竹笋采挖下克隆整合对毛竹林发笋成竹规律的影响

Effects of clonal integration on the growth regularity for shooting and young bamboo period of Moso Bamboo(Phyllostachys pubescens)forests under harvest bamboo shoots

【目的】为研发毛竹林高产高效生态经营技术提供一定参考。【方法】调查浙西南地区采挖毛竹林竹笋后的笋-幼竹生长过程,通过存活曲线分析毛竹林挖笋后的发笋成竹规律,探讨挖笋对竹笋中单宁、粗脂肪、粗蛋白等品质指标的影响。【结果】竹笋采挖提高了毛竹林地的发笋能力,挖笋样地的发笋数比未挖笋样地增加了12.8%(P<0.05),而挖笋后选留竹笋的存活率也显著高于未挖笋样地;与未挖笋样地相比,挖笋样地内毛竹新分株的平均胸径并未发生显著改变(P>0.05),挖笋不会降低新分株胸径而使林分衰退;竹笋间的非对称性竞争有利于竹笋地径的径级为Ⅰ-Ⅲ级竹笋的生长与存活,随着地径的提高竹笋死亡率显著降低,而径级Ⅳ级以上竹笋则有着较高的死亡率。盛笋早期以后,径级相对较小(Ⅳ级以上)的竹笋开始大量萌发,这类竹笋若不及时采挖,大部分会出现退笋,造成资源浪费;挖笋和未挖笋样地竹笋的含水率、蛋白质和粗脂肪含量在各笋期均未见显著差异(P>0.05),尽管挖笋样地竹笋的单宁含量在末笋期显著高于未挖笋样地,但两种样地其他笋期单宁含量均未见显著差异。【结论】毛竹林竹笋的采挖,可缓解竹笋间的非对称性的资源竞争,有效避免大量退笋导致的毛竹母株营养消耗,实现母株资源的克隆整合,增加竹笋产量。因此,合理的竹笋采挖有利于毛竹笋用林的高效生产及可持续性经营。

【Objective】To provide reference for the technology research and development of high production and high efficiency ecological management of Moso Bamboo forests.【Method】The growth regularity of shooting and young bamboo period of Moso Bamboo forests were investigated under harvest bamboo shoot treatments in Southwest Zhejiang province.The survival curve was used to analyze the growth regularity for shooting period of Moso Bamboo forests under harvest bamboo shoots,and the effects of harvest bamboo shoots on the content of tannin,crude fat and crude protein in bamboo shoots were studied.【Result】Significant differences of shooting capability were found between the harvest bamboo shoot and CK(unharvested bamboo shoots)stand,shoots quantity under harvest shoot treatments increased by 12.80%than that of CK(P<0.05).Compared to the unharvested bamboo shoots stand,DBH of the 1-year-old ramets of Moso Bamboo forests had no significant change after harvest bamboo shoot treatments(P>0.05).Asymmetric competition among bamboo shoots was conducive to the growth of bamboo shoots with diameter classⅠ-Ⅲ,and the bamboo shoots with ground diameter above classⅣhad a higher mortality.The mortality decreased gradually with increasing ground diameter of bamboo shoots.After the early period of the peak shooting,the bamboo shoots with relatively small diameter(above classⅣ)began to germinate in large quantities.If these bamboo shoots were not harvested in time,most of them would die,resulting in waste of resources.Moisture content,protein and crude fat content of bamboo shoots had no significant difference between the harvest bamboo shoot and unharvested bamboo shoots stand in different shooting period(P>0.05),but tannins content were increased in the bamboo shoots of the later cohorts under the harvest bamboo shoot treatments.【Conclusion】Harvest bamboo shoots in Moso Bamboo forest can alleviate the asymmetric resource competition among bamboo shoots,effectively avoid the nutrient consumption of the mother plant of Moso Bamboo caused by the death of bamboo shoots,and increase the production of bamboo shoots.The reasonable harvest bamboo shoots should be conducive for the efficient production and sustainable management of Moso Bamboo forest.