School of Environment

Tree Ring Laboratory

About Us

The Tree-Ring Laboratory was established at its present location in the School of Environment on The University of Auckland City campus in 2002. We maintain an active dendrochronology laboratory and wood storage facility. Lab members are performing and publishing high quality original research in dendrochronology and dendroclimatology. We also liaise with national and international bodies involved in tree-ring research and disseminate the results of research through public lectures and media.

Lab members :

Gretel Boswijk
Dendrochronologist, Lab Director

Gretel is a dendrochronologist and lecturer in Environmental Science and Environmental Change. Gretel has extended the modern kauri record back to 1724BC, using data from logging relics, building timbers and sub-fossil kauri. Current research is focussed on investigating the dendro-archaeological potential of timbers from colonial-era buildings and other structures.



Anthony Fowler
Geographer, Dendroclimatologist

Anthony is a Senior Lecturer in Geography, specialising in climate change (past, present, & future). He has been active in tree-ring research for several years, seeking to reconstruct past climate from annual growth rates. Anthony leds a Marsden Fund research programme investigating decadal- to millennial-scale variability in the El Niño - Southern Oscillation phenomenon, from kauri tree-rings. He also led the climate reconstruction objective of a major palaeoclimate programme funded by the Foundation for Research Science & Technology.


Jan Wunder

Jan Wunder
Forest Ecologist

Jan is a post-doctoral research fellow of the Swiss National Science Foundation. His project aims to reconstruct the climate variability of the South Pacific during the last millennium using tree rings of kauri. To achieve his goal, he is studying the tree physiology of kauri using high-resolution growth sensors, analysing growth & mortality patterns of kauri and boosting the sample depth of the kauri master chronology. For more details on Jan’s research, access to publications and pictures visit


Shane McCloskey

Shane McCloskey
Dendrochronologist; Forest Ecologist

Shane is a post-doctoral research fellow from Canada with experience in dendrochronology and forest ecology. Since his arrival, he has established a high-resolution microscope and image analysis system for the examination of intra-annual tree-ring features. His work will provide data on seasonal growth characteristics of kauri leading to a finer-scaled climate reconstruction of the El Niño - Southern Oscillation phenomenon.



John Ogden
Forest Ecologist

John is Associate Professor of Forest Ecology, specialising in forest dynamics, dendrochronology and vegetation dynamics. John has worked in Australia, the United States and New Zealand , and has a particular interest in the ecology of the long-lived conifers. He set up the first tree-ring laboratory at the University of Auckland, in the former Botany Department (now School of Biological Sciences). Although now mainly retired, John brings broad experience in ecology and biogeography to the group, and emphasises the need for a multi-proxy approach to investigate past environments.



Jonathan Palmer :
Forest Ecologist, Dendroecologist

Jonathan is based in Christchurch where he runs the Gondwana Tree-Ring Laboratory.  He has been involved in tree-ring studies for the last 25 years, and has been directly associated with the development of tree-ring records from a range of native species (including Phyllocladus spp., Lagarostrobos colensoi, Libocedrus bidwillii , Halocarpus biformis , Nothofagus solandri from throughout the country. Other research projects also extend into South-East Asia. One specific interest is the calibration of the Southern Hemisphere radiocarbon dating time-scale and he also leads research on sub-fossil kauri from OIS3.



Peter Crossley :
Research Technician

Peter is Research Technician to the Tree-ring Laboratory. A multi-talented individual, he brings many years of practical field experience (as well as wisdom and humour) to the group. He provides invaluable support in the field being skilled with corer and chainsaw, and in preparing samples for analysis.


Past Research Students:

Andrew Lorrey :
PhD Candidate

Drew came to the University of Auckland in July, 2002 with an Earth Sciences and Geology background. His PhD is titled 'The Late Quaternary palaeoclimate record in kauri tree rings.'  Drew has analysed cores from living trees, samples of building timbers and swamp kauri, contributing to the modern era, late Holocene, and pre-last glacial maximum (LGM) data sets. His work also includes New Zealand climate regime reconstruction using multi-proxy data, and interpretation of kauri low-frequency variance patterns within a palaeocirculation context.  He has investigated regional curve standardisation (RCS) applicability to kauri, ancient kauri tree fall patterns (with Tim Martin), and palaeoENSO analysis of ancient kauri tree ring chronologies. Drew is currently finishing his PhD, and is now based at NIWA undertaking palaeoclimate research and climate-energy application science.



Joelle Gergis:

Joelle's PhD research (completed 2006) aimed to develop of a 500 year, annual history of ENSO using high-resolution palaeoarchives (i.e. tree-rings, corals, ice-cores and historical documentary records). She updated some of the most northerly Kauri chronologies from Puketi, Trounson and Warawara forests. This extended tree-ring replication to 2002 and improved the reliability of transfer functions for subsequent climate analysis and the assessment of 20th century ENSO variability.  Joëlle is currently based in Melbourne, Australia undertaking a Diploma of Professional Writing and Editing at RMIT University. For more details on Joëlle's research and access to publications visit



Tim Martin:

With a background in forest ecology and physical geography, Tim’s PhD research (completed in 2007) focussed on developing a method for the reconstruction of storm events using tree-rings. Field work for this project was in the mountains of central and southern North Island, and the key study species were kaikawaka (Libocedrus bidwillii) and beech (Nothofagus spp). The research built a record of forest disturbance and storms spanning the last 700 years, and will contributed to the analysis of any long term trends in storm events. Tim now works as an ecologist for Wildland Consultants Ltd, specialising in terrestrial ecosystems of northern North Island.



Jenny Lux :

Jenny Lux completed a Masters thesis in Environmental Science in 2005 in which she researched the vegetation succession in a prehistoric Maori burn site within the Waipoua kauri. During her time at university she also was field assistant, helping collect tree-ring cores from other kauri forests in Northland. She currently works for an ecological consultancy based in Rotorua specialising in plant ecology and botany.  In her free time she is involved in vegetation monitoring for the Mt Ngongotaha Bush Restoration Trust, and is secretary of the Rotorua Botanical Society.



Apply now

Environment handbooks

Undergraduate courses

Postgraduate courses

Please give us your feedback or ask us a question

This message is...

My feedback or question is...

My email address is...

(Only if you need a reply)

A to Z Directory | Site map | Accessibility | Copyright | Privacy | Disclaimer | Feedback on this page