植被砍伐对土壤养分的影响

研究了不同砍伐频率下，香港、深圳和鹤山研究样地山坡地Ｎ、Ｐ、Ｋ含量的差异．不同采样地之间，养分全量和有效量差异显著．在尚未砍伐的山坡地，土壤养分含量显著高于经常砍伐的山坡地．未伐土壤的Ｎ含量顺序为香港样地＞深圳样地＞鹤山样地．下层土壤Ｐ的含量高于上层土壤．深圳样地常代土壤养分含量高于鹤山．结果建议采用最适砍伐频率和在最适季节砍伐，以便减少砍伐产生的不利影响．

Effect of vegetation harvesting on soil nutrients

The difference in N, P and K contents of hillside fields under different harvesting frequencies is investigated at Hong Kong, Heshan and Shenzhen study sites. There are significantdifferences in total and available nutrient contents among sampling locations. Soil nutrient contents on uncutting hills are significantly higher than those on often-cutting ones, and in the former case, soil N content is in the order of Hong Kong >Shenzhen >Heshan.Lower soil layers have a higher P content than upper ones. Often-cutting hill has a highernutrient content at Shenzhen than at Heshan. It is suggested that vegetation harvestingshould be done under optimal frequency and within optimal season to minimize its detrimental effect.