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林业科学 ›› 2016, Vol. 52 ›› Issue (5): 81-91.doi: 10.11707/j.1001-7488.20160510

• 论文与研究报告 • 上一篇    下一篇

人工模拟增雨对乌兰布和沙漠白刺生物量分配的影响

何季1, 吴波2, 鲍芳2, 李嘉竹2, 姚斌2, 叶静芸2, 刘建康3, 辛智鸣4   

  1. 1. 贵州大学农学院 贵阳 550025;
    2. 中国林业科学研究院荒漠化研究所 北京 100091;
    3. 北京林业大学 北京 100083;
    4. 中国林业科学研究院沙漠林业实验中心 磴口 015200
  • 收稿日期:2015-09-13 修回日期:2015-10-05 出版日期:2016-05-25 发布日期:2016-06-01
  • 通讯作者: 吴波
  • 基金资助:

    国家林业局林业公益性行业科研专项(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)。

Effects of Simulated Rain Addition on Biomass Allocation of Nitraria tangutorum in Ulanbuh Desert

He Ji1, Wu Bo2, Bao Fang2, Li Jiazhu2, Yao Bin2, Ye Jingyun2, Liu Jiankang3, Xin Zhiming4   

  1. 1. College of Agriculture, Guizhou University Guiyang 550025;
    2. Institute of Desertification Studies, Chinese Academy of Forestry Beijing 100091;
    3. Beijing Forestry University Beijing 100083;
    4. Experimental Center of Desert Forestry, Chinese Academy of Forestry Dengkou 015200
  • Received:2015-09-13 Revised:2015-10-05 Online:2016-05-25 Published:2016-06-01

摘要:

[目的] 研究人工模拟增雨对白刺枝条生长速率、地上生物量及叶枝比的影响,揭示不同增雨条件下白刺光合产物的分配特征及其对水分条件变化的适应性。[方法] 以乌兰布和沙漠东缘地区典型荒漠植物白刺为研究对象,在内蒙古磴口设置试验样地,对自然生长的白刺沙包进行人工模拟增雨(分别增加年均降水量的0%,25%,50%,75%和100%),增雨试验在2008-2014年连续进行。分析不同增雨条件下白刺的地上生物量、叶枝比、生殖枝和营养枝的生长速率及其季节内分配。[结果] 1) 2013年,75%和100%增雨对生殖枝和营养枝的干质量有显著影响; 2014年,100%增雨对生殖枝和营养枝的干质量有显著影响。增雨使白刺生长季前期生殖枝和营养枝的相对生长量和相对生长速率增加,说明在增雨条件下白刺生殖枝和营养枝的生长速度加快,使其在群落中能够捕获更多的光能和吸收更多的CO2。2) 2013年生长季内,随着增雨量的增加,营养枝增加的速率以及生殖枝降低的速率逐渐增加,说明增雨使白刺在生长季前期对生殖生长以及生长季后期对营养生长的投入增加。2014年生长季内,随着增雨量的增加,营养枝增加的速率以及生殖枝降低的速率逐渐降低,主要是由于该年生长季前期自然降雨极少,而模拟增雨减缓了生殖枝生物量降低的缘故。在面对不同的增雨量时对光合产物表现出不同的分配策略,说明白刺对水分条件的变化有一定的调节能力,在适应降水增加的过程中已经具备较强的适应性。3) 2013年,增雨使白刺地上生物量增加63.70%~151.60%,使叶枝比增加18.61%~48.83%; 2014年,增雨使白刺地上生物量增加72.32%~134.28%,使叶枝比增加40.87%~140.56%。地上生物量和叶枝比随着增雨量的增加呈逐渐上升的趋势,说明在增雨量较大时,白刺将生物量干质量相对多地分配到地上部分的同时,分配更多的光合产物来促进叶片的生长。[结论] 在未来全球气候变化条件下,白刺将通过提高枝条生长速率、调整干物质量在生殖枝和营养枝之间的累积以及增大光合产物对叶片的分配等一系列措施来积极应对降水的增加。

关键词: 模拟增雨, 荒漠植物, 生物量分配, 地上生物量, 叶枝比

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.

Key words: simulated rain addition, desert plant, biomass allocation, aboveground biomass, ratio of leaf to shoot

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