dc.contributor.advisor |
Stanley, MC |
en |
dc.contributor.advisor |
Tylianakis, JM |
en |
dc.contributor.advisor |
David, K |
en |
dc.contributor.author |
Lara Mendoza, Carolina |
en |
dc.date.accessioned |
2019-04-02T02:06:27Z |
en |
dc.date.issued |
2019 |
en |
dc.identifier.uri |
http://hdl.handle.net/2292/46349 |
en |
dc.description.abstract |
Urbanisation is one of the most rapid alterations of natural ecosystems, causing negative biodiversity impacts and potentially disrupting critical mutualistic interactions between species, like those between plants and their seed dispersers (frugivores). Most of what we currently know about the impacts of fragmentation on mutualistic networks comes from studies in agricultural landscapes rather than urban areas. Moreover, few studies have attempted to link network structure with associated ecosystem functions and combine this with other evidence of successful dispersal (i.e. seedling recruitment). In addition, network studies are limited by how data are collected as this may introduce biases in our interpretation of network structure. In this thesis, I investigated the impacts of altered landscape composition on plant-frugivore networks at forest fragments within and urbanised landscape and their outcomes: fruit consumption and seedling recruitment. This thesis consists of three main components. First, using a multi-level path model informed by direct observations from birds feeding on fruit, I investigated the link between landscape variables, changes in plant-frugivore network structure and the effects of those network changes on fruit consumption. I found that plant species had fewer frugivore partners in fragments surrounded by high urbanisation, and that fruit consumption was greater for plant species that had more frugivore partners and high complementarity in frugivore partner use. Overall, I showed that the negative effects of urbanisation on fruit consumption are not direct, but instead mediated through changes to plant-frugivore network structure. Second, I investigated how two different methods that are frequently used to sample plant-frugivore interactions generate different network properties, and provided a novel approach for combining data from these two methods by using a single link currency. I showed how any decision to use one method in isolation could strongly bias interpretation of network structure. Lastly, I estimated spatial patterns of genetic variation in tōtara (Podocarpus totara) using adult trees and seedlings collected at several forest fragments within an urban landscape, and determined long-distance recruitment using parentage analysis. I found higher genetic relatedness within fragments, resembling a source-sink pattern for parental trees and offspring, resulting from long-distance recruitment. This research contributes to our understanding of the impacts of fragmented landscapes on plant-frugivore mutualistic networks, by linking those networks to an ecological function. Furthermore, it highlights the importance of improved management and conservation of species interactions and forest fragments in urban areas that maintain plant populations and ensure persistence of species and their interactions. |
en |
dc.publisher |
ResearchSpace@Auckland |
en |
dc.relation.ispartof |
PhD Thesis - University of Auckland |
en |
dc.relation.isreferencedby |
UoA99265138410602091 |
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-sa/3.0/nz/ |
en |
dc.title |
Plant-frugivore interactions in an urbanised landscape |
en |
dc.type |
Thesis |
en |
thesis.degree.discipline |
Biological Sciences |
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 |
dc.rights.accessrights |
http://purl.org/eprint/accessRights/OpenAccess |
en |
pubs.elements-id |
767291 |
en |
pubs.org-id |
Science |
en |
pubs.org-id |
Biological Sciences |
en |
pubs.record-created-at-source-date |
2019-04-02 |
en |
dc.identifier.wikidata |
Q112949144 |
|