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在黑龙江省小兴安岭东部地区(东经444-4726 N?北纬2633-13141? 海拔400-1000 m), 对不同封育时间、不同坡向的蒙古栎林中的主要乔木树种径级结构进行分析。在阳坡,针对封育5年 16年和24年蒙古栎种群, 分别选择6个重复样地。在阴坡,也同样分别选择6块样地。每块样地的面积为20 m×20 m。在每块样地中, 测量各树的胸高直径,树高和冠幅直径。结果表明:在封育5年样地内,蒙古栎、糠椴和黄榆种群的数量均随着径级的增加而单调下降,表明均为增长型种群;在封育16年以后,由于林内乔木层的盖度较大,糠椴和黄榆种群均呈不同程度的衰退,已经成为蒙古栎种群的伴生种群;封育24年样地中,蒙古栎种群明显成为优势树种。在阳坡随封育时间延长乔木层盖度增长较快,而阴坡乔木层盖度增长较慢;糠椴和黄榆种群随封育时间延长逐步衰退的现象在阳坡比阴坡表现明显。图2表1参8。
In the eastern part of Xiaoxing’an Mountains in Heilongjiang Province (444-4726 N longitude, 2633-13141 N longitude and 400-1000 m altitude above sea level), the diameter structure of main arbor species in Quercus mongolica forest with different sealing time and slope aspect was analyzed. On the sunny slope, six replicate plots were chosen for the Quercus mongolica population within 5 years, 16 years and 24 years respectively. In the shady slope, also choose 6 plots respectively. The area of each plot is 20 m × 20 m. In each plot, the thoracic diameter, tree height, and crown diameter of each tree were measured. The results showed that the population of Quercus mongolica, Tilia mandshurica and Ulmus pumila decreased monotonously with the increasing of diameter class in the five years of incubation, which indicated that all the populations were all of an increasing population. After 16 years of enclosure, The coverage of the layer is larger, and the population of Tilia mandshurica and Ulmus pumilum have declined to some extent, and it has become an accompanying population of Quercus mongolica. In the 24-year-old plots, the Quercus mongolica population obviously became the dominant species. In the sunny slope, the coverage of arbor layer increased rapidly with the incubation time prolonged, while the cover of shady slope tree layer increased slowly. The phenomenon of branching population of M.sativa and P. elhlia gradually declining with the time of enclosure was obvious in sunny slope than in shady slope . Figure 2 Table 1 reference 8.