湖北利川水杉原生种群及其生境1948～2003年间变化分析

Analysis on the change of the original Metasequoia glyptostroboides population and its environment in Lichuan Hubei from 1948 to 2003

为保护和恢复水杉原生种群提供科学依据,对中国湖北利川水杉原生母树及其生境194 8～2 0 0 3年间的变化进行对比分析,指出了保护工作存在的问题及保护对策。主要结果有:1194 8年初步调查为10 0 0多株,1983年普查有5 74 6株,涉及4个镇(场)、4 5个行政村,分布面积为6万hm2 ;2 0 0 3年普查为5 388株,分布范围没有大的变化,有2种分布类型:散生分布的有896株,群落分布的有4 4 92株,最大的种群为10 5和12 3株。2中国政府对水杉的保护取得了巨大成绩,但过去只重视对个体的保护,忽视了对群落及其栖息环境的保护,导致由混交林变为纯林、结构趋于简单、生物多样性减少、天然更新困难,1983～2 0 0 3年的2 0年间已有386株水杉原生母树死亡,亟需对水杉原生种群及其栖息地进行保护。3应运用现代恢复生态学手段,开展水杉植被恢复重建理论研究,首先加强对集中分布种群及其栖息地进行就地保护,其次小河河谷实施种群及其栖息地恢复与重建。4人为活动对水杉的危害加重,应减少及停止一切有害的人为活动,改善水杉原生母树生境,提高居民、社区自主参与水杉保护的意识;进行生态移民和实施退耕还林等是一个可以考虑的方法。

Lichuan, located at the foot of the Wuling Mountain in southwest Hubei province of central China, is well known in the world for the discovery of living fossil-Metasequoia glyptostroboides Hu & Cheng in 1940s. Its natural habitat has been well protected by the Chinese government. In order to provide scientific foundation for the protection of Metasequoia resource, it is necessary to analyze the change of the Metasequoia original natural mother trees of (MONMT) and their environment from 1948 to 2003. The results and countermeasures are as followed: ①The distribution areas have little changed, involving 4 towns/farmland, 45 villages, 5746 individuals in 1983 and 5388 individuals in 2003, covering nearly 60000 hm^2, with the average density less than 0.1 ind./hm^2. The Metasequoia distribution has two main types: the scattered distribution type is mainly at the foothill or nearby houses, roads, villages and rivers while the population distribution type is mainly at the mountain and valleys with the minority at the low mountains and basins. The biggest numbers of Metasequoia population are 105 and 123. ②In the past, importance was only attached to individual protection while protection of Metasequoia population and environment was neglected, which led to the past mixed forests having becoming the pure ones, construction being simpler, biodiversity reducing and natural renewal difficult. From 1983 to 2003, 386 original Metasequoia mother trees died. So it is vital to enhance the protection of the only original Metasequoia population and their habitats in the world. ③Modern ecological means should be taken to protect the original Metasequoia population and their habitant environment, and research on Metasequoia vegetation restoration and reconstruction should be carried out. Restoration and reconstruction should be put into practice in the Xiaohe Valley, the concentrating distribution. ④Efficient measures should be taken to stop human activities harmful to Metasequoia and improve the environment of MONMT so as to promote the protection of the MONMT population and its ecosystem. Eco-emigration and returning the grain plots to forestry can be practiced.