冰雪灾害对江西九连山常绿阔叶林的影响

以江西九连山国家自然保护区常绿阔叶林为对象,研究林分不同层次优势种受灾程度,分析物种海拔、坡度对受灾程度的影响。结果表明:乔木上层和中层树木以断稍为主,乔木下层树木以断稍和腰折为主,小树和幼树以压弯为主。在平均受损指数MDI(Mean Damage Index)方面,乔木上层米槠MDI值最高,拟赤杨最低; 乔木中层鸭公树MDI值最高,浙江新木姜子最低; 乔木下层米槠MDI值最高,浙江新木姜子最低; 小树米槠MDI值最高,细枝柃最低; 幼树二列叶柃MDI值最高,狗骨柴最低。海拔对不同林分层次树木的部分受损指标有显著影响(P<0.05); 整体上,不同林分层次树木的受损指标在700～760 m海拔生境高于640～700 m海拔生境。不同坡度生境下树木的受损指标均无显著差异(P>0.05)。

Effects of the ice and snow damage to the evergreen broad-leaved forest of Jiulianshan Mountain in Jiangxi Province

The ice and snow damage to the evergreen broad-leaved forest of Jiulianshan Mountain National Natural Reserve in Jiangxi Province was studied,and effects of altitude,slope on the damage degree were analyzed. The results were as follows:the upper-layer and mid-layer trees were mostly in model of top breakage,the under-layer trees were subjected to top and trunk breakage,the saplings and seedlings were mostly suffered from bending. In term of MDI,seedlings<saplings<under-layer trees<mid-layer trees<upper-layer trees; species with the highest MDI in different story was respectively Castanopsis carlesii in upper-layer,Neolitsea chuii in mid-layer,C. carlesii in under-layer and sapling,Eurya distichophylla in seedling; however, species with the lowest MDI in different stories were respectively Alniphyllum fortunei in upper-layer,Neolitsea aurata var. chekiangensis in mid-layer and under-layer,Eurya loquaiana in sapling and Tricalysia dubia in seedling. The trunk breakage ratio and MDI of upper-layer trees,top breakage ratio and MDI of mid-layer trees; trunk breakage ratio and MDI of under-layer trees,bending ratio of saplings,trunk breakage ratio of saplings,uprooting ratio of saplings,MDI of saplings,trunk breakage ratio and MDI of seedlings were significantly different between different latitude habitats(P<0.05); In the whole,different damage indexes of trees under 700-760 m altitude habitat were higher than individuals under 640-700 m altitude habitat. Under different slope habitats,damage indexes in different layers had no significant difference(P>0.05).