J Plant Ecol ›› 2021, Vol. 14 ›› Issue (6): 1175-1188 .DOI: 10.1093/jpe/rtab064

• Research Articles • Previous Articles     Next Articles

Biotic and abiotic factors determine species diversity–productivity relationships in mountain meadows

Jia-Jia Liu1, Yong Xu1,2, You-Xia Shan2,3, Kevin S. Burgess4,* and Xue-Jun Ge1,5,*   

  1. 1 Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China, 2 University of Chinese Academy of Sciences, Beijing 100039, China, 3 Key Laboratory of Plant Resource Conservation and Sustainable Utilization, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China, 4 Department of Biology, Columbus State University, University System of Georgia, Columbus, GA 31907, USA, 5 Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou 510650, China

    *Corresponding author. E-mail: burgess_kevin@columbusstate.edu (K.S.B.); xjge@scbg.ac.cn (X.-J.G.)
  • Received:2020-12-19 Revised:2021-02-06 Accepted:2021-05-29 Online:2021-06-17 Published:2021-12-01

Abstract:

Aims

Species diversity–productivity relationships in natural ecosystems have been well documented in the literature. However, biotic and abiotic factors that determine their relationships are still poorly understood, especially under future climate change scenarios.

Methods

Randomized block factorial experiments were performed in three meadows along an elevational gradient on Yulong Mountain, China, where open-top chambers and urea fertilizer manipulations were used to simulate warming and nitrogen addition, respectively. Besides species diversity, we measured functional diversity based on five traits: plant height, specific leaf area and leaf carbon, nitrogen and phosphorus contents. Several abiotic factors relating to climate (air temperature and precipitation) and soil chemistry (pH, organic carbon concentration, total nitrogen concentration and phosphorus concentration) were also measured. Generalized linear mixed-effect models were used to investigate the responses of species diversity and productivity to elevation, warming, nitrogen addition and their interactions. The effects of biotic and abiotic factors on the direction and magnitude of their relationship were also assessed.

Important Findings

Species diversity decreased with increasing elevation and declined under warming at mid-elevation, while productivity decreased with increasing elevation. Functional richness, maximum air temperature, soil pH and their interactions showed strong but negative influences on the species diversity–productivity relationship; the relationship shifted from positive to neutral and then to slightly negative as these sources of variation increased. Our study highlights the negative effects of short-term warming on species diversity and emphasizes the importance of both biotic and abiotic drivers of species diversity–productivity relationships in mountain meadow communities.

Key words: climate warming, elevation, functional traits, nitrogen addition, plant community composition, soil pH, Yulong Mountain

摘要:
生物和非生物因素决定高山草甸物种多样性-生产力相互关系
自然条件下物种多样性-生产力相互关系取决于生物和非生物因素,但其相对重要性及相互作用仍不清晰,特别是在未来的气候变化情景下。为此,我们在中国玉龙雪山3处不同海拔的高山草甸开展了模拟气候变暖和大气氮沉降的完全随机组块析因试验。除物种多样性外,我们根据株高、比叶面积、叶片碳、氮、磷含量计算了实验处理下草甸植物群落的功能多样性,并将其作为关键生物因素。此外,我们测量了气温、降雨以及土壤的化学属性作为潜在重要的非生物因素。我们利用广义线性混合模型研究了物种多样性和植物生产力对海拔、增温、施肥及其可能的交互作用的响应,同时评估了上述生物和非生物因素对物种多样性-生产力相互关系的影响。研究结果表明,物种多样性随海拔升高而降低并且在增温处理下有下降趋势且在中间海拔最为强烈。相对而言,植物生产力仅随海拔升高而下降。功能丰富度、最高气温、土壤pH对物种多样性-生产力相互关系表现出强烈的负交互作用,即物种多样性-生产力相互关系随着这些因素的增加从正相互关系变为中性关系,然后变为轻微的负相互关系。我们的研究指出短期增温对高山草甸物种多样性的负面影响,并强调生物和非生物因素决定了自然条件下物种多样性-生产力相互关系。

关键词: 气候变暖, 海拔, 功能性状, 氮添加, 植物群落组成, 土壤pH, 玉龙雪山