Zuo Xiaoan, Yue Xiyuan, Lv Peng, Yu Qiang, Chen Min, Zhang Jing, Luo Yongqing, Wang Shaokun, Zhang Jing
Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou China; Laboratory of Stress Ecophysiology and Biotechnology (LSEB) NIEER, CAS Lanzhou China.
Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou China.
Ecol Evol. 2017 Jan 24;7(4):1125-1134. doi: 10.1002/ece3.2711. eCollection 2017 Feb.
Changes in plant community traits along an environmental gradient are caused by interspecific and intraspecific trait variation. However, little is known about the role of interspecific and intraspecific trait variation in plant community responses to the restoration of a sandy grassland ecosystem. We measured five functional traits of 34 species along a restoration gradient of sandy grassland (mobile dune, semi-fixed dune, fixed dune, and grassland) in Horqin Sand Land, northern China. We examined how community-level traits varied with habitat changes and soil gradients using both abundance-weighted and non-weighted averages of trait values. We quantified the relative contribution of inter- and intraspecific trait variation in specific leaf area (SLA), leaf dry matter content (LDMC), leaf carbon content (LCC), leaf nitrogen content (LNC), and plant height to the community response to habitat changes in the restoration of sandy grassland. We found that five weighted community-average traits varied significantly with habitat changes. Along the soil gradient in the restoration of sandy grassland, plant height, SLA, LDMC, and LCC increased, while LNC decreased. For all traits, there was a greater contribution of interspecific variation to community response in regard to habitat changes relative to that of intraspecific variation. The relative contribution of the interspecific variation effect of an abundance-weighted trait was greater than that of a non-weighted trait with regard to all traits except LDMC. A community-level trait response to habitat changes was due largely to species turnover. Though the intraspecific shift plays a small role in community trait response to habitat changes, it has an effect on plant coexistence and the maintenance of herbaceous plants in sandy grassland habitats. The context dependency of positive and negative covariation between inter- and intraspecific variation further suggests that both effects of inter- and intraspecific variation on a community trait should be considered when understanding a plant community response to environmental changes in sandy grassland ecosystems.
植物群落特征沿环境梯度的变化是由种间和种内性状变异引起的。然而，关于种间和种内性状变异在植物群落对沙地草原生态系统恢复的响应中所起的作用，我们却知之甚少。我们在中国北方科尔沁沙地沿沙地草原的恢复梯度（流动沙丘、半固定沙丘、固定沙丘和草原）测量了34个物种的五个功能性状。我们使用性状值的丰度加权平均值和非加权平均值，研究了群落水平的性状如何随栖息地变化和土壤梯度而变化。我们量化了种间和种内性状变异对比叶面积（SLA）、叶片干物质含量（LDMC）、叶片碳含量（LCC）、叶片氮含量（LNC）和株高在沙地草原恢复过程中对栖息地变化的群落响应的相对贡献。我们发现，五个加权群落平均性状随栖息地变化而显著变化。在沙地草原恢复过程中，沿着土壤梯度，株高、SLA、LDMC和LCC增加，而LNC降低。对于所有性状，相对于种内变异，种间变异对栖息地变化的群落响应的贡献更大。除LDMC外，就所有性状而言，丰度加权性状的种间变异效应的相对贡献大于非加权性状。群落水平对栖息地变化的性状响应主要归因于物种更替。虽然种内变化在群落性状对栖息地变化的响应中作用较小，但它对沙地草原栖息地中植物的共存和草本植物的维持有影响。种间和种内变异之间正负协变的背景依赖性进一步表明，在理解沙地草原生态系统中植物群落对环境变化的响应时，应同时考虑种间和种内变异对群落性状的影响。
