分层配土对青藏高原干旱区榆树光响应参数及模型适用性的影响
张照林 1詹东山 1陈振兴 2张永兴 3郝佳 2王尚涛 1甘永德1
作者信息
- 1. 青海大学土木水利学院，黄河上游生态保护与高质量发展实验室，水利部江河源区水生态治理与保护重点实验室，青海，西宁 810016
- 2. 青海省国土整治与生态修复中心，青海，西宁 810016
- 3. 中国地质调查局西宁自然资源综合调查中心，青海，西宁 810000
- 折叠
摘要
为揭示青藏高原干旱区盐碱地人工分层配土（ArtificiallyLayeredSoil，ALS）方式对植被光合能力的影响，评价光合-光响应模型在该地区典型植被中的适用性，以花土沟地区典型植被榆树为研究对象，设置ALS与野外原状土（Field Undisturbed Soil，FUS）两种处理。于2024—2025年生长季（7—9月），在典型晴朗天气下，采用GFS3000光合仪测定榆树叶片在14个光和有效辐射（Photosynthetically Active Radiation，PAR）梯度下的净光合速率（Net Photosynthetic Rate，Pn），构建Pn-PAR曲线；选取直角双曲线模型（Rectangular Hyperbola Model，RH）、非直角双曲线模型（Non-rectangular Hyperbola Model，NRH）、直角双曲线修正模型（Modified Rectangular Hyperbola Model，MRH）与指数模型（Exponential Model，EM）进行拟合，并以决定系数（R2）、均方根误差（RMSE）、平均绝对误差（MAE）和参数变异系数（Cv）评价模型表现。结果表明：ALS处理下榆树Pn整体高于FUS，最大净光合速率较FUS提高45.85%~111.11%，且气孔导度（Gs）整体更高、高值持续时间更长，弱光段表观量子效率（ApparentQuantumYield，AQY）总体更高，表明ALS分层结构可能通过调节土壤水盐过程、改善根际环境，协同增强榆树高光潜在光合能力、气孔调节能力与弱光利用效率。模型适用性方面，四种模型均能描述Pn-PAR总体趋势，其中NRH与MRH整体拟合误差更小、参数更合理；综合拟合优度与参数稳定性，模型适用性排序为:NRH≈MRH>EM>RH。本研究揭示了青藏高原干旱区盐碱地两种土壤结构下植被光合响应特征及模型适用性差异，可为该区植被恢复、盐碱地改良及光响应模型选择提供数据支持与理论依据。
Abstract
In this study, we investigated the effect of artificially layered soil (ALS) on the photosynthetic capacity of vegetation in saline-alkali land of the arid region of the Qinghai-Xizang Plateau, and we evaluated the applicability of photosynthetic light response models for typical vegetation in this region. this study took the typical Ulmus pumila in the Huatugou area as the research object. Two treatments were established: ALS and field undisturbed soil (FUS). During the growing seasons (July to September) of 2024-2025, under typical clear weatherconditions, the net photosynthetic rate (Pn) of Ulmus leaves was measured using a GFS-3000 photosynthesis system across 14 gradients of photosynthetically active radiation (PAR), and Pn-PAR curves were then constructed.Four modelsthe rectangular hyperbola model (RH), non-rectangular hyperbola model (NRH), modified rectangular hyperbola model (MRH), and exponential model (EM)were applied for curve fitting. Model performance was evaluated using the coefficient of determination (R2), root mean square error (RMSE), mean absolute error(MAE), and coefficient of variation of parameters. The results show that Pn under ALS was generally higher than that under FUS, with the maximum net photosynthetic rate increasing by 45.85%-111.11%. Stomatal conductance (Gs) was also generally higher and remained elevated for a longer duration under ALS, whereas the apparent quantum yield under low light was greater overall. These findings suggest that the layered structure of ALS may synergistically enhance the high-light photosynthetic capacity, stomatal regulation, and low-light utilization efficiency of Ulmus by modulating soil water-salt processes and improving the rhizosphere environment.Regarding model applicability, all four models effectively described the overall Pn-PAR trends, with the NRH and MRH showing smaller fitting errors and more reasonable parameters. Based on the combined evaluation of goodness-off it and parameter stability, model ranking in terms of applicability is as follows:NRHMRH>EM>RH. This study elucidates the photosynthetic response characteristics and differences in model applicability of vegetation under two soil configurations in saline-alkali land of the arid Qinghai-Xizang Plateau, providing data support and theoretical reference for vegetation restoration, saline-alkali land improvement, and light response model selection in this region.关键词
青藏高原干旱区/分层配土/榆树/光响应模型/光响应曲线Key words
Qinghai-Xizang Plateau arid region/layered soil/Ulmus pumila/light response model/light response curve引用本文复制引用
张照林,詹东山,陈振兴,张永兴,郝佳,王尚涛,甘永德.分层配土对青藏高原干旱区榆树光响应参数及模型适用性的影响[EB/OL].(2026-07-23)[2026-07-29].https://chinaxiv.org/abs/202607.00189.学科分类
植物学/环境生物学
