子午岭植被演替过程中土壤生物学特性的动态

土壤生物学特性在土壤有机质的形成和降解、营养循环等方面起重要作用。植被的恢复演替显著影响土壤生物学特性,尤其影响土壤酶活性。植被演替过程中土壤酶活性的研究结果表明,随着植被恢复年限的延长,土壤脲酶和转化酶的活性逐渐提高,17 a达到最大值,随后有所降低。土壤酶活性和土壤化学特性和微生物量的相关性分析表明,土壤转化酶和脲酶不仅互相之间具有显著的相关性,而且它们与土壤有机碳、全氮、微生物碳氮之间都具有显著的正相关性,说明土壤酶活性与土壤有机质紧密相关,与微生物的大小紧密相关,所以土壤酶活性可以表征土壤生物学肥力。

The dynamics of biological properties of soil during secondary forest succession in Ziwuling, Northwest China

Soil biological properties play key roles in soil organic matter formation and degradation,and nutrient cycling.Soil urease and invertase activities were determined during restoration of degraded vegetation in north Ziwuling region in the middle of loess Plateau in China.The result showed that urease and invertase activities n soil increased quickly,and tended to be the highest contents under SF17(17-year secondary forest),after that they slightly decreased,suggesting that increase of urease and invertase activities in soil occurred mainly at the early succession stages(before SF17).Soil urease and invertase activities were highly correlated not only with each other(P<0.01),but also with organic carbon,total nitrogen and microbial biomass C and N,suggesting that there was a close relationship between soil enzymes and soil organic matter,the size of microbial biomass.Thus Soil enzyme activities appear to be a sensitive index of the change in soil fertility during vegetation restoration in north Ziwuling region.