Pinus contorta (lodgepole pine)
- Summary of Invasiveness
- Taxonomic Tree
- Notes on Taxonomy and Nomenclature
- Distribution Table
- History of Introduction and Spread
- Risk of Introduction
- Habitat List
- Biology and Ecology
- Latitude/Altitude Ranges
- Air Temperature
- Rainfall Regime
- Soil Tolerances
- Notes on Natural Enemies
- Means of Movement and Dispersal
- Pathway Causes
- Pathway Vectors
- Impact Summary
- Economic Impact
- Environmental Impact
- Threatened Species
- Risk and Impact Factors
- Uses List
- Wood Products
- Prevention and Control
- Gaps in Knowledge/Research Needs
- Distribution Maps
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PicturesTop of page
IdentityTop of page
Preferred Scientific Name
- Pinus contorta Douglas ex Loudon
Preferred Common Name
- lodgepole pine
- Pinus contorta var. bolanderi Lemmon
- Pinus contorta var. contorta
- Pinus contorta var. latifolia Engelm.
- Pinus contorta var. murrayana (Balf.) Engelm.
Other Scientific Names
- Pinus bolanderi Parl.
- Pinus contorta subsp. bolanderi (Parl.) Critchf.
- Pinus contorta subsp. latifolia (Engelm.) Critchf.
- Pinus contorta subsp. murrayana (Balf.) Critchf.
- Pinus latifolia Engelm.
- Pinus murrayana Balf.
International Common Names
- English: beach pine; lodgpole pine; shore pine
- French: pin tortille; pin vrille
Local Common Names
- North America: coast pine
- Canada: Rocky Mountain pine; shore pine
- Germany: Dreh- Kiefer
- Italy: pino contorto
- Sweden: strandtall
- USA: Rocky Mountain pine; shore pine; Sierra lodgepole pine; tamarack pine
- PIUCN (Pinus contorta)
- engelmann spruce-lodgepole pine
- lodgepole pine
- mixed species
- ponderosa pine-lodgepole pine
- western wood
- white woods
Summary of InvasivenessTop of page
P. contorta is a fast-growing, short-lived conifer tree native to western North America. It has a very wide ecological tolerance and is widely planted in the Americas, Europe and New Zealand, because of its forestry value and for erosion control. It is considered a major weed, ranked as on of the five most invasive pines by Rejmanek and Richardson (1996), and declared as a Class B noxious weed by the New Zealand government (Simberloff et al., 2010). It has been reported as invasive in New Zealand, Chile and Argentina. Its invasiveness is mainly due to its small anemochorous seed, high seed production, short juvenile period <10 years) and short intervals between large crops (Richardson and Rejmanek, 2004). Invasive behaviour of P. contorta is associated with disturbance events such as wildfires, which leaves habitats such as grasslands, open forests and pastures more susceptible to invasion (Richardson et al., 1994). It can change vegetation structure, alter fire regimes and negatively impact native herbs and shrubs, reducing richness, abundance and diversity in areas with higher pine cover.
Taxonomic TreeTop of page
- Domain: Eukaryota
- Kingdom: Plantae
- Phylum: Spermatophyta
- Subphylum: Gymnospermae
- Class: Pinopsida
- Family: Pinaceae
- Genus: Pinus
- Species: Pinus contorta
Notes on Taxonomy and NomenclatureTop of page
P. contorta is a 2-needled pine of the subgenus Pinus (distinguished by having much resin, close-grained wood, sheath of leaf cluster persistent and two vascular bundles in each needle), section Pinus, subsection Contortae, along with the North American species P. banksiana, P. virginiana and P. clausa (Little and Critchfield, 1969). The stiff, usually twisted needles are 2.5-7.6 cm long; cones are near branch tips, each cone scale with a short spine.
P. contorta has evolved into several highly differentiated but interfertile geographic races that differ morphologically and ecologically. Four subspecies or varieties are recognized: P. contorta subsp. contorta (a coastal form known as shore pine, coast pine or beach pine); P. contorta subsp. bolanderi (local form in Mendocino County, northwest California, endemic on podzol soils; called the Bolander pine); P. contorta subsp. murrayana (a western montane race found from the Cascades (Oregon) to Mexico, but primarily in the Sierra Nevada of California; called the Sierra lodgepole pine or tamarack pine); and Pinus contorta subsp. latifolia (the extensively distributed continental interior (Rocky Mountain) race; called the Rocky Mountain lodgepole pine or black pine) (Critchfield, 1957; Lotan and Critchfield, 1990).
DescriptionTop of page
P. contorta is a medium-sized tree, occasionally reaching 35 m in height with a d.b.h. of 60 cm. The trunk is straight with little taper, especially in dense stands where the live crowns are small. The crown is narrowly conical; branches are slender and short. The bark is relatively thin <2 cm thick) and orange-brown to grey with fine scales.
The root system of P. contorta is generally shallow, but a taproot and vertical sinkers develop on well-drained sites. Because of its shallow root system, P. contorta is susceptible to windfall, particularly after stands are opened by harvesting (Lotan and Critchfield, 1990). Roots are associated with both ecto- and endo-mycorrhizae (Minore, 1979).
The evergreen needles occur in bundles of two and are 3-6 cm long. They are usually twisted, stiff, very sharp pointed and a dark to yellowish-green (Farrar, 1995).
Inflorescences, flowers and fruits
P. contorta is a monoecious species, with female strobili most often at the apical end of main branches in the upper crown, and male strobili on older lateral branches of the lower crown. The female cones are reddish-purple and develop in whorls of two to five and are 10-12 mm long. The pollen cones are pale yellow to yellowish-orange and occur in crowded clusters at the base of new shoots and are 8-14 mm long (Lotan and Critchfield, 1990).
Cones are short cylindrical to ovoid, 3-6 cm long, purplish brown, stalkless in small clusters at the nodes and usually closed on the tree for 10-20 years (Schopmeyer, 1974; Satterlund, 1975; Critchfield, 1980).
Pollen generally matures during mid-May to mid-July and seed cones in August, September or October, more than a year after pollination. Inland forms and high elevation stands apparently mature earlier than coastal forms or low elevation stands. Cone maturity is indicated by a change in colour from purple-green to light brown (Burns and Honkala, 1990).
DistributionTop of page
P. contorta is native to western North America. It has been widely planted, mainly for commercial purposes, and its exotic distribution covers the Scandinavian region, Iceland, United Kingdom, central Europe, the Baltic Region, New Zealand, Turkey, Argentina and Chile.
Distribution TableTop of page
The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.Last updated: 21 Jul 2022
|Continent/Country/Region||Distribution||Last Reported||Origin||First Reported||Invasive||Planted||Reference||Notes|
|Denmark||Present||Introduced||Planted||Reported as invasive in dune heaths along the west coast of the Jutland peninsula|
|United Kingdom||Present||1853||Planted||Reported as invasive in England|
|-Scotland||Present||Introduced||Spreads in forests disturbed by sheep grazing|
|-Wyoming||Present||Invasive||Invading dry and mesic meadows in the subalpine plateaus of Yellowstone National Park|
|Argentina||Present||Introduced||1960||Invasive||Reported as invasive in the Patagonian steppe; also planted in Valdivian temperate forest|
|Chile||Present||Introduced||1970||Invasive||Reported in the Araucania Region (Natural Reserve Malalcahuello) and Aysen Region (Coyhaique)|
History of Introduction and SpreadTop of page
P. contorta has been intentionally introduced throughout Europe and in New Zealand. The first records of plantations are from Scandinavia, the UK and New Zealand between the 1880s and 1920s, when several trial plantations where established. Further plantations were established in New Zealand for commercial purposes or for erosion control (Richardson, 1998). In northern Europe, P. contorta was widely planted because it presented higher yield per ha and a faster growth than the native Scots pine (Pinus sylvestris) (Karlman, 1981).
IntroductionsTop of page
Risk of IntroductionTop of page
P. contorta is widely planted in temperate regions due to its commercial value. It spreads by seeds, which can be dispersed by wind and by humans (Richardson, 1998). Because this species is highly commercialized and there have been repeatedly introduced worldwide, the probability of colonizing new habitats remains high. In New Zealand, Chile and Argentina it has been reported as invasive (Simberloff et al., 2010). In New Zealand, the vigorous natural regeneration of P. contorta has caused it to spread throughout large areas, leading the government to declare it as a highly noxious weed (Ledgard, 2001).
HabitatTop of page
P. contorta prefers temperate and boreal climates. It has a wide ecological amplitude, to both climate and soil conditions, which allows it to survive in harsh environments (Juntunen, 2010). P. contorta seedlings are relatively resistant to frost injury and often survive in ‘frost-pockets’. The species has a habitat tolerance from sea level up to 3900 m above sea level, and is adapted to maritime, continental and subalpine conditions. The coastal form (var. bolanderi) grows mainly between sea level and 610 m, whereas the inland form (var. latifolia) occurs from 490 to 3660 m (Little, 1979; Lotan and Critchfield, 1990). In its native range (covering the ranges of the four P. contorta varieties), the minimum temperatures ranges between -57°C and 7°C, and maximum temperatures between 27°C and 38°C; annual precipitation varies between 250 and 500 mm (Lotan and Critchfield, 1990).
Iceland is the northernmost latitudinal area where the species has been planted, and Chile (Coyaique Province) is the southernmost area. Coyhaique Province has a continental trans-andean climate, with cold humid climate (Langdon et al., 2010).
P. contorta thrives in a wide variety of topographic situations. It grows well on gentle slopes and in basins, but good stands are also found on rough and rocky terrain and on steep slopes and ridges, including bare gravel.
The species grows on soils that vary widely, including dry and moist soils. However, drought is a leading factor in the loss of P. contorta seedlings during dry summers. Growth is best where soil parent materials are granites, shales, and coarse-grained lavas. Although fertile soils with high levels of nitrogen favour the growth of P. contorta, it can also grow on infertile soils (Despain, 2001; Elfving et al., 2001).
P. contorta is considered a pioneer species, and, owing to its capability to regenerate after fire and rapid growth when young, it is able to participate in several successional roles. Its relative shade intolerance and the reduced growth rate in old stands will often allow for replacement by secondary species in natural successions. The replacement age may vary considerably, and under poor site conditions P. contorta can remain dominant until the final climax stage (Elfving et al., 2001).
Habitat ListTop of page
|Terrestrial||Managed||Managed forests, plantations and orchards||Principal habitat||Harmful (pest or invasive)|
|Terrestrial||Managed||Managed forests, plantations and orchards||Principal habitat||Productive/non-natural|
|Terrestrial||Managed||Managed grasslands (grazing systems)||Secondary/tolerated habitat||Harmful (pest or invasive)|
|Terrestrial||Managed||Managed grasslands (grazing systems)||Secondary/tolerated habitat||Productive/non-natural|
|Terrestrial||Managed||Industrial / intensive livestock production systems||Secondary/tolerated habitat||Productive/non-natural|
|Terrestrial||Managed||Disturbed areas||Secondary/tolerated habitat||Harmful (pest or invasive)|
|Terrestrial||Managed||Disturbed areas||Secondary/tolerated habitat||Productive/non-natural|
|Terrestrial||Natural / Semi-natural||Natural forests||Principal habitat||Harmful (pest or invasive)|
|Terrestrial||Natural / Semi-natural||Natural forests||Principal habitat||Natural|
|Terrestrial||Natural / Semi-natural||Natural forests||Principal habitat||Productive/non-natural|
|Terrestrial||Natural / Semi-natural||Natural grasslands||Principal habitat||Harmful (pest or invasive)|
|Terrestrial||Natural / Semi-natural||Natural grasslands||Principal habitat||Productive/non-natural|
|Terrestrial||Natural / Semi-natural||Scrub / shrublands||Principal habitat||Harmful (pest or invasive)|
|Terrestrial||Natural / Semi-natural||Scrub / shrublands||Principal habitat||Productive/non-natural|
|Littoral||Coastal dunes||Secondary/tolerated habitat||Harmful (pest or invasive)|
|Littoral||Coastal dunes||Secondary/tolerated habitat||Productive/non-natural|
Biology and EcologyTop of page
Like all species in the genus Pinus and most species in the family Pinaceae, P. contorta has a haploid complement of n = 12 chromosomes (Wright, 1962). Wheeler and Guries (1982) compared seed and cone morphology with allozyme frequencies and found that, although 38% of the variation in cone morphology was due to differences among subspecies, and 19% due to variation among populations within subspecies, for allozymes only 3% of the variation was among subspecies and 6% among populations within subspecies.
In Canada, P. contorta subsp. latifolia hybridizes and introgresses with jack pine (P. banksiana) in both western Alberta and the Northwest Territories, where the two closely related species are sympatric and natural hybrids are commmon. P. contorta has been successfully crossed with Virginia pine (P. virginiana). Repeated efforts have been made to hybridize P. contorta with P. sylvestris (subsection Sylvestres), but these have resulted in only empty or inviable seed (Critchfield, 1980).
P. contorta is a prolific seed producer and has a short juvenile period. In its native range it produces abundant crops every 3-4 years and reaches maturity after less than 10 years (Lotan and Perry, 1983). In New Zealand, cones are produced annually, with abundant crops at irregular intervals (Ledgard, 2001). In New Zealand and Chile, coning has been reported from 5 year old trees (Ledgard, 2001; Peña et al., 2008). Seed dispersal is poor, with seeds typically staying within 100 m of the parent tree.
Ledgard (2001) proposed that rainfall is the major influence on age of seed production (age of first coning and number of cones) and fecundity, with higher rainfall decreasing fecundity. This suggestion followed field observations in New Zealand, where at low elevation and low rainfall sites (50 m and 700 mm annual rainfall), 10 % of lodgepole pines produced cones at age 5, 100% coned by age 8, and 11 year old trees carried an average of 70 cones per tree; whereas trees of identical origin and age planted at higher elevation and higher rainfall sites (850 m and 1250 mm) had 1.5% coning at age 6, 26% by age 8 and 80% by age 11, and where 8 year old trees had an average of 18 cones per tree (Ledgard 2001).
P. contorta can form viable seed banks by cone burial. 15 year after cone maturation, germination capacity decreased to 50%, compared with 98% when the cones first matured (Teste et al., 2011).
Some of the cones of P. contorta are serotinuos (closed) and benefit from wildfires. The serotinous cone habit changes between subspecies and among populations: in populations of P. contorta subsp. murrayana serotiny is rare; most populations of P. contorta subsp. contorta bear nonserotinous cones; and P. contorta subsp. borlanderi and P. contorta subsp. latifolia bear predominantly serotinous cones (Despain, 2001). In Oregon, USA, where the non-serotinous cone habit is prevalent, seedfall ranged from about 35,000 to over 1.2 million per ha (Dahms, 1963).
Physiology and phenology
Most seed dispersal is by wind in autumn. Even though germination of viable seeds is better in bare soil, drought and frost limit seedling establishment. In mountainous areas, such as in New Zealand and Coyhaique in Chile, the survival of conifer seedlings on bare mineral soil is usually very low due to frost heave over winter (Ledgard, 2001; Fajardo and Piper, 2014).
Under low light levels, the potential for natural regeneration is very low (only in dry and cold climates in canopy gaps). Natural regeneration is favoured in the open, especially after wildfires. Initial growth rates (under 5 years) are high, and can be more than 50 cm per year after the third growing season on productive sites.
In dense stands, P. contorta has a high self-pruning capacity and its crown spatial requirements are low. Light conditions beneath mature closed-canopy stands are high and associated with well-developed understorey vegetation.
The potential productivity of P. contorta is medium, with a site index (50 yrs at breast height) of less than 30 m. Growth declines after about 80-120 years. It generally lives for less than 300 years (Klinka et al., 1999).
Pines are known for mutualistic associations with several species of fungi. This association is crucial in seedling establishment, and has been considered a limitation in the establishment of pines in novel habitats. The closely related fungal genera Rhizopogon and Suillus both show host specificity to the Pinaceae (Nuñez et al., 2009). Pinus plantations in the southern hemisphere are dominated by nonnative ectomycorrhizal fungi, including Rhizopogon, Suillus, Thelephora, and Pisolithus (Tedersoo et al., 2007; Dickie et al., 2010). Dickie et al. (2010) studied the ectomycorrhizal fungal communities associated with the invasive species P. contorta in New Zealand, and found 14 ectomycorrhizal species associated with P. contorta, 93% of which were nonnative ectomycorrhizal species and 7% cosmopolitan fungi.
Growth is best where soil parent materials are granites, shales, and coarse-grained lavas. Although fertile soils with high levels of nitrogen favour the growth of P. contorta, it can also grow on infertile soils (Despain, 2001; Elfving et al., 2001).
ClimateTop of page
|C - Temperate/Mesothermal climate||Preferred||Average temp. of coldest month > 0°C and < 18°C, mean warmest month > 10°C|
|Cf - Warm temperate climate, wet all year||Preferred||Warm average temp. > 10°C, Cold average temp. > 0°C, wet all year|
|D - Continental/Microthermal climate||Preferred||Continental/Microthermal climate (Average temp. of coldest month < 0°C, mean warmest month > 10°C)|
|Df - Continental climate, wet all year||Preferred||Continental climate, wet all year (Warm average temp. > 10°C, coldest month < 0°C, wet all year)|
|E - Polar climate||Tolerated||Polar climate (Average temp. of warmest month < 10°C)|
|ET - Tundra climate||Tolerated||Tundra climate (Average temp. of warmest month < 10°C and > 0°C)|
Latitude/Altitude RangesTop of page
|Latitude North (°N)||Latitude South (°S)||Altitude Lower (m)||Altitude Upper (m)|
Air TemperatureTop of page
|Parameter||Lower limit||Upper limit|
|Absolute minimum temperature (ºC)||-60|
|Mean annual temperature (ºC)||-3||18|
|Mean maximum temperature of hottest month (ºC)||27||38|
|Mean minimum temperature of coldest month (ºC)||-57||7|
RainfallTop of page
|Parameter||Lower limit||Upper limit||Description|
|Dry season duration||0||3||number of consecutive months with <40 mm rainfall|
|Mean annual rainfall||250||5000||mm; lower/upper limits|
Rainfall RegimeTop of page
Soil TolerancesTop of page
- seasonally waterlogged
- very acid
Special soil tolerances
Notes on Natural EnemiesTop of page
In its native habitat, the American red squirrel (Tamiasciurus hudsonicus) is the most important predator of P. contorta seeds, with comsuption rates of 20% to 80% of annual production (Despain, 2001). The Douglas squirrel (Tamiasciurus douglasi) is common in North America where nonserotinous trees predominate, and T. hudsonicus where serotinous trees predominate (Lotan and Perry, 1983). Other predators include rodents, such as Peromyscus, Microtus, Clethrionomys and Eutamais, which gather the dispersed seeds, and some birds that scavenge some seeds from the forest floor. Seed- and cone-eating insects are not a major threat for P. contorta; three insects (Diorvetria abietella, Eucosma recissoriana, and Laspeyresia sp.) are known to attack the cones, but seed crops do not appear to be greatly reduced by these insects (Lotan and Perry, 1983; Despain, 2001).
In its introduced range, mortality of P. contorta by biotic vectors has been reported in plantations, caused by pine weevils, voles and parasitic fungi, some of which are also found in its native range. Of the parasitic fungi, the snow blight fungi Phacidium infestons, Scleroderris canker and Gremmeniella abietina are the most common in Scandinavia (Karlman, 2001; Hansson and Karlman, 2008). In Scotland, the pine beauty moth (Panolis flammea) has affected P. contorta plantations (Watt and Hicks, 2000).
In Sweden, vertebrate herbivores of P. contorta include voles, moose and the capercaillie (Tetrao urogallus). Voles eat the bark of seedlings and saplings, the moose the twigs, shoots of young trees and bark, and the capercaillie primarily the needles of old trees (Engelmark et al., 2001).
In New Zealand, there are no records of predation of seeds in cones, but on mineral soil, seed losses can be of up to 15%, due to insects and to a lesser extent mice (Ledgard, 2001). Also, seedlings and saplings are eaten by rabbits and sheep, which find P. contorta more palatable than other conifers (Crozier and Ledgard, 1990).
Means of Movement and DispersalTop of page
The winged seeds are dispersed mainly by wind. In North America, seeds have been recorded 60 m from the seed source, 8 km in New Zealand and 3 km in Argentina and Chile (Ledgard, 2001; Langdon et al., 2010).
P. contorta is extensively grown intentionally as an exotic tree for commercial purposes and has been introduced to Europe, New Zealand and South America.
Pathway CausesTop of page
|Forestry||Large plantations in the British Isles, Fennoscandia, Iceland and New Zealand||Yes||Elfving et al. (2001); Richardson (1998); Richardson et al. (2008); Simberloff et al. (2010)|
|Habitat restoration and improvement||Habitat restoration||Yes||Elfving et al. (2001); Richardson (1998); Richardson et al. (2008); Simberloff et al. (2010)|
|Timber trade||Deliberate introduction||Yes||Elfving et al. (2001); Richardson (1998); Richardson et al. (2008); Simberloff et al. (2010)|
Pathway VectorsTop of page
Impact SummaryTop of page
|Economic/livelihood||Positive and negative|
Economic ImpactTop of page
The economic impacts of P. contorta are in terms of plantation losses in Europe due to diseases of P. contorta; and in terms of costs incurred to control the invasion in New Zealand. In Europe there has been a major concern about emerging infections of sweet fern rust (Cronartium comptoniae) and canker fungus (Gremmeniella abietina), the latter affecting plantations in Sweden (Karlman, 2001; Stenlid et al., 2011). In Sweden, several outbreaks of G. abietina have severely damaged plantations of P. contorta, mainly in areas with harsh climate. Although the impact of this infection was economic, there is serious concern that these diseases will spread to native conifers (Karlman, 2001).
In New Zealand, great efforts have been made to eradicate P. contorta and prevent its spread, as well as raising social awareness of the problem (Ledgard, 2001). In dense areas of invasion the costs of eradication are NZ $100-$200/ha, and also require NZ $50-$100/ha for follow-up and maintenance. In very dense infestations in difficult habitats necessitating helicopters, intensive labour, expensive chemicals, or a combination of all these, costs range from NZ $1000 to $2500/ha (Williams and Timmins, 2002).
Environmental ImpactTop of page
Several impacts have been reported for the genera Pinus as an invasive, including affecting ecosystem processes and ecosystem services, such as the reduction in streamflow and modifying the nutrient cycle (van Wilgen et al., 2001; Symberloff et al., 2010).
For P. contorta, studies have confirmed that it has negative impacts in invaded grasslands and open forests in Chile (for more detail see Peña et al., 2008; Langdon et al., 2010; Urrutia et al., 2013; Cóbar-Carranza et al., 2014). Studies in the Malalcahuello National Reserve, south-central Chile, have concluded that the invasion of P. contorta has negative effects on the native forest, which consists of a low tree density forest formed by Nothofagus antarctica and Araucaria araucana, the latter of which is protected by IUCN and Chilean laws (Urrutia et al., 2013; Cóbar-Carranza et al., 2014). These negative effects include changes in vegetation structure, by the addition of a new structural element into the ecosystems, an increase in the vegetation density and biomass, changes in size and distribution of fuel, and an increase in flammability of vegetation, therefore potentially impacting the fire regime (Cóbar-Carranza et al., 2014). P. contorta also affects native herbs and shrubs, reducing richness, abundance and diversity in areas with higher pine cover (Urrutia et al., 2013). Similar results in vegetation biodiversity were found in New Zealand, where, during 30 years of invasion, species richness of grasses, herbs, shrubs, trees, ferns, mosses and lichens in invaded areas was reduced from 26 to 7 species, including the loss of all native species (Ledgard and Paul, 2008).
Threatened SpeciesTop of page
Risk and Impact FactorsTop of page
- Invasive in its native range
- Proved invasive outside its native range
- Has a broad native range
- Abundant in its native range
- Highly adaptable to different environments
- Is a habitat generalist
- Tolerates, or benefits from, cultivation, browsing pressure, mutilation, fire etc
- Pioneering in disturbed areas
- Fast growing
- Has high reproductive potential
- Has propagules that can remain viable for more than one year
- Has high genetic variability
- Damaged ecosystem services
- Ecosystem change/ habitat alteration
- Increases vulnerability to invasions
- Modification of fire regime
- Modification of successional patterns
- Monoculture formation
- Negatively impacts forestry
- Reduced native biodiversity
- Threat to/ loss of endangered species
- Threat to/ loss of native species
- Competition - monopolizing resources
- Competition - shading
- Rapid growth
- Highly likely to be transported internationally deliberately
- Difficult/costly to control
UsesTop of page
Outside of its native range P. contorta is an important forestry species, particularly in Europe where it is more productive than the native P. sylvestris. In Sweden, P. contorta stands were mainly planted for pulp and timber production (Elfving et al., 2001). In Sweden and Latvia, plantations are used for biomass production for biorefineries (Backlund and Bergsten, 2012; Jansons et al., 2013). In Estonia, plantations have been established for reclamation of oil shale mining areas, abandoned agricultural land and for afforestation (Kuznetzova et al., 2009).
In New Zealand, Chile and Denmark, P. contorta has been used for soil conservation, including the protection of slopes against erosion and for dune stabilization (Brockerhoff and Kay, 1998; Danish Forest and Nature Agency, 2007; Peña et al., 2008). Due to its fast growth and tolerance of poor soils P. contorta is often used for afforestation of abandoned and disturbed areas, and for soil improvement. In Iceland it is used for Christmas trees (Juntunen, 2010). Because of its invasive capacity, P. contorta is also considered a research model to understand the invasion process and impacts of pines.
Uses ListTop of page
- Erosion control or dune stabilization
- Land reclamation
- Soil conservation
- Soil improvement
- Research model
- Miscellaneous materials
- Christmas tree
Wood ProductsTop of page
- Short-fibre pulp
- Building poles
- Roundwood structures
Sawn or hewn building timbers
- Carpentry/joinery (exterior/interior)
- Exterior fittings
- For light construction
- Wall panelling
Prevention and ControlTop of page
Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.
In South America, where regulations for prevention and control of pine invasions are very weak, certification through the Forestry Stewardship Council (FSC) may be a promising means of reducing the threat of conifer invasions. The FSC-certification criteria permit the use of introduced species, although with stipulations that minimize damage from invasions (Simberloff et al., 2010).
In New Zealand, planting of appropriate pine species, avoiding planting in take-off sites for dispersal of seeds by wind, and ensuring appropriate management on adjacent land are considered essential for preventing the initial spread of pines (Richardson et al., 1994). Other preventative strategies include the removal of existing and potential sources of spread, discouraging the planting of P. contorta, promoting growth of surrounding vegetation, and grazing with sheep (Ledgard, 2001).
In New Zealand, because of the inaccessibility of the affected areas and the cost of eradication, containment is often the most practical option. Containment area management practices include the removal of source trees, planting two or three rows of less spread-prone species at the boundaries of an area of P. contorta, and hand pulling of young trees.
Eradication and Control
Physical removal is the major control measure in Australia; this is sometimes complemented by applying arboricides. In Kosciusko National Park, New South Wales, the complete removal of plantations of P. contorta, P. nigra and P. ponderosa was deemed necessary to eliminate the seed source of potential invasions (Richardson et al., 1994).
In New Zealand, the control of P. contorta includes aerial application of herbicides, grazing of seedlings and saplings, burning, and foliar application of herbicides (Richardson et al., 1994; Ledgard, 2009; Gous et al., 2014). Cutting below the lowest needles and removing all side branches, with or without the application of chemicals to the stump, has been the most successful method of eradicating invasive pines in New Zealand (Richardson et al., 1994; Ledgard, 2009). Trees can be destroyed before they are able to produce seed (Ledgard, 2001).
Brockerhoff and Kay (1998) suggested the use of biological control in New Zealand, using an insect species that feed on P. contorta cones. Based on host species, structure specificity and their impact on seed production, Conophthorus ponderosae (Scolytidae), Eucosma rescissoriana (Tortricidae) and Pissodes validirostris (Curculionidae) are the most promising biocontrol candidates.
Control of P. contorta is long-term and requires monitoring. All wilding control operations require at least two removal sweeps separated by 5-10 years to be successful (Ledgard, 2001; 2009).
Gaps in Knowledge/Research NeedsTop of page
There are few specific studies regarding the economic and environmental impacts of P. contorta, and there is no information available regarding social and cultural impacts.
ReferencesTop of page
Alexander RR, 1966. Site indexes for lodgepole pine with corrections for stand density: instructions for field use. Ft. Collins, Colorado, USA: Rocky Mountain For. and Range Exp. Station, USDA Forest Service Research Paper, RM-24.
Alexander RR; Tackle D; Dahms WG, 1967. Site indexes for lodgepole pine with corrections for stand density: methodology. Ft. Collins, Colorado, USA: Rocky Mountain For. and Range Exp. Station, USDA For. Serv., Res. Pap. RM-29.
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17/09/14 datasheet updated by:
Ana Jose Cobar, University of Concepcion, Chile
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