北京林业大学生态与自然保护学院 北京 100083
School of Nature Conservation,Beijing Forestry University
Pinus kwangtungensis is an endangered species endemic to China. It is classified as a national second-class protected wild plant species in China, and a vulnerable species on the International Union for Conservation of Nature (IUCN) Red List. In order to reveal the survival pressure status, we carried a comprehensive field investigation on the natural populations of Pinus kwangtungensis by setting up quadrats along an altitudinal gradient from 994 m to 1710 m in the Nanling National Nature Reserve, Guangdong Province. Combined with the literature collection method, the ecological factors, such as DBH(diameter at breast height), tree height, and canopy of different trees in the community, were measured, and the spatial pattern and the average survival pressure index of Pinus kwangtungensis population were analyzed and calculated at different altitudes gradient. The results are as follows. 1) The altitude and the temperature affected the spatial pattern of the community, the spatial pattern of Pinus kwangtungensis population was mainly aggregated distribution along thealtitude gradient. However, with the increasing of altitude, the values of Iδ and m* gradually increased, that is to say, the aggregation intensity of Pinus kwangtungensis population was increasing, after a certain height, the value of K gradually decreased, the aggregation intensity also decreased, the intra- and inter-species competition was slowed down, the survival pressure became lessening. It shows that with the increase of altitude, the population survival pressure firstly increased and then decreased, higher altitude is beneficial to the survival of Pinus kwangtungensis. There is a “competitive driving” between species, and its existence can also be verified. 2) The average survival pressure index of Pinus kwangtungensis population showed a decreasing trend along the altitude gradient (R2=0.31，P<0.05). The survival pressure is higher at middle and low altitude, the aggregation intensity at high altitudes is decreased, and the survival pressure also is decreased. It is possible to migrate to high altitudes for better survival, and, the Pinus kwangtungensis population will eventually become extinct due to factors such as the gradual shrinkage of the distribution area, poor living conditions and maladaptation, there is an existence of “competitive driving”. 3) The complexity of the interspecific structure of the community was resulted in fierce competition of the intra- and inter-species. The average survival pressure index of Pinus kwangtungensis population was different at the same altitude gradient; 4)The average survival pressure index of Pinus kwangtungensis in planted forest was 50. It is threatened by the competition tree species and needs to be strictly protected. The seedling regeneration of Pinus kwangtungensis population is slow, which belonged to a declining population, and there is a phenomenon of “competitive driving” among species, which may be considered an important ecological factor leading Pinus kwangtungensis to be an endangered species.
王俊,潘鸿,谢磊,崔国发.华南五针松濒危机制的生态学研究.生态学报,,(). http://dx. doi. org/10.5846/stxb202103120670复制