Climate warming increases root exudation rates of dominant species in alpine meadow on the Qingzang Plateau

doi:10.17521/cjpe.2024.0470

Abstract

Abstract:

Aims Plant root exudates have received increasing attention as a key link in plant-soil-microbe interactions in recent years. However, studies on the impact of climate warming on the root exudation rates of grassland plants remain relatively limited.
Methods In this study, we conducted a laboratory controlled experiment with 10 dominant plant species in alpine meadows of the Qingzang Plateau. We collected root exudates in situ to quantitatively analyze the changes in root carbon exudation rates of the dominant species under experimental warming (+4 °C) and identified the factors influencing these changes.
Important findings Our results showed that: (1) Warming significantly increased the root carbon exudation rate of most dominant species, with an overall increase of (83.48 ± 6.00) μg·g^-1·h^-1 (81.71%), but it decreased the root exudation rate in leguminous plants (11.15%); (2) The changes in root exudation rates induced by warming were closely related to plant nutrient traits and morphological traits, with root nitrogen content explaining the highest variation. These findings suggest that climate warming will enhance the root exudation rates of dominant species in alpine meadows and highlight the critical role of functional traits in regulating root exudation responses to warming. This study contributes to the understanding rhizosphere carbon dynamics in the context of climate change and provides scientific evidence for predicting changes in the soil carbon on the Qingzang Plateau.

Key words: root exudation rate, plant functional trait, climate warming, alpine meadow, plant economics spectrum

ZHENG Zi-Yi, CHEN Jiang-Hui, LIU Hui-Ying. Climate warming increases root exudation rates of dominant species in alpine meadow on the Qingzang Plateau[J]. Chin J Plant Ecol, 2025, 49(9): 1363-1373.

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URL: https://www.plant-ecology.com/EN/10.17521/cjpe.2024.0470

https://www.plant-ecology.com/EN/Y2025/V49/I9/1363

Figures/Tables 5

Table 1 Linear mixed effects model results of the effect of warming on carbon exudation rates of 10 dominant species in alpine meadows on the Qingzang Plateau

固定效应 Fixed effect	模型自由度 NumDF	残差自由度 DenDF	F	p
处理 Treatment (T)	1	40	103.20	<0.001^***
物种 Species (S)	9	40	29.51	<0.001^***
处理×物种 T × S	9	40	7.27	<0.001^***

Fig. 1 Effects of warming on root carbon (C) exudation rates of 10 dominant species in alpine meadows on the Qingzang Plateau (mean ± SE, n = 3). The upper left inset shows the effect of warming on root carbon exudation rates of all species (n = 30). Asterisks indicate significant differences between control and warming (*, p < 0.05; ***, p < 0.001), and ns indicates no significant differences between control and warming (p > 0.05).

Fig. 2 Effects of warming on the economic phenotypes of dominant plants in alpine meadows on the Qingzang Plateau. The red arrow indicates the direction of the warming treatment, the brown arrows indicate the root traits, and the green arrows indicate the leaf traits. LC, leaf carbon content; LN, leaf nitrogen content; NPR, net photosynthetic rate; RC, root carbon content; RN, root nitrogen content; Root C exudation, root carbon exudation rate; RTD, root tissue density; SLA, specific leaf area; SPAD, relative chlorophyll content; SRA, specific root area; SRL, specific root length; Warming, warming treatment. PC1, principal component 1; PC2, principal component 2.

Fig. 3 Contribution of plant functional traits to changes in root carbon exudation rate (n = 60). LC, leaf carbon content; LN, leaf nitrogen content; NPR, net photosynthetic rate; RC, root carbon content; RN, root nitrogen content; RTD, root tissue density; SLA, specific leaf area; SPAD, relative chlorophyll content; SRA, specific root area; SRL, specific root length. MSE, mean squared error.

Fig. 4 Linear fit of root carbon exudation rate to key plant traits. Gray shading indicates 95% confidence intervals, and the solid line represents a significant slope of the linear fit (p < 0.05).

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