简介:Soilfoodwebstructureisfundamentaltoecosystemprocessandfunction;moststudiesonsoilfoodwebstructurehavefocusedonagro-ecosystemsunderdifferentmanagementpracticesandnaturalterrestrialecosystems,butseldomongreenhouses.ThisstudyexploredthestaticandtemporalvariabilityofsoilfoodstructureintwogreenhousesofShandongProvince,NorthChinaoveratwo-yearperiod.Thestaticpropertiesweremeasureddirectlybysurveyingfunctionalgroupcompositionandaseriesofparametersportrayingthespeciesproperties,linkproperties,chainpropertiesandomnivorypropertiesoftheweb,aswellasindirectlythroughcalculationofnematodeindices,enrichmentindex(EI),structureindex(SI),andchannelindex(CI).Thedynamicvariabilityofgreenhousesoilfoodstructurewasdescribedbythedynamicsoffunctionalgroups,Bray-Curtis(BC)similarityandclusteranalysis.Theresultsshowedthatthegreenhousesoilfoodwebcontained14functionalgroups,withmicrobeshavingthehighestmeanbiomass,followedbyprotozoa.Ofthethreefunctionalgroupsofprotozoa,flagellateswerethedominantgrouponmostsamplingdates,amoebaeonlybecamethedominantgroupduringthesummer,whileciliatesweretheleastprevalentgroup.Allnematodeswereassignedintooneofthefourfunctionalgroups,bacterivorous,fungivorous,herbivorousandomnivorous,andthefungivorousnematodeshadthelowestmeanbiomass.Miteswereassignedintothreefunctionalgroupsandtheomnivorousnoncryptostigmaticmiteswerethedominantgroup.Allthefunctionalgroupsshowedsignificantseasonalchanges.Thesoilfoodwebconnectancewas0.15,themaximumfoodchainlengthwas5,andtheaveragefoodchainlengthwas3.6.TheprofilesoftheEIandSIshowedthatthefoodwebwasresourcedepletedwithminimalstructure.TheresultsofCIindicatedthatthebacterialdecompositionpathwaywasthedominantpathwayinthefoodwebofthegreenhousesoilsstudiedandtheresultsofBCsimilarityshowedthatthesoilfoodwebhadhig
简介:微卫星标记(SSR)是分子育种中常用的遗传标记,葫芦科中仅有黄瓜、甜瓜、西瓜进行了大规模的SSR标记开发,其他作物均不同程度地面临SSR标记缺乏的情况。利用近源物种间分子标记具有一定的通用性,本研究合成源于黄瓜、甜瓜和西瓜的60对SSR标记,从中筛选出42对可用标记,对甜瓜、西瓜、黄瓜、南瓜、苦瓜、冬瓜、节瓜和丝瓜8种葫芦科作物进行验证,分析这三种瓜类SSR标记在葫芦科中的穿梭性。结果表明,42对标记中有29对(69%)能在8种常见葫芦科作物中都得到有效扩增,在5种及5种以上物种中有扩增的引物达到38对,占90.5%,表明这三种瓜类SSR标记在葫芦科作物中有良好的穿梭性,这为葫芦科中数目庞大的未测序作物提供一种切实可行、高效低成本的分子标记开发方法。
简介:高岭土矿山的开发已经导致当地生态环境受到较为严重的破坏,建立一个有效的生态补偿机制有利于矿山生态恢复。本文以福建省闽清县白中镇普贤高岭土矿山废弃地为例,讨论了高岭土矿山的生态补偿问题,分别为补偿主体、补偿客体、补偿方式、补偿金的使用以及补偿标准。而其中补偿标准又是最为重要的,主要由矿山开发前为林地时所具有的生态价值和矿山开发后进行生态恢复所需费用决定。计算结果表明,该矿山开发前所具有的生态价值为2050280.86元,矿山开发后进行生态恢复所需费用为1971762.6元,因此,开发此矿山大致需要补偿4022043.46元,补偿标准为251377.72元/hm^2。