Sammanfattning

Leaf litter is a major source of carbon and energy for stream food webs, while both leaf-decomposing microorganisms and macroinvertebrate leaf shredders can be affected by fungicides. Despite the potential for season-long fungicide exposure for these organisms, however, such chronic exposures have not yet been considered. Using an artificial stream facility, effects of a chronic (lasting up to 8 wk) exposure to a mixture of 5 fungicides (sum concentration 20 mu g/L) on leaf-associated microorganisms and the key leaf shredder Gammarus fossarum were therefore assessed. While bacterial density and microorganism-mediated leaf decomposition remained unaltered, fungicide exposure reduced fungal biomass (<= 71%) on leaves from day 28 onward. Gammarids responded to the combined stress from consumption of fungicide-affected leaves and waterborne exposure with a reduced abundance (<= 18%), which triggered reductions in final population biomass (18%) and in the number of precopula pairs (<= 22%) but could not fully explain the decreased leaf consumption (19%), lipid content (<= 43%; going along with an altered composition of fatty acids), and juvenile production (35%). In contrast, fine particulate organic matter production and stream respiration were unaffected. Our results imply that long-term exposure of leaf-associated fungi and shredders toward fungicides may result in detrimental implications in stream food webs and impairments of detrital material fluxes. These findings render it important to understand decomposer communities' long-term adaptational capabilities to ensure that functional integrity is safeguarded. (C) 2017 SETAC.

Nyckelord

Aquatic hyphomycetes; Chronic exposure; Gammarus fossarum; Leaf litter breakdown; Population development

Publicerad i

Environmental Toxicology and Chemistry
2017, Volym: 36, nummer: 8, sidor: 2178-2189

SLU författare

• Feckler, Alexander

  • Institutionen för vatten och miljö, Sveriges lantbruksuniversitet
    

• Bundschuh, Mirco

  • Institutionen för vatten och miljö, Sveriges lantbruksuniversitet
    

Globala målen

SDG14 Bevara och nyttja haven och de marina resurserna på ett hållbart sätt för en hållbar utveckling
SDG2 Avskaffa hunger, uppnå tryggad livsmedelsförsörjning och förbättrad nutrition samt främja ett hållbart jordbruk


UKÄ forskningsämne

Miljövetenskap
Ekologi


Publikationens identifierare

DOI: https://doi.org/10.1002/etc.3756

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/86299