Ecosystem nitrogen retention is regulated by plant community trait interactions with nutrient status in an alpine meadow
Ecosystem nitrogen retention is regulated by plant community trait interactions with nutrient status in an alpine meadow
复制标题
高寒草甸生态系统氮保留受植物群落性状与营养状况相互作用的调节
DOI：
10.1111/1365-2745.12924
复制
发表时间：
2018
影响因子：
5.5
通讯作者：
Zhao Xinquan
中科院分区：
文献类型：
--
作者：
Wang Fangping;Shi Guoxi;Nicholas Ostle;Yao Buqing;Ji Mingfei;Wang Wenying;Ma Zhen;Zhou Huakun;Zhao Xinquan
生物氮（N）的保留是一个重要的生态系统功能的背景下，不断土地利用集约化，氮沉降和全球变暖。然而，由于实验证据的缺乏，限制了人们对不同植物群落成分如何影响陆地生态系统氮素保留的了解。本研究通过15 N标记实验，测试了植物群落特征（包括植物物种丰富度/多样性、优势度和功能性状）在不同养分有效性下如何影响植物氮素吸收和保留。通过为期3年的试验研究了青藏高原高寒草甸土壤中添加N（10 g N m-2 year-1）和P（5 g P m-2 year-1）对15 N的影响，结果表明：随着N和P的添加，15 N在植物和土壤N库中的滞留量增加，其中P的添加对15 N滞留量的增加最大。土壤养分条件的变化也促进了不同植物群落对生态系统氮素的保持。在对照样地中，生态系统15 N保留量受物种丰富度和根系生物量的影响;而氮添加处理显示出比叶面积的群落加权平均值（CWM）的重要影响，并且添加P的样地记录了较低的CWM根氮含量（根N）和较大的CWM根：冠比作为重要决定因素。在氮素缺乏和氮素丰富条件下，生态系统氮素保持量分别受保护植物和开发植物的种类和/或性状的影响，而在中性条件下，物种丰富度和群落植物生物量对生态系统氮素保持量影响最大。植物群落特征和营养元素地球化学之间的相互作用作为生态系统氮保持机制的发现，提供了一种手段来预测高寒草甸生态系统中的植被将如何响应预期的全球变化。
Biotic nitrogen (N) retention is an important ecosystem function in the context of ongoing land‐use intensification, N deposition and global warming. However, a paucity of experimental evidence limits understanding of how different plant community components influence N retention in terrestrial ecosystems.In this investigation, we conducted a15N labelling experiment to test how plant community properties, including plant species richness/diversity, dominance and functional traits, influence plant N uptake and retention under different nutrient availabilities. A 3‐year experiment examined the effects of adding N (10 g N m−2year−1) and phosphorus (P) (5 g P m−2year−1) to an alpine meadow on the Qinghai‐Tibetan Plateau.Results show that15N retention increased with the addition of N and P; the addition of P produced the largest increase of15N retention in plant and soil N pools. Changes in soil nutrient conditions also facilitated different plant community controls on ecosystem N retention. Ecosystem15N retention was influenced by species richness and root biomass in the control plots; whereas the N addition treatment showed an important effect of community‐weighted means (CWM) of specific leaf area, and plots with additional P recorded lower CWM of root nitrogen content (root N) and larger CWM root:shoot ratios as important determinants.Synthesis. Ecosystem N retention was influenced by conservative and exploitative plant species and/or their traits under N deficient and abundant conditions, respectively, whereas species richness and community plant biomass were most influential under middle condition. The discovery of an interaction between plant community traits and nutrient biogeochemistry as a mechanism for ecosystem N retention offers a means to predict how vegetation in alpine meadow ecosystems will respond to expected global change.