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 2021, indigenous forest health assessments were completed in Lake Taupo Forest. The key findings from this assessment were:

• The health of the individual plots has decreased since 2019, with two plots classified as unhealthy and one as threatened, following an overall trend downwards from 2015.

• Plot vitality is largely stabilising with an increase in both healthy and unhealthy plots.

• The regenerative health of the plots is steadily decreasing with fourteen plots now considered poor in their regenerative health.

• Deer and pigs are impacting all plots, most notably with browsing, rooting, and tracking through the sites.

As a result of these findings, animal control measures will be considered to reduce deer and pig impact on plot vitality.