Yang Yuting, Chen Zhifei, Xu Bingcheng, Ghanizadeh Hossein, Li Wei, Ding Chengqin, Zhou Ronglei, Wen Zhongming
College of Grassland Agriculture, Northwest A&F University, Yangling, Shaanxi, China.
College of Life Sciences, Guizhou University, Guiyang, Guizhou, China.
Front Plant Sci. 2023 Aug 15;14:1145709. doi: 10.3389/fpls.2023.1145709. eCollection 2023.
Fertilization could influence ecosystem structure and functioning through species turnover (ST) and intraspecific trait variation (ITV), especially in nutrient limited ecosystems. To quantify the relative importance of ITV and ST in driving community functional structure and productivity changes under nitrogen (N) and phosphorous (P) addition in semiarid grasslands. In this regard, we conducted a four-year fertilizer addition experiment in a semiarid grassland on the Loess Plateau, China. We examined how fertilization affects species-level leaf and root trait plasticity to evaluate the ability of plants to manifest different levels of traits in response to different N and P addition. Also, we assessed how ITV or ST dominated community-weighted mean (CWM) traits and functional diversity variations and evaluated their effects on grassland productivity. The results showed that the patterns of plasticity varied greatly among different plant species, and leaf and root traits showed coordinated variations following fertilization. Increasing the level of N and P increased CWM_specific leaf area (CWM_SLA), CWM_leaf N concentration (CWM_LN) and CWM_maximum plant height (CWM_H) and ITV predominate these CWM traits variations. As a results, increased CWM_H, CWM_LN and CWM_SLA positively influenced grassland productivity. In contrast, functional divergence decreased with increasing N and P and showed negative relationships with grassland productivity. Our results emphasized that CWM traits and functional diversity contrastingly drive changes in grassland productivity under N and P addition.
受精作用可能通过物种更替（ST）和种内性状变异（ITV）影响生态系统结构和功能，尤其是在养分受限的生态系统中。为了量化在半干旱草原施加氮（N）和磷（P）的情况下，ITV和ST在驱动群落功能结构和生产力变化方面的相对重要性。在这方面，我们在中国黄土高原的一个半干旱草原上进行了为期四年的施肥实验。我们研究了施肥如何影响物种水平的叶和根性状可塑性，以评估植物响应不同N和P添加量而表现出不同性状水平的能力。此外，我们评估了ITV或ST如何主导群落加权平均（CWM）性状和功能多样性变化，并评估了它们对草地生产力的影响。结果表明，不同植物物种间可塑性模式差异很大，施肥后叶和根性状呈现出协同变化。增加N和P水平会增加CWM_比叶面积（CWM_SLA）、CWM_叶氮浓度（CWM_LN）和CWM_最大株高（CWM_H），且ITV主导这些CWM性状变化。结果，CWM_H、CWM_LN和CWM_SLA的增加对草地生产力产生了积极影响。相反，功能离散度随N和P增加而降低，并与草地生产力呈负相关。我们的结果强调，在添加N和P的情况下，CWM性状和功能多样性对草地生产力变化的驱动作用形成对比。
