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Updated: Jun 26, 2025

A Simple Protocol for Mapping the Plant Root System Architecture Traits
Published on: February 10, 2023
Phosphorus addition enhances heterotrophic respiration but reduces root respiration in a subtropical plantation
Yun Xia1, Benjamin L Turner2, Yiqing Li3
1School of Geographical Science, Fujian Normal University, Fuzhou 350007, China; Key Laboratory of Humid Subtropical Eco-geographical Process of Ministry of Education, Fujian Provincial Key Laboratory for Plant Eco-physiology, Fujian Normal University, Fuzhou 350117, China; Institute of Geography, Fujian Normal University, Fuzhou 350007, China.
Abstract:
Soil respiration (Rs) is a major component of the global carbon (C) cycle and is influenced by the availability of nutrients such as phosphorus (P). However, the response of Rs to P addition in P-limited subtropical forest ecosystems and the underlying mechanisms remain poorly understood. To address this, we conducted a P addition experiment (50 kg P ha-1 yr-1) in a subtropical Chinese fir (Cunninghamia lanceolata) plantation forest. We separated Rs into heterotrophic respiration (Rh), root respiration (Rr), and mycorrhizal hyphal respiration (Rm), and quantified soil properties, microbial biomass (phospholipid fatty acid, PLFA), fungal community composition (ITS), and the activity of extracellular enzymes. Phosphorus addition significantly increased Rs and Rh, but decreased Rr and did not influence Rm. Further, P addition increased fungal, bacterial, and total PLFAs, and phenol oxidase activity. Conversely, P application decreased root biomass and did not alter the relative abundance of symbiotrophic fungi. Phosphorus enrichment therefore enhances soil C emissions by promoting organic matter decomposition by heterotrophic activity, rather than via increases in root or mycorrhizal respiration. This advances our mechanistic understanding of the relationship between fertility and soil respiration in subtropical forests, with implications for predicting soil C emissions under global change.
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