Rapid landscape transformation in South Island, New Zealand, following initial Polynesian settlement

David B. McWethy, Cathy Whitlock, Janet M. Wilmshurst, Matt S. McGlone, Mairie Fromont, Xun Li, Ann Dieffenbacher-Krall, William O. Hobbs, Sherilyn C. Fritz, Edward R. Cook

Research output: Contribution to journalArticlepeer-review

158 Scopus citations

Abstract

Humans have altered natural patterns of fire for millennia, but the impact of human-set fires is thought to have been slight in wet closed-canopy forests. In the South Island of New Zealand, Polynesians (Māori), who arrived 700-800 calibrated years (cal y) ago, and then Europeans, who settled ∼150 cal y ago, used fire as a tool for forest clearance, but the structure and environmental consequences of these fires are poorly understood. High-resolution charcoal and pollen records from 16 lakes were analyzed to reconstruct the fire and vegetation history of the last 1,000 y. Diatom, chironomid, and element concentration data were examined to identify disturbance-related limnobiotic and biogeochemical changes within burned watersheds. At most sites, several highseverity fire events occurred within the first two centuries of Māori arrival and were often accompanied by a transformation in vegetation, slope stability, and lake chemistry. Proxies of past climate suggest that human activity alone, rather than unusually dry or warm conditions, was responsible for this increased fire activity. The transformation of scrub to grassland by Europeans in the mid-19th century triggered further, sometimes severe, watershed change, through additional fires, erosion, and the introduction of nonnative plant species. Alteration of natural disturbance regimes had lasting impacts, primarily because native forests had little or no previous history of fire and little resilience to the severity of burning. Anthropogenic burning in New Zealand highlights the vulnerability of closed-canopy forests to novel disturbance regimes and suggests that similar settings may be less resilient to climateinduced changes in the future.

Original languageEnglish (US)
Pages (from-to)21343-21348
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume107
Issue number50
DOIs
StatePublished - Dec 14 2010
Externally publishedYes

Bibliographical note

Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.

Keywords

  • Deforestation
  • Human impacts
  • Land cover change

Fingerprint Dive into the research topics of 'Rapid landscape transformation in South Island, New Zealand, following initial Polynesian settlement'. Together they form a unique fingerprint.

Cite this