濒危植物长苞铁杉的地理分布和资源现状及致危因素分析

Geographic distribution,current status of resources and endangered factors of endangered plant Nothotsuga longibracteata

根据野外调查的结果,对福建天宝岩国家级自然保护区马石坑、广东南岭国家级自然保护区老蓬顶、湖南莽山国家级自然保护区泽子坪和鬼子寨、广西猫儿山国家级自然保护区小老山、贵州梵净山国家级自然保护区鱼坳、湖南黄桑国家级自然保护区源头山、湖南城步县奇山和江西大余县石溪的长苞铁杉〔Nothotsuga longibracteata(W.C.Cheng)Hu ex C.N.Page〕居群的生境和生存现状进行了比较分析。结果表明:长苞铁杉的地理分布相对狭窄,多呈零星或小片分布;该种正面临分布区缩小和居群规模下降,甚至濒临灭绝的危险。在长苞铁杉集中分布的这些区域,大多数居群面临生存威胁;各居群的个体数量有较大差异,其中,天宝岩居群最大,长苞铁杉数量达几千株;石溪居群和源头山居群最小,长苞铁杉数量只有几十株。全球气候变化、人类活动影响和本身更新困难是导致长苞铁杉濒危的原因,其中,人类活动影响是长苞铁杉致危的直接原因。根据长苞铁杉生存状况,建议对其伴生的阔叶树进行疏伐,适当开辟林窗,有利于长苞铁杉的更新;自然保护区的建立对长苞铁杉的保护发挥了重要的作用,而在其他非保护区的分布区,也应加大宣传力度并采取相应保护措施;实施迁地保护可以有效保护长苞铁杉这一珍稀树种。

According to field survey results,current status of habitats and existence of Nothotsuga longibracteata（W.C.Cheng） Hu ex C.N.Page in Mashikeng of Tianbaoyan National Nature Reserve of Fujian,Laopengding of Nanling National Nature Reserve of Guangdong,Zeziping and Guizizhai of Mangshan National Nature Reserve of Hu＇nan,Xiaolaoshan of Mao＇ershan National Nature Reserve of Guangxi,Yu＇ao of Fanjingshan National Nature Reserve of Guizhou,Yuantoushan of Huangsang National Nature Reserve of Hu＇nan,Qishan of Chengbu County of Hu＇nan,Shixi of Dayu County of Jiangxi were comparatively analyzed.The results show that geographic distribution of N.longibracteata is relatively narrow,which mostly shows a scattered or fragmental distribution.The species is experiencing distribution area reducing,population size decreasing and risk of verging on extinction.Among regions of N.longibracteata distributed concentratedly,most populations face threat to survival.The individual number of each population of N.longibracteata has great differences,Tianbaoyan population is the biggest with several thousands plants,Shixi and Yuantoushan populations are the smallest with several tens plants.Global climatic change,influence of human activity and difficulty of itself renewal cause extinction of N.longibracteata,in which human activity influence is a direct reason.According to existence status of N.longibracteata,clearing out their companion broad-leaved trees and opening up forest gap properly are beneficial to renewal of N.longibracteata.The establishment of nature reserves plays an important role in conservation of N.longibracteata,and in other non-reserve areas,propaganda work should be deepened and corresponding protective measures should be taken.It is suggested that ex-situ conservation should be carried out to conserve N.longibracteata effectively.