dc.contributor.advisor |
Beggs, J |
en |
dc.contributor.advisor |
Wardle, D |
en |
dc.contributor.author |
Tomlinson, Anne |
en |
dc.date.accessioned |
2014-02-13T20:17:43Z |
en |
dc.date.issued |
2014 |
en |
dc.date.submitted |
2014 |
en |
dc.identifier.uri |
http://hdl.handle.net/2292/21610 |
en |
dc.description.abstract |
Macroinvertebrate decomposers play a key role in the fragmentation of plant detritus thereby affecting decomposition and nutrient cycling. Issues facing native New Zealand decomposer communities are loss of habitat resulting from forest fragmentation and possible competition from introduced detritivores. New Zealand has a diverse assemblage of introduced litter macroinvertebrates, including millipedes (Diplopoda) and isopods (Isopoda), but there is limited knowledge of species distributions, interactions with native fauna and impacts on ecosystem processes. The focus of this thesis is on native and exotic millipede and isopod communities, and had two aims: (1) To increase understanding of the factors driving the abundance and distribution of native and exotic millipedes and isopods in native forests in the Auckland region; and (2) To quantify the impacts of a native and an exotic millipede species on litter decay and nutrient release and to determine whether differences in the rates and timing of these processes affected the growth and nutrient uptake of puriri (Vitex lucens) seedlings in a microcosm study. The influence of tree species identity in millipede abundance and species richness was revealed in a survey in the Waitakere Ranges. A survey of millipedes and isopods in forest fragments on Auckland’s North Shore also revealed the importance of litter composition in driving the abundance and diversity of exotic millipedes and native isopods. All the isopod species were native, but while introduced millipedes were dominant in small forest fragments, there was no evidence that their presence had a negative impact on overall abundance and diversity of the native millipede and isopod fauna. The increase in biomass of the exotic millipede Oxidus gracilis in the microcosm study was reflected in higher rates of decay of high nutrient litters, increased nitrogen and phosphorus release, and higher soil pH and ammonium and phosphorus levels, but lower nitrate levels in treatments with this species. However, plant growth rates and foliar nutrients were not enhanced by higher ammonium and phosphorus levels in exotic millipede treatments and the plants showed evidence of nitrogen limitation, suggesting that puriri may require nitrogen in the form of nitrate rather than ammonium. There was no evidence of interspecific competition between the two millipede species in this study, but the results indicate that the effects of exotic millipedes on critical ecosystem processes and plant communities could be profound. |
en |
dc.publisher |
ResearchSpace@Auckland |
en |
dc.relation.ispartof |
PhD Thesis - University of Auckland |
en |
dc.rights |
Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher. |
en |
dc.rights.uri |
https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm |
en |
dc.rights.uri |
http://creativecommons.org/licenses/by-nc-nd/3.0/nz/ |
en |
dc.title |
Interactions between native and exoticdetritivores and impacts on ecosystem processes |
en |
dc.type |
Thesis |
en |
thesis.degree.grantor |
The University of Auckland |
en |
thesis.degree.level |
Doctoral |
en |
thesis.degree.name |
PhD |
en |
dc.rights.holder |
Copyright: The Author |
en |
pubs.author-url |
http://hdl.handle.net/2292/21610 |
en |
dc.rights.accessrights |
http://purl.org/eprint/accessRights/OpenAccess |
en |
pubs.elements-id |
426742 |
en |
pubs.record-created-at-source-date |
2014-02-14 |
en |
dc.identifier.wikidata |
Q112907368 |
|