Wood production, litter fall and humus accumulation in a Czech thinning experiment in Norway spruce (Picea abies (L.) Karst.)
Wood production, litter fall and humus accumulation in a Czech thinning experiment in Norway spruce (Picea abies (L.) Karst.)
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DOI：
10.1016/j.foreco.2005.01.011
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发表时间：
2005-04
影响因子：
3.7
通讯作者：
M. Slodičák;J. Novák;J. P. Skovsgaard
中科院分区：
文献类型：
--
作者：
M. Slodičák;J. Novák;J. P. Skovsgaard
本文报道了位于捷克共和国维特科夫前农田上的偶数龄挪威云杉的间伐试验结果。这项实验是在IUFRO的赞助下建立的欧洲范围内的一系列实验的一部分。维特科夫的现场生产率很高。实验包括五个处理，两个区组四个(伪)重复。这些处理包括四个间伐制度和一个不间伐的对照。间伐制度是基于两个水平的模拟机械化、两个不同的选择原则(主要从下向间伐或树冠间伐)、三种不同的间伐操作顺序(早期、后期或取决于可用的种类)和两种不同的机架宽度(3.5或5.0米)来定义的。除不间伐对照外，所有处理都包括早期、重度间伐，目标是最终收获每公顷400棵预选树木。在未稀疏的对照中，茎的数量仅通过自然死亡而减少。经过29年的观察，从8年生到37年生，试验表明，由于间伐，林分蓄积生长减少了14%-23%。在最初的重度间伐之后，如果在第一次间伐后不久进行，则后续的间伐会导致体积增长的更大幅度的减少。随着机架宽度的增加，卷增长的减少量略有增加。混交间伐(冠层间伐)导致林分蓄积生长最大幅度的减少，但这种模式似乎取决于立地或其他当地条件。在39年生时，未间伐对照和间伐样地凋落物干重变化范围为8500~8700kgha−1(干重)，叶凋落物占7100~7800kgha−1。全有机层中积累的生物量干重为8万~10万kgha−1。有机层积累了720~950kgha−1的氮，通过凋落物的年归还量为75 kgha−1。有机层的生物量含有2万kgha−1的碳。未间伐对照和间伐样地凋落物含量差异不显著，但间伐样地生物量和养分(除钙外)含量较低。这支持了与未间伐的挪威云杉相比，间伐林分的有机层中养分分解和循环更快的理论。
This paper reports results from a thinning experiment in even-aged Norway spruce, located on former agricultural land at Vitkov in the Czech Republic. The experiment is part of a European-wide series, established under the auspices of IUFRO. Site productivity at Vitkov is high. The experiment includes five treatments with four (pseudo) replications in two blocks. The treatments comprise four thinning regimes and an unthinned control. The thinning regimes were defined based on two levels of simulated mechanization, two different selection principles (thinning pre-dominantly from below or crown thinning), three different sequences of thinning operations (early, late or depending on available assortments), and two different rack widths (3.5 or 5.0m). All treatments, except the unthinned control, include an early, heavy thinning and aim for a final crop of 400 pre-selected trees per ha. In the unthinned control, stem number is being reduced only through natural mortality. After 29 years of observations, from age 8 to 37 years, the experiment demonstrates a reduction of 14–23% in stand volume growth due to thinning. Following an initial, heavy thinning, subsequent thinnings result in a larger reduction in volume growth if they are carried out shortly after the first thinning. The reduction in volume growth increases slightly with increasing rack width. Assortment thinnings (crown thinning) lead to the largest reduction in stand volume growth, but this pattern seems to depend on site or other local conditions. At an age of 39 years, litter fall in an unthinned control and a thinned plot ranged from 8500 to 8700kgha−1(dry weight), with foliar litter accounting for 7100–7800kgha−1. The dry weight of biomass accumulated in the holorganic L-, F-, and H-horizons ranged from 80,000 to 100,000kgha−1. The organic horizons accumulated 720–950kgha−1of nitrogen, with an annual return of nitrogen through litter fall at 75kgha−1. The biomass in the organic horizons contained 20,000kgha−1of carbon. There were no differences between litter fall in the unthinned control and the thinned plot, but a lower content of biomass and nutrients (except calcium) in the thinned plot. This supports the theory of faster decomposition and cycling of nutrients in organic horizons of thinned stands, as compared to unthinned stands of even-aged Norway spruce.