Uptake and distribution of the inorganic components NH4+ and NO3- in PM2.5 by two Chinese conifers

Jiaxing Fang; Shaoning Li; Na Zhao; Xiaotian Xu; Yongbin Zhou; Shaowei Lu

doi:10.1016/j.scitotenv.2023.167573

Uptake and distribution of the inorganic components NH₄⁺ and NO₃^- in PM_2.5 by two Chinese conifers

Sci Total Environ. 2024 Jan 10:907:167573. doi: 10.1016/j.scitotenv.2023.167573. Epub 2023 Oct 5.

Authors

Jiaxing Fang¹, Shaoning Li¹, Na Zhao², Xiaotian Xu², Yongbin Zhou³, Shaowei Lu⁴

Affiliations

¹ Forestry College of Shenyang Agricultural University, Shenyang 110866, China; Institute of Forestry and Pomology, Beijing Academy of Forestry and Pomology Sciences, Beijing 100093, China; Beijing Yanshan Forest Ecosystem Observation and Research Station, Beijing 100093, China.
² Institute of Forestry and Pomology, Beijing Academy of Forestry and Pomology Sciences, Beijing 100093, China; Beijing Yanshan Forest Ecosystem Observation and Research Station, Beijing 100093, China.
³ Institute of Modern Agricultural Research, Dalian University, Dalian 116622, China; Life Science and Technology College, Dalian University, Dalian 116622, China. Electronic address: yyzyb@163.com.
⁴ Forestry College of Shenyang Agricultural University, Shenyang 110866, China; Institute of Forestry and Pomology, Beijing Academy of Forestry and Pomology Sciences, Beijing 100093, China; Beijing Yanshan Forest Ecosystem Observation and Research Station, Beijing 100093, China. Electronic address: hblsw8@163.com.

PMID: 37804978
DOI: 10.1016/j.scitotenv.2023.167573

Abstract

Plants can effectively purify PM_2.5 in the air, thereby improving air quality. Understanding the mechanisms of the uptake and distribution of PM_2.5 in plants is crucial for enhancing their ecological benefits. In this study, the uptake and distribution of the water-soluble inorganic compounds ammonium (NH₄⁺) and nitrate (NO₃^-) ions in PM_2.5 by the two native Chinese conifers Manchurian red pine (Pinus tabuliformis) and Bunge's pine (P. bungeana) were investigated using a one-time aerosol treatment method combined with ¹⁵N tracing. The results showed the following: (1) Plants can efficiently uptake NH₄⁺ (0.08-0.21 μg/g) and NO₃^- (0.03-0.68 μg/g) from PM_2.5. Manchurian red pine uptakes these compounds more effectively with increases of 2.01-fold for NH₄⁺ and 1.02-fold for NO₃^- compared with Bunge's pine. (2) The aboveground organs of the plants uptake and distribute more ¹⁵N than the belowground organs. The branches had the highest unit mass uptake (0.08-1.60 μg/g) and rate of distribution (16.91-53.60 %) for NH₄⁺, while the leaves had the highest unit mass uptake (0.15-1.18 μg/g) and rate of distribution (50.78-84.88 %) for NO₃^-. (3) The ability of the aboveground organs to uptake ¹⁵N is influenced by the concentration of PM_2.5, which showed an overall increase with increasing concentrations with some fluctuations in specific organs. However, the belowground organs were not affected by the concentration of PM_2.5. (4) A larger specific leaf area, root-shoot ratio, branch biomass ratio, coarse root biomass ratio, and lower trunk biomass ratio favors the uptake of NH₄⁺ from PM_2.5, whereas these traits had a minimal influence on the uptake of NO₃^-. Manchurian red pine uptaked significantly more NH₄⁺ compared with Bunge's pine, which benefited from the traits described above. These findings further revealed the mechanism of PM_2.5 uptake by plants and its relationship with PM_2.5 concentration and plant traits, and provided a scientific basis for how to effectively utilize plants to reduce PM_2.5 pollution and purify the environment in areas with different pollution concentrations.

Keywords: (15)N tracing; Atmospheric purification by plants; NH(4)(+) and NO(3)(−); One-time aerosol treatment method; Particulate matter; Uptake and distribution.

MeSH terms

Air Pollutants* / analysis
Ammonium Compounds* / analysis
Particulate Matter / analysis
Pinus*
Tracheophyta*
Water

Substances

Air Pollutants
Ammonium Compounds
Particulate Matter
Water