernifluum＞Ulmus davidiana var. japonica. The relation between competition intensity and individual growth of objective tree nearly conformed to power function, and the changing of competition intensity is very small when the diameter of the objective tree grows upto 25 cm. The model can simulate and predict the intraspecific and interspecific competition efficiently. The study provides a new approach to measure the competition intensity.