鄂西亚高山日本落叶松人工林雪灾调查

Damage of Sub-Alpine Larix kaempferi Plantation Induced by Snow Storm in Western Hubei

以建始县国营林场日本落叶松人工林为对象,采用普查和典型抽样相结合的方法调查林木受灾程度及相关影响因子,分析立地因子、林分结构特征和林木生长特性与受灾程度的相关关系及其影响程度,为预防雪灾和提高雪灾抵御能力提供参考和借鉴。研究结果表明:海拔对受害程度具有极显著影响,以海拔1800m为区分线,上下区域受灾程度存在显著差异,高海拔区域受灾程度是低海拔区域的2倍;不同坡向和不同坡向类型的受灾程度具有显著或极显著差异,其中东坡受灾程度最为严重,而半阴半阳坡>阳坡>阴坡;林分抵御雪灾的能力随着林龄的增长而增强,25年以上的林分的受灾程度明显较轻;密度超过2000株.hm-2的林分受灾程度极为严重,是密度1000株.hm-2以下的林分的近3倍;倾伏木与未受损木间有显著差异,高径比小的林木具有较强的抗倒伏能力,主要侧根数量较多、平均粗度较粗、根系生物量大的林木的抗倒伏能力明显较强。适地适树、合理密度控制、促进根系发育是提高林木抵御雪灾能力的有效途径。

General survey and typical sample plot investigation were used in this study to investigate the snow induced damage degree of Larix kaempferi plantation and the related influence factors in a state-owned forest farm in Jianshi county.This paper analyzed the correlations between the damage degree with the site index,stand structure and individual growth characteristics,as well as influence level of the factors to provide reference in enhancing the ability to defend for snow induced damage.The results showed that the elevation had extremely significant influence to damage degree.There was a significant difference in damage degree between area above 1 800 meter and area under 1 800 meter,and the damage degree in the high elevation area was twice of that in low elevation area.There was also a significant difference or extremely significant difference in the damage degree in different slope and slope type.Eastern slope was most serious and the damage degree on the different slope types was half-shady slope 〉sunny slope〉shady slope.The ability in defending snow induced damage enhanced with the increasing stand age and the damage degree was obviously lighter in stands older than 25 years.The damage degree of stands with density over 2 000 trees·hm^-2 was extremely serious and was about three times serious of that of stands with density less than 1 000 trees·hm^-2.There was a significant difference in their biological characters between uprooting individual and undamaged individual.The individuals which had lesser ratio of height to diameter,more main lateral root quantity,thicker main lateral root and more root biomass had obviously stronger ability of defending snow storm.The results suggest that the measures of choosing right trees to adapt the local sites,appropriately controlling stand density and promoting rooting would effectively enhance the ability of defending snow induced damage.