Environmental Reporting, Ministry for the Environment and Statistics New Zealand
"The pressure from animal and plant pests is one of the biggest threats to biodiversity in the land environment. Pest predators (such as stoats and possums) eat eggs, birds, lizards, insects, and snails. Other animal pests (such as deer and goats) damage and kill trees and other plants and can compete with indigenous animals for the plants’ fruit and seed. Pest plants can out-grow the local vegetation. All these activities can dramatically change both our indigenous and agricultural environments.
This data set relates to the ""Land pests"" measure on the Environmental Indicators, Te taiao Aotearoa website."
Source: Department of Conservation
Method: "Maps of distribution of our most damaging pest animals and plants: red deer, Douglas fir, feral goat, lodgepole pine, possums, rats, stoats, Himalayan tahr.
In 2007, existing datasets and Department of Conservation (DOC) expert opinion were aggregated and digitised to produce GIS maps of national distribution for these pests and weeds. In 2014, these maps were updated by incorporating new distribution data acquired from DOC’s Tier 1 monitoring programme.
The effect of pests is related to their abundance. This indicator does not include data on the abundance of these pests and weed species. The problems caused by some pests will be much higher in particular areas than in other areas.
The Douglas fir and lodgepole pine maps may include intentionally-planted plantations. Data is presented as a raster dataset (100*100m cell size).
The accuracy of the data source is of high quality."