LENZ (Land Environments of New Zealand) is an environmental classification intended to underpin a range of conservation and resource management issues. LENZ was originally envisioned as a framework for conservation management that would take advantage of the natural relationship between the environment and species distributions. Rather than occurring randomly, species tend to occur in areas having similar environmental conditions. As a consequence, similar environments tend to support similar groups of plants and animals, provided they have not been substantially modifed by human activity.
LENZ capitalises on the species-environment relationships by identifying climatic and landform factors likely to influence the distribution of species. LENZ uses these factors to define a landscape classification that groups together sites that have similar environmental conditions. Such a classification can then be used to indicate sites likely to have similar potential ecosystem character - not necessarily the same in all respects but likely to have similar groups of species and similar biological interactions and processes.
One major advantage of this approach, as opposed to directly mapping land cover for example, is its ability to predict the potential character of sites where natural ecosystems have been substantially modified (e.g. by land clearance or fire) or replaced by introduced plants and animals (e.g. pests and weeds).
Although LENZ was originally envisioned as a tool for biodiversity management, it has a much wider application. This is because the environmental factors that control the distributions of many land based plants and animals (temperature, water supply, availability of nutrients, etc.) are also factors that provide major constraints on human land uses such as agriculture, horticulture, and forestry.
Some applications which use LENZ include:
- assessing the biodiversity value of surviving natural ecosystem remnants and their ability to represent historic biotic patterns;
- identifying the most efficient use of limited financial resources for biodiversity management, including management of protected natural areas and other areas of land with high biodiversity values;
- identifying sites where similar problems are likely to arise in response to human activities, or where similar management activities are likely to have a particular affect;
- identifying the geographic extent over which results from site-specific studies can be reliably extended;
- providing a framework for regulatory activities and reporting on the state of the environment;
- setting targets for restoration projects, including identifying suitable sources of plants and animals for re-establishment;
- identifying environments throughout the world that are similar to New Zealand's environments to assist with predicting what new harmful organisms could successfully establish and spread in New Zealand if they were to arrive;
- optimising the management of productive land uses, including locating optimal sites for particular crops or cultivars.