摘要
基于广西猫儿山自然保护区两块不同海拔的1hm2样地在2002年和2008年的两次调查数据和资料,采用相对邻体密度指数?r,来衡量物种的空间格局和聚集程度。具体分析了现存水青冈(Fagus longipetiolata)和南方铁杉(Tsuga chinensis var.tchekiangensis)两种古老孑遗植物在猫儿山的空间分布格局和生长更新状况。对其更新状况和径级结构分析后得知,水青冈在2002年和2008年径级结构基本一致,呈现反J型(类似于"L"形状)分布。南方铁杉在2002年和2008年个体的径级都主要集中在20-36cm范围内,呈现类正态分布。两物种6年间均未有新增个体产生,均存在一定程度的更新困难。通过相对邻体密度点格局分析发现:两物种在不同尺度上的分布格局不同,水青冈在取样尺度小于11m时,表现为显著聚集分布,而南方铁杉在取样尺度2-20m之间表现为显著聚集分布。空间分布点图显示:水青冈在样地中分布面积较广,而南方铁杉的分布仅集中在猫儿山八角田样地的西南角。针对现状,要解决两孑遗物种的存活和发展问题,应该及时采取就地保护、人工辅助更新和迁地保护等综合措施增加种群多度和扩大种群分布面积。
Aims Current knowledge about tree distributions in species-rich communities is almost exclusively derived from tropical rain forests. The Natural Reserve of Mao＇ershan Mountain has complicated landforms and high biodiversity, including relic plants. Our objective was to analyze distribution patterns and regeneration conditions of two relic plants to find survival conditions and coexistence mechanisms.
Methods Using a stem map of two 1 hm2 permanent plots at different altitudes in the Mao＇ershan Mountain Natural Reserve, we analyzed the distribution pattern, regeneration condition and size distribution of two relic plants： Tsuga chinensis var. tchekiangensis and Fagus longipetiolata. Spatial patterns were analyzed by R program. Confidence intervals were generated from 999 Monte Carlo simulations under the null hypothesis of com- plete spatial randomness.
Important findings Regeneration conditions and size distribution of both species determined no new individuals had appeared in six years. Diameter at breast height （DBH） classes for 2002 and 2008 were inverse J type for F. longipetiolata and normal distribution for T. chinensis var. tchekiangensis. Both species have regeneration prob- lems. There were fewer individuals of T. chinensis than E longipetiolata. Continuously sampling data to analyze spatial point pattern using the relative neighborhood density showed that both species had different distribution patterns at different ~cales. Fagus longipetiolata were significantly aggregated at scales 〈11 m, as did T. chinensis at scales from 2 to 20 m. Fag-us longipetiolata was widely distributed in its plot, while T. chinensis was distributed in the southwest of the plot. Integrative measures should be adopted to protect both relic species from regeneration difficulties, such as local protection, artificially aided regeneration and ex-situ conservation to increase their populations and enlarge their areas of distribution.
出处
《植物生态学报》
CAS
CSCD
北大核心
2012年第2期144-150,共7页
Chinese Journal of Plant Ecology
基金
"十一五"国家科技支撑计划重点项目(2008-BAC39B02)
广西教育厅科研项目(201010LX148)
广西科技计划项目(1140002-1-1)资助
关键词
水青冈
点格局
更新
相对邻体密度
孑遗植物
南方铁杉
Fagus longipetiolata
point pattern
regeneration
relative neighborhood density
relic plants
Tsugachinensis var. tchekiangensis
