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草业学报 ›› 2016, Vol. 25 ›› Issue (12): 53-62.DOI: 10.11686/cyxb2016061

• 研究论文 • 上一篇    下一篇

羊草形态及生物量分配可塑性对土壤供磷能力的响应研究

郭丰辉1, 侯向阳1*, *, 丁勇1, 李西良1, 武自念1, 王珍1, 胡静1, 李新乐2, 马文静1, 赵劲博1   

  1. 1.中国农业科学院草原研究所,国家牧草改良中心,内蒙古 呼和浩特 010010;
    2.中国林业科学研究院沙漠林业实验中心,内蒙古 磴口 015200
  • 收稿日期:2016-03-01 修回日期:2016-04-12 出版日期:2016-12-20 发布日期:2016-12-20
  • 通讯作者: houxy16@126.com
  • 作者简介:郭丰辉(1987-),男,山东滨州人,硕士。E-mail:guofhui@163.com
  • 基金资助:
    国家重点基础研究发展计划(973计划)(2014CB138806),“十二五”国家科技支撑计划(2012BAD12B02),内蒙古自治区自然科学基金重大项目(2015ZD02),中央级科研院所基本科研业务费项目(1610332015001)和国家自然基金(31502008)资助

Plasticity of plant morphology and biomass allocation of Leymus chinensis under different phosphorus conditions

GUO Feng-Hui1, HOU Xiang-Yang1, *, DING Yong1, LI Xi-Liang1, WU Zi-Nian1, WANG Zhen1, HU Jing1, LI Xin-Le2, MA Wen-Jing1, ZHAO Jin-Bo1   

  1. 1.Institute of Grassland Research of Chinese Academy of Agriculture Sciences, National Forage Improvement Center, Hohhot 010010, China;
    2.Experimental Center of Desert Forestry of China Academy of Forestry, Dengkou 015200, China
  • Received:2016-03-01 Revised:2016-04-12 Online:2016-12-20 Published:2016-12-20

摘要: 植物形态及生物量分配变化是天然草原退化过程中的主要表现之一,通过研究植物形态及生物量分配对环境的响应规律有助于揭示草原退化及植被演替的内在机理。本试验研究了羊草形态、生物量累积及分配对土壤供磷能力的可塑性响应。试验采用有效磷含量低于3 mg P2O5/kg的土壤设置0,30,90,180 mg P2O5/kg 4个磷肥添加梯度,形成4种具有不同供磷能力的土壤,用于对羊草植株的培养,并于后期进行各项指标的测定。结果表明,1)土壤供磷能力的减弱明显减小了羊草的株高、各构件生物量,表现为高磷添加量显著高于低磷添加量,株高、叶生物量、茎生物量、根生物量、总生物量的降低幅度分别达到了14%,50%,51%,79%,63%。 2)羊草个体形态及生物量分配对土壤供磷能力的响应并不完全一致,生物量累积对供磷量的敏感度最大,生物量分配次之,形态的敏感度最差,可塑性指数分别为0.58,0.31,0.19;单个性状指标以根干重最为敏感,可塑性指数达到了0.79。3)相关分析表明,羊草地上干重与叶宽、节间数、株高达到了极显著水平,此3个形态指标对羊草地上生物量的贡献率分别为30%,27%,26%,是形态指标中解释羊草地上生物量产生差异的主要因子。本试验在课题组前期研究的基础上,进一步从个体水平上探索羊草对土壤供磷能力的响应,与课题组前期试验结果相结合,可有助于探索天然草原退化和植被演替的内在原因。

Abstract: Changes in plant morphology and biomass allocation are the main factors in the natural grassland degradation process. Studying the responses of plant morphology and biomass allocation under different conditions could help to reveal the mechanism of grassland degradation. We conducted a pot experiment and evaluated the morphological responses and biomass accumulation and allocation of Leymus chinensis under different phosphorus (P) conditions. The treatments consisted of 0, 30, 90, and 180 mg P2O5/kg added to soil to provide four different P-availability conditions for cultivation of L. chinensis. The results showed that: 1) plant biomass and height were reduced under low-P availability, and were significantly increased under higher-P availability. Plant height, leaf biomass, stem biomass, root biomass, and total biomass were 14%, 50%, 51%, 79%, and 63% lower, respectively, under low-P availability than under high-P availability. 2) Plant morphology and biomass allocation showed different responses to P availability. Biomass accumulation was the most sensitive to P conditions, and morphology was the least sensitive; the plasticity indexes were 0.58, 0.31, and 0.19, respectively, for biomass accumulation, allocation, and morphology. The most sensitive single trait indicator was root dry mass with the plasticity index of 0.79. 3) The correlations between aboveground dry mass and leaf width, internode number, and plant height were all significant. Understanding the responses of L. chinensis to different P conditions can help to reveal the mechanisms of vegetation succession and degradation in the grassland ecosystem.