草业学报2019，Vol.28Issue(2)：33-40,8.DOI:10.11686/cyxb2018561
荒漠植物白刺新固定碳在植物-土壤系统中的分配
Distribution of newly fixed carbon of Nitraria tangutorumin the plant-soil system
摘要
Abstract
Characterizing the carbon turnover in terrestrial ecosystems is critical for understanding and predicting carbon dynamics in ecosystems.We used in situ 13 C pulse labeling to track photosynthetic carbon fluxes of Nitraria tangutorumfrom 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.tangutorumdesert ecosystem.It was found that the distribution of 13C-newly fixed carbon in leaves, stems, and roots of N.tangutorumand in soil was significantly different in different labeling periods.The 13 C abundance value in leaves and stems rose rapidly to the highest value after labeling for 1h, at which point the 13 C abundance value was 520.1‰and 592.5‰, 14 and 20times higher than the control, respectively.Thereafter, the 13 C abundance value gradually decreased with time until it stabilized.The labeled 13 C was found in the roots and soil after labeling 18 h, and the 13 C 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 1hand 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 13 C in the plantsoil system during the 32 days.Based on the 13 C partitioning pattern and biomass production, we estimate a total of 2895.6kg C·ha-1·yr-1 was fixed by these desert plants during the vegetation growth season.This study suggests that N.tangutorumplays an important role in carbon sequestration in the carbon cycle of desert ecosystems.关键词
荒漠植物/新固定碳/分配动态/分配格局/稳定同位素Key words
desert plant/newly fixed carbon/distribution dynamics/distribution pattern/stable isotope引用本文复制引用
李新乐,鲍芳,吴波,曹艳丽,刘明虎,段瑞兵..荒漠植物白刺新固定碳在植物-土壤系统中的分配[J].草业学报,2019,28(2):33-40,8.基金项目
中央级公益性科研院所基本科研业务费专项资金(CAFYBB2017QA028) （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 （）
