This layer comes from the Threatened Environment Classification (TEC) version 2012, which is a source of national scale background information on New Zealand's land environments. Specifically, it shows how much native (indigenous) vegetation remains within land environments, and how past vegetation loss and legal protection are distributed across New Zealand's landscape. The TEC uses indigenous vegetation as a surrogate for indigenous biodiversity. This includes indigenous ecosystems, habitats and communities: the indigenous species, subspecies and varieties that are supported by indigenous vegetation, and their genetic diversity. The TEC is most appropriately applied to help identify places that are priorities for formal protection against clearance and/or incompatible land-uses, and for ecological restoration to restore lost species, linkages and buffers. The TEC is a combination of three national databases: Land Environments New Zealand (LENZ), classes of the 4th Land Cover Database (LCDB4, based on 2012 satellite imagery) and the protected areas network (version 2012, reflecting areas legally protected for the purpose of natural heritage protection).
For more information see: Cieraad E, Walker S, Price R, Barringer J. 2015. An updated assessment of indigenous cover remaining and legal protection in New Zealand’s land environments. New Zealand Journal of Ecology 39(2) - downloadable from http://newzealandecology.org/nzje/3235.pdf .
A users guide is available at http://www.landcareresearch.co.nz/resources/maps-satellites/threatened-environment-classification
NOTE: If you have previously downloaded TEC and want the 2012 update, you only need to download the attachment (look up table) and join to the original LENZ/TEC grid dataset as directed.