简介:2011年以来海安县畜牧兽医站推广鸡新城疫低毒力活疫苗(ZM10株),开展免疫效果比较试验等研究工作,制定出综合免疫程序、疫苗免疫操作规范、消毒技术、饲养管理技术等鸡新城疫综合防控技术,并在全县范围进行大面积推广应用,新城疫的动态免疫密度一直保持在100%,六年来全县鸡新城痍发病率、死亡率显著下降,获得较高的经济社会效益。
简介:Background:Forestmanagementstrategiessuchasthinninghavelongbeenusedtoenhanceecosystemfunctions,especiallyinplantations.Thinninginplantationswithhighdeerdensity,however,maynotyieldadesiredincreaseinunderstoryvegetationbecausedeergrazeongerminatingplantsafterthinning.Here,weexaminethechangesinunderstoryvegetationafterthinninginplantationsthathavebeenovergrazedbysikadeertoprovideinsightintotheeffectsofthinningonecosystemfunctionssuchassoilconservationandbiologicaldiversity.Methods:WeconductedoursurveyintheTanzawaMountainsofeasternJapan.Wesurveyedthechangeinunderstoryvegetationwithinandoutsideofthreedeerexclosuresonasingleslopewiththreelevelsofunderstoryvegetationcover:sparse(1%,exclosure'US'),moderate(30%,exclosure'MM'),anddense(80%,exclosure'LD')over10yearsaftera30%thinningofanold-growthcedarandcypressplantationwhichwasovergrazedbysikadeer.Results:Understoryvegetationcover,biomassandspeciesrichnessincreasedwithinandoutsidethe'US'and'MM'exclosuresafterthinning,andbiomasswasgreaterwithinthanoutsidetheexclosuresat10yearsafterthinning.Unpalatablespeciesdominatedboth'US'and'MM'exclosuresbeforethinning,andtreesandshrubsdominatedwithintheexclosuresovertimeafterthinning.Incontrast,unpalatable,grazing-tolerant,perennial,andannualspeciesincreasedoutsidethe'US'and'MM'exclosures.Nonoticeablechangeswereobservedwithinandoutsidethe'LD'exclosurewhencomparedwiththe'US'and'MM'exclosures.Conclusions:Ourresultssuggestthatthinningastandby30%basedonvolumeresultedinanincreaseinunderstoryvegetationcovermainlycomposedofbothunpalatableandgrazing-tolerantspeciesinaplantationforestwhereunderstoryvegetationissparseormoderateandsikadeerdensityishigh.Weemphasizethatestablishingdeerexclosuresorcontrollingdeerisessentialtomaintainingsimilarunderstoryvegetationbothwit