TY - JOUR
T1 - Bracken growth, toxin production and transfer from plant to soil
T2 - a 2-year monitoring study
AU - García-Jorgensen, Daniel B.
AU - Diamantopoulos, Efstathios
AU - Kisielius, Vaidotas
AU - Rosenfjeld, Mette
AU - Rasmussen, Lars H.
AU - Strobel, Bjarne W.
AU - Hansen, Hans Chr B.
PY - 2021
Y1 - 2021
N2 - Background: Bracken fern (Pteridium aquilinum) produces several toxic glycosides, of which ptaquiloside (PTA) is the most well documented. PTA is released from bracken to soil and leaches to surface water and to groundwater. This study presents the first comprehensive monitoring study of bracken biomass, PTA content in the biomass, release by precipitation and concentrations in soil solution at 50 cm depth. Laboratory experiments were carried out to estimate the degradation kinetics of PTA in different soil horizons and moisture contents. Results: The PTA concentration in bracken was highest at the earliest development stages of the plant, i.e., May, declining through the growing season until negligible contents at senescence. The maximum seasonal PTA content in the canopy peaked in early summer, with values up to 1600 mg m−2. Results show that on average 0.2% of the PTA present in the canopy is washed per mm of incident rain, resulting in up to 13.1 mg PTA m−2 being washed off during single rain events. Once in the soil, PTA dissipates rapidly showing a half-lives ranging from 3.3 to 73 h with observed degradation rates showing a tenfold decrease with soil depths increasing from top soil to 25 cm soil depth. Concentrations of PTA in soil solution were positively correlated with the content of PTA in the canopy, with maximum pore water concentrations up to 4,820 ng L−1 during a pulse event taking place in July 2019. Conclusions: The production of PTA in bracken was found to be proportional to biomass growth, while the mass of PTA being released is a function of volume and intensity of precipitation, as well as the bracken development stage. Leaching of PTA takes place in the form of pulses linked to precipitation events, with concentrations in the soil solution exceeding levels which are known to pose a risk to human health.
AB - Background: Bracken fern (Pteridium aquilinum) produces several toxic glycosides, of which ptaquiloside (PTA) is the most well documented. PTA is released from bracken to soil and leaches to surface water and to groundwater. This study presents the first comprehensive monitoring study of bracken biomass, PTA content in the biomass, release by precipitation and concentrations in soil solution at 50 cm depth. Laboratory experiments were carried out to estimate the degradation kinetics of PTA in different soil horizons and moisture contents. Results: The PTA concentration in bracken was highest at the earliest development stages of the plant, i.e., May, declining through the growing season until negligible contents at senescence. The maximum seasonal PTA content in the canopy peaked in early summer, with values up to 1600 mg m−2. Results show that on average 0.2% of the PTA present in the canopy is washed per mm of incident rain, resulting in up to 13.1 mg PTA m−2 being washed off during single rain events. Once in the soil, PTA dissipates rapidly showing a half-lives ranging from 3.3 to 73 h with observed degradation rates showing a tenfold decrease with soil depths increasing from top soil to 25 cm soil depth. Concentrations of PTA in soil solution were positively correlated with the content of PTA in the canopy, with maximum pore water concentrations up to 4,820 ng L−1 during a pulse event taking place in July 2019. Conclusions: The production of PTA in bracken was found to be proportional to biomass growth, while the mass of PTA being released is a function of volume and intensity of precipitation, as well as the bracken development stage. Leaching of PTA takes place in the form of pulses linked to precipitation events, with concentrations in the soil solution exceeding levels which are known to pose a risk to human health.
KW - Bracken fern
KW - Emerging pollutants
KW - Leaching
KW - Monitoring
KW - Phytotoxins
KW - Production
KW - Ptaquiloside
KW - Release
U2 - 10.1186/s12302-021-00484-0
DO - 10.1186/s12302-021-00484-0
M3 - Journal article
AN - SCOPUS:85104077044
VL - 33
JO - Environmental Sciences Europe
JF - Environmental Sciences Europe
SN - 2190-4707
M1 - 45
ER -