Ruapehu beech forests predicted to provide super supper for rodents
For more information contact:
Bhrent Guy
Ruapehu Community Relations manager
Date: 29 September 2008
The long hot summer of 2008 has provided bumper conditions for beech forests on the flanks of Mt Ruapehu to produce huge amounts of beech seed this coming summer. It is predicted the beech forests could produce up to 18,000 seeds per square metre - the equivalent of seed 10 - 20 cm deep across the forest floor. While this is great for beech forest regeneration, beech masting, as this huge sporadic production of beech seeds is known, also provides a massive storehouse of fresh seeds for mice and rats.
If the masting occurs as expected, DOC scientists predict that by winter 2009 mice and rat numbers will be extremely high. They in turn will provide a source of food for stoats, which will become very abundant. These stoats then go on to have a huge impact on native birds after the mouse population crashes when it runs out of beech seeds the following spring. "The increase in rat and stoat numbers has a major consequence for our native wildlife," said DOC scientist Nick Singers. "Juvenile kiwi and vulnerable hole-nesting species such as short-tailed bat, kakariki and kaka in areas on the southern side of Mt Ruapehu, especially in the Karioi Rahui, will be preyed on by rats and stoats. We expect their survival in the area to be really threatened."
"It is also likely that many of the 2009 clutch of whio (blue duck) will be killed by the increased numbers of stoats in places like the top reaches of the Whakapapa and Manganui-o-te-Ao rivers, where there is mountain beech forest", he predicted. "Given the scale of the problem there is little we could do throughout the whole of Tongariro National Park, but it is still possible to manage these pests in some of the most important places."
DOC staff will be taking the opportunity to meet with members of the community and discuss options for the control of rats and stoats with them. "Successful outcomes for our native birds and bats depend on our ability to control pests," says DOC Area Manager Kevin Cannell. "This potential beech masting presents a major threat to the gains made over the years in protecting Ruapehu's native fauna, and we will be talking to the communities around the area to seek their support to combat this threat".