从植物生态学的角度对2008年初南方冻雨冰雪灾害对典型的亚热带山地常绿阔叶林造成的损害情况做了研究。对12个优势种和亚优势种的受灾情况做了对比分析, 对不同径级和不同地形因子下林木抵抗冻雨灾害的差异做了对比。统计检验结果显示林木受损程度存在显著的种间差异、径级差异和地形级差异。优势种米槠(Castanopsis carlesii)比多数亚优势种受害更严重; 各树种抗冻雨灾害能力以山茶科和樟科的种较强, 而壳斗科的多个种, 如米槠、栲(C. fargesii)受灾较为严重; 林木的受损比例随着胸径(diameter at breast height, DBH)增加而增大; 在未受灾的各级林木中, 超过70%的个体集中在最小一级径阶(1-5 cm)。χ²检验显示坡度、坡向、坡位等地形因子对林木受损状况有显著的影响, 随着坡位上升, 林木受损程度逐渐加重, 上坡位的林木受损比例最大, 下坡位最小, 这可能与随着坡位升高, 迎风面降温效果更迅速有关。对于坡向和坡度而言, 位于半阳坡的林木受灾比例显著高于半阴坡, 位于坡度级III (15°-25°)、IV (25°-35°)、V (35°-45°)上的林木受灾最严重。该研究结果对于亚热带常绿阔叶林的保育和应对未来可能再次发生的冰雪灾害有重要意义; 同时对于森林恢复和演替、乡土阔叶树种的选育及森林经营等方面的研究和应用也有重要的参考价值。

Aims The forest ecosystem of north Guangdong Province, China was severely damaged by a freezing rain and ice storm in early 2008. Our aim is to assess tree damage and factors that influence it in a subtropical montane evergreen broadleaved forest.

Methods A 2-hm² plot was set up in the storm-damaged montane evergreen broadleaved forest in Chebaling National Nature Reserve. The plot was divided into 50 subplots, each 400 m², for sampling and measurement of plants and environmental factors. Damages to individual trees were recorded by visual estimation and then translated into a 0-6 scale of damage class. We compared the severity of damage for 12 dominant and co-dominant species. We also assessed variations in tree abundance in different diameter at breast height (DBH) classes and topographic regimes.

Important findings Significant variations in tree damage existed among species, DBH classes and topographic positions. Species of Theaceae and Lauraceae were more resistant to storm damage than species of other families. Most damaged were species of Fagaceae, such as Castanopsis fargesii and the dominant C. carlesii, which was more severely damaged than most co-dominant species. The proportion of damaged trees increased with DBH, with > 70% of the undamaged individuals being concentrated in the smallest DBH class (1-5 cm). χ² test indicated that topographic factors, i.e., slope inclination, aspect and position, had significant effects on the severity of tree damage. Trees on the upslope position were more susceptible to damage than those on the downslope or midslope positions, which might be due to increased cooling by wind on the upper slope. For slope aspects, semi-sunny slopes generally had a significantly higher proportion of damaged trees than semi-shady slopes. For slope inclination, the highest proportion of severely damaged trees was on slope classes of 15°-25°, 25°-35° and 35°-45°. Findings have significant implications for conservation of subtropical evergreen broadleaved forest, protection of forests from possible future damage by ice storms and forest management.