Houghton, K.M.; Bolton, A.; Weaver, L. 2024 Roadmap to an updated ecosystem typology for groundwater. Lower Hutt, N.Z.: GNS Science. GNS Science report 2024/35. 19 p.; doi: 10.21420/1EWP-C334
Abstract
This groundwater-specific typology work is part of a larger project aiming to develop a unified ecosystem typology for Aotearoa New Zealand. In this current work, existing specific typologies have been assessed against a series of end-user principles and a global ecosystem classification framework; the IUCN GET (International Union for Conservation of Nature Global Ecosystem Typology). <b>Mapping Groundwater Typologies to the IUCN GET</b>We identified four typologies within the scientific literature that were most similar to those in current use in Aotearoa New Zealand for our assessment against the IUCN GET. All selected typologies could be nested under the single IUCN GET functional group SF1.2 Groundwater Ecosystems. However, we note that another functional group exists, SF1.1 Underground streams and pools, which may include cave systems. None of the literature reviewed considers this functional group, and data on these ecosystems is sparse in Aotearoa New Zealand, although groundwater cave species have been discovered.<b>Mapping Groundwater Typologies to the End-User Principles</b> Four typologies were selected for further assessment; however, none of these met all end-user principles. Each typology was updateable, reasonably flexible, generally robust and defined based on a clear rationale. Some mapping had been completed, and the typologies were spatially and/or temporally explicit. However, the typologies were neither comprehensive nor specific to Aotearoa New Zealand, and only one typology used any biotic data.<b>Groundwater Typology Roadmap Summary</b>This report provides a roadmap to define the steps needed to create an Aotearoa-New-Zealand-focused ecosystem typology that is consistent with end-user principles. The roadmap acknowledges that current groundwater typologies do not meet the end-user principles, which is partly due to an absence of data on groundwater ecosystems. We identify necessary steps toward determining whether a groundwater ecosystem classification for the country should be determined by biotic or abiotic factors, or a combination of both. We also highlight considerations and challenges for this project and recognise the need for substantial investment and endorsement from numerous stakeholders.<b>Overview of the Proposed Process to Define Groundwater Ecosystems</b>• Undertake statistical analysis of nationally consistent abiotic datasets to identify provisional category boundaries with a reasonable number of units.• Carry out a classification case study in an area with good environmental and biodiversity data and coverage.• Undertake statistical analysis on combined environmental and biological data to determine important chemical or lithological drivers.• Identify classification boundaries.• Repeat in other regions with similar lithologies/chemistry to ensure that units are consistent.• If typology units are not consistent, repeat process until predictive capability is achieved. (auths)
