不同年龄木麻黄林地根际土壤养分含量和酶活性动态

在福建省东山县滨海沙地，开展了不同年龄木麻黄林地根际和非根际土壤养分和酶活性的测定，研究结果表明：（1）不同年龄木麻黄林地根际pH小于非根际土壤，随林龄增长根际土壤和非根际土壤pH值均表现为下降趋势；根际土壤有机质、全氮和水解氮含量高于非根际土壤，各土层有机质含量在中龄林时最大；从中龄林阶段至过熟林，水解氮含量下降；全磷和速效磷含量从幼林发育至中龄林、近熟林逐渐减少，至过熟林略有恢复；根际土壤全钾、速效钾含量呈增加趋势。（2）不同年龄木麻黄林地根际CEC值、水解性总酸度、交换性盐基总量、交换性Mg^2＋均大于非根际土壤；幼林龄根际交换性Ca^2＋低于非根际；土壤CEC值在中龄林时最高。（3）不同年龄木麻黄林地根际土壤磷酸酶、过氧化物酶和多酚氧化酶活性均大于非根际土壤；随着林木的生长，根际和非根际土壤磷酸酶活性逐渐升高，并且根际与非根际间的差异也呈增大趋势；根际过氧化物酶活性从幼龄林到中龄林下降，随着林木生长至过熟林有所升高；根际多酚氧化酶活性在过熟林阶段高于其它发育阶段。

Rhizosphere Soil Nutrient and Enzyme Activity in Different Stand Age of Casurina equisetifolia Protection Forest

This article emphatically reviews the difference of soil chemical properties and biochemical activities between the rhizosphere and non-rhizosphere soil in different stages of Casuarina equisetifolia.It also reviews their dynamic patterns during Casuarina equisetifolia development.The result showed as follows:(1)In different stages of C.equisetifolia protection forest development, the pH value in rhizosphere soil was lower than that in non-rhizosphere soil and it shows the trend of declination in both rhizosphere soil and non-rhizosphere soil;The contents of organic matter,total N and hydrolytic N in rhizosphere soil was more than those in non-rhizosphere soil;Hydrolytic N shows the trend of declination in both rhizosphere soil and non-rhizosphere soil form half-mature stage to mature-stage;the content of total P and available P decreases from young stage to near-mature stage,and rehabilitate a little at mature stage;the content of total K and available K increases in rhizosphere soil.(2)In different stages of C.equisetifolia plantation development,the CEC,hydrolytic acidity and exchange Mg~(2 ) in rhizosphere soil were more than those in non-rhizosphere soil,except for exchange Ca~(2 ) in young C.equisetifolia protection forest;the CEC of soil arrive its max in half-mature stage.(3)As for the variation of the soil enzyme activity in different stages of C.equisetifolia protection forest,phosphataese,peroxidase and polyphenol oxidase were more active in rhizosphere soil than in non-rhizosphere soil;there was no obvious change on activity of urease;during stages of C.equisetifolia forest development,the active of phosphataese shows the trend of increase in both rhizosphere soil and non-rhizosphere soil,moreover,the difference between rhizosphere soil and non-rhizosphere soil were more obviously;the active of polyphenol oxidase in rhizosphere soil was more than that in other stages.