带状采伐毛竹林恢复的质量特征研究

以安徽省黄山区毛竹林样地内2018年春笋和新竹为研究对象,以传统择伐林为对照(CK),设置4个梯度的采伐强度,分别为3m采伐带(D1)、6m采伐带(D2)、9m采伐带(D3)和12m采伐带(D4),分析带状采伐后毛竹林主要生产力指标(春笋数量、新竹数量、胸径和生物量等)的差异,探讨不同强度带状采伐方式对毛竹林恢复更新的影响程度,为毛竹林合理带状采伐提供理论依据。结果表明:(1)4种带状采伐处理单位面积发笋数量均大于对照,且随采伐强度增加,单位面积发笋数量呈现增加的趋势;较高采伐强度(9m和12m采伐带)下单位面积退笋数量和退笋率比采伐强度较低处理(3m和6m采伐带)和CK更低;单位面积成竹数量和成竹率以较高采伐强度(9m和12m采伐带)处理下相对较高。(2)4种带状采伐处理的新竹平均胸径均小于对照,较高采伐强度(9m和12m采伐带)下新竹平均胸径显著小于母竹,林地中小径级新竹比例增加,且新竹胸径与采伐带边距呈负相关关系。(3)4种带状采伐处理下单位面积新竹地上生物量均小于对照,表现为CK>D3>D4>D2>D1。研究认为,毛竹林恢复的质量特征对不同强度带状采伐措施存在响应差异,6~9m采伐带的毛竹林恢复能力较强,但毛竹林带状采伐后恢复是一个周期性过程,需要综合考虑不同强度带状采伐措施对新竹质量影响的长期效应。

Qualitative Recovery Characteristics of Moso Bamboo Forests under Strip Clearcutting

In November 2017, we designed 5 treatments under different strip clearcutting in Moso bamboo forests in Huangshan District of Anhui Province, including the contrast (CK), 3 m logging strip (D1), 6 m logging strip (D2), 9 m logging strip (D3) and 12 m logging strip (D4). We investigated several indexes of spring shoot and new bamboo in 2018, mainly including the number of spring shoot and new bamboo, the diameter of breast height (DBH) of new bamboo and the biomass of new bamboo. We discussed the effects of different strip clearcutting measures on Moso bamboo forest restoration in order to provide a theoretical basis for scientific and reasonable logging widths of strip clearcutting of Moso bamboo forests. (1) The number of spring shoot per hectare in four logging treatments was larger than that of CK, and it increased with the increase of logging intensity. The number and rate of degraded shoot per hectare in treatments with higher intensity (9 m and 12 m logging strips) was lower than that of treatments with lower intensity (3 m and 6 m logging strips) and CK. (2) The mean DBH of new bamboo in four logging treatments were lower than that of CK, and the mean DBH of new bamboo in treatments with higher intensity (9 m and 12 m logging strips) was significantly lower than that of mother bamboo, and it was negatively correlated with logging strip margin. The proportions of new bamboo with small and medium DBH were increased in treatments with higher intensity (9 m and 12 m logging strips). (3) The biomass of aboveground per hectare of new bamboo in four logging treatments were lower than that of CK, following the order of CK, D3, D4, D2, and D1, respectively. There are different responses to different strip clearcutting measures on qualitative characteristics in Moso bamboo forests. In conclusion, the recovery ability of spring shoot and new bamboo in 6-9 m logging strips is better. However, the recovery of Moso bamboo forest after strip clearcutting is a periodic process, and it is necessary to consider the long term effects of different logging intensity on the quality of new bamboo.