四川白河自然保护区连香树的空间分布与种群特征

Spatial Distribution and Population Characteristics of Cercidiphyllum japonicum in Baihe Nature Reserve, Sichuan Province

以四川白河自然保护区连香树为研究对象,采用访问法、样线法和样方法相结合,调查连香树的空间分布位点、种群特征和干扰因素。调查结果表明:保护区有连香树365株,适宜面积约1 995.46 hm2;海拔1 900～2 200 m区域的连香树株数占总株数的89.53%,尤其是海拔2 000～2 100 m分布最为密集(占43.01%);径级分布为纺锤形,自然更新差,种群呈不稳定状态,胸径在12～32 cm之间的有238株(占65.20%)。连香树主要分布区与传统耕作区和放牧区的重叠性高,林地转化成耕地及放牧践踏是连香树种群数量和栖息地下降的主要原因;减少人为干扰、就地保护与监测、建立天然母树园、种子繁殖和扦插是保护连香树种群的有效措施。

Cercidiphyllum japonicum is a national class II protected species. It is a relict plant and has high scientific research and protection value. The Baihe Nature Reserve is one of the important distribution areas of natural Cercidiphyllum japonicum population in Sichuan province, and its spatial distribution, population status, natural regeneration and threat factors are rarely reported. In this paper, the spatial distribution, population characteristics of Cercidiphyllum japonicum and disturbance factors were investigated based on interviews, quadrate method and line intercept method in Baihe Nature Reserve, Sichuan province. The results show that there are 365 plants, and the suitable area is about 1 995.46 hm^2 in Baihe Nature Reserve. The number of Cercidiphyllum japonicum accounts for 89.53% of the total number of plants in the 1 900~ 2 200 m area, especially the 2 000 ~ 2 100 m above sea level (43.01%). The diameter distribution of Cercidiphyllum japonicum population is spindle-shaped, the natural regeneration is poor, and the population is in an unstable state. There are 238 plants (65.20%) with diameter between 12~32 cm. The overlap between the main distribution areas and the traditional farming areas and grazing areas is high. The conversion of forest land into arable land and grazing trampling are the main reasons for the decline of the population and habitat of Cercidiphyllum japonicum. Reducing human interference, in-situ protection and monitoring, the establishment of natural parent tree gardens, seed propagation and cottage are effective measures to protect the Cercidiphyllum japonicum population.