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麻竹(Dendrocalamus latiflorus Munro),秆高20~25 m,直径15 cm~30 cm,是我国南方栽培最广的大型合轴丛生竹种[1]。麻竹笋、材、叶兼用,在广东、广西、福建、四川等省区形成了优势笋竹产区。竹林年年择伐利用,老竹和笋株采伐后产生大量竹蔸,因其须根继续吸收土壤中的水分、养分,并通过地下茎与分株共享资源,保持着生理活性难以自行腐烂分解[2],持续占据竹丛地下生长空间,影响新笋质量和数量。随着竹林经营的延续,丛蔸逐年高抬,形成低效竹林。
传统竹林经营采用物理方法人工挖取老竹蔸。为探索人工促进竹蔸消退轻便技术,顾小平等人通过将KOH和/或生石灰的固态物质或水溶液灌入竹蔸内加速竹蔸腐烂的技术,已获得了国家发明专利[3];且朱颜等人用此法筛选最佳药剂处理浓度,验证此法经济有效[4]。李超等分离筛选腐朽竹蔸中的微生物,获得降解毛竹木质素和纤维素的优良菌株,但未能用于实践推广[5];另有通过在竹蔸内施肥促进竹蔸腐烂的方法,但需要3~4年时间[6,7]等。既有清除竹蔸的研究中,多以散生竹毛竹为研究载体[3-11]。而针对丛生竹丛蔸高抬和密集竹蔸的人工促进消退的轻便技术鲜有研究。
相关研究表明,竹子是一种典型的非均质结构,木质素、半纤维素和果胶组分把中空的薄壁细胞和近似实心的竹纤维束粘结在一起。强碱溶液会打断植物细胞壁中纤维素、半纤维素与木质素之间连接的酯链,将竹材细胞角隅区域和复合胞间层中的木质素与胶质组分选择性脱除,增加纤维素之间的空隙度[12,13],此法可使竹蔸结构疏解,加速其腐烂消退。本文通过适度钻通蔸腔,施放不同浓度的氢氧化钾溶液,测定强碱浸蚀后竹蔸理化性状表现,为竹蔸消退“物理+化学”人工促进技术研发提供科学依据。
Determination and Analysis of the Etching Effect of Potassium Hydroxide Solution on Dendrocalamus latiflorus Bamboo Stumps
doi: 10.12172/202205230003
- Received Date: 2022-05-23
- Available Online: 2022-09-21
- Publish Date: 2022-12-30
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Key words:
- Bamboo stump /
- Etching /
- Erosion corrosion /
- Potassium hydroxide
Abstract: Dendrocalamus latiflorus bamboo stumps occupied the stump space after selective cutting of old bamboos and bamboo shoots, which was an important reason for low efficiency of bamboo shoot forest. The test of bamboo stumps etching with potassium hydroxide solution showed that the erosion of strong alkali solution made the inner wall of the bamboo stump soften, the thin-walled cells were damaged, the vascular bundles were stripped and collapsed, and the structure and hardness of the outer wall were limited. The individual bamboo stump was physically inactivated, which was conducive to the participation of natural microorganisms in promoting decay. The strong alkali erosion resulted in significant changes in lignin, cellulose, hemicellulose and ash content of bamboo stumps, and 0.50 g/mL potassium hydroxide solution was the best treatment concentration in this experiment. When the stump chamber was treated with potassium hydroxide solution, the pH value decreased to weak alkalinity, and the potassium carbonates in the reactant were all environmentally friendly.