2025-01-17 バージニア工科大学(Virginia Tech)
<関連情報>
- https://news.vt.edu/articles/2025/01/eng-cee-rippy-salt-pollution-mitigation.html
- https://www.sciencedirect.com/science/article/pii/S0048969724084687
雨水貯留池の植物群落に及ぼす除塩剤と凍結防止剤の使用の影響: 塩ストレスと植物修復の可能性の特性化 The impact of deicer and anti-icer use on plant communities in stormwater detention basins: Characterizing salt stress and phytoremediation potential
S. Long, M.A. Rippy, L. Krauss, M. Stacey, K. Fausey
Science of The Total Environment Available online: 15 January 2025
DOI:https://doi.org/10.1016/j.scitotenv.2024.178310
Graphical abstract
Highlights
- Plant salt stress in stormwater detention basins varied by drainage area type.
- Salt thresholds were exceeded primarily in winter, but also during spring/summer.
- 33 % of observed plant species could tolerate conductivities >2 dS/m.
- Within-tissue salt levels were highest in Typha (top phytoremediation candidate).
- Basins with Typha remediate 5–6 % of winter salt mass in an above-average snow year.
Abstract
We present the results of a 1-year study that quantified salt levels in stormwater, soils, and plant tissues from 14 stormwater detention basins across Northern VA in an above-average snow year. We characterize (1) the level of salt stress plants experience, (2) the extent to which current plant communities feature salt tolerant species, and (3) the capacity of these species to phytoremediate soils and reduce the impacts of deicer and anti-icer use. Our results suggest that detention basin vegetation experience a range of salt stress levels that depend on drainage area type (roads: moderate to high > parking lots: low to moderate > pervious areas: none). Established thresholds for salt sensitive vegetation (Na+, Cl+, electrical conductivity, sodium adsorption ratio, exchangeable sodium percentage) were exceeded at least twice in stormwater or soils from all systems draining roads and half of systems draining parking lots. Winter exceedances were most common, but saline conditions did persist into the growing season, particularly at sites draining roads. Two hundred fifty-five plant species were identified across all detention basins, including 48 natives capable of tolerating elevated salt levels (electrical conductivity ≥2 dS/m). Within-tissue concentrations of sodium and chloride ions were highest in Typha (latifolia and angustifolia) (11.1 mg Na+/g; 30 mg Cl–/g), making it our top phytoremediation candidate. Scaling these concentrations up, we estimate that a standard-size highway detention basin (2000–3000 m2) with 100 % cattail cover can phytoremediate up to 100 kg of Na+ and 200 kg of Cl– per year. Uptake at this level is not sufficient to offset winter salt application, constituting only 5–6 % of basin inputs. This suggests that phytoremediation should not be considered a standalone solution to basin salinization, although it could be one approach of many in a broader salt management strategy.