不同栽杉代数林下植被营养元素的生物循环

通过对南平溪后２９年生杉木林不同连栽代数林林下植被生物量、营养元素及养分循环的研究。结果表明：３代杉木林林下植被总生物量、草本生物量、灌木层生物量均高于２代的和１代的。林下植被层的Ｎ、Ｐ２Ｏ５、Ｋ２Ｏ、Ｆｅ、Ｍｎ、Ｃｕ、Ｚｎ营养元素含量均随连栽代数增加而下降；同一林分林下植被层中，草本层上述各营养元素含量高于灌木层的。不同栽杉代数林下植被营养元素积累量大小顺序均为Ｎ〉Ｋ２Ｏ〉ＣａＯ，ＭｇＯ〉Ｐ２Ｏ

Nutrient Elements Biological Cycle of Undergrowth under Different Rotations of Continuously Planting Chinese Fir

Through studies on biomass,nutrient elements and nutrient cycle of undergrowth of 29-year-old Chinese fir plantations under different rotations of continuously planting in Xihou of Nanping city, the result indicated that the total undergrowth biomass,gerb layer biomass,shrub layer biomass under the third planting were all higher than that under the second and first. The contents of nutrient elements such as N,P2O5, K2O, Fe, Mn, Cu, Zn decreased along with the increasing of continuously planting and the contents of nutrient elements of gerb layer were higher than that of shrub layer under the same stand;the accumulations of nutrient elements of undergrowth were all in the sequence of N>K2O>CaO,MgO>P2O5,Mn>Fe>Zn>Cu under different rotations of planting; the annual uptake and return increased along with the increasing of continuously planting,and the recycling rate of individual nutrient element followed the order of the second planting>the third planting>the first planting.