Liu Xiangrong, Hou Lingyu, Ding Changjun, Su Xiaohua, Zhang Weixi, Pang Zhongyi, Zhang Yanlin, Sun Qiwu
State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China.
State Key Laboratory of Efficient Production of Forest Resource, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China.
Front Microbiol. 2024 Nov 27;15:1477571. doi: 10.3389/fmicb.2024.1477571. eCollection 2024.
Many studies have identified stand age and soil microbial communities as key factors influencing soil respiration (Rs). However, the effects of stand age on Rs and soil microbial communities throughout the growth cycle of poplar ( cv.'I-214') plantations remain unclear.
In this study, we adopted a spatial approach instead of a temporal one to investigate Rs and soil microbial communities in poplar plantations of 15 different ages (1-15 years old).
The results showed that Rs exhibited clear seasonal dynamics, with the highest rates observed in the first year of stand age (1-year-old). As stand age increased, Rs showed a significant decreasing trend. We further identified r-selected microbial communities (copiotrophic species) as key biological factors influencing the decline in Rs with increasing stand age. Other abiotic factors, such as soil temperature (ST), pH, soil organic carbon (SOC), nitrate nitrogen (NO -N), and the C/N ratio of plant litter (Litter C/N), were also significantly correlated with Rs. Increased stand age promoted fungal community diversity but suppressed bacterial community diversity. Bacterial and fungal communities differed significantly in abundance, composition, and function, with the Litter C/N ratio being a key variable affected by microbial community changes.
This study provides crucial empirical evidence on how stand age affects Rs, highlighting the connection between microbial community assemblages, their trophic strategies, and Rs over the growth cycle of poplar plantations.
许多研究已将林分年龄和土壤微生物群落确定为影响土壤呼吸（Rs）的关键因素。然而，在杨树（品种‘I-214’）人工林的整个生长周期中，林分年龄对Rs和土壤微生物群落的影响仍不清楚。
在本研究中，我们采用空间方法而非时间方法来调查15个不同年龄（1至15年）的杨树人工林中的Rs和土壤微生物群落。
结果表明，Rs呈现出明显的季节动态，在林分年龄的第一年（1年生）观察到最高速率。随着林分年龄的增加，Rs呈现出显著下降趋势。我们进一步确定r选择型微生物群落（富营养型物种）是随着林分年龄增加影响Rs下降的关键生物因素。其他非生物因素，如土壤温度（ST）、pH值、土壤有机碳（SOC）、硝态氮（NO₃-N）和植物凋落物的碳氮比（凋落物C/N），也与Rs显著相关。林分年龄增加促进了真菌群落多样性，但抑制了细菌群落多样性。细菌和真菌群落在丰度、组成和功能上存在显著差异，凋落物C/N比是受微生物群落变化影响的关键变量。
本研究提供了关于林分年龄如何影响Rs的关键实证证据，突出了杨树人工林生长周期中微生物群落组合、其营养策略与Rs之间的联系。
