Forestry In Focus: Ungulate Management Study

Introduction

Top of the South Wood Council (TOTSWC) is leading five forestry innovation projects funded by Te Hoiere Project. Our Forestry in Focus series examines these in depth, this time taking a closer look at the ungulate management study.

Who is involved?

This study is led by TOTSWC with the support of Te Hoiere Project and Te Hoiere Forestry Group. Special thanks to Mosaics Aotearoa, Whirika Consulting Limited, Department of Conservation and Ngāti Kuia for their advice and support.

Where is it?

The study is underway in four different commercial forests within Te Hoiere/Pelorus catchment known to be affected by ungulate (deer, pigs and goats) browsing and trampling. The 5m x 5m square plots with 2.2m high fences have been designed to keep out ungulates; separating off these sites was the best option for the study due to budget and land availability. Possums and other pest animals are not included in the study scope.

How long is the study for?

Work began in 2024 as part of an initial investigation. It is hoped field trials can continue to provide data past June 2025 if ongoing resourcing and support can be secured. This will return far greater insights if monitoring can continue over a longer period and plant survival measured.

What is the study’s aim?

Ungulates are known to place a lot of pressure on native vegetation, disrupting the ecological balance and threatening biodiversity.

This research aims to assess the impact ungulates have on native forest using the four study areas and to look at how excluding them impacts vegetation composition, structure and flora biodiversity. By creating the exclusion zones and assessing the effects of ungulate management, the study aims to provide valuable insights into the restoration and conservation of the forest ecosystem. Different ungulate management techniques are also being used to see if this has a positive impact on the forest outside of the exclusion areas.

The specific aims of the study are:

• to generate quantitative data on the impacts of ungulates in Te Hoiere catchment and the environmental net gains from removing them
• to provide evidence based, practical recommendations for effective plantation forest management strategies and conservation initiatives
• to provide information to landowners and managers in Te Hoiere on the benefits of effective ungulate management programs.

Why these sites?

The five study sites, located in native forest, are all commercial plantation forests.

Paired plots, designed for comparison, have been set up within the native forest with one fenced to exclude ungulates and the other not fenced. The unfenced plots in each management area are measured for comparison to inform the relative success of ungulate management compared to full exclusion/fencing.

Different management approaches are also being applied to the different study areas.

Alongside the full ungulate exclusion (the fenced plots), management techniques include community-based culling (unstructured recreational hunting), systematic culling on a quarterly basis at a defined frequency and seasonal culling during autumn and late winter/early spring. The study would also like to test thermal drones as a management tool in the future to identify the location of pest animals and sending cullers directly there.

What has been found so far?

Data collection, in the form of ecological surveys, will be continually gathered on a three-monthly basis following a baseline survey at the time of plot installation. Each survey visit involves a photo being taken, a vegetation survey, and an ungulate faecal pellet count. Baseline surveys have noted the presence of high number of ungulates in all the study areas and the impacts these are having on plant survival.

TOTSWC’s Angela Mackenzie says:

The issue of pest animals is complex and is as much a quantitative as it is a qualitative science and community issue.

People experience and value these animals differently and even though they may understand the impacts that these animals have on indigenous (and exotic) flora and fauna, water quality and carbon sequestration, some still place value on them in the natural environment for a variety of reasons.

What a lot of people don’t realise is that much of our forests, both native and exotic, would look very different if ungulates weren’t present especially in the numbers that in some of the areas of Te Hoiere they currently are. To further add to this complex issue is the fact that these animals are highly mobile so even if one landowner is undertaking control measures, it only takes movement from neighbouring properties for numbers to quickly increase.

This study has been designed to reflect these realities and identify practical, replicable solutions while demonstrating the positive impacts changes in management practices can have. There is a saying ‘it takes a village’ but rather than a village this project is aimed at a much broader scale to provide landowners with a greater understanding and the best available tools to undertake this important mahi.