浙江天童植物群落演替对土壤化学性质的影响

对浙江天童植物群落演替过程的土壤腐殖质层、0～10cm层和10～20cm层化学因子的比较研究结果表明,随着进展演替,土壤全氮含量呈明显增长趋势,但硝态氮、氨态氮、速效氮、速效磷和速效钾含量除演替初期的裸地、灌丛较小外,森林群落阶段增长趋势一般不明显;土壤pH值则缺乏明显的规律性,但有机质含量呈明显增长趋势,而富里酸和胡敏酸含量,除栲树木荷林和栲树林较高,裸地最低外,其它演替阶段增长趋势也不明显;HA/FA在腐殖质层缺乏明显的规律性,但在0～10cm和10～20cm层则呈减少趋势。可见,常绿阔叶林次生演替能增加土壤有机物质含量,促进土壤有机物质的矿化和再合成作用;而土壤化学性状的改善,也为常绿阔叶林的进展演替奠定了基础。

Effect of plant community succession on soil chemical properties in Tiantong, Zhejiang Province

Comparative studies on the chemical factors in humus layer and 0～10 and 10～20cm soil layers at the main succession stages of evergreen broad-leaved forest in Tiantong, Zhejiang Province show that as succession proceeded, the total N content increased distinctly,but the contents of NO₃^--N,NH₄⁺-N and available N,P and K had no distinct increase. No obvious variation was found for soil pH. Soil organic matter content increased distinctly, and the amounts of humic acid(HA) and fulvic acid(FA) were relatively high in Castanopsis fagasii and C.fagasii＋Schima superba forests and lowest in bare land. The HA/FA in humus layer didn't show any obvious pattern, but decreased in 0～10 and 10～20cm soil layers. The results suggested that the secondary succession of evergreen broad-leaved forest could increase soil organic matter, and promote its mineralization and re-synthesis. On the other hand, the improvement of soil chemical properties could also provide better prerequisite for progressive succession of evergreen broad-leaved forest.