雷竹林严重低温寒害与立竹性状和林地覆盖经营的关系

Damage characteristics of Phyllostachys violascens forests and relationship with bamboo status and mulching management exposed to freezing stresses

关键词:  雷竹, 低温寒害, 林地覆盖经营, 立竹年龄

Key words:  Phyllostachys violascens, freezing rain and snow hazards,mulching management, bamboo age

摘要:

为探讨雷竹林严重低温寒害特征及其影响因子,2016年1月下旬至2月上旬严重低温寒害后调查了不同林地覆盖经营年限雷竹林不同年龄和胸径立竹的受损情况。结果表明:持续低温寒害使雷竹叶片失水结冰、失绿、黄枯,严重的整株叶片枯黄脱落; 竹秆干缩,颜色变黑,叶鞘枯黄,立竹死亡。严重低温寒害气候条件下,3 cm≤DBH<5 cm立竹的受损类型主要为Ⅰ～Ⅲ类,较小径级(DBH < 3 cm)和较大径级(DBH≥5 cm)立竹的Ⅳ类受损情况明显提高; 2年生、3年生立竹受损程度类型主要为Ⅰ类和Ⅱ类,而1年生、3年生以上立竹受损程度类型主要为Ⅲ类和Ⅳ类; 短期林地覆盖(≤3 a)雷竹林立竹受损类型主要为Ⅰ～Ⅲ类,而长期林地覆盖(≥5 a)雷竹林主要为Ⅲ类和Ⅳ类,且Ⅳ类受损率明显提高,休养式覆盖雷竹林Ⅳ类受损率低于20%,显著低覆盖3 a及以上雷竹林。研究表明,严重低温寒害气候条件下,立竹年龄、立竹胸径和林地覆盖经营对雷竹林立竹受损程度均有重要影响,宜留养3～5 cm立竹,合理调控竹林立竹年龄结构,留足2～3年生立竹,采取休养式林地覆盖经营方式,连续林地覆盖年限不宜超过3 a。

Abstract:

To analyze the damage characteristics of Phyllostachys violascens forests and relationship with mulching management after the freezing rain and snow events, the damage characteristics of bamboo with different ages and diameters at breast height(DBH)from the bamboo stand under different periods and types of mulching management were investigated. The bamboo leaves were hurt severely, turning yellow with icing cover, dehydration or complete leaf abscission. The stems of serious damaged bamboos shrinked and became black, and chlorisis occured to the leaf sheaths. The damage degrees of bamboo with 3 cm≤DBH<5 cm were Type Ⅰ and Type Ⅲ damages, while Type Ⅳ damage for bamboo with DBH<3 or DBH≥5 increased obviously. The damage degree of 2- and 3-year old bamboo was Type Ⅰ and Type Ⅱ damages, while that of 1- and >3-year old bamboo was Type Ⅲ and Type Ⅳ damages. The damage degree of bamboo from the bamboo stand with short-term mulching management(≤3 a)showed Type Ⅰ and Type Ⅲ damages, while that for long-term mulching management(≥5 a)was Type Ⅲ and Type Ⅳ damages. Furthermore, the bamboo of Type Ⅳ damage from stand of respite-mulching(3-year mulching + 2-year respite)was lower than 20%, which was damaged more slightly. It can be concluded that bamboo ages, DBH and mulching management influence damage degree of bamboo greatly under freezing stress. The bamboo with medium DBH(3 cm≤DBH<5 cm)and 2-and 3-year old was damaged slightly which is suitable bamboo with high tolerance under low temperature stress. Bamboo from the stands in long-term mulching management(≥5 a)was damaged greatly, while that for bamboo stand of respite-mulching(3-year mulching + 2-year respite)management was damaged slightly. The suitable duration for mulching management is three years to increase resistance of bamboo against freezing stress.