青藏高原高寒草地植物地上-地下化学计量对降水变化的不对称响

doi:10.1093/jpe/rtaf199

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青藏高原高寒草地植物地上-地下化学计量对降水变化的不对称响

收稿日期:2025-03-24 接受日期:2025-11-12

Asymmetric responses of plant aboveground and belowground stoichiometry to precipitation in Tibetan alpine grasslands

Xiaoqing Duan^a,b, Guang Zhao^a,*, Nan Cong^a,b, Zhoutao Zheng^a,b, Yixuan Zhua, Shenggong Li^a,b, Jun Yan^c, Mengke Cai^d, Mengxue Liu^a, Xiao Liu^a, Yangjian Zhang^a,b,e

^aNaqu Alpine Grassland Ecosystem National Observation and Research Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China

^bUniversity of Chinese Academy of Sciences, Beijing 100190, China

^cNagqu Agricultural and Animal Husbandry Science and Technology Research and Promotion Center, Nagqu 852000, China

^dCollege of Tourism, Wuyi University, Wuyishan 354300, China eSchool of Life Sciences, Hebei University, Baoding 071002, China

^*Corresponding author. E-mail: zhaoguang@igsnrr.ac.cn

Received:2025-03-24 Accepted:2025-11-12
Supported by:
This research was supported by the National Key Research & Development Program of China (2022YFF1301801), The Science and Technology Project of Tibet Autonomous Region (XZ202201ZY0002N; XZ202202YD0010C; XZ202401JD0015; XZ202501ZY0118), the Second Tibetan Plateau Scientific Expedition and Research program (2019QZKK0302), the National Natural Science Foundation of China (4210011372), and the Naqu Science and Technology Planning Project (NQKY-2023-04).

摘要/Abstract

摘要： 降水是调控植物生态化学计量特征的关键气候驱动因子，对生态系统功能具有重要影响。然而，植物地上与地下组织对降水变化的响应机制，尤其在高寒生态系统中，仍不明晰。本研究利用青藏高原1500 km降水梯度样带，系统测试并分析了高寒草地生态系统中植物与土壤的碳 (C)、氮 (N)、磷 (P) 化学计量特征。结果表明，植物地上部C、N、P平均含量 (389.39 g kg–¹、15.32 g kg–¹、1.22 g kg–¹) 与土壤养分含量 (8.12 g kg–¹、0.94 g kg–¹、0.39 g kg–¹) 均低于内蒙古草原，反映出高寒干旱环境存在养分限制。此外，降水对植物化学计量格局变化具有主导作用，植物地上与地下组织呈现相反的响应模式：随降水增加，地上部分C含量、C:N和C:P显著降低，而地下组分则升高。植物地上组织N、P含量高于地下部分，反映出更强的内稳性调控能力。土壤C、N含量随降水增加而上升，但土壤P含量下降，指示该生态系统存在P限制特征。植物C:N和N:P分别与土壤化学计量呈负相关和正相关关系，印证了不同器官特异的养分调控策略。本研究揭示了植物不同组分的非对称化学计量响应特征，以及地下养分动态在植物适应降水格局变化中的关键作用。本研究对深入理解气候变化背景下高寒生态系统养分循环的地下过程调控机制具有重要意义。

关键词: 生长策略, 干旱指数, 不对称响应, 草地样带, 高寒生态系统

Abstract: Precipitation is a key climatic driver regulating plant nutrient stoichiometry, with significant implications for ecosystem function. However, the differential responses of aboveground and belowground plant components to precipitation variability remain poorly understood, especially in alpine ecosystems. We investigated carbon (C), nitrogen (N), and phosphorus (P) stoichiometry in plants and soils across a 1500-km precipitation gradient on the Tibetan Plateau. C, N, and P concentrations in both aboveground biomass (389.39 g kg⁻¹, 15.32 g kg⁻¹, 1.22 g kg⁻¹) and soil nutrients (8.12 g kg⁻¹, 0.94 g kg⁻¹, 0.39 g kg⁻¹) were lower than in Mongolia Plateau grasslands, indicating nutrient limitation in cold, arid conditions. Precipitation had a dominant influence on stoichiometric patterns, with aboveground and belowground tissues showing opposing responses. C concentrations, and C:N and C:P ratios in aboveground biomass decreased with precipitation, while those in belowground biomass increased. N and P concentrations were consistently higher in aboveground tissues, reflecting stronger homeostatic control. Soil C and N increased with precipitation, while soil P declined, indicating P limitation. Plant C:N and N:P ratios were negatively and positively correlated with soil stoichiometry, respectively, suggesting organ-specific nutrient regulation. These findings highlight asymmetric stoichiometric responses between plant compartments and the role of belowground nutrient dynamics in plant adaptation to changing precipitation regimes. Our study emphasizes the importance of belowground traits in ecosystem nutrient cycling under climate change.

Key words: growth strategies, Aridity Index, asymmetric responses, grassland transect, alpine ecosystem

. 青藏高原高寒草地植物地上-地下化学计量对降水变化的不对称响[J]. Journal of Plant Ecology, DOI: 10.1093/jpe/rtaf199.

Xiaoqing Duan, Guang Zhao, Nan Cong, Zhoutao Zheng, Yixuan Zhu, Shenggong Li, Jun Yan, Mengke Cai, Mengxue Liu, Xiao Liu, Yangjian Zhang. Asymmetric responses of plant aboveground and belowground stoichiometry to precipitation in Tibetan alpine grasslands[J]. J Plant Ecol, DOI: 10.1093/jpe/rtaf199.

[1]	. 香椿的树木年轮宽度与超年生殖行为的相互关系：对树轮学研究的警示[J]. Journal of Plant Ecology, 2024, 17(1): 1-.
[2]	. [J]. Journal of Plant Ecology, 2022, 15(1): 57-70.
[3]	. [J]. Journal of Plant Ecology, 2020, 13(3): 273-280.