Effects of stream acidification on fungal biomass in decaying beech leaves and leaf palatability

Abstract : We examined the effect of surface water acidification on rates of decomposition, ergosterol concentrations (as a measure of fungal biomass), and palatability to shredders of common beech leaves (Fagus sylvatica L.) in five mountain streams (pH 4.7-7.1). Leaf decomposition was significantly faster in the circumneutral streams (pH 6.4-7.1; k > or = 0.00175 d(-1)), when compared to acidic streams (pH 4.7-4.9; k < or = 0.00100 d(-1)). Fungal biomass showed no particular trend along the acidification gradient except that it peaked earlier in the stream closest to neutrality. Leaf palatability, measured as the feeding activity of the leaf-shredding amphipod Gammarus fossarum Koch, varied with the exposure time in the streams. Except for the higher palatability of leaves exposed during 6 weeks at the highest pH, patterns among streams were mostly similar. These results suggest that reduced processing rates in the most acidic streams were not related to differences in fungal biomass associated with decomposing leaves and that microbial conditioning was only slightly delayed by acidification. Possible effects of low pH and related variables (Ca, Al) on microbial decomposition and detritivorous macroinvertebrates are discussed to clarify the inhibition of beech leaf decomposition in the studied systems.
Document type :
Journal articles
Complete list of metadatas

Cited literature [26 references]  Display  Hide  Download

https://hal.archives-ouvertes.fr/hal-01333517
Contributor : Open Archive Toulouse Archive Ouverte (oatao) <>
Submitted on : Friday, June 17, 2016 - 4:12:43 PM
Last modification on : Friday, June 7, 2019 - 10:55:31 AM
Long-term archiving on : Sunday, September 18, 2016 - 11:05:40 AM

File

dangles_9639.pdf
Files produced by the author(s)

Identifiers

Collections

Citation

Olivier Dangles, Eric Chauvet. Effects of stream acidification on fungal biomass in decaying beech leaves and leaf palatability. Water Research, IWA Publishing, 2003, Vol. 37 (N° 3), pp. 533-538. ⟨10.1016/S0043-1354(02)00359-7⟩. ⟨hal-01333517⟩

Share

Metrics

Record views

206

Files downloads

195