Reduced-impact logging in Indonesian Borneo: some results confirming the need for new silvicultural prescriptions
Reduced-impact logging in Indonesian Borneo: some results confirming the need for new silvicultural prescriptions
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印度尼西亚婆罗洲的减少影响伐木：一些结果证实需要新的造林方案
DOI：
10.1016/s0378-1127(02)00533-9
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发表时间：
2003
影响因子：
3.7
通讯作者：
H. Priyadi
中科院分区：
文献类型：
--
作者：
P. Sist;D. Sheil;K. Kartawinata;H. Priyadi
在东加里曼丹的龙脑香混合山地森林中，在三个约100公顷的区块中，对减少影响伐木（RIL）和常规技术（CNV）进行了比较。在24个一公顷的样地中使用收获前和收获后的评估来评估损害。RIL技术几乎将被摧毁的树木数量减半（36对60棵树/公顷）。RIL的主要好处是减少了打滑损害（RIL中原始树木种群的9.5%对CNV中的25%）。采伐前，CNV（仅3个样地）和RIL（9个样地）的平均冠层开度相似（3.6%和3.1%），差异不显著（χ2=2.73，P=0.254）。采伐后，CNV（n=9个样地）和RIL（n=8个样地）的平均林冠开度分别为19.2%和13.3%，RIL和CNV的林冠等级分布差异极显著（χ2=43.56，P<0.001）。CNV图显示，最开放类别中≥30%的测量比例高于RIL。在更大的尺度上，每单位木材体积提取的滑道面积在RIL隔间中减半（15 m2 vs 27 m2 m − 3对于CNV）。然而，在高采伐强度（>8株/公顷）下，RIL中的林分损害和冠层干扰接近低或中等采伐制度下的CNV记录。超过这个采伐强度阈值，RIL在减少树木损害方面的有效性是有限的。在可采伐木材密度通常超过10棵树/公顷的龙脑香混交林中，最小直径砍伐限制显然不足以将采伐率保持在8棵树/公顷以下。在此基础上，提出了三条造林原则：（1）保持一定的伐桩间距;（2）采用定向采伐，保证单木林隙;（3）仅采伐60-100cm胸径的树干。林业工作者、决策者和核证者应将这些作为可持续森林管理的标准。我们强调需要扩大采伐研究，以研究更大森林景观的影响和权衡，将RIL扩展到造林概念之外，并包括其他森林产品和服务的维护。
Reduced-impact logging (RIL) and conventional techniques (CNV) were compared in a mixed dipterocarp hill forest in East Kalimantan in three blocks of about 100ha each. Damage was evaluated using pre- and post-harvesting assessments in 24 one-hectare sample plots. RIL techniques nearly halved the number of trees destroyed (36 vs 60 trees/ha). RIL’s main benefit was in the reduction of skidding damage (9.5% of the original tree population in RIL vs 25% in CNV). Before logging, mean canopy openness in CNV (three plots only) and RIL (9 plots) was similar (3.6 and 3.1%) and not significantly different (χ2=2.73, P=0.254). After logging, the mean canopy openness was 19.2% in CNV (n=9 plots) and 13.3% in RIL (n=8 plots), and the distributions of the canopy class in RIL and CNV significantly different (χ2=43.56, P<0.001). CNV plots showed a higher proportion of measurements in the most open class ≥30% than in RIL. At a larger scale, the area of skidtrail per unit timber volume extracted was halved in the RIL compartment (15m2vs 27m2m−3for CNV). However, under high felling intensity (>8 trees/ha), both stand damage and canopy disturbance in RIL approached those recorded in CNV under low or moderate felling regime. Over this felling intensity threshold the effectiveness of RIL in reducing tree damage is limited. In mixed dipterocarp forest where harvestable timber density generally exceeds 10 trees/ha, a minimum diameter felling limit is clearly insufficient to keep extraction rates below 8 trees/ha. Based on these new results and previous studies in Borneo, we suggest three silvicultural rules: (1) to keep a minimum distance between stumps of ca. 40m, (2) to ensure only single tree gaps using directional felling, (3) to harvest only stems with 60–100cm dbh. Foresters, policy makers and certifiers should consider these as criteria for sustainable forest management. We emphasise the need to expand harvesting studies to look at impacts and trade-offs across larger forest landscapes, to expand RIL beyond silvicultural concepts and to include the maintenance of other forest goods and services.