学科分类
/ 3
47 个结果
  • 简介:ThispaperhighlightstheresearchanddevelopmentactivitiesbeingdoneonurbanforestryinthePhilippines.TherolethatR&Dplaysinurbanforestryislikewisediscussedintheintroduction.Recommendedtreespeciesforurbanplantingarepresentedincludingtheircharacteristicsanddistribution.Researchesrelatedtourbanforestrybeingconductedarelistedwithashortdescriptionofeachproject.Developmentactivitiesonurbanforestryarelikewisediscussed.Finally,recommendedR&DagendaandresearchableareasbasedonthePhilippineAgenda21andtheDepartmentofEnvironmentandNaturalResources(DENR)R&DFrameworkarepresented.

  • 标签: 菲律宾 城市森林 “研究与开发” 城市生态系统 树木种类
  • 简介:FROMWOMEN'SMOUNTAINPRODUCTIONBRIGADESTOWOMEN'STREEFARMS¥ByXieJingxiangYouxicountyissituatedinamountainous,poorlyforestedregio...

  • 标签:
  • 简介:DiscussionofXixia’sForestryAModelfortheDevelopmentofChina’sTownshipForestry¥byXuGuozhenPovertyisstillaserioussocialandeconomi...

  • 标签: China MODEL
  • 简介:ThehistoricaltransitionoftimberdistributionpatterninChinawaspresentedfirstlywithmainpartsoftimberflowsinChina,whichincludedtimbermarkets,timbertransportsystemandregulationsoftimbertransport.BasedontheoverviewontropicaltimberflowsinChina,thetradeflowsoftropicaltimberfromproductionandimportsoftropicaltimbertoexportoftropicaltimberproductswereanalyzedbyvividillustrations.Atthesametime,problemsintimbertradeflowsinChinawereanalysedintheend.

  • 标签: 热带木材 木材分布 木材市场 对外贸易
  • 简介:江苏省质监局日前发布的2015年文具产品风险监测质量分析报告显示,样品中不少产品标签标识中缺少应有的信息,而最令消费者担忧的是文具中普遍检出了有害物质。笔、橡皮、修正液等文具中检出邻苯二甲酸酯(塑化剂的一种)、有机溶剂残留和卤代烃等。其中,邻苯二甲酸酯被研究证实发挥着类似雌性激素的作用,可致男孩“女性化”和女孩性早熟。

  • 标签: 文具 邻苯二甲酸酯 有机溶剂残留 质量分析 风险监测 标签标识
  • 简介:WOMEN’SPARTICIPATIONINSOCIALFORESTRYByLuoRonghuaiLuoshuiisavillageinNinglangCountyinYunnanProvince.MostofoftheMosuonationalit...

  • 标签:
  • 简介:Inrecentyears,thequantityandqualityofglobalforestresourcesaredecliningcontinually.Contrarily,thebothinChinaareincreasing,whichisdeeplyrelatedtothesustainableforestmanagementandeco-systemmanagementinChina.Withthetrendthatworldcommunityknowsmoreabouttheimportantroleofforest,moreandmorefunctionsofforestarerecognized.TheimpactandfunctionsofChina'sforestrydeservemoreconcern.Basedonsomeexperiencesinthefieldofforestryresearch,theauthors...

  • 标签:
  • 简介:林木生长函数是林木生长规律的定量描述。利用非线性回归法,详细论述了确定林木生长非线性函数的方法,结合计算机程序和实测数据,建立了某红松林木生长函数的数学模型。分析计算结果表明,林木生长数学模型与实测数据有较高拟合精度,相对误差平均值约1.8%。

  • 标签: 回归分析 非线性回归 生长函数
  • 简介:Forestshavemultiplebenefitsandfunctions,includingmitigationofclimatechange.Theimpactsofforestsontheglobalcarboncycleincludeforestsascarbonsinks,wood-basedproductsascarbonsinks,bio-energy,andproductionanduseofnon-timberproducts.Inthepastdecades,forestcoverofChinahasincreasedfrom8.6%to18.21%bylarge-scaleafforestationandconversionofcroplandintoforests.Forestbiomasscarbon(C)stockincreasedfrom4.3PgC(1PgC=1015gC)intheearly1980sto5...

  • 标签:
  • 简介:Asanemergingindustry,China'swoodfloorindustrydatesbacktotheearly1980s.Despitealatestart,ithasdevelopedrapidlyduringthelast20years.ThepastdecadeshavewitnessedgreatchangesinChina'swoodfloorindustry.Withhighquality,manyproducts"madeinChina"areavailablewidelyabroadnowadays.Currentglobaleconomicshocks,however,affectChina'sdomesticrealestatesector;hencethefallingdomesticsalesofwoodfloor.Thepaperaimstoidentifythecurrentsituationoffloorindustry...

  • 标签:
  • 简介:Inaviewofnaturalconditionsofestablishingnaturereserve,anindexsystemwaspreparedforquantitativeassessmentonstatusofendangeredspecies,andthusdegreeofendangeredspeciesinTibetwasevaluated.Takingasub-ecozoneasbasicunit,top5animalsand1plantwithhighEaswellasthenumberofspeciesineachunitwereenumerated;andthedegreeoflandutilizationwasfiguredout.Afterward,weselected6coefficients,assignedweight,andframedformulatoreckonproportionofnaturereserve,thusanareaofnaturereserveineachsub-ecozonewasobtained.In5schemesofweightassignment,aschemewithmediumareaofnaturereservewasselected.Allsub-ecozoneswereclassifiedinto4gradespriorconservation,1wasingradeA,2ingradeB,2ingradeC,and11ingradeD.Totalplannedareawasapproximately365135km2,about48834km2smallerthantheactualareaof413969km2,ratioofnaturereserveinTibetdiminishesfrom34.4%to30.38%.Basedon3factorsofhumandisturbance,ratioofbuffer-experimentalzoneinproposednaturereservewascalculated.Itwasdemonstratedthatexistingsizeofnaturereservesisexcessiveonthewhole,andtheirdistributionisnotreasonableentirely.Thesizeofnaturereservesin3sub-ecozonesofnorthernChangtangshoulddecrease,anddecrementofareaisapportionedamongother13sub-ecozoneswhichshouldincreasenaturereserve.HeterogeneityofregionaldistributionofrarespeciesinTibetisquiteobvious,soproposedareadistributionofnaturereservesismorescatteredthantheexisting.

  • 标签: endangerment DEGREE sub-ecozone land UTILIZATION nature
  • 简介:Urbangreening,urbanforestryandurbangreenstructureplanningalllookatacityasaunitandintendtoimprovethestatusofgreenspaceinthecity.Eventhoughtheyarenewterms,theirconceptshaveevolvedoveraratherlongperiod.Thispaperpresentsahistoricalreviewofwesternconceptsforurbangreeningsincethe1850s.Thefirstaimistoestablishanoverviewofhowtheurbangreeningconcepthasdevelopedandwhattherelationshipsarebetweenthehistoricalconceptsandurbangreening,urbanforestryandurbangreenstructureplanningtoday.Thesecondarypurposeistounderstandsomekeyissuesforurbangreeningthroughtheexaminationofhistoricalprecedents.Basedonaliteraturereview,thepaperpresentsseveralhistoricalconceptsforurbangreening-rampartareaplanning,parksystem,greenbelts,greenwedgesandgreenways.Thenewconceptofurbangreenstructureisalsointroduced.Eachconceptisdefined.Thesocialbackgroundandtheinfluenceoncitydevelopmentaredescribed.Thereviewshowsthattheconceptofurbangreeninghasalonghistory,parallelwiththedevelopmentofthecityplanningconcepts.Thescopeofurbangreeninghasbecomelargeroverthepastyears.Thefunctionsofurbangreenspacehavechangedfromsingle-purposetomulti-purpose.Thestudyindicatesthathistoricalconceptsmaystillgiveinspirationintoday'surbangreeningprocess.

  • 标签: 城市森林 城市绿地 城市绿化规划 城市绿化带 公园
  • 简介:Man-madeforest,whichistheforestecosystemofrehabilitationandreconstruction,playsasignificantroleintheprovisionofforestproductsandimprovementtheecologicalenvironment.Inthispaper,weestablishedtheAR(5)modeltopredictChina'sforestareafrom2009to2015.Thisstudyshowstheslowgrowthofthenationalplantationareatrendwithsomefluctuations,buttheoverallgrowthrateisnotlarge.WeproposedthatononehandChinashouldcontinuetoincreasetheplantationarea,ont...

  • 标签:
  • 简介:生长收获方程是构成木材产量经济分析基础的产量函数。传统的生长收获模型与木材产量函数分析的区别在于其侧重点不同。生长收获模型倾向于强调预测准则,而产量函数分析则着眼于模型参数的解释。尽管这两类分析目前仍有差异,但越来越趋于一致。有人建议用下列准则判断产量函数的适用性:(1)模型与实际生物学习性的吻合性,(2)各参数的统计显著性,(3)拟合优度。我们补充第四条准则:(4)自变量最低共线性。虽然在产量函数分析中也考虑统计显著性和拟合优度,但重点强调的是生物学基本原理和最低共线性,而函数形式和预估变量的选择则在上述准则中权衡。

  • 标签: 函数分析 木材产量 拟合优度 统计显著性 共线性 分析基础
  • 简介:TheforestproductstradefromothercountriestoChinaispredominantlyandtremendouslyincreasingandmanydealers,officialsandscholarsareconvincedthatthistrendwillcontinue.Thispapercovers5topics:(1)AnalysisonChina'sforestresources;(2)AnalysisonthesupplyanddemandfactorsofforestproductsinChina;(3)TheimporttradeofrecentmainforestproductsinChina;(4)ThemarketcharacteristicsofforestproductsinChina;(5)ThedevelopmenttrendsofforestproductsinChina.

  • 标签: 中国 林产品贸易 进口贸易 贸易量 贸易额
  • 简介:瑞典:Sōdra公司已经对针叶锯材市场销售疲软的情况做出反应,8月底削减其在拉姆克维拉(Ramkvilla)、图绍斯市(Torsas)和Langasjō工厂的生产量总计约5万~6万m^3。第1步,在拉姆克维拉和图绍斯市节日期间约4个星期的停产时间将多延长2个月。这2家工厂将于6月4日停止锯切加工,8月27日恢复。

  • 标签: 锯材生产 针叶材 DRA 市场销售 节日期间 锯切加工
  • 简介:ThepaperanalyzedthecurrentstatusofforeigntradeofforestindustryinChinaandthenationalandinternationalmarketchanges.Basedontheanalysis,theorientationandtransformationofforeigntradepolicyforChina'sforestindustrywerediscussed.

  • 标签: