论文部分内容阅读
樟子松已成为三北沙区防护林主要乔木造林树种,但是,最早于20世纪50年代在科尔沁沙地引种的沙地樟子松却出现了生长衰退、枯梢直至死亡的现象,而天然状态的樟子松在该阶段却正处于旺盛生长期。为了比较沙地人工樟子松林与天然林的林分结构、生长特点及所处立地的生态因子的异同,对辽宁省彰武县章古台(最早引种沙地樟子松区)和内蒙古自治区红花尔基(天然樟子松分布区)的樟子松林进行了综合调查。结果表明,Weibull分布函数可较好地模拟人工林树木直径分布,正态分布函数可用于模拟天然林树木直径分布。基于树干解析的树木生长模型(Chapman-Richards)分析,人工林胸径、树高与材积的相对生长率与平均生长率的最大值比天然林分别提早11、22年,6、18年和35、59年。人工林材积的生长加速度高峰值出现在14年,而天然林则出现在33年;人工林的数量成熟龄为43年,天然林为102年;因此,可以推断天然林的寿命比人工林要长近60年。这一结果可以归纳为以下综合作用:1)两种起源地生态因子的巨大的差异,主要包括:人工林区的纬度、平均气温、降水量、蒸发量、海拨高度等较天然林区高;2)人工林的林分密度较天然林大;3)人工林区的干扰强度较天然林强。图4表6参23。
Pinus sylvestris var. Mongolica has become the main species of tree species for shelterbelts in Sanbei Sandy Area. However, Pinus sylvestris var. Mongolica, introduced in the Horqin Sandy Land as early as the 1950s, appears to have the phenomenon of growth decline and shoot death till its death. Of the Pinus sylvestris is in this stage is in a strong growth period. In order to compare the similarities and differences of stand structure, growth characteristics and eco-factors of artificial Pinus sylvestris var. Mongolica and natural forest in sand land, a comparison was made between Zhanggutai (earliest introduced Scotch pine in Zhangwu County, Liaoning Province) and Inner Mongolia Autonomous Region A comprehensive investigation was conducted on the Mongolian pine forest in Honghuaerji (natural Pinus sylvestris distribution). The results show that Weibull distribution function can simulate the diameter distribution of plantation trees well, and the normal distribution function can be used to simulate the distribution of tree diameter in natural forests. Based on the Chapman-Richards analysis of tree trunk, the maximum relative growth rate and average growth rate of DBH, tree height and volume were 11, 22, 6, 18 and 35 years earlier than that of natural forest respectively, 59 years. The peak value of plantation biomass growth appears in 14 years, while that of natural forest appears in 33 years; the mature age of plantation is 43 years and that of natural forest is 102 years; therefore, it can be inferred that the life of natural forest is longer than that of plantation Nearly 60 years. This result can be summed up as follows: 1) The huge differences of ecological factors between the two origins include: the latitude, average temperature, precipitation, evaporation and altitude of artificial forest are higher than that of natural forest ; 2) The stand density of plantation is larger than that of natural forest; 3) The disturbance intensity of plantation is stronger than that of natural forest. Figure 4 Table 6 参 23.