Contrasting terpene emissions from canopy and understory vegetation in response to increases in nitrogen deposition and seasonal changes in precipitation

Jianbo Fang; Xiangping Tan; Ziyin Yang; Weijun Shen; Josep Peñuelas

doi:10.1016/j.envpol.2022.120800

Contrasting terpene emissions from canopy and understory vegetation in response to increases in nitrogen deposition and seasonal changes in precipitation

Environ Pollut. 2023 Jan 15:317:120800. doi: 10.1016/j.envpol.2022.120800. Epub 2022 Dec 3.

Authors

Jianbo Fang¹, Xiangping Tan², Ziyin Yang³, Weijun Shen⁴, Josep Peñuelas⁵

Affiliations

¹ Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
² Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China.
³ University of Chinese Academy of Sciences, Beijing, 100049, China; Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China.
⁴ Guangxi Key Laboratory of Forest Ecology and Conservation, State Key Laboratory for Conservation and Utilization of Agro-bioresources, College of Forestry, Guangxi University, Nanning, Guangxi, 530004, China. Electronic address: shenweijun@gxu.edu.cn.
⁵ CREAF, Campus Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, 08193, Catalonia, Spain; CSIC, Global Ecology Unit CREAF - CSIC-UAB, Bellaterra, Barcelona, 08193, Catalonia, Spain.

PMID: 36473640
DOI: 10.1016/j.envpol.2022.120800

Abstract

Given global change and shifts in climate are expected to increase BVOC emissions, the quantification of links between environmental conditions, plant physiology, and terpene emission dynamics is required to improve model predictions of ecosystem responses to increasing nitrogen deposition and changes in precipitation regimes. Here, we conducted a two-factor field experiment in sub-tropical forest plots to determine effects of N addition (N), precipitation change (PC), and NP (N and PC combined treatment) on wet and dry season terpene emissions and leaf photosynthetic parameters from canopy and understory species. Changes of β-ocimene and sabinene under PC and NP in the wet season (0.4-5.6-fold change) were the largest contributor to changes in total terpene emissions. In the dry season, the standardized total terpene emission rate was enhanced by 144.9% under N addition and 185.7% under PC for the understory species, while the total terpene emission rate was lower under NP than N addition and PC, indicating that N addition tended to moderate increases in PC-induced understory total terpene emissions. In the wet season, the total terpene emission rate under N and PC was close to ambient conditions for the canopy species, while the total terpene emission rate was enhanced by 54.6% under NP, indicating that N and PC combined treatment had an additive effect on canopy total terpene emissions. Total terpene emission rates increased with rates of net leaf photosynthesis (P_n) and transpiration (Tr) and there was a decoupling between terpene emission rates and P_n under NP, indicating that complex effects between PC and N decreased the regularity of single-factor effects. We recommend that N and PC interaction effects are included in models for the prediction of terpene emissions, particularly from canopy vegetation during the wet season as a major source of forest ecosystem terpene emissions.

Keywords: Nitrogen deposition; Seasonal changes in precipitation; Seasonal terpene emission; Vegetation vertical structure.

MeSH terms

Ecosystem*
Nitrogen
Photosynthesis / physiology
Seasons
Terpenes*

Substances

Terpenes
Nitrogen