Integrating canopy spectra into the optical phenotype under nitrogen deposition in a subtropical evergreen broad-leaved forest

doi:10.1093/jpe/rtag113

J Plant Ecol ›› Advance articles DOI:10.1093/jpe/rtag113

Integrating canopy spectra into the optical phenotype under nitrogen deposition in a subtropical evergreen broad-leaved forest

Yarong Feng^1,5, Zhihui Wang^*2, Fangyan Liu^1,3, Long Yang², Zhongyu Sun², Huaiqiang Liu⁴, Dongming Liu¹, Liping Wei¹, Nan Liu^*1

1. Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China;
2. Guangdong Provincial Key Laboratory of Remote Sensing and Geographical Information System, Guangdong Open Laboratory of Geospatial Information Technology and Application, Guangzhou Institute of Geography, Guangdong Academy of Sciences, Guangzhou 510070, China;
3. Yunnan Provincial Food and Drug Verification and Inspection Center, Kunming 650000, China;
4. School of Marine Sciences & Research Center of Ocean Climate, Sun Yat-Sen University & Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China;
5. University of Chinese Academy of Sciences, Beijing 100049, China
^*Corresponding authors:
Nan Liu
Email: liunan@scbg.ac.cn
Zhihui Wang
Email: wangzhihui@gdas.ac.cn

Received:2025-10-10 Revised:2026-02-02 Accepted:2026-03-24 Published:2026-05-25
Supported by:
This work was supported by National Natural Science Foundation of China (42471408), Young Talent Project of GDAS (2025GDASQNRC-0202), GDAS’ Project of Science and Technology Development (2024GDASZH-2024010102), the Science and Technology Program of Guangzhou (2024A04J4416), South China Botanical Garden, Chinese Academy of Sciences (JCYJXM-202516) and the Guangdong Science and Technology Plan Project (2023B1212060046).

氮沉降下亚热带常绿阔叶林冠层光谱与光学表型的整合

Abstract

Abstract: The increasing pressure of nitrogen deposition on forest ecosystems is driving the need for large-scale monitoring of plant functional responses. Hyperspectra is a powerful tool for estimating leaf traits, yet key gaps persist in linking canopy spectral signals to plant functional adaptations under nitrogen enrichment. Many traits lack distinct spectral signatures and substantial “non-coding” spectral regions remain poorly interpreted.
To address this, we conducted a canopy nitrogen addition experiment (including control, 25 kg N ha^-1 y^-1 (CN25), 50 kg N ha^-1 y^-1 (CN50)) at a subtropical forest in China. We collected canopy spectra and 35 leaf functional traits across morphology, resource allocation and physiological metabolism. Key findings include: (1) A statistically significant co-inertia structure was confirmed between canopy spectra and leaf traits; (2) Notably, nitrogen deposition did not alter the trait-spectrum relationship, under CN50 the coupling between leaf traits and canopy spectra was significantly enhanced compared to the control; and (3) Dominant species exhibited limited but discernible shifts in their ecological strategies along nitrogen gradients, with specific spectral features serving as indicators of transitions in resource allocation.
This study demonstrates that canopy spectra are associated with multidimensional leaf traits under nitrogen deposition, effectively serving as integrated optical phenotypes that capture functional variations. The consistent relationship between spectrum and plant traits enables the real-time, non-destructive monitoring of ecological responses via hyperspectral remote sensing.

Key words: Nitrogen deposition, Leaf trait, Canopy spectra, Co-inertia analysis, Hyperspectral remote sensing, Subtropical forest, Trait-Spectrum relationship

摘要：
氮沉降对森林生态系统的胁迫日益加剧，推动了对植物功能响应开展大范围监测的需求。高光谱技术提供了估算叶片性状的有力工具，但在氮富集背景下，植物功能适应与冠层光谱信号的关联机制仍存在关键空白。许多性状缺乏明确的光谱特征，且大量“非编码”光谱区域尚待深入解读。为填补上述空白，我们在中国亚热带森林开展了一项冠层氮添加实验（设置对照、25 kg N ha^-1 y^-1（CN25）、50 kg N ha^-1 y^-1（CN50）三个处理），同步采集了冠层光谱数据，以及涵盖了植物形态、资源分配与生理代谢方面的35个叶片功能性状数据。主要发现如下：（1）冠层光谱与叶片性状之间存在显著的协惯量结构；（2）值得注意的是，氮沉降并未改变性状与光谱间的关联，在CN50处理下，叶片性状与冠层光谱的耦合程度较对照组显著增强；（3）优势物种沿氮梯度在生态策略上表现出有限但可辨别的转变，特定光谱特征可作为资源分配模式转变的指示指标。
本研究表明，在氮沉降下冠层光谱与多维度叶片性状相关联，可作为一种综合的光学表型以反映植物功能性状的变化。光谱与植物性状间的稳健关联，使得借助高光谱遥感对生态响应进行实时无损监测成为可能。

关键词: 氮沉降, 叶片性状, 冠层光谱, 协惯量分析, 高光谱遥感, 亚热带森林, 性状-光谱关系

Yarong Feng, Zhihui Wang, Fangyan Liu, Long Yang, Zhongyu Sun, Huaiqiang Liu, Dongming Liu, Liping Wei, Nan Liu. Integrating canopy spectra into the optical phenotype under nitrogen deposition in a subtropical evergreen broad-leaved forest[J]. J Plant Ecol, DOI: 10.1093/jpe/rtag113.

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[2]	Yanju Gao, Akash Tariq, Fanjiang Zeng, Jordi Sardans, Dhafer A Al-Bakre, Josep Peñuelas. Seasonal dynamics and allocation patterns of foliar phosphorus fractions in deep-rooted desert species under phosphorus-poor environments [J]. J Plant Ecol, 2026, 19(2): 1-.
[3]	Deyun Chen, Zhiyun Lu, Yanping Wang, Chunyu Hou, Jianping Wu. Available nutrients and microbial alpha diversity contribute to CO₂ emission in a subtropical primary forest: insight from a 4 m soil vertical profile [J]. J Plant Ecol, 2026, 19(2): 1-.
[4]	Yaping Lin, Qiufang Zhang, Hao Sun, Jiaohong Lu, Zehong Yao, Quanxin Zeng, Chenxing Lian, Huizhi Pi, Xiaochun Yuan, Yuehmin Chen. Parallel patterns of microbial carbon and nitrogen use efficiency in response to nitrogen addition across soil depths in a Castanopsis faberi forest [J]. J Plant Ecol, 2026, 19(2): 1-.
[5]	Yuyao Nan, Chuanshan Zou, Xingchang Wang, Qi Wang. Leaf non-structural carbohydrates dominantly drive background insect herbivory of temperate tree species in Northeast China [J]. J Plant Ecol, 2026, 19(2): 1-.
[6]	Zhiwen Guo, Jun Tang, Guozhen Lai, Liting Liu, Xiangping Wang. Structural diversity primarily drives forest biomass along altitudinal gradients in subtropical forests [J]. J Plant Ecol, 2025, 18(6): 1-.
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[8]	Yuguang Ke, Hongqiang Wang, Yushu Zhang, Jiale Chen, Yalong Shi , Yadong Yang, Qiang Yu, Xiwen Li, Ang Li, Jianguo Wu, Honghui Wu. Ecosystem stability declines consistently with nitrogen addition across a gradient of organic to inorganic nitrogen ratios [J]. J Plant Ecol, 2025, 18(5): 1-28.
[9]	Ya-Jing Zhang, Ya-Li Si, Shi-Bo Ju, Wan-Ying Jiang, Ming-Zhen Zhao, Jing Liu, Mulualem Tigabu, Xiang-Qing Ma, Ming Li. Synergistic Effects of Nitrogen Deposition and Phosphorus Distribution Patterns on Root morphological and chemical traits, and Nutrient Efficiency in Chinese Fir [J]. J Plant Ecol, 2025, 18(4): 1-50.
[10]	Chao Wang, Jiayin Feng, Jian Song, Hongpeng Wang, Jinhua Zhang, Jingyi Ru, Yaru Lyu, Wenjing Ma, Zixuan Yang, Mengyu Yan, Xueli Qiu, Shiqang Wan. Nighttime warming reshapes thermal regimes in freshwater wetlands: cascading effects on carbon dynamics [J]. J Plant Ecol, 2025, 18(4): 1-41.
[11]	Yang Wang, Yu-Ping Dong, Zhao-Jie Ren, Ling Hu, Tong-Yue Deng, Zun-Tian Zhao. Mosses record historical variations of atmospheric nitrogen deposition in a mountain area of northern China [J]. J Plant Ecol, 2025, 18(3): 1-10.
[12]	Juan Huang, Xi'an Cai, Runcheng Zhu, Juxiu Liu, Yuelin Li, Mianhai Zheng, Jiangming Mo. Responses of leaf traits of plantation tree species in South China under long-term nitrogen deposition [J]. J Plant Ecol, 2025, 18(3): 1-13.
[13]	Yangping Guo, Xincong Chen, Fujia Wu, Wenwen Liu, Yihui Zhang. Latitudinal variation in leaf functional traits of an invasive salt-marsh plant and its relationship with growth performance [J]. J Plant Ecol, 2025, 18(1): 1-19.
[14]	Yuantian Fang, Xunyang He, Qingquan Xie, Dejun Li. Increasing tree phylogenetic diversity stimulates microbial functional potential in a subtropical forest [J]. J Plant Ecol, 2024, 17(6): 1-13.
[15]	Jing Zhu, Xue-Lin Wang, Xing Jin, Lan Jiang, Hong-Yu Lin, Yang Hu, Jin-Fu Liu, Zhong-Sheng He. Relative position of seeds driven the seedling growth are mediated by root-leaf traits [J]. J Plant Ecol, 2024, 17(2): 0-rtae004.