Journal of Plant Ecology ›› 2025, Vol. 18 ›› Issue (5): 1-29.DOI: 10.1093/jpe/rtaf089

• •    

亚热带森林氮添加通过改变土壤pH和细菌群落结构削弱凋落物分解的主场优势效应

  

  • 收稿日期:2025-04-08 接受日期:2025-07-12 出版日期:2025-10-01 发布日期:2025-09-28

Nitrogen addition weakens home-field advantage of litter decomposition by altering soil pH and bacterial communities in a subtropical forest

Chunhui Lia,†, Jiguang Fengb,c,†, Liu Liua, Xu Sund, Jinsheng Lie, Zhuangzhuang Qiana, Ranran Fua, Qingshui Yuf, Biao Zhuf, Xiao Taoa,f,*   

  1. aSchool of Forestry and Landscape Architecture, Anhui Provincial Key Laboratory of Forest Resources and Silviculture, Hefei Urban Ecosystem Research Station of the National Forestry and Grassland Administration, Anhui Agricultural University, Hefei 230036, China
    bMinistry of Education Key Laboratory for Ecology and Resource Use of the Mongolian Plateau, Inner Mongolia Key Laboratory for Grassland Ecology, and School of Ecology and Environment, Inner Mongolia University, Huhhot 010021, China
    cNational Key Laboratory of Water Disaster Prevention, Jiangsu Key Laboratory of Soil and Water Processes in Watershed, College of Geography and Remote Sensing, Hohai University, Nanjing 211000, China
    dSchool of Life Sciences, Anhui Agricultural University, Hefei 230036, China
    eCollege of Resources and Environment, Anhui Agricultural University, Hefei 230036, China
    fState Key Laboratory for Vegetation Structure, Function and Construction (VegLab), Ministry of Education Key Laboratory for Earth Surface Processes, and College of Urban and Environmental Sciences, Peking University, Beijing 100871, China

    *Corresponding author. E-mail: taoxiao@ahau.edu.cn
    These authors contributed equally to this work.
  • Received:2025-04-08 Accepted:2025-07-12 Online:2025-10-01 Published:2025-09-28
  • Supported by:
    This study was founded by the National Natural Science Foundation of China (grant numbers 32271954 and 32201395).

摘要: 主场优势(Home-field advantage, HFA)假说认为,植物凋落物在原生环境中的分解速率高于非原生环境。尽管HFA效应在调节陆地生态系统碳和养分循环中发挥着重要作用,但氮沉降如何影响HFA效应仍不明确。本研究以亚热带城市麻栎林(Quercus acutissima)和马尾松林(Pinus massoniana)为研究对象,设置4个氮添加水平(0、30、50、100 kg N ha−1 year−1),开展了为期12个月的凋落物野外互置实验;此外,通过对全球森林氮添加实验进行meta分析,验证HFA对氮添加的响应规律是否具有普适性。结果表明,在对照条件下凋落物分解表现出显著的HFA效应,HFA指数为3.98;然而,氮添加显著削弱了HFA效应;在100 kg N ha−1 year−1处理下,HFA指数下降至−6.12。进一步分析发现,HFA指数与两个林分间细菌群落的差异性显著正相关。这主要是因为氮添加改变了马尾松林土壤细菌多样性和群落组成,并通过降低土壤pH导致林分间细菌群落趋同。类似地,meta分析结果显示,物种水平的HFA指数及其对氮添加的响应也随氮添加量的增加而降低,表明氮添加减弱HFA效应具有普适性。综上所述,氮输入引起的土壤酸化通过改变细菌群落间接削弱了HFA效应,这一发现有助于更好地预测氮沉降背景下森林生态系统HFA效应及碳氮循环的动态变化。

关键词: 碳循环, 凋落物分解, 主场优势, 微生物群落组成, 微生物多样性

Abstract: The home-field advantage (HFA) hypothesis predicts that litter decomposes faster in its home environment than elsewhere. Given the critical role of HFA effect in mediating terrestrial carbon and nutrient cycling, it remains unclear how nitrogen (N) deposition affects this effect. Here, we conducted a 12-month field experiment involving reciprocal litter translocation, with four N addition levels (0, 30, 50 and 100 kg N ha–1 year–1), in Quercus acutissima and Pinus massoniana stands in a subtropical urban forest and a mini meta-analysis of the effect of N addition on HFA in global forests. Results showed that a significant positive HFA of 3.98 was observed, but N addition (particularly with high rates) tended to weaken it, by decreasing it to –6.12 at 100 kg N ha–1 year–1. Conversely, the combined HFA index increased with bacterial community dissimilarity between stands. Such relationships were due to that N addition changed soil bacterial diversity and composition in P. massoniana stand and led to the convergence of bacterial communities between stands, mainly by lowering soil pH. Similarly, our experiment and meta-analysis showed that the species-level HFA index and its response to N addition also decreased with N addition rate (P < 0.05), suggesting the generalization of how N addition affects HFA. Our findings suggest that soil acidification driven by N inputs indirectly reduces HFA through altering bacterial communities, which helps to better understand and predict the dynamics of HFA effect and the cycling of carbon and nitrogen in forest ecosystems under N deposition.

Key words: carbon cycling, litter decomposition, home-field advantage, microbial community composition, microbial diversity