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作 者 ：蒋子涵,金光泽*

期 刊 ：生态学报 2010年 30卷 21期 页码：5843~5852

关键词：阔叶红松林(Pinus koraiensis)；径向生长；纵向生长；择伐；年轮分析；

Keywords:Pinus koraiensis, diameter growth, vertical growth, selection cutting, dendrochronological analysis,

摘 要 ：对择伐37a后的阔叶红松(Pinus koraiensis)林与原始林主要组成树种的年轮和树高数据进行分析,旨在了解择伐对其径向与纵向生长的影响。结果表明：(1)择伐显著促进了主要树种的径向生长(P<0.01),但生长增加量在树种间存在显著差异(P<0.01),其反应的强弱与耐荫性有关(r=-0.79, P<0.01),因择伐所导致的生长加速会持续26—29a。(2)择伐显著减小了主要树种的树高-胸径比(P<0.01),即同等胸径时择伐林的树木较矮,因此在计算择伐林蓄积量时应对树高进行实测。(3)径向生长率与树高、胸径之间存在显著相关性(原始林：r =0.65*,r =0.58*;择伐林：r =0.53*,r =0.48*),择伐林内每一树高级的径向生长率均高于原始林,其中树高级在10 m以下的树木差异最大(0.69),说明择伐有利于林下树木的生长。择伐显著增加了DBH＜40 cm树木的径向生长率,其中胸径在20—40 cm之间的树木有较大的伐后生长率,应予以保护。

Abstract:The mixed broadleaved-Korean pine (Pinus koraiensis)forest is one of the most complex and common vegetation types in northeast China. It is well known for its high biodiversity, complex stand structure and unique species composition. Because of unrestrained timber harvesting practices, the extent of the mixed forest has been greatly reduced and old-growth forest stands can only be found in reserves and national forest parks. The study objective was to determine whether the diameter and vertical growth response to selection cutting was immediate for five species. Two 1 hm2(100 m×100 m)plots were sampled, including half the plot in the selection cutting area (which was measured 37 years after commercial selection cutting)and half in the control area (virgin forest). Forest inventory and increment estimations on five major tree species were carried out in the two plots. For the two stands, living stems with DBH (diameter at breast height: 1.3 m above ground level)over 2.0 cm and height over 30 cm were measured to determine which is the major tree species. We randomly selected 15 living trees with a diameter above 10cm in the selection cutting area, from which two cores, each at 180, were took at breast height. Depending on the species, 15 additional trees with a diameter above 10cm were cored in the control area. The following three results were obtained. (1)The selection cutting significantly increased the survivor′s mean annual diameter growth for the five major tree species. The post-cut survivors′ growth of all major species responded similarly with an increase in the range of 39.70%. There was a significant correlation between species-specific response and shade tolerance(r=-0.79, P<0.01). The increasing rate of the strongest shade-tolerant species (Pinus koraiensis)increased the least, while the weakest shade-tolerant species (Acer mono)increased the most. Different tree species showed contrasting patterns of response: Acer tegmentosum showed a rapid growth in the first 5-year period after harvest, while Abies nephrolepis′ growth was highest for the third 5-year period. For all the major tree species, improved environmental conditions resulting from selection cutting lasted for 26-29 years following harvest. (2)Selection cutting significantly reduced the tree height-diameter rate (P<0.01), indicating that mean basal diameters are the same but lower heights occur in the selection cutting area. In order to calculate timber volumes accurately, we recommend that height should be measured. (3)The growth rates in the control and selection cutting areas were positively correlated with tree height (control area: r=0.65*; selection cutting area: r =0.53*)and DBH (control area: r=0.58*; selection cutting area:r=048*), but not with the trees′ age. The mean annual diameter growth of all trees in the selection cutting area was higher than that in control area; however, the difference was more significant among trees under 10 m (0.69), which indicated that selection cutting was good for understory growth. In addition, selection cutting showed different effects in different DBH classes. Selection cutting did not significantly affect trees with DBH more than 40 cm (40 cm≤DBH<50 cm: P=061; DBH≥50 cm: P=0.54). However, the effect was significant between trees with DBH less than 40 cm in the selection cutting area and in the virgin forest(P<0.01).The highest mean annual diameter growth was exhibited at 30 cm≤DBH<40 cm(3.92 mm/a),followed by 20 cm≤DBH<30 cm(3.64 mm/a),and the lowest at DBH<10 cm(2.44 mm/a). This indicated that trees with DBH in the range of 20-40cm should be particularly protected.

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