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›› 1964, Vol. 9 ›› Issue (1): 1-31.

• 论文及研究报告 •    下一篇

森林更新调查及鉴定标准

黄中立   

  1. 中国林业科学研究院林业科学研究所
  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:1965-10-01 发布日期:1965-10-01

FOREST REGENERATION SURVEY AND ITS STANDARD

Huang Zhongli   

  1. Institute of Forest Science, Academy of Forest Science
  • Received:1900-01-01 Revised:1900-01-01 Online:1965-10-01 Published:1965-10-01

摘要: 森林更新的质量鉴定标准是森林更新调查得出确切论断的重要依据。鉴定标准一般包括单位面积株数和苗木分布情况两项因素。文中对于现在苏联及我国比较通用的聂斯切洛夫教授森林更新株数标准以及其他十余种标准进行了分析比较,认为该项标准首先应分别树种,分别林型或地位级,参照林分生长过程表上的林分株数生长过程来编制。具体作法是以林分每公顷株数及平均胸径关系曲线为准绳,选定介于因林分郁闭自然死亡而株数减少的速度与株数完全不减少之间的速度,作为更新林分最常出现的株数减少的速度;再预定以5厘米,10厘米,15厘米,20厘米作为郁闭时林分平均胸径,从对数图纸所绘曲线上四个点出发,便可以作出四条平行线,将各树种各地位级更新林分株数变异情况规划为五个部分,作为鉴定更新的五个等级,在每个等级以内可以预测该更新林分郁闭的年度,郁闭胸径以及郁闭时林分的每公顷株数。根据这种方法已将我国现已编成林分生长过程表的十几种树木54个分地位级或林型的表都编订各级更新株数标准数字,并求出216个相应的关系式。关于调查幼苗和幼树的分布,一般以采用立木度这项指标较好。立木度是更新林分将来能否郁闭成林的指标,可以在用小样地对同一林分进行多次抽样时,样地内出现“有”,“无”更新苗的百分数来表示。本文认为这类小样地应以圆形而其面积接近于该更新树种近熟林时期单株的平均树冠面积为合适。在更新林分逐渐郁闭的过程中,各次调查的立木度也逐步增加,直到林分郁闭,立木度等于百分之百时为止。更新林分的立木度也可以与成林的立木度联系起来,虽然两个指标的依据不同,但可以互相结合,然后便可以引导更新林分逐步走上及时抚育、合理经营的道路。文中并提出关于两种以上树种或两种以上不同测树因子更新林分复合立木度的计算原理和方法。最后关于森林更新调查方法分别不同的更新方式提出各种要求及改进意见。

Abstract: The standards of forest regeneration survey of Prof. V. G. Nescherov. USSR and many authors of other country are compared and studied. Some of them take the ideal of deriving regeneration standards from yield tables as the basis of their studies. It is necessary to take the number of trees per hectare of different age classes in yield tables as a reference of projecting the standards,of forest regeneration survey for various types and site classes of different tree species. Plot the number of trees over the average diameter on the double logarithmic paper it is found that the curve appearing negative and slightly convex upward which superposes the mortality of fully stocked stands. As the horizontal line on above graph denotes no decreasing of number of trees with increasing average diameter, the most probable case of mortality after forest regeneration will follow the equal divided line of the angle made by the horizontal line and that curve. Take 5 cm, 10 cm, 15 cm and 20 cm as the predicting average diameters of fully stocked stands, four parallels can be drawn from corresponding points on that curve with the same slope as the divided line of that angle. These four parallels cut the area under curve into 5 parts which might represent 5 grades of forest regeneration. Therefore the predicting average age, average diameter and average number of trees per hectare for the regenerated stands for each grade can be figured out. According to above method, the author develops 216 allometric equations and corresponding standards of forest regeneration survey for 54 site classes or types of main tree species in China that have yield tables already constructed. The author adopts the degree of stocking as a proper index of seedling distribution. The percent of plot which incur seedling on a series of plots by systematic sampling will denote the degree of stocking. It is proposed that the small plot should be circular in. shape and its area should be approximately equal to the average crown projection area of the premature trees of various species. As the stands grow old, the crown canopies begin to close up, the degree of stocking becomes greater and greater till 100% or more. The calculating measure of degree of stocking of regenerated stands must be concord with that old stands though they are based upon different mensurational elements so that the stands can be managed and thinned in a unified way. The principle and method of calculating the degree of stocking for multiple species and for stands with different mensurational basis are also mentioned. Finally, proposals and betterments are given to the method of survey for various ways of forest regeneration.