Macroinvertebrate-wood associations during decay of plantation pine in New Zealand pumice-bed streams: stable habitat or trophic subsidy?

Abstract

AbstractExtensive areas of production pine forest in New Zealand have been planted in the North American native Pinus radiata. We investigated the use of pine large woody debris (LWD) by aquatic invertebrates in central North Island spring-fed streams with pumice beds to provide an improved basis for managing LWD inputs following logging. Invertebrate faunas in early summer were dominated by Ephemeroptera and Diptera on inorganic substrates, and by these groups and Trichoptera (predominantly Pycnocentria funerea; Conoesucidae) on wood. Densities of total invertebrates and P. funerea, Eukiefferiella sp. (Diptera), and the ephemeropterans Coloburiscus humeralis (Coloburiscidae), Zephlebia dentata, and Austroclima sepia (both Leptophlebiidae) were significantly higher on wood than on inorganic substrates in summer. These dominant species showed varying preferences for wood at different stages of decay. Austroclima sepia appeared to prefer wood at early to intermediate stages of decay, P. funerea and Z. denta...