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.
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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.
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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%.
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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.
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Wilding pines also affect our hydroelectricity dams which rely on water flow from up stream.
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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.
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The wildfire risk increases when wilding conifers dominate a landscape.
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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.
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Unlike managed plantations which have fire breaks, wilding conifers self-seed outside of a uniformed block and can grow in challenging terrain.
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While a tree itself can’t start a fire, the risk does increase with human interaction.
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A stand of pine trees among walking and biking trails, development, roading are a potential fire risk.
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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.
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Pines grow well in our climate, they favour it.
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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.
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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.
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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.
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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.
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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.
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The heightened fire risk with an increasingly wooded landscape in the dry Central Otago climate may also have consequences in landowners declining public access.
