We used a pool of 3 common riparian-plant species in Portugal (alder, oak and
eucalyptus) to examine the potential long-term impacts of riparian diversity loss on the
feeding behaviour and body composition of a stream invertebrate shredder
(Limnephilidae). Fine-mesh bags containing mixtures of the 3 leaf species were
immersed in a mixed-forested stream to allow microbial colonization. After 2 weeks,
colonized leaves were transferred to microcosms containing stream water and all
combinations of 1 to 3 non-colonized leaf species enclosed in mesh containers. The
experiment ran for 6 months. In each month, a portion of leaf material was used to
inoculate new microcosms containing non -colonized leaf material, keeping the leaf
species composition constant. After 2 and 6 months, those leaves were used to feed
invertebrate shredders for a period of 8 days. Leaf consumption and FPOM production
by the shredder were affected by leaf species diversity, with higher values in mixtures
with 3 leaf species. Leaf mass loss and FPOM production were also affected by leaf
species identity, but not by time of leaf diversity loss. C:N ratio of FPOM was affected
by leaf identity and showed a positive linear relationship with initial leaf C:N ratio.
Invertebrate C:N ratio increased along time of leaf diversity loss. Results suggest that
the riparian-plant diversity loss can affect leaf consumption, FPOM production and
invertebrate body composition, but effects did not appear to change at longer times.FEDER-POFC-COMPETE and FCT supported this study (PEst-C/BIA/UI4050/2011,
PTDC/AAC-AMB/117068/2010), IF (SFRH/BD/42215/2007) and SD
(SFRH/BPD/47574/2008)Fundação para a Ciência e a Tecnologia (FCT) - PEst-C/BIA/UI4050/2011, PTDC/AAC-AMB/117068/2010, SFRH/BD/42215/2007, SFRH/BPD/47574/200
