Species richness mediates within‐species nutrient resorption: Implications for the biodiversity–productivity relationship. (29th April 2019)

• Record Type: Journal Article
• Authors: Lü, Xiao‐Tao; Hu, Yan‐Yu; Wolf, Amelia A.; Han, Xing‐Guo
• Editors: Le Bagousse‐Pinguet, Yoann
• Is Part Of: Journal of ecology. Volume 107:Number 5(2019:Sep.)
• Page Start: 2346
• Page End: 2352
• Publication Date: 2019-04-29
• Subjects: biodiversity loss -- ecosystem functioning -- intraspecific variation -- litter quality -- plant functional trait -- plant–soil feedback -- species complementarity; Plant ecology -- Periodicals; 577.05
• DOI: 10.1111/1365-2745.13180
• Languages: English
• ISSNs: 0022-0477

Abstract

Abstract: Between‐species variation in nutrient resorption is one of the mechanisms explaining the positive relationship between biodiversity and primary productivity. Yet, the role of within‐species variations in nutrient resorption in mediating the relationship between biodiversity and productivity remains unclear. We examined how within‐species nutrient resorption, and ultimately productivity, respond to changes in species richness by using four traits related to nitrogen and phosphorus use in four dominant species from different plant functional groups in a biodiversity removal experiment in the temperate steppe. Nitrogen and phosphorus concentrations in both green and senesced leaves in all species significantly decreased with increasing plant species richness, suggesting that plants used those limiting nutrients more efficiently with increasing biodiversity. Plants in higher diversity communities resorbed more nutrients during senescence, which may facilitate reproduction and vegetative regrowth in the next year. Synthesis . Our results highlight the importance of considering within‐species variation in nutrient resorption as an important underlying mechanism explaining the positive effects of biodiversity on primary productivity and ecosystem carbon accumulation. Abstract : Plants in higher‐diversity communities resorbed more nutrients during senescence, which may facilitate reproduction and vegetative regrowth in the next year. Our results highlight the importance of considering within‐species variation in nutrient resorption as an important underlying mechanism explaining the positive effects of biodiversity on primary productivity and ecosystem carbon accumulation. 摘要: 生物多样性与生产力之间存在正向相关关系， 对这一关系内在驱动机制的探讨是国际生态学研究的热点问题， 主要的科学假说包括取样效应 (Sampling effect） 和互补效应 （Complementarity effect）。以往的研究认为植物群落内不同物种对土壤资源的互补性利用 （种间作用） 是导致生物多样性和生产力存在正向关系的重要原因之一， 却忽视了单种植物的养分利用特征 （种内变化） 随着群落中生物多样性的变化会发生怎样的改变， 这种改变进而会如何作用于生产力。本研究利用位于中国内蒙古典型草原的物种去除实验平台， 分析了羊草、大针茅、细叶葱、猪毛菜等四种来自四个不同的植物功能群的代表性植物在枯萎过程中养分回收效率随群落中植物物种多样性的变化情况。研究结果表明上述四种植物夏季绿色成熟叶片和秋季枯萎叶片中的氮磷养分含量均随着群落中物种多样性的增加而降低， 这说明在高多样性的群落中植物会提高自身的养分利用效率。在枯萎过程中， 多数植物的养分回收效率随着群落中植物多样性的增加而升高， 回收的这部分养分会进入植物的繁殖器官和储藏器官从而有利于植物的繁殖生长和下一个生长季的营养生长。本研究从植物养分利用特征种内变化这一新的角度解释了为什么生物多样性与生产力之间存在正向相关关系。