Forests & Biodiversity
Cascading effects from climate change are impacting our native plants, animals, and their habitats.
The forests of Aotearoa New Zealand are of great importance to our national identity. They are home to many of our native birds, insects, and other plants and animals only found here. They are also places of peace, solitude and recreation. It is in forests where we seek fresh air and sustenance, including rongoā Māori (healing) and kai (food).
Changes to our climate are having an impact here too. Though some of these changes can be hard to notice, they could have big effects. Changes in temperature and rainfall will alter growing seasons, flowering times, where species can live, and many other parts of our forests.
One example linked to warmer summer temperatures is the increased frequency of beech mast events. This is where beech trees produce a load of seeds, usually every 2-6 years, which then provide food for some forest pests. This flows on to impact our native plants, animals, and their homes.
Beech mast often leads to an outbreak of pests such as rats, mice, and stoats. These predator plagues pose an increased threat to native forest birds and long tailed bats. These events may become more frequent as average temperatures rise, placing further pressure on our native plants and animals.
The predator plague cycle
In a year when beech mast occurs, heavy seeding of beech trees leads to a rapid increase in mouse and rat numbers as they feed on the seeds. Stoats then feed on the mice and rats, causing their population to boom as well. Stoats and rats are both predators of native animals. When the mast ends, rats and stoats both prey on birds and bats for food, threatening the survival of native species.
Recently, large mast events were recorded in three consecutive years between 2017 and 2019, and research suggests these events could become more common. We can now detect beech mast events from space using satellite imagery of flowering, since beech trees flower more heavily before mast events. This gives us more time to prepare.
It's important we target our conservation efforts to control predators around the times and places when mast events occur to ensure a future for our native animals in these forests.
On these maps, red shows where heavy flowering has been detected, while teal indicates that heavy flowering has not been detected. Grey means that no cloud-free imagery was available that we can use to see mast events.
The connection between mast events and climate is still an active area of research. The evidence suggests that mast years are becoming more common, especially at high elevation, and that these increases are linked with warmer summers.
As temperatures rise with climate change, mast events could increase the need to manage predator population booms and protect our native plants and animals.
Helping to control predators
Increases in predator populations place pressure on our native birds and bats, as there are more predators to prey on them.
Predator Free 2050 is working towards an Aotearoa where our native animals are safe from extinction and thrive alongside us. To do this, they are working towards eradication of our three most damaging predators (rats, stoats, and possums) – and everyone has a role to play.
Get involved in your local Predator Free 2050 efforts below:
What's being done to help?
Helping with the predator population booms from beech mast is important, but so is predator control outside a mast event. If we can lower predator numbers before mast events, their expansion during the events is likely to have less of an impact on our native plants and animals.
Each of us have knowledge and understanding about where we live, and harnessing that knowledge is one of the best ways to help combat the impacts of climate change.
Changes to the national climate play out differently in different locations. Some places are likely to get drier, and others wetter; alpine environments will be impacted differently than coastal environments.
Getting involved and offering your skills to your local predator control efforts can help our native species survive and thrive in the face of increasing pressure from predators.
One example of a local predator control effort is The Forest Bridge Trust just north of Auckland. With involvement of local landowners and community volunteers the Trust is working towards creating a “ forest bridge” for native species across a 130,000 hectare rural and residential area by 2025. The predator-controlled corridor will connect the existing wildlife sanctuaries at Mataia Restoration Project in the west to Tawharanui Regional Park in the east.
- For more information see the link below.
The trust engages with local communities on their vision for conservation in the area and is involved in fencing and planting. It has an active education programme helping people understand the threats to our natural places and wildlife.
To make sure long-term predator control succeeds, the trust works with communities to establish networks of trap and bait stations in key locations that can be maintained by landowners and community volunteers.
Groups like the Forest Bridge Trust exist across Aotearoa. You can get involved too by volunteering to help your local predator control community group.
Now let's see how climate change is affecting other parts of te taiao (the environment), heading from our forests down towards our coasts and ocean...
