衡阳紫色土丘陵坡地土壤酶活性对植被恢复的响应

摘要

以典型的衡阳紫色土丘陵坡地植被不同恢复阶段为研究对象。采用空间代替时间序列的方法，选用立地条件基本相似的裸荒地、草本群落、灌木群落和乔木群落4种类型表示恢复的4个阶段，通过调查取样和实验分析，探索不同恢复条件下0～10、10～20、20～40 cm土层酶活性的分布特征，以及土壤酶活性对植被恢复的响应。结果表明：1）随着恢复的进行，脲酶、蔗糖酶与碱性磷酸酶活性显著增加(P＜0.05)，过氧化氢酶活性显著减小(P＜0.05)。2）随着土层的加深，脲酶、蔗糖酶与碱性磷酸酶活性显著减小(P＜0.05)，过氧化氢酶活性显著增加(P＜0.05)。3）脲酶、蔗糖酶与碱性磷酸酶之间呈极显著正相关(P＜0.01)，且均与土壤含水量、物理性黏粒、土壤有机碳、全氮、全磷、碱解氮、速效钾、阳离子交换量呈极显著正相关(P＜0.01)，与容重及pH值呈显著或极显著负相关(P＜0.05或P＜0.01)。4）过氧化氢酶与脲酶呈极显著负相关(P＜0.01)，与蔗糖酶与碱性磷酸酶相关性不显著(P＞0.05)，与土壤有机碳、全氮、碱解氮、速效钾及阳离子交换量呈显著或极显著负相关(P＜0.05或P＜0.01)，与 pH 值呈显著正相关(P＜0.05)。5）土壤脲酶、蔗糖酶与碱性磷酸酶可敏感地反映植被过程中土壤质量的变化，植被恢复可改善表层与深层土壤的生物学性质。%By using the space series to replace time courses, four typical sample plots, bare land stage(Ⅰ), herbaceous community stage(Ⅱ), shrubby community stage(Ⅲ), arborea community stage(Ⅳ) in similar and typical sites on the sloping-land with purple soils in Hengyang, standing for four different re-vegetation stages, were selected as the study objects to explore the distribution characteristics of soil enzyme activities in 0-10, 10-20, 20-40 cm soil layers and the responses of the soil enzyme activitive to re-vegetation. The results showed that: 1)The activities of URE(Urease), INV(Invertase) and APE (Alk-phosphatase) significantly increased(P<0.05), but the activity of CAT(Catalase) was in adverse in the process of re-vegetation(P<0.05); 2)With increasing soil depth, the activities of URE, INV and APE significantly decreased(P<0.05), but the activities significantly increased(P<0.05); 3)There existed very significant positive correlation among the activities of URE, INV and APE(P<0.01), and the activities of them were all very significantly positively correlated with WC(Water content), CLY(Clay), SOC(Soil organic carbon), TN(Total N), TP(Total P), AN(Available N), AK(Available K) and CEC(Cation exchange capacity)(P<0.01), and very significantly or significantly negatively correlated with BD(Bulk density) and pH values(P<0.05 orP<0.01); 4) The activities of CAT was very significantly negatively correlated with the activities of URE(P<0.01), and no significant correlated with the activities of INV and APE(P>0.05), very significantly or significantly negatively correlated with SOC,TN,AN,AK and CEC(P<0.05 orP<0.01), and significantly positively correlated with pH values(P<0.05); 5)The activities of URE,INV and APE could be used as the sensitive indicators for the dynamitic changes of soil qualities, and re-vegetation could improve the biological properties in both surface and deeper soil layer.