文献类型：期刊文献

中文题名：荒漠植物白刺新固定碳在植物-土壤系统中的分配

英文题名：Distribution of newly fixed carbon of Nitraria tangutorumin the plant-soil system

作者：李新乐[1,2] 鲍芳[1] 吴波[1] 曹艳丽[1] 刘明虎[2] 段瑞兵[2]

第一作者：李新乐

机构：[1]中国林业科学研究院荒漠化研究所;[2]中国林业科学研究院沙漠林业实验中心内蒙古磴口荒漠生态系统国家定位观测研究站

年份：2019

卷号：28

期号：2

起止页码：33-40

中文期刊名：草业学报

外文期刊名：Acta Prataculturae Sinica

收录：CSTPCD;;Scopus;北大核心:【北大核心2017】；CSCD:【CSCD2019_2020】；

基金：中央级公益性科研院所基本科研业务费专项资金(CAFYBB2017QA028);国家自然科学基金青年项目(31400421;31600394);中国林业科学研究院荒漠化所结余项目(IDS2018JY-3;IDS2018JY-9)资助

语种：中文

中文关键词：荒漠植物;新固定碳;分配动态;分配格局;稳定同位素

外文关键词：desert plant;newly fixed carbon;distribution dynamics;distribution pattern;stable isotope

分类号：S512.101

摘要：定量生长季内荒漠植物新固定碳在植物-土壤的分配规律,对理解全球碳循环有着重要意义。采用野外原位13C-CO2脉冲标记法,测定植物各器官及土壤13 C丰度值,比较不同标记时间段白刺新固定碳分配在不同器官、土壤和呼吸损失中的分配规律,并量化了白刺光合碳向地上、地下碳库的转移。结果表明:不同标记时间段内13 C-新固定碳在白刺叶、茎、根、土壤中的分配差异明显。在标记后1h内,叶片和茎中13 C丰度值迅速上升到最高值,13C丰度值分别达到520.1‰和592.5‰,比对照分别增加14和20倍,此后13 C丰度值随时间推移逐渐下降,直至趋于稳定;而标记后18h在根系和土壤中发现被标记的13 C,13 C丰度值分别达到9.5‰和-23.8‰,白刺新固定碳经地上部呼吸和土壤呼吸损失量分别在标记1和18h后达到最大。标记32d后,白刺新固定碳在地上部和地下部13 C分配比例分别占35.59%和32.49%,呼吸损失(地上呼吸+土壤呼吸)占31.92%。荒漠植物白刺生长季年固碳量为2895.6kg C·hm-2·yr-1,表明白刺在荒漠生态系统碳循环中起着重要的碳汇作用。
Characterizing the carbon turnover in terrestrial ecosystems is critical for understanding and predicting carbon dynamics in ecosystems.We used in situ 13C pulse labeling to track photosynthetic carbon fluxes of Nitraria tangutorum from shoot to root and soil in the Ulanbuh Desert.The objectives of this study were:1)To determine the transfer dynamics of newly photosynthesized carbon to different carbon pools including leaves,stems,roots,soil,and respiration.2)To quantify the allocation rate of newly fixed carbon among different carbon pools.3)to estimate the carbon budget of a N.tangutorum desert ecosystem.It was found that the distribution of 13C-newly fixed carbon in leaves,stems,and roots of N.tangutorum and in soil was significantly different in different labeling periods.The 13C abundance value in leaves and stems rose rapidly to the highest value after labeling for 1 h,at which point the 13C abundance value was 520.1‰and 592.5‰,14 and 20 times higher than the control,respectively.Thereafter,the 13C abundance value gradually decreased with time until it stabilized.The labeled 13C was found in the roots and soil after labeling 18 h,and the 13C abundance values reached 9.5‰and-23.8‰,respectively.The amount of newly fixed carbon lost through shoot respiration and soil respiration reached a maximum after labeling for 1 h and 18 h,respectively.At the end of the labeling period,about 35.59%of labeled carbon was transferred to the shoots,16.67%was retained in root,31.92%was lost as respiration(shoot respiration+soil respiration)and 15.82%remained in the soil.In the three carbon pools,i.e.,shoot,root,and soil pools,shoots consistently had the highest proportion of 13C in the plant-soil system during the 32 days.Based on the 13C partitioning pattern and biomass production,we estimate a total of 2895.6 kg C·ha^-1·yr^-1 was fixed by these desert plants during the vegetation growth season.This study suggests that N.tangutorum plays an important role in carbon sequestration in the carbon cycle of desert ecosystems.