Nitrogen addition enhances tree radial growth but weakens its recovery from drought impact in a temperate forest in northern China

Jing Cao; Hongyan Liu; Bo Zhao; Zongshan Li; Boyi Liang; Liang Shi; Zhaopeng Song; Lu Wu; Qiuming Wang; Elizabeth L Cressey; Yanpeng Zhu; Shuang Li

doi:10.1016/j.scitotenv.2023.166884

Nitrogen addition enhances tree radial growth but weakens its recovery from drought impact in a temperate forest in northern China

Sci Total Environ. 2023 Dec 10:903:166884. doi: 10.1016/j.scitotenv.2023.166884. Epub 2023 Sep 9.

Authors

Jing Cao¹, Hongyan Liu², Bo Zhao³, Zongshan Li⁴, Boyi Liang⁵, Liang Shi⁶, Zhaopeng Song¹, Lu Wu⁷, Qiuming Wang², Elizabeth L Cressey⁸, Yanpeng Zhu¹, Shuang Li¹

Affiliations

¹ State Key Laboratory of Environmental Criteria and Risk Assessment, State Environmental Protection Key Laboratory of Regional Eco-process and Function Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
² College of Urban and Environmental Science and MOE Laboratory for Earth Surface Processes, Peking University, Beijing 100871, China.
³ Lhasa Plateau Ecosystem 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. Electronic address: zhaobo@igsnrr.ac.cn.
⁴ State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing, China.
⁵ College of Forestry, Beijing Key Laboratory of Precise Forestry, Institute of GIS, RS & GPS, Beijing Forestry University, Beijing 100083, China.
⁶ Lhasa Plateau Ecosystem 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.
⁷ China Meteorological Administration Training Center, Beijing 100081, China.
⁸ Geography, Faculty of Environment, Science and Economy, University of Exeter, Exeter EX4 4RJ, UK.

PMID: 37696401
DOI: 10.1016/j.scitotenv.2023.166884

Abstract

Forest growth in the majority of northern China is currently limited by drought and low nitrogen (N) availability. Drought events with increasing intensity have threatened multiple ecosystem services provided by forests. Whether N addition will have a detrimental or beneficial moderation effect on forest resistance and recovery to drought events was unclear. Here, our study focuses on Pinus tabulaeformis, which is the main plantation forest species in northern China. We investigated the role of climate change and N addition in driving multi-year tree growth with an 8-year soil nitrogen fertilization experiment and analyzing 184 tree ring series. A moderate drought event occurred during the experiment, providing an opportunity for us to explore the effects of drought and N addition on tree resistance and recovery. We found that N addition was beneficial for increasing the resistance of middle-aged trees, but had no effect on mature trees. The recovery of trees weakened significantly with increasing N addition, and the reduction in fine root biomass caused by multiyear N addition was a key influencing factor limiting recovery after moderate drought. Our study implies that the combined effect of increasing drought and N deposition might increase the risk of pine forest mortality in northern China.

Keywords: Chinese pine; Fine root biomass; Moderate drought event; Plantation forest; Tree ring.