10.5061/DRYAD.9ZW3R22CR
Turunen, Jarno
Centre for Economic Development, Transport and the Environment
Elbrecht, Vasco
Zoological Research Museum Alexander Koenig
Steinke, Dirk
University of Guelph
Aroviita, Jukka
0000-0003-3330-0731
Finnish Environment Institute
Riparian forests can mitigate warming and ecological degradation of
agricultural headwater streams
Dryad
dataset
2020
2020-12-21T00:00:00Z
2020-12-21T00:00:00Z
en
411617 bytes
3
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
1. Riparian forests are commonly advocated as a key management option to
mitigate the effects of agriculture on headwater stream biodiversity and
ecosystem functions. However, the benefits of riparian forests might be
reduced by uninterrupted catchment-scale pollution. 2.We studied the
effects of riparian land use on multiple ecological endpoints in headwater
streams in an agricultural landscape. We studied stream habitat
characteristics, water temperature and algal accrual, and macrophyte,
benthic macroinvertebrate and fish communities in 11 paired forested and
open agricultural headwater stream reaches that differed in their extent
of riparian forest cover but had similar water quality. 3.
Hydromorphological habitat quality was higher in forested reaches than in
open reaches. Riparian forest had a strong effect on the summer water
temperature regime, with maximum and mean water temperatures and
temperature variation in forested reaches substantially lower than in open
reaches. 4. Macrophyte communities differed between forested and open
reaches. The mean abundance of bryophytes was higher in forested reaches
but the difference to open reaches was only marginally significant,
whereas graminoids were significantly more abundant in open reaches.
Within-stream dissimilarity of benthic macroinvertebrate community
structure was significantly related to the difference in riparian land use
between reach pairs. The relative DNA sequence abundance of
pollution-sensitive EPT (Ephemeroptera, Plecoptera, Trichoptera) species
tended to be higher in forested reaches than in open reaches. Finally,
fish densities were not significantly different between forested and open
reaches, although densities were higher in forested reaches. 5. This
unequivocal evidence for the ecological benefits of forested riparian
reaches in agricultural headwater streams suggests that riparian forest
can partly mitigate the adverse impacts of agricultural diffuse pollution
on biota. The strong effect of forests on stream water temperature suggest
that riparian forest could also mitigate harmful effects on headwater
stream biodiversity and ecosystem functions of the predicted more frequent
high summer temperatures.