Appendix 2: Tools and databases
What is the Land Environments of New Zealand (LENZ) classification?
LENZ is a national environment-based classification of ecosystems mapped across New Zealand’s landscape. LENZ uses 15 climate, land form and soil variables likely to influence the distribution of species to classify and map areas that have similar environmental or ecosystem character. The classification is used to identify areas that are similar regardless of where they occur – sites not necessarily the same in all respects but likely to have similar groups of species and similar biological interactions and processes (ie, similar ecosystems). For example, swampy areas on poorly drained recent soils on coastal plains and in river valleys in eastern New Zealand occur from Gisborne to mid-Canterbury. Although geographically separated from each other, these areas are environmentally similar and form one type of LENZ environment (Environment I: Central Poorly Drained Recent Soils).
LENZ can be used at four levels of detail containing 20, 100, 200 or 500 environments respectively. Map 1 shows the LENZ level 1 classification of 20 environments for New Zealand. Note the location of P and R, which together comprise 20 per cent of New Zealand’s total area. P and R also comprise 50 per cent of the environments protected on public land. The different levels of LENZ simply reflect greater detail and hence an increase in the number of environments. Different levels are more or less appropriate for use depending on the level of detail needed to address a particular question. For our analysis of legally protected areas for indigenous biodiversity this report used LENZ level II which maps 100 different environments nationally. Level II is considered appropriate for national to regional scale assessments. LENZ levels III and IV would be appropriate for local scale assessments.
To identify each different land environment a letter and numbering system is used, ie, A to T for each of the environments at level I or 20 environments nationally. As levels of detail increase (ie, 100, 200 and 500 environments) numbers and additional letters are added to the A to T system to identify the further division of ecosystem boundaries within the level I environment, eg, A1 for LENZ level II or 100 environments, A1.1 for LENZ level III or 200 environments and A1.1a for LENZ level IV or 500 environments. Map 1 shows the LENZ level I classification or 20 environments for New Zealand.
What is the Land Cover Database?
The Land Cover Database 1 (LCDB1) is a digital theme-based map of land cover for mainland New Zealand. It was completed in June 2000 but based on satellite images from the Spot II satellite taken over the summer of 1996/97. Sixteen land-cover classes were used for most regions with a 17th class (riparian willows) added in some regions. The cover classes address cultural (modified by people) and natural landscapes, eg, Urban Area, Mines and Dumps, Primarily Pastoral, Indigenous Forest, etc. The 17 classes were classified manually with boundaries superimposed on satellite images that were field checked. These satellite images have a 20 m spatial resolution. The overall classification accuracy was independently assessed at 93 per cent at ±25 m. The minimum mapping unit used was one hectare and the data is suitable for application at the 1:50,000 mapping scale or coarser.
To identify areas of indigenous vegetation eight land-cover classes from the Land Cover Database (indigenous forest, inland water, coastal wetlands, inland wetlands, coastal sands, scrub, tussock and bare ground) were combined into one indigenous vegetation class. By overlaying information from the Land Cover Database with areas of public conservation land and private land we know there are about 14,033,769 hectares of indigenous vegetation remaining in New Zealand and about 8,210,570 hectares is legally protected. This leaves about 5,823,199 hectares of indigenous vegetation scattered across New Zealand. Some of this will be protected by council covenant schemes on private land or in council reserves. Some remnants in plantation forests will be protected under the Forest Accord, a scheme run with the Forest Stewardship Council (the Ministry of Agriculture and Forestry estimate there is about 1,000,000 hectares of indigenous vegetation scattered through production forests). Some areas will be managed outside legal protection schemes for conservation and although not legally protected will still contribute to indigenous biodiversity outcomes, eg, community or non-government organisation (NGO) pest and weed control activities and restoration programmes.
