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

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M g2+均大于非根际土壤;幼林龄根际交换性C a2+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。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.国家“十五”科技攻关项目(2004BA516A13-15);; 国家林业局南方山地用材林培育重点实验室资助项

Rhizosphere Soil Nutrient and Enzyme Activity in Mixed Forest of Casurina Equisetifolia and Pinus elliotti

对木麻黄湿地松混交林的根际土壤养分及酶活性进行测定,结果表明:混交林根际与非根际土壤pH值均呈下降,加剧了土壤酸化。速效钾除外,混交林中木麻黄根际各种矿质养分含量都小于对应的纯林;土壤阳离子交换总量减小,土壤营养贮量和养分供应能力有所下降。多酚氧化酶除外,根际土壤脲酶、磷酸酶、过氧化物酶活性混交林中小于纯林。混交后木麻黄在促进湿地松生长的同时可能对自身的生长不利,在沿海沙地营造木麻黄湿地松混交林,两树种均对土壤养分的过量索取可能会加剧地力的退化。Soil chemical properties and biochemical activities between the rhizosphere and non-rhizosphere soil in different stands of Casuarina equisetifolia was researched.The chief results are as follows:the pH value in rhizosphere and non-rhizosphere soil of mixed stand went down and the soil acidification increased.Except for available K,the contents of mineral nutrient in the rhizosphere soil of mixed stand were lower than those of pure C.equisetifolia stand.In C.equisetifolia-P.elliotti mixed plantation,CEC minished,nutrient-holding and providing capacities of soil was diclined.Uresese,phosphataese and peroxidase of rhizosphere soil in mixed stand were less active than those in pure C.equisetifolia stand,except for polyphenol oxidase.C.equisetifolia of mixed plantation was harmful to itself growth while conduce to P.elliotti growth.国家“十五”科技攻关项目(2004BA516A13-15

Rhizosphere Soil Chemical Properties and Enzyme Activities of Multi-rotation Casuarina Equisetifolia Plantation

在福建省东山县滨海沙地,对连栽条件下木麻黄林地根际和非根际土壤化学性质和酶活性进行了对比研究。结果表明:二代木麻黄林的根际和非根际土壤PH值均小于一代林,表明木麻黄连栽引起根际土壤酸化;根际土壤有机质、CEC值、水解性总酸度、全氮、水解氮、速效钾、交换性Mg2+和CA2+含量随着木麻黄连栽而降低,且心土层(20~40CM)差异更大,但土壤全磷、全钾变化不大;与一代林相比,二代木麻黄根际土壤磷酸酶和过氧化物酶活性减弱,多酚氧化酶活性增大,脲酶无明显变化。第二代木麻黄林地根际土壤养分的消耗、生物活性的降低和有毒物质的累积等,可能造成土壤肥力衰退,林木生长受阻。The comparative trial was conducted to study the chemical properties and enzyme activities of the rhizosphere and non-rhizosphere soil supporting the first and second generation Casuarina equisetifolia plantation on coastal sand at Dongshan County of Fujian Province.The results showed that the pH value in rhizosphere and non-rhizosphere soil in the second generation plantation was lower than the first generation plantation,indicating that the multi-rotation plantation increased the acidity of rhizosphere soil.The contents of organic matter,CEC,Hydrolytic acidity,total N,Hydrolytic N,available K,exchange Mg2+ and Ca2+ in rhizosphere soil of second generation plantation was also lower than that of the first generation,and the difference in 20～40cm depth of soil was obvious,but there was no significant difference for total P and total K.Compared with the first generation,the activities of phosphataese and peroxidase in rhizosphere soil of second generation were decreased,while the activities of polyphenol oxidase were increased,but there was no obvious change on activity of urease.The soil fertility would decline and forest growth decrease in multi-rotation Casuarina equisetifolia plantation,due to the soil nutrient consumption,biochemical activity reduction and toxic substance accumulation.国家自然科学基金项目(41176092);国家“十一五”科技支撑计划(2009BADB2B0302);国家林业局南方山地用材林培育重点实验室、福建省森林培育与林产品加工利用重点实验室资助项

应用气液两相流模型模拟湖泊风生流

采用了基于两相流理论的三维相问界面计算模型模拟湖泊风生流，并采用交错网格的有限体积法求解。该模型应用于昆明市滇池的风生流模拟，实际计算表明：该模型算法程序简单，计算结果合理，能较真实的反映湖泊风生流的流态特征

应用气液两相流模型模拟湖泊风生流

采用了基于两相流理论的三维相间界面计算模型模拟湖泊风生流,并采用交错网格的有限体积法求解。该模型应用于昆明市滇池的风生流模拟,实际计算表明该模型算法程序简单,计算结果合理,能较真实的反映湖泊风生流的流态特征

一种适体坐标下复连通区域的流场数值计算方法

本文介绍了一种简便地处理复连通域内流场数值计算问题的方法。将复连通域分解成多个单连通域，分别进行网格划分，再组合还原，通过网格变换系数将地形对流场的影响带到流场计算过程中去。完成流场计算