Ecosystem representation and changes in the ecological integrity of managed ecosystems
This measure relates to a range of indicators that collectively measure and report on ecosystem integrity (EI).
Background
It is important that the full range of New Zealand’s ecosystems are protected in a healthy and functioning state to maintain the services they provide and the species they support. DOC regularly undertakes a ranking exercise to prioritise the management of a network of just under 1000 ecological management units (EMUs).
Just under 600 EMUs are currently being managed, but some rare ecosystems are under-represented.
What did we measure?
EMUs were prioritised in 2018 using the systematic conservation planning tool Zonation to maximise representation across all classes while taking into account the species that are present in each unit.
Ecosystem classifications were derived from published classifications for terrestrial ecosystems and river ecosystems and an unpublished classification for lake ecosystems. A deterministic model was then used to predict the EI of the EMUs under the complete suite of management actions planned for 2019/20 (planned implementation) and the activities that were allocated resources (funded implementation).
What did we find?
- Just under 600 EMUs are currently being managed, but this network does not fully represent the range of terrestrial, lake and wetland ecosystems in New Zealand.
- Most ecosystem types are over-represented in the places that are currently being managed, particularly beech and conifer–broadleaved forests, while the rare ‘Temperature Inversion’ ecosystem type and conifer-dominant ecosystems are under-represented (Figure 1).
- The potential gain in EI in managed ecosystems is lower than would be expected had all planned management actions been funded in 2019/20, particularly for geothermal and conifer-dominant forest ecosystems (Figure 2).
- Places that are managed to have high EI are found throughout New Zealand (see Figure 3 - Maps).
Figures
Figure 1: Ecosystem representation in the managed ecosystems within the Top 850 ranked ecosystem management units (EMUs) in 2019/20.
Figure 2: Difference in the predicted ecological integrity (EI) between the planned and funded ecosystem management prescriptions in 2019/20 by ecosystem class.