Sequential impacts of Polynesian and European settlement on vegetation and environmental processes recorded in sediments at Whangapoua Estuary, Great Barrier Island, New Zealand

Whangapoua Estuary, Great Barrier Island, New Zealand, is central to a proposed Marine Reserve, and is currently managed for conservation by the Department of Conservation. This paper describes the sequential impacts of Maori and European people on the process of estuarine vegetation succession in time and space, and the rate of estuarine sedimentation. Multiple cores from one estuary gave confidence in assessing the temporal sequence of vegetation change, but bioturbation and other disturbance factors made it difficult to interpret ¹⁴C dates from the estuarine environment. The modern vegetation zonation pattern on the estuary is an active succession, which has been generated by rapid estuary in-filling, probably initiated as a consequence of erosion following Maori burning of the adjacent forest. European forest clearance for agriculture resulted in a further increase in estuarine sedimentation, and may have re-activated earlier sediments trapped in adjacent swamps. The combined effects of two phases of human exploitation have resulted in large-scale loss of nutrients and top-soil from catchments throughout Great Barrier Island. Conservation management of the estuary should take account of the anthropogenic impacts that have driven the plant succession and created the current vegetation zonation pattern. This pattern is neither static nor ‘natural’, but rather an on-going response to the changing human activities in the surrounding catchment.     

Exploring Indigenous Understandings of River Dynamics and River Flows: A Case from New Zealand

Indigenous communities are particularly sensitive to the use and development of freshwaters, as they hold distinct perspectives on water which reflect their identity, and their custodial obligations to manage tribal waters. Within New Zealand, Maori (the indigenous people) have, for generations, voiced their concerns about the continual modification of waterways within their tribal territories. Until about the mid-nineteenth century, water quality was at the forefront of issues concerning human manipulation of rivers and streams. A range of new issues then arose that were increasingly concerned with reduced river flows. Of the many techniques developed to address these issues, many rely heavily on professional expertise and objective, scientific philosophies, which often fail to recognize cultural values, and benefit from cultural knowledge. This essay presents examples of the knowledge of streams and rivers held within Maori communities that could benefit contemporary resource management if it can be determined how cultural knowledge and practices and scientific approaches can be communicated and integrated.