简介:温室气体甲烷的空间与时间的可变性(在在亚马逊上的空气的CH4)从卫星转菠的大小用数据被学习大气红外线在为时期2003-12的NASA水卫星上更健全。结果在亚马逊盆低地区域上显示出这气体的显著可变性,在沼泽地区域发生的地方。CH4有明确的季节的行为,随它在旱季期间的集中的进步增加,在湿季节期间由减少列在后面。有关这可变性,现在的学习在modulating显示ENSO的重要角色在北亚马逊上的CH4排出物的可变性,这个协会在哪儿似乎主要响应ENSO相关的降水在充满的区域被连接到变化,变化。在这个区域,CH4减少(增加)由于ElNi?o相关(LaNi?一相关)干(湿)。在另一方面,在东南的亚马逊上烧在期间的生物资源的增加(减少)很干燥(湿)年在这个区域在CH4排出物解释增加(减少)。现在的分析识别亚马逊的二个主要区域,它的北、东南的部门,与CH4的显著interannual变化。这结果可能为未来在CH4,的集中监视变化是有用的秒大多数重要温室气体,在这个区域。
简介:Background:ThefloodplainforestsofAraguaiaRiver,aclear-waterriverinthesoutheasternAmazon(TocantinsState,Brazil),arecharacterizedbyseasonalfloodingupto3.5mheight,lownutrientlevelsinthewater,andseasonaldroughtperiodsof4–5months.Methods:Westudiedtheforestdynamics(treediametergrowth,treemortalityandrecruitment)ofthisuniqueforestecosystemovera5-yearperiodbyrepeatedcensusesin12permanentplotsestablishedalongafloodinggradient.Results:Thecumulativebasalareaintheplotsincreasedby0.84(±0.45)m2?ha~(–1)?yr~(–1)(mean±SD)intheannualy-flooded(AF)plotsinlowerterrainandby0.69(±1.00)m2?ha~(–1)?yr~(–1)inthehighernon-annualyflooded(NAF)plots,correspondingtoanabovegroundbiomassincreaseof0.81(±0.57)and0.69(±1.58)Mg?ha~(–1)?yr~(–1)intheAFandNAFplots,indicatingarecentcarbonsinkinthebiomass.Meandiametergrowthratewas1.8(±0.44)mm?yr~(–1)intheAFand2.0(±0.56)mm?yr~(–1)intheNAFplots(correspondingtoacoarsewoodproductionof1.53(±1.29)and2.02(±0.52)Mg?ha~(–1)?yr~(–1)),indicatingnofloodingeffectonradialgrowth.Meanmortalityratesinthe5-yearperiodwere1.9(±0.37)%?yr~(–1)intheAFplotsand1.8(±0.87)%?yr~(–1)intheNAFplotswithnodifferencesalongthefloodinggradient.HighestmortalitieswereregisteredintheAFplotsforthe10–20cmdbhclass(2.4%?yr~(–1)),likelyasaconsequenceofflooding,andintheNAFplotsforthe40–50cmdbhclass(3.0%?yr~(–1)),probablymainlycausedbyENSO-relateddroughts.Conclusions:Weconcludethatthesedrought-affectedtropicalfloodplainforestshavealowerstandingbiomassandabovegroundproductivitythancentralAmazonianfloodplainforestsinmorehumidclimates,andtheimprintofthefloodinggradientonstanddynamicsisrelativelyweak,whichmayresultfromthelowerfloodingheightandtheinteractionoffloodingwithlownutrientsupplyandperiodicdrought.