Vol14 No.8: 1615-1623
【Title】Impacts of warming on root biomass allocation in alpine steppe on the north Tibetan Plateau
【Author】MA Xing-xing1,2; YAN Yan1; HONG Jiang-tao1,2; LU Xu-yang1; WANG Xiao-dan1*
【Addresses】1 Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China; 2 University of Chinese Academy of Sciences, Beijing 100049, China
【Citation】Ma XX, Yan Y, Hong JT, et al. (2017) Impacts of warming on root biomass allocation in alpine steppe on the north Tibetan Plateau. Journal of Mountain Science 14(8). DOI: 10.1007/s11629-016-3966-7
【Abstract】Biomass is an important component of global carbon cycling and is vulnerable to climate change. Previous studies have mainly focused on the responses of aboveground biomass and phenology to warming, while studies of root architecture and of root biomass allocation between coarse and fine roots have been scarcely reported in grassland ecosystems. We conducted an open-top-chamber warming experiment to investigate the effect of potential warming on root biomass and root allocation in alpine steppe on the north Tibetan Plateau. The results showed that Stipapurpureahad significantly higher total root length, root surface area and tips than Carexmoocroftii. However,there were no differences in total root volume, mean diameter and forks for the two species. Warming significantly increased total root biomass (27.60%), root biomass at 0–10 cm depth (27.84%) and coarse root biomass (diameter > 0.20 mm, 57.68%) in the growing season (August). However, warming had no significant influence on root biomass in the non-growing season (April). Root biomass showed clear seasonal variations: total rootbiomass, root biomass at 0–10 cm depth and coarse root biomass significantly increased in the growing season. The increase in total root biomass was due to the enhancement of root biomass at 0–10 cm depth, to which the increase of coarse root biomass made a great contribution. This research is of significance for understanding biomass allocation, carbon cycling and biological adaptability in alpine grassland ecosystems under future climate change.
【Keywords】Coarse root; Fine root; Root architecture; Warming; Climate change; Open-top chambers