不同收获与清林方式对杉木林养分的影响

Effect of harvesting and cleaning on nutrition in Chinese fir plantation

对三代杉木林全株、全木和传统收获及传统和全木收获后火烧清理迹地林分营养元素变化进行了研究 ,结果表明 :杉木林采用全株收获和全木收获的营养元素损失量分别是传统收获的1 99倍和1 64倍 ;采伐剩余物火烧导致林地生态系统中N和P2O5 大量损失 ;采用传统收获及随后火烧清理采伐剩余物 ,N和P2O5 损失量比仅采用全株或全木收获的均高。若缩短轮伐期 ,则可能导致立地N和P2O5 的严重亏缺 ;全株或全木收获导致大量盐基离子移出林地 ,可能导致土壤较为严重的酸化趋势。

The trasferrence of nutrient elements caused by three different harvesting systems of complete tree harvesting,whole tree harvesting and conventional harves ting under the third rotational stand of Chinese fir were compared in this paper.The result indicated that the loss of nutrient elements due to complete tree and whole tree harvesting was 1 99 and 1 64 times that of due to conventional harvesting,respectively.Slash burning resulted in great loss of N and P2O5 in forest ecosystem.The loss of N and P2O5 from stands due to adopting conventional silvicultural system (harvesting and following burning) was both higher than that of whole tree and complete tree harvesting without burning.Thus,shortening rotation length may cause serious deficiency of site N and P2O5 on site.Complete tree and whole tree harvesting can cause substantial base ion removal from the stand and resulted in seriously soil acidification.