B. Mckie et Ps. Cranston, Colonisation of experimentally immersed wood in south eastern Australia: responses of feeding groups to changes in riparian vegetation, HYDROBIOL, 452(1-3), 2001, pp. 1-14
We investigated macroinvertebrate abundance and functional feeding groups c
olonising experimentally-positioned woody substrates of different species i
n streams with three different riparian vegetation types. Native Eucalyptus
forest formed a dense closed canopy over our streams; introduced (exotic,
alien) pine plantation forest did not fully shade the streams, and grasslan
d streams were completely open, although with woody riparian vegetation wel
l upstream of our sites. Macroinvertebrate assemblages varied taxonomically
and functionally with both wood species and riparian vegetation compositio
n. Two specialist feeding groups responded clearly to riparian vegetation:
wood gougers were most common in forested streams, and algal grazers in mor
e open streams. Gougers colonised native Eucalyptus wood in preference to a
lien species. Other feeding groups responses showed complex interactions be
tween vegetation and wood type. Our results indicate the importance of samp
ling appropriate substrates when assessing questions of this type - if seek
ing shifts in functional organisation, the substrates on which the feeding
groups of interest occur must be sampled. The composition of the riparian s
trip may influence xylophilous communities as much as the structure (i.e. w
hether closed or open).