雨雪冰冻重灾区湿地松受害情况调查及其原因初步分析

Investigation on the Damage of Pinus elliottii in the Freezing Rain and Snow Area and the Analysis on the Reason

从大面积勘查、林分分析、单株生长调查及其基本密度测量等方面研究2008年年初我国南方雨雪冰冻重灾区湿地松受害情况及其受害原因。结果显示,生长、树龄和所处海拔基本相近的湿地松林分受灾情况表现出随纬度降低而损害程度加重的规律,即从我国南方30°—26°N左右,湿地松受灾情况逐渐加重,折断、倒伏的比率最高达到80%。树龄和割脂这2个因素对同一个地点的湿地松受灾程度影响较大,其中树龄龄在13～18年之间的林分因较早违规割脂,受灾最严重,而胸径在20cm、树龄在20年左右、割脂时间比较长的林分受灾也较严重。在受损的湿地松林分中,能够抵抗雪压而不倒伏的单株一般是基本密度较大、生长较好的优势株,但是同一林分内倒伏株和直立株基本密度差异并不显著。经营管理较好的林分抗雪压的能力显著高于粗放经营的林分。

Investigation on the damage of Pinus elliottii in the freezing rain and snow area of southern China was done in 2008.The results of the survey in 15 forest region revealed that the damage of P.elliottii,which have the same age and altitude location approximately,was increased from about latitude 30°—26° N in southern China.The percentage of broken and collapsed trees was up to 80%.The 13～18 years old P.elliottii in the same forestry center were damaged most heavily because these stands with DBH lower than 20 cm were illegally taped early.While the 20-year-old P.elliottii with DBH about 20 cm were damaged heavily either because being taped for several years.The single pine with higher basic density and DBH usually couldn＇t be overpowered in the damaged forest although no significant differences exist between the damaged and undamaged stands in one forest area.The unmanaged stand was more susceptible to break and uproot than the managed one.