J Plant Ecol ›› 2023, Vol. 16 ›› Issue (1): rtac056.DOI: 10.1093/jpe/rtac056

• Research Articles •    

Effects of tree mycorrhizal type on soil respiration and carbon stock via fine root biomass and litter dynamic in tropical plantations

Guodong Zhang1, Guiyao Zhou2,*, Xuhui Zhou2,3,*, Lingyan Zhou2, Junjiong Shao2, Ruiqiang Liu3, Jing Gao2, Yanghui He3, Zhenggang Du3, Jianwei Tang4 and Manuel Delgado-Baquerizo5   

  1. 1 Coastal Ecosystems Research Station of Yangtze River Estuary, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, Fudan University, Shanghai 200433, China, 2 Tiantong National Field Observation Station for Forest Ecosystem, Center for Global Change and Ecological Forecasting, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China, 3 Northeast Asia ecosystem Carbon sink research Center (NACC), Center for Ecological Research, Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, School of Forestry, Northeast Forestry University, Harbin 150040, China, 4 Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China, 5 Laboratorio de Biodiversidad y Funcionamiento Ecosistémico, Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS), CSIC, Av. Reina Mercedes 10, E-41012 Sevilla, Spain

    *Corresponding author. E-mail: gyzhou@des.ecnu.edu.cn (G.Z.); xhzhou@des.ecnu.edu.cn (X.Z.)
  • Received:2021-05-13 Revised:2021-09-30 Accepted:2022-03-21 Online:2022-04-13 Published:2023-02-01

Abstract: 树种菌根类型通过细根生物量和凋落物动态影响土壤呼吸和土壤碳储存
热带森林是高生产力但同时也是脆弱的生态系统之一。一些全球范围的造林项目计划未来十年在热带地区种植数百万棵树。树种菌根类型影响森林土壤碳储存已成为共识,但在热带地区,树种菌根类型如何影响土壤呼吸(Rs)和碳储存,目前仍知之甚少。为研究树种菌根类型对Rs和土壤碳储存的影响,本实验在一个近30年热带同质园的3种丛枝菌根(AM)树种和3种外生菌根(EM)树种的单种林中,测量了其Rs和表层20 cm的碳含量,以及有关的生物因子(如根生物量、凋落物动态、土壤微生物)和非生物因子(如微气候)。研究结果表明,AM单种林的Rs、土壤碳含量,以及凋落物周转速率和细根生物量显著高于EM单种林。分析表明,与其他生物和非生物因子比较,树种菌根类型对Rs和土壤碳含量的影响最大。进一步分析表明,菌根类型是通过细根生物量和凋落物动态(凋落物产量、凋落物现存量、凋落物周转速率)直接和间接影响Rs和土壤碳含量。本研究结果强调了树种菌根类型对森林碳循环的影响,表明在热带地区种植AM树种可能比种植EM树种更能促进土壤固碳。


Key words: mycorrhizal, soil respiration, tropical forests, carbon storage, afforestation

摘要:

Tropical forests are among the most productive and vulnerable ecosystems in the planet. Several global forestation programs are aiming to plant millions of trees in tropical regions in the future decade. Mycorrhizal associations are known to largely influence forest soil carbon (C) stocks. However, to date, little is known on whether and how different tree mycorrhizal types affect soil respiration (Rs) and C stocks in tropical forests. In this study, we used a three-decade tropical common garden experiment, with three arbuscular mycorrhizal (AM) and three ectomycorrhizal (EM) monocultures, to investigate the impacts of tree mycorrhizal type on Rs and soil C stocks. Associating biotic (e.g. root biomass, litter dynamic, soil microbes) and abiotic factors (e.g. microclimate) were also measured. Our results showed that AM stands supported significantly higher Rs and soil C stock, litter turnover rate and fine root biomass than EM stands. Further statistical analysis displayed that tree mycorrhizal type was the most important factor in regulating Rs and soil C stock compared with other biotic or abiotic factors. Moreover, we found that mycorrhizal type directly and indirectly affected Rs and soil C stocks via fine root biomass and litter dynamic, i.e. litter production, litter standing crop and litter turnover rate. Our findings highlight important effects of tree mycorrhizal type on forest C cycle, suggesting that planting AM tree species could contribute to promotion of soil C stock in tropical ecosystems.

关键词: 菌根, 土壤呼吸, 热带森林, 碳储存, 造林