间伐对川中丘陵区人工柏木林下天然更新的影响

以川中丘陵区"带状采伐+补阔"试验基地作为研究对象,调查其林下天然更新情况。结果表明:(1)采伐带、保留带天然更新的幼树幼苗明显高于对照样地(P<0.05)。10m、8 m、6 m、4m采伐带、保留带的天然更新幼树幼苗分别是对照的10.63倍、9.38倍、7.92倍、7.50倍和3.33倍、3.75倍、4.38倍、6.04倍。(2)采伐带、保留带、对照样地内的更新幼树幼苗的树高均显现为左偏单峰结构,且均以树高≤0.1m的幼苗数量最多。不同带宽采伐带和保留带内天然更新的幼树幼苗高度分级占比不尽相同。(3)所有处理下的天然更新的幼树幼苗均呈聚集状分布的状态,且聚集强度较大。(4)除柏木外,天然更新的树种种类多以香樟、香椿、乌桕等喜阳或半喜阳的为主。

The Effect of Intermediate Cutting on Natural Regeneration of Cupressus funebris Plantation

By experimental base of "strip cutting & planting broadleaf trees", the natural regeneration under the forest was investigated in the hilly area of central Sichuan. The results showed that (1) the natural regeneration seedlings in cutting and reserving zones were significantly higher than those in control plots ( P < 0.05). The seedlings of natural regenerated young trees in 10 m, 8 m, 6 m, 4 m cutting belts and reserved belts were 10.63 times, 9.38 times, 7.92 times, 7.50 times and 3.33 times, 3.75 times, 4.38 times and 6.04 times of the control respectively.(2) The tree height of the regenerated saplings in the cutting zone, reserved zone and control plot showed a left-sided single-peak structure, and the number of seedlings with tree height of less than 0.1M was the largest. The proportion of seedling height grading of natural regeneration was different in different bandwidth harvesting belts and retaining belts .(3) Natural regenerated young seedlings after undergoing all treatments showed aggregate distribution, and aggregation intensity was high.(4) In addition to cypress, most of the naturally regenerated tree species were sunny or semi-sunny, such as camphor, toon and Chinese tallow.