In 2003 NZFM began a monitoring program to assess the health and vitality of important indigenous vegetation types and tree species within Lake Taupo and Rotoaira Forests. The program will also identify any significant threats to the integrity of these indigenous forest remnants so that management action can be considered. Seventeen plots were established within Rotoaira Forest in 2003, with two additional plots established in 2004 as recommended by the initial survey. A further plot was added in 2008. In Lake Taupo Forest 25 plots were established in 2004 and 2 additional plots were added in 2011 to capture frost flat vegetation. Plots are re-assessed every two years.
In 2019 Lake Taupo Forest plots were assessed.
Key findings from the re-assessment in 2019 were:
- There was a general trend for plot health to be stabilising, but for plot vitality to show decline.
- Plots with poor health and vitality are still found most often in the regenerating hardwood forest type, and this can be attributed to natural selection processes, strong weather events and heavy browsing on regeneration.
- Browsing animals were still having significant impact on overall regeneration and associated plot vitality scores, consistent with damage in previous years.
The following recommendations were made:
Animal damage – Animal control meaures should be considered to reduce deer and pig impact on plot vitality.
Additional plots – No additional plots will be required if the inaccessible plots in 2019 are able to be access again in 2021.
These plots will be reassessed in 2021, with the Rotoaira Forest indigenous forest plots undergoing a re-assessment this year.