致死性干旱对8种树种幼苗非结构性碳水化合物的影响

未来极端干旱的强度与频率将增加,势必影响树木的生长与生存.然而,非结构性碳水化合物(nonstructural carbohydrate,NSC)的含量变化对树木死亡的贡献尚不清楚.本研究以亚热带地区常见落叶树种(无患子、枫香)和常绿树种(深山含笑、苦槠、木荷、青冈栎、杜英、樟树)为研究对象,设置对照(CK)和致死性干...

The Effects of Lethal Drought on Non-structural Carbohydrates in Seedlings of 8 Tree Species

Tree growth and survival will be affected by the high frequency and severity of extreme drought in the future due to climate change. However, the role of non-structural carbohydrates (NSC) in tree mortality is still unclear. Seedlings of 2 common deciduous tree species (Sapindus mukurossi, Liquidambar formosana) and 6 evergreen tree species (Michelia maudiae, Castanopsis sclerophylla, Schima superba, Cyclobalanopsis glauca, Elaeocarpus decipiens, Cinnamomum camphora) in the subtropical region of China were planted under well-watered (CK) and drought (D) treatments to analyze the difference in NSC (including soluble sugars (SS) and starch (ST)) during the tree mortality among the 8 tree species. The result shows that lethal drought reduced the SS content in the roots, stems and leaves of M. maudiae, C.sclerophylla, E. decipiens and C. camphora, the ST content in the roots, stems and leaves of L. formosana, M. maudiae, C. sclerophylla, and C. glauca, and the NSC content in the roots, stems and leaves of M. maudiae, C. sclerophylla, C. glauca, E. decipiens and C. camphora. However, NSC was accumulated in S. mukurossi (roots, stems, and leaves) and S. superba (leaves and roots). All Tthese results suggest that most of the species might experience the threat of carbon starvation during the process of drought-induced mortality depending on species and organs. Moreover, drought responses of NSC did not differ significantly between the deciduous and evergreen species. These findings can provide a reference for research of impacts of global climate change on tree eco-physiology and for the management of subtropical forests.