New Zealand Journal of Marine and Freshwater Research abstracts

---

Leaf breakdown and colonisation by invertebrates in a headwater stream: comparisons of native and introduced tree species

S. M. PARKYN*
M. J. WINTERBOURN

Department of Zoology
University of Canterbury
Private Bag 4800
Christchurch, New Zealand

*Present address: National Institute of Water & Atmospheric Research Ltd, P. O. Box 11 115, Hamilton, New Zealand.

Abstract  Leaf breakdown, colonisation by invertebrates, food choice by a facultative shredder, and composition and activity of the microflora of leaves of three native and three introduced trees were investigated in a small headwater stream, South Island, New Zealand. Leaves of each species were immersed and collected after 1, 32, 60, and 95 days to measure mass loss and invertebrate colonisation. Additional leaves collected after 60 days were used for food choice and respiration experiments, and others taken after 95 days (some species) were examined with scanning electron microscopy. Leaf breakdown rates followed the sequence: elm > red beech > willow > mahoe > oak > mountain beech. Elm (introduced) and mahoe (native) supported the highest invertebrate densities, but shredders were most abundant on willow (introduced) and red beech (native) leaves. In laboratory choice trials the facultative shredder Olinga jeanae showed a preference for elm and red beech leaves which were fastest to break down and had high respiration rates. We found that leaves of introduced trees can be preferred by shredders and hence, no strong associations were apparent between shredders and these native trees.

Keywords  leaf breakdown; invertebrate colonisation; food choice; shredders; respiration; microflora

New Zealand Journal of Marine and Freshwater Research, 1997, Vol. 31: 301-312

0028-8330/97/3103-0301 $7.00/0 (c) The Royal Society of New Zealand 1997

PDF file of entire paper: medium quality (2002K); (scanned from paper original: notes about this process)

---

This year's abstracts | Journal home page | All abstracts | Publishing home page