Mexican weeping pine (Pinus patula)

Present distribution

Scientific name:	Pinus patula Schiede ex Schltdl. & Cham
Common name(s):	Mexican weeping pine

Map showing the present distribution of this weed.

Habitat:

Forests, woodlands and grasslands. Invasive pest along forest margins and in high rainfall woodland (FAO 2009). In Hawaii it is replacing the native
alpine grassland. Dislikes poorly drained moorland soils, established plants tolerate drought. This species is not hardy in the colder areas of the
country; it tolerates temps down to -5 to -10ºC (Wiki 2009).

Potential distribution

Potential distribution produced from CLIMATE modelling refined by applying suitable landuse and vegetation type overlays with CMA boundaries

Map Overlays Used

Land Use:
Forestry; pasture dryland; pasture irrigation

Ecological Vegetation Divisions
Grassy/heathy dry forest; lowland forest; foothills forest; forby forest; damp forest; riparian; wet forest; rainforest; high altitude shrubland/woodland; granitic hillslopes; western plains woodland; alluvial plains grassland

Colours indicate possibility of Pinus patula infesting these areas.

In the non-coloured areas the plant is unlikely to establish as the climate, soil or landuse is not presently suitable.

map showing the potential distribution of pinus patula

Red= Very high	Orange = Medium
Yellow = High	Green = Likely

Impact

QUESTION	COMMENTS	RATING	CONFIDENCE
Social
1. Restrict human access?	Tree, to 40 m (FLOZ 2009). Often found in pure dense stands (WAF 2009). Potential to significantly restrict access. High nuisance value. People and/or vehicles access with difficulty.	MH	MH
2. Reduce tourism?	Unlikely. Aesthetics affected. Minor effects to aesthetics and/or recreational uses (i.e. aware but not bothered or activity inhibited).	ML	M
3. Injurious to people?	Early growth is quite rapid but, in England, once trees reach a good size they blow down or die (PFAF 2009). Injury is possible from senescence, falling branches and debris.	MH	M
4. Damage to cultural sites?	Early growth is quite rapid but, in England, once trees reach a good size they blow down or die (PFAF 2009). Falling trees and branches may damage cultural structures.	MH	M
Abiotic
5. Impact flow?	No information.	M	L
6. Impact water quality?	No information.	M	L
7. Increase soil erosion?	Seedlings do not produce a deep enough root system to be able to survive the 1st dry season (WAF 2009). Early growth is quite rapid but, in England, once trees reach a good size they blow down or die (PFAF 2009). Likely to cause soil erosion after toppling. Moderate probability of large scale soil movement	ML	MH
8. Reduce biomass?	Tree, to 40 m (FLOZ 2009). Often found in pure dense stands (WAF 2009). Biomass may increase.	L	MH
9. Change fire regime?	No information.	M	L
Community Habitat
10. Impact on composition (a) high value EVC	EVC = Plains Grassy Woodland (E); CMA =Corangamite; Bioregion =Central Victorian Uplands; VH CLIMATE potential. Major displacement of some dominant spp. within a strata/layer (or some dominant spp. within different layers).	MH	H
(b) medium value EVC	EVC = Wet heathland (D); CMA =West Gippsland; Bioregion =Gippsland Plains; VH CLIMATE potential. Minor displacement of some dominant or indicator spp. within any one strata/layer (e.g. ground cover, forbs, shrubs & trees).	ML	H
(c) low value EVC	EVC = Heathy Woodland (LC); CMA = Glenelg Hopkins; Bioregion =Glenelg Plain; VH CLIMATE potential. Major displacement of some dominant spp. within a strata/layer (or some dominant spp. within different layers).	MH	H
11. Impact on structure?	The species is an aggressive invader in medium- to high-altitude areas (above 1500 masl. in Zimbabwe and above 1 200 masl. in South Africa)…Pines increase the acidity of the soil, which may seriously threaten the indigenous biodiversity (FAO 2009). The tree is invasive because it forms dense pure stands that shade out native herbaceous plants and shrubs (Weber 2003). Minor effect on >60% of the layers or major effect on < 60% of the floral strata.	MH	MH
12. Effect on threatened flora?	The species has invaded afromontane forests, miombo woodlands, and grasslands…Invasive pest along forest margins and in high rainfall woodland (FAO 2009). In Hawaii it is replacing the native alpine grassland (Wiki 2009). “Several endemic plant species are threatened by expanding populations of this tree in Malawi” (Weber 2009). Replacement or at least population reductions are likely.	MH	M
Fauna
13. Effect on threatened fauna?	In Hawaii it is replacing the native alpine grassland (Wiki 2009). Pines increase the acidity of the soil, which may seriously threaten the indigenous biodiversity (FAO 2009). The tree is invasive because it forms dense pure stands that shade out native herbaceous plants and shrubs (Weber 2003). Reduction of habitat/ food likely. Reduction in habitat for threatened spp, leading to reduction in numbers of individuals, but not to local extinction.	MH	M
14. Effect on non-threatened fauna?	In Hawaii it is replacing the native alpine grassland (Wiki 2009). Pines increase the acidity of the soil, which may seriously threaten the indigenous biodiversity (FAO 2009). The tree is invasive because it forms dense pure stands that shade out native herbaceous plants and shrubs (Weber 2003). Reduction of habitat/ food likely. Reduction in habitat for fauna spp., leading to reduction in numbers of individuals, but not to local extinction.	MH	MH
15. Benefits fauna?	No information.	M	L
16. Injurious to fauna?	No information.	M	L
Pest Animal
17. Food source to pests?	Pests include leaf-eating adult beetles, adult bark beetles (mottled pine bark weevil) and sucking insects such as pine woolly aphid. Diseases of P. patula include foliage leaf cast, tip die-back of the branches and armillaria root rot (WAF 2009). Supplies food for one or more minor pest species (e.g. blackbirds or environmental insect pests).	ML	MH
18. Provides harbour?	No information	M	L
Agriculture
19. Impact yield?	Unlikely to impact yield. Little or negligible effect on quantity of yield.	L	M
20. Impact quality?	In Hawaii it is replacing the native alpine grassland (Wiki 2009). Has the potential to reduce food for livestock. Minor impact on quality of produce (e.g. < 5% reduction).	ML	M
21. Affect land value?	In Hawaii it is replacing the native alpine grassland (Wiki 2009). Likely to be a pest especially in pasture, but control is possible (FAO 2009). Unlikely to affect land value. Little or none.	L	M
22. Change land use?	No information.	M	L
23. Increase harvest costs?	In Hawaii it is replacing the native alpine grassland (Wiki 2009). Chemical and mechanical control is possible (FAO 2009). Likely to significantly increase production costs. Minor increase in cost of harvesting – e.g. slightly more time or labour is required.	MH	M
24. Disease host/vector?	Diseases of P. patula include foliage leaf cast, tip die-back of the branches and armillaria root rot. (WAF 2009). Likely to provide harbour to these pests which could negatively affect production forestry. Provides host to minor (or common) pests, or diseases.	M	MH

Invasive

QUESTION	COMMENTS	RATING	CONFIDENCE
Establishment
1. Germination requirements?	“Seedlings establish especially well in disturbed sites”. The tree is invasive because it forms dense pure stands that shade out native herbaceous plants and shrubs (Weber 2003). The species has invaded afromontane forests, miombo woodlands, and grasslands. Invasive pest along forest margins and in high rainfall woodland (FAO 2009). In Hawaii it is replacing the native alpine grassland (Wiki 2009). Is able to germinate and establish in grassland, and forest understory. Requires natural seasonal disturbances such as seasonal rainfall, spring/summer temperatures for germination.	MH	MH
2. Establishment requirements?	It is generally restricted to moist temperate to sub-humid temperate climates, although it has also been recorded in subtropical climates. The species thrives on a wide variety of soils, including those derived from dolerite, granite, dolomite, quartzite and sandstone…The species has invaded afromontane forests, miombo woodlands, and grasslands…Invasive pest along forest margins and in high rainfall woodland (FAO 2009). In Hawaii it is replacing the native alpine grassland (Wiki 2009). Can establish under moderate canopy/litter cover.	MH	MH
3. How much disturbance is required?	“Seedlings establish especially well in disturbed sites” (Weber 2009). Invasive pest along forest margins and in high rainfall woodland (FAO 2009). In Hawaii it is replacing the native alpine grassland (Wiki 2009). Establishes in relatively intact or only minor disturbed natural ecosystems (e.g. wetlands, riparian, riverine, grasslands, open woodlands); in vigorously growing crops or in well-established pastures.	MH	MH
Growth/Competitive
4. Life form?	Tree (FAO 2009). Other.	L	H
5. Allelopathic properties?	The needles contain a substance called terpene, this is released when rain washes over the needles and it has a negative effect on the germination of some plants, including wheat (PFAF 2009). Allelopathic properties seriously affecting some plants.	MH	MH
6. Tolerates herb pressure?	The majority of insect pests that cause damage to P. patula are defoliators (WAF 2009). Is damaged by herbivory. Not enough information. Consumed and recovers slowly.	ML	M
7. Normal growth rate?	Early growth is quite rapid but, in England, once trees reach a good size they blow down or die (PFAF 2009). Moderately rapid growth that will equal competitive species of the same life form.	MH	MH
8. Stress tolerance to frost, drought, w/logg, sal. etc?	Thrives in a light well-drained sandy or gravelly loam, dislikes poorly drained moorland soils, established plants tolerate drought. This species is not hardy in the colder areas of the country; it tolerates temperatures down to between -5 and -10°C. Plants usually form multi-stemmed trees in Britain due to frost damage (PFAF 2009). It does not stand long periods of temperatures as low as –10°C (Wiki 2009). The common soil features include acidity and good moisture supply (WAF 2009). Tolerant to at least two and susceptible to at least one.	ML	MH
Reproduction
9. Reproductive system	Plants are strongly out breeding, self-fertilized seed usually grows poorly (PFAF 2009). Sexual (either cross or self-pollination).	L	MH
10. Number of propagules produced?	Is a prolific seeder every year and its seed averages only 0.127 seeds per milligram (FAO 2009). 143 000 seeds/kg (WAF 2009). Likely to be over 2000.	H	MH
11. Propagule longevity?	The seed may remain in the cone for seven years with loss of viability of less than 40 percent (FAO 2009). Greater than 25% of seeds survive 5-10 years in the soil.	ML	M
12. Reproductive period?	Viable seed being set by the fifth year (FAO 2009). Pine of this size would live over 100 years (estimate). Mature plant produces viable propagules for 10 years or more	H	MH
13. Time to reproductive maturity?	Pinus patula is a precocious species, flowering as early as two years, with viable seed being set by the fifth year. (FAO 2009). 2-5 years to reach sexual maturity.	ML	MH
Dispersal
14. Number of mechanisms?	Paired seeds at base of cone scale, triangular, mottled gray, 0.2 inches long with a 0.75 inch wing…Wind dispersed. Escaping from forest plantings into surrounding forests (HEAR 2009). The seed, which is winged, is blown by wind for several kilometres (FAO 2009). Very light, wind dispersed seeds.	H	H
15. How far do they disperse?	The seed, which is winged, is blown by wind for several kilometres (FAO 2009). Very likely that at least one propagule will disperse greater one kilometre.	H	MH

References

ECOS (2009) ECOS: Tree Species Effects on Ecosystem Processes. Description of Pinus patula. Available at http://www.nrem.iastate.edu/ECOS/Species/PinusPatul.html (viewed 17/06/09)

FAO (2009) Food and Agriculture Organization of the United Nations: Case studies of two invasive alien tree species in southern Africa. Available at
http://www.fao.org/DOCREP/005/AC846E/ac846e09.htm (viewed 17/06/09)

FLOZ (2009) Flora of Zimbabwe. Pinus patula. Available at http://www.zimbabweflora.co.zw/speciesdata/species.php?species_id=102970 (viewed 17/06/09)

Hear (2009) HEAR: Pinus patula as a weed. Available at: http://www.hear.org/species/pinus_patula/ (viewed 17/06/09).

PFAF (2009) Plants for a future. Pinus patula. Available at: http://www.ibiblio.org/pfaf/cgi-bin/arr_html?Pinus+patula (viewed 17/06/2009).

WAF (2009) World Agroforestry Centre. Pinus patula. Available at: http://www.worldagroforestrycentre.org/sea/products/afdbases/af/asp/SpeciesInfo.asp?SpID=1306 (viewed 17/06/2009).

Weber, E. (2003) Invasive plant species of the world. A reference guide to environmental weeds. CABI publishing.

Wiki (2009) Wikipedia: Pinus patula. Available at http://en.wikipedia.org/wiki/Pinus_patula (viewed 17/06/2009).

Global present distribution data references

Australian National Herbarium (ANH) (2009) Australia’s Virtual Herbarium, Australian National Herbarium, Centre for Plant Diversity and Research, Available at http://www.anbg.gov.au/avh/ (verified 25/06/2009).

Department of the Environment and Heritage (Commonwealth of Australia). (1993 – On-going) Australian Plant Name Index (APNI)
http://www.cpbr.gov.au/apni/index.html (verified 15/06/2009).

Department of Sustainability and Environment (DSE) (2006) Flora information system [CD-ROM], Biodiversity and Natural Resources Section, Viridans Pty Ltd, Bentleigh.

Global Biodiversity Information Facility (GBIF) (2008) Global biodiversity information facility, Available at http://www.gbif.org/ (verified 15/06/2009).

Integrated Taxonomic Information System. (2008) Available at http://www.itis.gov/ (verified 15/06/2009).

Missouri Botanical Gardens (MBG) (2009) w³TROPICOS, Missouri Botanical Gardens Database, Available at http://mobot.mobot.org/W3T/Search/vast.html (verified 15/06/2009).

Royal Botanic Gardens Melbourne. (2003) Census of Vascular Plants of Victoria. Available at
http://www.rbg.vic.gov.au/research_and_conservation/plant_information/viclist (verified 15/06/2009).

United States Department of Agriculture. Agricultural Research Service, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN) [Online Database]. Taxonomy Query. (2009) Available at http://www.ars-grin.gov/cgi-bin/npgs/html/taxgenform.pl (verified 15/06/2009).

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