简介:WemappedtheforestcoverofKhadimnagarNationalPark(KNP)ofSylhetForestDivisionandestimatedforestchangeoveraperiodof22years(1988-2010)usingLandsatTMimagesandotherGISdata.SupervisedclassificationandNormalizedDifferenceVegetationIndex(NDVI)imageclassificationapproacheswereappliedtotheimagestoproducethreecoverclasses,viz.denseforest,mediumdenseforest,andbareland.Thechangemapwasproducedbydifferencingclassifiedimageriesof1988and2010asbeforeimageandafterimage,respectively,inERDASIMAGINE.Errormatrixandkappastatisticswereusedtoassesstheaccuracyoftheproducedmaps.Overallmapaccuraciesresultingfromsupervisedclassificationof1988and2010imagerieswere84.6%(Kappa0.75)and87.5%(Kappa0.80),respectively.Forestcoverstatisticsresultingfromsupervisedclassificationshowedthatdenseforestandbarelanddeclinedfrom526ha(67%)to417ha(59%)and105ha(13%)to8ha(1%),respectively,whereasmediumdenseforestincreasedfrom155ha(20%)to317ha(40%).ForestcoverchangestatisticsderivedfromNDVIclassificationshowedthatdenseforestdeclinedfrom525ha(67%)to421ha(54%)whilemediumdenseforestincreasedfrom253ha(32%)to356ha(45%).BothsupervisedandNDVIclassificationapproachesshowedsimilartrendsofforestchange,i.e.decreaseofdenseforestandincreaseofmediumdenseforest,whichindicatesdenseforesthasbeenconvertedtomediumdenseforest.Areaofbarelandwasunchanged.Illicitfelling,encroachment,andsettlementnearforestscausedthedenseforestdeclinewhileshortandlongrotationplantationsraisedinvariousyearscausedtheincreaseinareaofmediumdenseforest.ProtectivemeasuresshouldbeundertakentocheckfurtherdegradationofforestatKNP.
简介:中国对虾“黄海5号”(品种登记号:GS-01-008-2017)是由中国水产科学研究院黄海水产研究所完成选育。培育单位自2009年开始,利用人工定向交尾技术,每年度大规模、标准化构建全(半)同胞家系;以WSSV抗性、生长速度和养殖存活率等作为育种目标性状,利用VIE荧光染料标记家系个体,在混养条件下,开展WSSV感染、生长速度和养殖存活率性状测试试验,记录家系个体的抗WSSV存活时间、收获体重和养殖存活率等信息;性状测试结束后,建立遗传评估模型,利用BLUP方法评估家系和个体的性能差异;制定多性状选择指数选留优秀的家系和个体,参考亲缘关系制定配种方案,生产下一世代家系。
简介:丰田2号(试验号浙9102)和丰田5号(试验号浙465),是由浙江省农科院蚕桑研究所20世纪90年代初育成的桑树人工多倍体新品种.据育种单位和浙江桐乡市田间栽培及室内生物测试,丰田2号等多倍体品种的产叶量和养蚕成绩名列前茅,成为当地蚕农竞相推广的首选良种.为将多倍体桑品种新技术成果尽快转化为经济效益,江油从1998年起,从浙江省农科院蚕桑研究所等科教单位引进30余个近年来育成的桑树三、四倍体新品种,近年多年多点的实用经济性状的选拔试验.第一批(1999~2003)8个供试新品种中,以丰田2号和丰田5号达到桑叶增产能力强,养蚕效益高的选拔目标.现简介如后.
简介:Forthepurposeofofforestation,planninganddevelopmentintheThree-NorthRegion,aseriesof6LandsatTMscenesfrom1996to1997wereusedtoclassifyland-useconditionsinthewholeKorqinSandyLandsateasternpartofInnerMongolia,China,withanareaofabout430×306squarekilometers.Lateron,Siteclassiflcationwasmadeandmappedforthe4southernsandycounties.Theannotationsymbolforeachagglomerationofsiteconditioniscomprisedofsixparts:landunit,landusepattern,soi...