Foliage/atmosphere exchange of mercury in a subtropical coniferous forest in south China
| Autor: | Shuxiao Wang, Jiming Hao, Mariah Taylor, Charles T. Driscoll, Yao Luo, Lei Duan, Guangyi Xu, Mengshu Shao |
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| Rok vydání: | 2016 |
| Předmět: |
Atmospheric Science
Biogeochemical cycle Pinus massoniana 010504 meteorology & atmospheric sciences Meteorology Soil Science chemistry.chemical_element 010501 environmental sciences Aquatic Science 01 natural sciences 0105 earth and related environmental sciences Water Science and Technology Transpiration Tree canopy Ecology biology Paleontology Forestry biology.organism_classification Mercury (element) Deposition (aerosol physics) chemistry Environmental chemistry Soil water Environmental science Terrestrial ecosystem |
| Zdroj: | Journal of Geophysical Research: Biogeosciences. 121:2006-2016 |
| ISSN: | 2169-8953 |
| DOI: | 10.1002/2016jg003388 |
| Popis: | Foliage/atmosphere exchange is an important pathway of deposition and loss in the biogeochemical mercury (Hg) cycle of terrestrial ecosystems. The foliage/atmosphere fluxes of Hg0 were observed over four seasons in a Masson pine (Pinus massoniana) forest in south China. Hg0 exchange showed a bidirectional process but without clear compensation point. Hg0 emissions peaked midday in all four seasons, probably associated with Hg photoreduction on needle surface. Peaks in Hg0 adsorption/deposition often occurred in the morning, especially in spring and autumn. Although current-year needles accumulated Hg at a rate of 19.4 µg m−2 yr−1, they were a net Hg0 source of 1.7 µg m−2 yr−1 to the atmosphere as their release of Hg exceeded inputs. In addition, previous-year needles emitted Hg0 at an average rate of 9.2 µg m−2 yr−1. Based on the mass balance of Hg in the forest canopy, the dry deposition of Hg was estimated 52.5 µg m−2 yr−1, much higher than the wet deposition (to 14.4 µg m−2 yr−1). Although Hg in the atmosphere is considered the main source of Hg in folia, soil water may contribute to Hg0 emission by plant transpiration. These processes should be further studied in the future. |
| Databáze: | OpenAIRE |
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