林业科学2016，Vol.52Issue(5)：81-91,11.DOI:10.11707/j.1001-7488.20160510
人工模拟增雨对乌兰布和沙漠白刺生物量分配的影响
Effects of Simulated Rain Addition on Biomass Allocation of Nitraria tangutorum in Ulanbuh Desert
摘要
Abstract
[Objective]This research was carried out to investigate the effects of simulated rain addition on branch growth rate,aboveground biomass,and leaf/shoot ratio and to explore the allocation characteristics of photosynthetic products and adaptation of desert species Nitraria tangutorum to different rain addition treatments. [Method]A field experiment was set in Dengkou of Inner Mongolia to investigate a typical desert plant N. tangutorum growing at the eastern edge of the Ulanbuh Desert. The species grown under natural environment were subjected to five rain addition treatments ( increased by 0%,25%,50%,75% and 100% of local mean annual precipitation,respectively) from 2008 to 2014 successively. The aboveground biomass,ratio of leaf to shoot,branch growth rate,and seasonal distribution of dry mass of reproductive and vegetative branches under five rain addition treatments were analyzed.[Result]1 ) 75% and 100%treatments showed significant effects on branch dry mass in 2013 and 100% treatments showed significant effects on branch dry mass in 2014. The relative growth yield and relative growth rate of N. tangutorum branches increased after rain addition in the early growing season. These results indicated an incremental growth rate of reproductive and vegetative branches which means N. tangutorum shrubs would capture more optical energy and absorb more carbon dioxide from the surrounding environment. 2) In the growing season of 2013,the rate of biomass gain in vegetative branches and the rate of biomass loss in reproductive branches increased with the increase of rain addition,suggesting an advanced allocation of reproductive growth in the early growing season and vegetative growth in the late growing season. In growing season of 2014 ,the rate of biomass gain in vegetative branches and the rate of biomass loss in reproductive branches declined with the increase of rain addition. These biomass changes were mainly due to the very little natural rainfall in the early growing season and simulated rain addition slowed down the biomass decrease in reproductive branches. With different rainfall additions,N. tangutorum showed different biomass allocation strategies,indicating that N. tangutorum possess absolute regulatory ability and adaptability to precipitation variation. 3) In 2013,the aboveground biomass increased by 63. 70%-151. 60% and the ratio of leaf to shoot increased by 18. 61% -48. 83% after rain addition. In 2014,the aboveground biomass increased by 72. 32% - 134. 28% and the ratio of leaf to shoot increased by 40. 87% -140. 56% after rain addition. Aboveground biomass and the ratio of leaf to shoot increased with the increase of rain addition,gradually. The facts that rain addition led to the increase of aboveground biomass and the ratio of leaf and shoot suggested N. tangutorum shrubs would allocate more photosynthetic products to the above-ground portion and accelerate the growth of leaves.[Conclusion]In conclusion, N. tangutorum would enhance the growth rate of branches and leaves, regulate the photosynthetic product allocation between reproductive and vegetative branches, and increase photosynthetic product allocation on leaves to adapt to increased precipitation in the context of global climate change.关键词
模拟增雨/荒漠植物/生物量分配/地上生物量/叶枝比Key words
simulated rain addition/desert plant/biomass allocation/aboveground biomass/ratio of leaf to shoot分类
农业科技引用本文复制引用
何季,吴波,鲍芳,李嘉竹,姚斌,叶静芸,刘建康,辛智鸣..人工模拟增雨对乌兰布和沙漠白刺生物量分配的影响[J].林业科学,2016,52(5):81-91,11.基金项目
国家林业局林业公益性行业科研专项(201104077) （201104077）
中央级公益性科研院所基本科研业务费专项资金重点项目(CAFYBB2007008)。 （CAFYBB2007008）
