29 August 2015
It is acknowledged that the recent high-intensity rainstorms have triggered slips within recently harvested areas of plantation forest. Newly planted trees and decaying logging slash have been deposited into streams and on to beaches on the East Coast, Wairoa and Northern Hawkes Bay.
At the same time, mature stands of pines did a really good job at holding other erosion-prone slopes intact while neighbouring farmland failed. It is also well documented that any erosion-prone slope in a plantation forest has a "window of vulnerability" following harvest but equally, for the rest of the 30-year cycle, it provides protection.
The recent slope failures have occurred both under Gisborne District Council's resource consenting process and the Hawke's Bay Regional Council's permitted activity control regime. Neither of these RMA regulatory regimes has proved effective in preventing post-harvest landsliding on some of New Zealand's most erodible land, says Trevor Helson, CEO of Eastland Wood Council in a column in the Gisborne Herald.
In a geologically young country, slope failures are natural. Lake Waikaremoana was created by a large landslide that occurred within an undisturbed native forest, and today there are many logs in that lake bed. In more recent times the landslides that blocked the Manawatu and Waioeka Gorges occurred despite the mature native forest cover. The Matata flooding just a few years ago is another.
Eastland Wood Council members are struggling to understand the logic behind Gisborne District Council's opposition to the proposed RMA reform for four key reasons:
■ Very little will change in the regulation of forestry earthworks or harvesting in Gisborne if the proposed National Environmental Standard (NES) for Plantation Forestry is introduced. The NES directs that the council retain full control via its resource consenting process for the region's very highly erodible land.
■ For the first time ever anywhere in New Zealand, a land owner with highly erodible bare land will need to obtain a resource consent to plant a tree crop on that land. The NES gives councils new powers to ensure that a tree crop destined for clear fell harvest doesn't go on slopes where the risk of failure after harvest is judged unacceptably high. Eastland Wood Council members support having the right tree in the right place.
■ Gisborne District Council's chief soil conservator has been very involved in the design of the proposed NES for the past seven years and has been very effective in ensuring the NES accommodates the high-erosion landscape that characterises the Gisborne region.
■ GDC's chief soil conservator has also contributed to and has peer-reviewed the Erosion Susceptibility Classification mapping that underpins NES. This work, prepared by experts from Landcare Research — including Dr Mike Marden of Gisborne — classifies land on an erosion risk hierarchy that goes from green zones through yellow to orange to red zones, the latter being the worst of the worst erosion prone land; 500,000 hectares of New Zealand (not including DoC estate) is classified as red zone, of which 186,000ha is in the Gisborne region; 66,000ha of that is plantation forest while the rest is pastoral farmland or reverting to native.
Seven years working collaboratively with Fish & Game, Forest & Bird, DoC, three regional and district councils (including Gisborne) and the NZ Farm Forestry Association, with input from technical experts from Niwa, GNS, Landcare Research, Scion and NZIER have shaped the proposed NES for Plantation Forestry.
All those people have thrashed out this standard and all have had their opinions heard, discussed and resolved, so after seven years we now have an agreed document. Why then is there so much resistance to this initiative?
Source: Opinion column in Gisborne Herald, by Trevor Helson, chief executive, Eastland Wood Council