New Zealand Journal of Marine and Freshwater Research abstracts
Effects of channel morphology on temporal variation in invertebrate community
structure in two North Island, New Zealand rivers
R. T. FOWLER
R. G. DEATH
Institute of Natural Resources--Ecology
Massey University
Private Bag 11 222
Palmerston North, New Zealand
email: rfowler@kma.co.nz
Abstract Abundance and species composition of benthic
invertebrate communities were investigated in two rivers of contrasting channel
form, the Tukipo and Waipawa, in the Southern Hawke's Bay, New Zealand. Monthly
collections between December 1995 and December 1996 yielded a total of 89 taxa
from the two sites;
Deleatidium spp. numerically dominating the braided
Waipawa whereas
Pycnocentrodes spp.,
Pycnocentria funerea,
Aoteapsyche spp., and Elmidae were most common in the constrained
Tukipo. Although disturbance frequency was similar between rivers, the
streambed substrates were smaller, and hence less stable in the Waipawa. Number
of taxa, total abundance, and community composition changed through time in
both rivers. The Waipawa community changed least throughout the year; perhaps
because of greater numbers of rare taxa at the Tukipo whereas greater
resilience of taxa and community dominance by the mobile generalist
Deleatidium spp. in the Waipawa lead to greater constancy. At a broader
taxonomic scale, invertebrate communities of the Waipawa were also more similar
to communities in two South Island braided rivers (Ashley and Rakaia) than the
Tukipo. Thus, although braided river communities may show some similarities
throughout New Zealand, the community of the constrained channel was clearly
different both in taxonomic composition and temporal change of that
composition.
Keywords benthic invertebrate communities; community
structure; flow frequency; flow magnitude; Hawkes Bay; persistence; physical
stability; temporal variation
M98034
Received 24 June 1998; accepted 6 October 1999
Short communication
PDF file of entire paper: medium quality (773K); (scanned from paper original: notes about this process)
This year's abstracts |
Journal home page |
All abstracts |
Publishing home page
