An Holistic Approach to Erosion and Land Management

Future Forests Research Ltd (FFR) recently organised a very topical workshop in Gisborne on the subject of erosion on steep lands. Attendance drew from a wide range of invitees including central government agencies, local government, several Crown Research Institutes, Federated Farmers, forestry companies and Environmental Groups. The objective of the meeting was to initiate discussion between regulators, land managers and scientists through better understanding of what we know, or need to know, about the drivers of severe land sliding events on the extensive marginal hill country lands in New Zealand. There is up to 3 million hectares of such land in New Zealand.

The opening presenter at the workshop highlighted a very important fact – landslides are natural landscape- changing processes that are largely unmanageable, whereas the risk associated with the event is manageable. Speakers from NIWA, GNS and Landcare showed erosion not as an occasional, unlucky event, but rather as a regular and almost annual event somewhere in New Zealand. The impacts of these events on different land uses was highlighted in the discussions.

For farmers, the top priority was infrastructure –roads, fencing and buildings. For forest growers, the priority was to minimise the consequences of the event –debris flows, slips and off-site impacts on other land uses. Ultimately the development of an integrated approach to developing resilient land use systems is required. This involves not only foresters operating on steep lands, but also those seeking to operate below them.

The forest industry recognises that it must improve and maintain good forest practices on these erosion-prone lands and development of codes of practice and training is underway. However the underlying message is that severe landslides will continue to happen in big storms irrespective of land cover and best practice and the key question remains, how to best strike the balance between regulating land use and correctly identifying and then managing the inevitable hazard that results from these increasingly frequent erosion events. This more holistic approach will enable the best land use on the appropriate land class for the maximum benefit of all.

Severe erosion in Northern Hawkes bay following storms early 2011