Impacts of wilding pines
What is a wilding pine?
A wilding pine is a pine tree that has not been planted but has self-seeded by itself.
Blown by the wind to a place where it is not meant to be.
The negative impacts of wilding pines are diverse and can be grouped into 5 major headings.
If we don't prevent their spread, wilding pines can alter natural landscapes and have the potential to significantly change our way of life.
WATER
Research shows that Wilding Pines can have a significant impact on our waterways.
Pines, with their extensive root systems, compete with crops for water. Dense infestations can reduce water flowing into rivers and reservoirs by 30% to 40%.
This has significant rollon effects on our agricultural sector who require irrigation for crops.
The rapid growing rate of a pine tree not only depletes soil moisture but also compromises the fertile topsoil essential for successful cultivation.
Wilding pines also affect our hydroelectricity dams which rely on water flow from up stream.
Our work is important.
Removing wilding pine infestations especially in high drought zones like Central Otago has shown to improve water reserves.
FIRE
Every part of a pine tree is flammable.
Green needles, the sap from the truck, right down to the ground with the dried duff.
The wildfire risk increases when wilding conifers dominate a landscape.
Due to the range of tree sizes in a wilding invasion and all the needles and dry twigs on their branches create a ladder of easily ignitable ‘fuel’ that can exacerbate a fire.
Unlike managed plantations which have fire breaks, wilding conifers self-seed outside of a uniformed block and can grow in challenging terrain.
While a tree itself can’t start a fire, the risk does increase with human interaction.
A stand of pine trees among walking and biking trails, development, roading are a potential fire risk.
Over summer as our climate reaches extreme temperatures the risk of wildfires is a very real threat.
LAND USE
A national assessment of risk commissioned by the Ministry of Primary Industry (MPI) in 2016 showed approximately 70% of the Otago region as very highly vulnerable to wilding conifer infestation.
Pines grow well in our climate, they favour it.
A wilding pine invasion reduces the viability of using high country land for pastoral farming . Central Otago relies on its rural productive land for its social and economic well-being.
When they invade an area in numbers, they visually degrade the landscape and change the soil's composition, leaving it more acidic.
Livestock cannot be farmed under pine forest.
BIO-DIVERSITY
Wilding pines are prolific resource competitors.
As an introduced species they possess traits that give them a competitive advantage over native plants; efficiently acquire sunlight, water, and nutrients from the soil needed for survival and growth.
When situated next to a humble native, the conifer will suck more resources, leaving little for the native.
Central Otago homes endemic vulnerable alpine species which can easily be overthrown with the invasion of a wilding pine seedling.
Their ability to change the soil composition makes it less favourable for the developing natives.
Their ability to disperse and rapidly colonise areas can overwhelm an environment.
Conifer do not offer much food for wildlife which is why under a dense pine tree forest there is little birdlife.
The introduction of wilding conifers disrupts the natural balance of an ecosystem transforming it into a monoculture.
LANDSCAPE RECREATION
Landscapes are significantly altered when dense stands of wilding pines emerge.
Iconic views become obscured. Recreation and tourism opportunities are greatly reduced, and productive land uses require more intensive management to eliminate or suppress wilding pines.
Many people come to Central Otago because of the recreation opportunities that exist here; the rail trail biking, trout fishing, hunting, four-wheel driving, hikes and landscape and heritage photography. An appreciation of the outstanding landscape that exists in Central Otago is an important aspect of these recreation activities for many people.
Uncontrolled wilding spread on landscape would have significant adverse effects on the quality and enjoyment of these recreation pursuits.
The heightened fire risk with an increasingly wooded landscape in the dry Central Otago climate may also have consequences in landowners declining public access.
