亚热带森林群落草本植物对林下光环境的响应  

Herbaceous plant in response to understory light regimes in a subtropical forest community

作　　者：胡砚秋[1] 柯娴氡[1] 徐明锋[1] 李文斌[1] 苏志尧[1] 

机构地区：[1]华南农业大学林学与风景园林学院,广东广州510642

出　　处：《中南林业科技大学学报》2016年第8期72-76,共5页Journal of Central South University of Forestry & Technology

基　　金：广东省科技计划项目(2013B020305008);广东省林业科技创新专项资金项目(2011KJCX031-02)

摘　　要：确定森林群落中林下草本植物的分布及其对光照的响应,不仅能揭示草本植物对光的生态需求,而且能为其引种和利用提供关键参考。在东源康禾自然保护区的常绿阔叶林内设置2 hm^2样地,样地划分为50个20m×20 m样方,在样方内设置小样方进行林下草本植物(包括禾本科竹亚科植物)调查。用半球面影像技术测定林下光照指标,进而分析草本植物分布与林下光环境的关系。结果表明,林下光环境的变异为草本植物的生长提供了多样的小生境,不同光照需求的物种在样地内均广泛分布;林下散射光与林下草本分布的除趋势对应分析(DCA)排序轴的相关性高于直射光与排序轴的相关性,说明林下散射光与林下植物的分布关系更为密切;不同光照总立地因子的样方组间草本植物的多度和丰富度没有显著差异,但非参数回归分析的结果清晰地反映了不同草本植物对光照响应的差别,如山麦冬Liriope spicata喜阴且不耐强光,黑莎草Gahnia tristis、箬竹Indocalamus tessellatus在不同光照条件下生长变化不大,说明物种对光照的变化不敏感、适应性更强。在草本植物的引种和利用过程中,可以结合目标地点的光照条件选择适生的物种。Determining the distribution and ecological response of herbaceous plants for light has implications for revealing the demands of plants for radiation, as well as for species introduction and utilization. In this study, a 2 hm2 plot was set up, which was further divided into fifty 20 m× 20 m subplots, for sampling herbaceous plant （including graminoid bamboo plants） abundance and distribution and measuring understory light regimes using hemispherical photography. Understory herbaceous plant patterns in relation to the light factors were analyzed based on the field collected data. The results showed that herbaceous species with different light demands distributed widely in the sample plots, suggested that the variation of understory light environment led to habitat heterogeneity. The correlation of transmitted diffuse radiation （TDIF） to detrended correspondence analysis （DCA） axis were much higher than that of transmitted direct radiation （TDIR）, indicating that TDIF had greater influence in shaping the distribution of understory herbaceous plants. Herbaceous plant abundance and richness had no significant difference among the total site factors （TSF） groups, but non-parametric multiplicative regression （NPMR） analysis clearly reflected the different responses of herbaceous species to varied understory light conditions. For example, Liriope spicata preferred shady environment and was intolerant to strong radiation, while Gahnia tristis and lndocalamus tessellatus were more adaptable to the variation of light environment, the abundance of these two species had no pronounced changes under different light conditions. These results suggested that light conditions of habitat and species light adaptability should be taken into consideration in herbaceous plants introduction or utilization.

关 键 词：草本植物 亚热带森林群落 林下光照 物种多样性 

分 类 号：S781.5[农业科学—木材科学与技术]