样方面积和数量对测定次生林凋落物精度的影响

经研究林地凋落物的重量分布特征,发现其总体分布具有偏态分布的特点。在中间区段(约为湿重 1.5S),凋落物重量在林地具有均匀分布的若干性质。测定林地凋落物累积量时,在27°山坡上,当样方面积超过0.5m~2后,所需样方数目渐趋稳定。因此建议设置样方时面积以为0.5—1.0m~2为佳。本文还计算出样方面积不同时,为保证一定精度所需的最少样方数。只要能够达到这一数目,任何大小的样方都能满足精度的需要。最后,通过研究坡度对凋落物收集的影响,可以看出,随坡度增大,林地凋落物重量的变异程度增加,同一取样面积上需设置的最小样方数目也随之增加。

EFFECS OF QUADRATE SIZE AND NUMBER ON PRECISION ESTIMATING LITTER AMOUNT OF SECONDARY FOREST

This study is carried out in secondary forest of Betula plctyphylla.Ey analyzing the distribution featines of litter amovnt on forest fleer . it is discovered that there are some characteristics of non-normal distribution , in the intervals (about green weight X ±1.5Sx-) there are some features of uniform distribution for litter amount ,on forest floor. While estanrating litter amount , the required minmum quadrate number is almost the same as quadrate size exceeds 0.5m2 on a 27° hillside. Therefore, it is ...