New Zealand Wetland Condition Index (WCI)
Description and method logic
The New Zealand Wetland Condition Index (WCI) was developed for State of the Environment monitoring and reporting in all freshwater wetlands in New Zealand. It is a semi-quantitative metric comprising five ecological indicators based on the major threats and stressors known to degrade wetlands.
The New Zealand National Wetland Monitoring System (NWMS) approach determines overall ecological condition of a wetland by comparing against an assumed natural state, such as pre-settlement, to measure a Wetland Condition Index (WCI). The WCI is informed by the relevant monitoring methods in the 'Handbook for Monitoring Wetland Condition'. The approach has been updated (2017) to address additional reporting requirements for State of the Environment monitoring.
The WCI indicators are scored at both a broad wetland-wide scale and a more detailed plot scale to account for differences in scale and monitoring requirements, and to underpin scores with quantitative scientific data. The plot-based approach is the foundation for the Protected Natural Areas Programme in New Zealand. This approach initiates a process in which detailed field reconnaissance, ground-truthing, establishment of representative plots, and collection of data, together with integrating existing information, are necessary steps to facilitate informed assessment and scoring of indicators.
Condition is scored using five indicators to reflect the extent and impact of modification (disturbance), where a high degree of modification provides a low score. The indicators relate to the major threats known to damage wetlands. The sum of the indicator scores provides a WCI. Indicator component scores are averaged to produce a score out of 5 for the indicator, and summed to provide an overall WCI score out of a maximum of 25. The higher the score, the better the ecological condition.
It is derived from a process involving wetland classification, mapping and delineation of vegetation types, field reconnaissance, ground-truthing, establishing representative plots, and collection of data to facilitate informed assessment of the indicators.
The WCI can be used to compare changes at different levels and scales, e.g., within an individual wetland, or across a wetland type in a watershed, region, or nation-wide, to gauge the effectiveness of policies, rules and other legislation. This system is the basis for the development of community-based and additional monitoring systems (e.g. WetMAK https://www.landcare.org.nz/resource-item/wetmak).
Criteria groupings of the method
The indicators and component indicators are:
Desktop data to inform the survey includes:
Plot field data includes:
Indicator data includes a range of project- and module-based indicators and measurables.
Depending on the type of assessment carried out, the main skills needed generally include:
Each of the indicators is measurable, and the sum of the indicator scores providing the WCI. Outputs include analysis and evaluation of both the total WCI, the scores of the individual indicators and components, and a brief monitoring report.
The WCI can be used for State of the Environment wetland monitoring requirements, to inform council policy, plans and management priorities etc., gauge the effectiveness of these mechanisms, and form the basis for community-based monitoring systems.
Criteria by category
Physical and chemical
For State Government, the State of the Environment monitoring and reporting on New Zealand terrestrial wetlands.
Lake Maratoto Peatland wetland condition
Clarkson B.R. 2014. Lake Maratoto peatland: 20 years of vegetation change (1993-2013). Landcare Research Contract Report LC1809 26 p.
Moanatuatua Peat Scientific Reserve Restoration Plan
Watts CH, Clarkson BR, Campbell DI 2019. Moanatuatua Peat Scientific Reserve Restoration Plan. Landcare Research Report LC3605 for Department of Conservation. 35 p
New Zealand wetland condition monitoring
Clarkson B, Sorrell B 2018. New Zealand wetland condition monitoring. In: Dorney J, Savage R, Tiner R, Adamus P eds Wetland and stream rapid assessment: development, validation, and application. Elsevier, USA. ISBN: 978-0-12-805091-0. Pp. 511–520.
Restoring wetland ecosystem function
‘Using the WCI: Ecological change at the Cockayne Reserve’ within Chapter 13: Monitoring
Last updated: 20 January 2021
This page should be cited as:
Department of Environment and Science, Queensland (2021) New Zealand Wetland Condition Index (WCI), WetlandInfo website, accessed 1 February 2023. Available at: https://wetlandinfo.des.qld.gov.au/wetlands/resources/tools/assessment-search-tool/new-zealand-wetland-condition-index-wci/