木麻黄基干林带后的风速变化规律和空间分布

以木麻黄基干林后沿风速为研究对象,从2006年11月到2007年3月在东山岛调查了不同发育阶段的木麻黄基干林后有效防护距离内的风速。结果表明:基干林带后风速总体上呈上升趋势,但在5h-10h有所下降,10h后风速一直上升,直到25h处接近于空旷地;空间分布呈平滑的上升曲面,局部有凸起和下凹区域,等值线分布疏密相间,局部区域弯曲不直。国家“十一五”科技支撑计划项目(2006BAD03A14-01);; 福建省重大科技专项(2006NZ0001-2

厦门地区无偿献血者HEV隐性感染情况及基因型分析

目的了解厦门地区无偿献血者中戊型肝炎的感染情况。方法对2005年3月—2007年4月厦门地区20389人(次)无偿献血者做整群抽样,捕获法ElISA检测IgM抗-HEV、并对IgM抗-HEV阳性样本做HEVrT-PCr检测,经测序后分析其基因型及序列同源性。结果20389份无偿献血者血样本中,IgM抗-HEV阳性率为0.91%(186/20389);186例IgM抗-HEV阳性中有4例经rT-PCr检测为HEV阳性。献血者中病毒血症总阳性率为2/10000(4/20389),4例病毒血症中Ⅰ型与Ⅳ型感染各2例。结论厦门地区无偿献血者中,存在HEV隐性感染者。厦门市卫生局医学科研项目资助课题(编号:WSK0516

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

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

无偿献血者中隐匿性乙型肝炎病毒感染及表面抗原突变分析

采用多种免疫学检测和核酸检测相结合的方法调查了我国南方某城市无偿献血者中隐匿性乙型肝炎病毒(HBV)感染的存在情况。结果在9023例乙肝表面抗原(HBsAg)阴性的无偿献血者中,共发现17例HBV DNA阳性,隐匿性HBV感染者的发生率为0.19%(95%CI:0.11～0.30%)。序列分析显示其中6例在HBsAg"a"表位(aa124～aa147)存在不同程度氨基酸突变,突变发生率为42.9%(6/14,有3例未扩增出"a"表位片段序列),G145R突变是该地区隐匿性HBV携带者中发生频率最高的突变(4/6,66.7%)。隐匿性HBV感染者中基因型C的比例(10/17)显著高于HBsAg阳性的HBV感染者(0/15,P<0.01)

Characteristics of soil microelements contents in the rhizospheres of different vegetation in

为了解黄土高原不同植被土壤微量元素的根际效应,分析了该地区柠条、沙棘、沙打旺、柳枝稷、阿尔泰狗娃花和茵陈蒿6种植被根际与非根际土壤中有机碳、全氮、Mn、Cu、Fe、Zn含量.结果表明:6种植被中,柠条、阿尔泰狗娃花和茵陈蒿根际土壤的有机碳、全氮含量高于非根际土壤;除柠条和沙棘外,其余4种植被非根际土壤pH值均显著高于根际土壤.6种植被根际土壤有效Mn含量均低于非根际;柠条、沙打旺和柳枝稷根际有效Cu含量显著高于非根际,表现出强烈根际富集现象.除沙打旺外,其他5种植被根际有效Fe含量均略高于非根际.沙打旺、柳枝稷、茵陈蒿和阿尔泰狗娃花表现出强烈的有效Zn根际富集现象.根际与非根际土壤有机碳、全氮与有效Mn、有效Zn,以及有效Mn与有效Zn呈极显著正相关.根际土壤pH值与有效Mn和有效Zn呈显著负相关.由于不同植物根系的生长特征、根际pH值及微生物种类等的差异,不同植被根际的微量元素含量不同,茵陈蒿根际4种微量元素含量高于其他植被. 更多还原<br /

Characteristics of soil microelements contents in the rhizospheres of different vegetation in

为了解黄土高原不同植被土壤微量元素的根际效应,分析了该地区柠条、沙棘、沙打旺、柳枝稷、阿尔泰狗娃花和茵陈蒿6种植被根际与非根际土壤中有机碳、全氮、Mn、Cu、Fe、Zn含量.结果表明:6种植被中,柠条、阿尔泰狗娃花和茵陈蒿根际土壤的有机碳、全氮含量高于非根际土壤;除柠条和沙棘外,其余4种植被非根际土壤pH值均显著高于根际土壤.6种植被根际土壤有效Mn含量均低于非根际;柠条、沙打旺和柳枝稷根际有效Cu含量显著高于非根际,表现出强烈根际富集现象.除沙打旺外,其他5种植被根际有效Fe含量均略高于非根际.沙打旺、柳枝稷、茵陈蒿和阿尔泰狗娃花表现出强烈的有效Zn根际富集现象.根际与非根际土壤有机碳、全氮与有效Mn、有效Zn,以及有效Mn与有效Zn呈极显著正相关.根际土壤pH值与有效Mn和有效Zn呈显著负相关.由于不同植物根系的生长特征、根际pH值及微生物种类等的差异,不同植被根际的微量元素含量不同,茵陈蒿根际4种微量元素含量高于其他植被. 更多还原<br /

Photosynthetic characteristics of Bothriochloa ischaemum under drought stress and elevated

采用盆栽控制试验,研究了黄土丘陵区乡土种白羊草在不同水分水平(80%FC和40%FC)和CO2浓度(375和750&mu;mol&middot;m-2&middot;s-1)处理下的光合生理变化特征.结果表明:干旱胁迫使白羊草的最大净光合速率(Pnmax)、表观量子效率(AQE)、气孔导度(gs)、蒸腾速率(Tr)、最大光化学效率(Fv/Fm)、潜在光化学效率(Fv/Fo)和光合色素含量降低,丙二醛(MDA)和脯氨酸(Pro)含量升高.水分充足条件下,与正常大气CO2浓度相比,大气CO2浓度倍增下白羊草的Pnmax、MDA和Pro含量无显著差异.干旱胁迫下,CO2浓度升高提高了白羊草的最大荧光(Fm)、Fv/Fm、Fv/Fo、叶绿素含量和AQE,Pnmax比正常CO2浓度下高23.3%,差异达到显著水平,而MDA和Pro含量均显著降低.CO2浓度升高对干旱胁迫引起的白羊草光合能力下降有一定的补偿作用,减轻了干旱胁迫对白羊草的伤害.</span