Pastoral land cover and intensity changes in the Waikato region 2001-2018

Report: TR 2022/51

Authors: Reece Hill (Landsystems) and Dan Borman (Waikato Regional Council)

The Waikato region encompasses most of New Zealand’s central North Island with a land area of about 2.5 million ha. Of this area about half (1.3 million ha) is in pastoral land use. Since the 2000s, conversion from planted forest to pastoral land, and conversion of non-dairy pastoral land to dairy has increased the area of pastoral land and its intensity of use. With land use intensification, greater pressure can be placed on existing soil and water resources. Maintaining the quality of these resources is vital to the Waikato region’s prosperity. This requires knowledge of the location and changes in land use pressures. This knowledge is fundamental to understanding trends and developing and prioritising sensible management practices and policy.

This report provides the first comprehensive spatial analysis of pastoral land cover change and intensity for the Waikato region. Conversion of planted forest to pastoral land, and changes in the intensity of pastoral land use in the Waikato region between 2001 to 2018 at three timesteps (2002-2008, 2008-2012, and 2012-2018) is presented. A multiple intersect-based spatial analysis method using Manifold® Professional System Release 9 was used to derive two main metrics: (1) conversion of planted forest to pastoral land, and (2) pastoral land intensity change.

Metrics were interrogated sub-regionally by management zone, land use capability class, and farm type to determine where, and on what land, pressures may be increasing or decreasing with respect to pastoral land intensity changes. Two pastoral land intensity indicators identify the changes in pastoral land intensity through time (every five years), for different parts of the region (management zones), and on different types of land (land use capability class).