Reproductive ecology of mānuka (Leptospermum scoparium) under various fire regimes

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dc.contributor.advisor Perry, G en Battersby, Paul en 2015-01-07T02:35:39Z en 2014 en
dc.identifier.citation 2014 en
dc.identifier.uri en
dc.description Full text is available to authenticated members of The University of Auckland only. en
dc.description.abstract The main aims of this study were to evaluate whether serotiny in mānuka can be used as proxy for fire history and to assess the interactions among serotiny, flammability and various environmental parameters at sites throughout New Zealand. Using the palaeocharcoal record, 31 sites were placed into categories based on length of time exposed to fire, and the proportion of closed capsules at each site used as an indicator of serotiny. Environmental parameters were obtained through the NIWA Cliflo database and correlated with serotiny and flammability at each site. Flammability and germination experiments were conducted in laboratory settings on a subset of the 31 sites. Results show there was a latitudinal gradient of serotiny, with more intensely serotinous populations (higher proportion of closed capsules) in northern regions. Environmental parameters such as high soil moisture deficit and lack of seasonal summer rainfall, acting in conjunction with fire are important in determining serotiny at a site. Fire regime can be used to predict serotiny at a coarse fire vs no fire dichotomy but relationships among divisions within the fire category are difficult to establish. No correlation exists between flammability and serotiny; germination results show that mānuka seeds are not adversely affected by heat, with considerable variation among sites. Finer scale fire classification on the basis of serotiny is not possible due to the overriding effects of the anthropogenic fire regime, and thus serotiny in mānuka can only be used as a coarse indicator of fire history. Fire and the environment cannot be viewed separately in the expression of fire-adapted traits as sites with abiotic conditions that appear to favour serotiny were also more likely to receive episodes of burning. It is likely that the Quaternary fire regime in NZ was sufficient to maintain serotiny, if not flammability traits, and the effect of anthropogenic fires was to expand the abundance and range of mānuka across the landscape and also significantly increase serotiny expression in the species. The LGM theory was hypothesised to explain the observed patterns of higher serotiny in northern regions compared to the south. en
dc.publisher ResearchSpace@Auckland en
dc.relation.ispartof Masters 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 Restricted Item. Available to authenticated members of The University of Auckland. en
dc.rights.uri en
dc.title Reproductive ecology of mānuka (Leptospermum scoparium) under various fire regimes en
dc.type Thesis en The University of Auckland en Masters en
dc.rights.holder Copyright: The Author en
pubs.elements-id 471901 en
pubs.record-created-at-source-date 2015-01-07 en

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