摘要
通过对渭北黄土高原刺槐人工林最大林木的树干解析和年轮分析描述了林分最大两株林木的树高、直径和材积生长过程。结果表明 ,矮林树高初期生长迅速 ,“好”立地的最大木高生长大于“差”立地上的最大木 ,矮林和“差”立地上的乔林之间树高生长过程达到最高峰的年龄为 4～ 8a ,“好”立地上的乔林为 12a左右。直径生长可以分为速生期和缓慢生长期 ,年轮波动在速生期幅度大 ,进入缓慢生长期后幅度小但频度加大。依据直径生长过程可以区分为两组 :第一组为最大木和次大木速生期为造林后 6～ 8a的林分 ;第二组林木的速生期可持续到 2 5a左右。年轮宽度的灵敏度指数在林分内最大木和次大木之间和在林分间差异都较大 ,刺槐矮林趋于比乔林大。生长越迅速 ,受到的人为干扰越强 ,年轮变化对干扰的反映越敏感 ,年轮灵敏度指数就越高。抚育间伐时常常伐去了利用价值高的个体 。
Growth process of height, diameter and volume of the largest two stems of some sampled black locust stands on Weibei-loess plateau were described by analyzing stem disks and growth rings. The results show that height of coppice grows faster than that of high forest of black locust during their young period. On 'good' site, the largest stems exhibit faster height growth than that on 'poor' site. Height growth of coppice and high forest on 'poor' sites culminated at an age of 4～8 year and on 'good' site at age around 12 years. Diameter growth process may be distinguished as two periods: fast and slow growing period. In fast growing period, tree ring fluctuates with larger range, while it waves in smaller range but larger frequency during slow growing period. Two groups may be differentiated according to diameter growth process: group with stands whose fast growing periods of largest and second largest stems are within 6～8 year;and group of stands whose fast growing periods last till about 25 years after afforestation. Sensibility index of tree rings are rather different between two largest stems and among stands, they tend to be larger for coppice than that for high forest of black locust?The faster the trees grow and the strong the stands were interfered, more sensible their tree rings react to them and therefore the higher the sensibility index of tree rings are?Some valuable big trees were often thinned during tending and former suppressed stems were left in the stands.
出处
《山东农业大学学报（自然科学版）》
CSCD
北大核心
2003年第1期44-49,共6页
Journal of Shandong Agricultural University：Natural Science Edition
基金
德国Andreas -Stihl基金会项目
