With a high-energy resolution micro-X-ray fluorescence (μ-XRF) analysis setup, which basically consists of an X-ray microbeam formed by an X-ray focusing lens combined with an X-ray apparatus and a wavelength dispers...With a high-energy resolution micro-X-ray fluorescence (μ-XRF) analysis setup, which basically consists of an X-ray microbeam formed by an X-ray focusing lens combined with an X-ray apparatus and a wavelength dispersive position sensitive spectrometer with a flat crystal (PSS), preliminary results have been obtained. The counting rate of the analyzed element linearly increased with the power of X-ray apparatus, and the energy resolution, full width of half maximum (FWHM) of Kα lines of Ti and Cr reached 16.6 and 23.6 eV, respectively. The Cr Kβ and Mn Kα lines in a sample of stainless steel could clearly be resolved. The above-mentioned results are also compared with those obtained by synchrotron radiation light microbeam combined with the PSS. The facts show that the high-energy resolution element analysis is feasible by using the setup. Moreover, problems for the setup and the ways to resolve them are discussed as well.展开更多
Background The increase in the frequency and intensity of droughts is pointed out as one of the main factors altering biogeochemical cycles in the Amazon basin.An eco-nutritional approach using X-ray fluorescence micr...Background The increase in the frequency and intensity of droughts is pointed out as one of the main factors altering biogeochemical cycles in the Amazon basin.An eco-nutritional approach using X-ray fluorescence micro-analysis(μXRF)is proposed to verify the long-and short-term effects of droughts on the growth and xylem nutrient concentrations of Cedrela fissilis Vell.Methods Fourteen radii were selected from a tree-ring width chronology and X-rayed by Itrax Multiscanner.Profiles of ring width,wood density,and concentrations of aluminum(Al),phosphorus(P),sulfur(S),calcium(Ca),potassium(K),manganese(Mn),iron(Fe)and strontium(Sr)together with Al/Ca,Ca/Mn,K/Ca,Sr/Ca and Mn/S ratios were constructed and correlated with precipitation,temperature,the difference between precipitation and potential evapotranspiration(P-PET)and standardized precipitation-evapotranspiration index(SPEI).Results During dry years,C.fissilis showed narrower,less dense rings,lower Al,P,S and Ca,and higher K and Fe concentrations(the opposite was found in wet years).Ring width decreased(together with Al,P,S,K,Ca,Mn,Fe,Sr,Al/Ca,K/Ca and Sr/Ca)and wood density increased(together with Ca/Mn and Mn/S),which was associated with an increase in evapotranspiration and temperature over time,mainly since 1990.Cedrela fissilis showed a tendency to increase its capacity for resistance,and a recovery and resilience in growth over time associated with responses in Al,Ca,P and S.However,it showed a risk in the capacity for recovery of the pre-drought density values,associated with unsatisfactory responses in Al,Ca,K,Fe and P.Conclusions This study is the first attempt to analyze tree-ring nutritional evidences of C.fissilis trees to climate sensitivity and resilience to drought,based on long-term data from seasonal moist tropical forests of the Amazon.Our data suggested that C.fissilis is undergoing alterations in the concentration,use and redistribution of nutrients associated with increasing wood density and decreasing growth over time,due to the increase of drought frequency in the southern Amazon.展开更多
文摘With a high-energy resolution micro-X-ray fluorescence (μ-XRF) analysis setup, which basically consists of an X-ray microbeam formed by an X-ray focusing lens combined with an X-ray apparatus and a wavelength dispersive position sensitive spectrometer with a flat crystal (PSS), preliminary results have been obtained. The counting rate of the analyzed element linearly increased with the power of X-ray apparatus, and the energy resolution, full width of half maximum (FWHM) of Kα lines of Ti and Cr reached 16.6 and 23.6 eV, respectively. The Cr Kβ and Mn Kα lines in a sample of stainless steel could clearly be resolved. The above-mentioned results are also compared with those obtained by synchrotron radiation light microbeam combined with the PSS. The facts show that the high-energy resolution element analysis is feasible by using the setup. Moreover, problems for the setup and the ways to resolve them are discussed as well.
基金We thank the Wood Anatomy and Tree-Ring Laboratory(LAIM)(FAPESP project:2009/53951-7)Department of Forest Sciences,Luiz de Queiroz College of Agriculture(ESALQ)+6 种基金DROR was supported by a fellowship from the Fundação de AmparoàPesquisa do Estado do São Paulo(FAPESP,grants#2018/22914-8,2020/04608-7)RSS was supported by VULBOS project(UPO-1263216),VURECLIM(P20_00813)AH by PinCaR project(UHU-1266324)both from FEDER Funds,Andalusia Regional Government,Consejería de Economía,Conocimiento,Empresas y Universidad 2014-2020RSS and AH were also supported by EQC2018-004821-P and IE19_074 UPO projects cofounded by Spanish“Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020”and“Plan Andaluz de Invetigación,Desarrollo e Innovación(PAIDI 2020)”,respectivelyRCB was supported from FAPESP(Grant#2020/11502-0)MJF and MTF were supported from FAPESP-FAPEAM(#01/2020)and CAPES(PROCAD/Amazônia,#21/2018)This study was also partially funded by PIRE-project(FAPESP,Grant#2017/50085-3).
文摘Background The increase in the frequency and intensity of droughts is pointed out as one of the main factors altering biogeochemical cycles in the Amazon basin.An eco-nutritional approach using X-ray fluorescence micro-analysis(μXRF)is proposed to verify the long-and short-term effects of droughts on the growth and xylem nutrient concentrations of Cedrela fissilis Vell.Methods Fourteen radii were selected from a tree-ring width chronology and X-rayed by Itrax Multiscanner.Profiles of ring width,wood density,and concentrations of aluminum(Al),phosphorus(P),sulfur(S),calcium(Ca),potassium(K),manganese(Mn),iron(Fe)and strontium(Sr)together with Al/Ca,Ca/Mn,K/Ca,Sr/Ca and Mn/S ratios were constructed and correlated with precipitation,temperature,the difference between precipitation and potential evapotranspiration(P-PET)and standardized precipitation-evapotranspiration index(SPEI).Results During dry years,C.fissilis showed narrower,less dense rings,lower Al,P,S and Ca,and higher K and Fe concentrations(the opposite was found in wet years).Ring width decreased(together with Al,P,S,K,Ca,Mn,Fe,Sr,Al/Ca,K/Ca and Sr/Ca)and wood density increased(together with Ca/Mn and Mn/S),which was associated with an increase in evapotranspiration and temperature over time,mainly since 1990.Cedrela fissilis showed a tendency to increase its capacity for resistance,and a recovery and resilience in growth over time associated with responses in Al,Ca,P and S.However,it showed a risk in the capacity for recovery of the pre-drought density values,associated with unsatisfactory responses in Al,Ca,K,Fe and P.Conclusions This study is the first attempt to analyze tree-ring nutritional evidences of C.fissilis trees to climate sensitivity and resilience to drought,based on long-term data from seasonal moist tropical forests of the Amazon.Our data suggested that C.fissilis is undergoing alterations in the concentration,use and redistribution of nutrients associated with increasing wood density and decreasing growth over time,due to the increase of drought frequency in the southern Amazon.
