Pacific Island Ecosystems at Risk (PIER)


Magnolia grandiflora


RISK ASSESSMENT RESULTS: Low risk, score: 0


Australian/New Zealand Weed Risk Assessment adapted for Hawai‘i.

Research directed by C. Daehler (UH Botany) with funding from the Kaulunani Urban Forestry Program and US Forest Service

Information on Risk Assessments
Original risk assessment

Magnolia grandiflora; southern magnolia

Answer

1.01

Is the species highly domesticated?

y=-3, n=0

n

1.02

Has the species become naturalized where grown?

y=-1, n=-1

y

1.03

Does the species have weedy races?

y=-1, n=-1

n

2.01

Species suited to tropical or subtropical climate(s) (0-low; 1-intermediate; 2-high) – If island is primarily wet habitat, then substitute “wet tropical” for “tropical or subtropical”

See Append 2

1

2.02

Quality of climate match data (0-low; 1-intermediate; 2-high) see appendix 2

2

2.03

Broad climate suitability (environmental versatility)

y=1, n=0

n

2.04

Native or naturalized in regions with tropical or subtropical climates

y=1, n=0

n

2.05

Does the species have a history of repeated introductions outside its natural range? y=-2

?=-1, n=0

y

3.01

Naturalized beyond native range y = 1*multiplier (see Append 2), n= question 2.05

y

3.02

Garden/amenity/disturbance weed y = 1*multiplier (see Append 2)

n=0

n

3.03

Agricultural/forestry/horticultural weed y = 2*multiplier (see Append 2)

n=0

n

3.04

Environmental weed y = 2*multiplier (see Append 2)

n=0

n

3.05

Congeneric weed y = 1*multiplier (see Append 2)

n=0

n

4.01

Produces spines, thorns or burrs

y=1, n=0

n

4.02

Allelopathic

y=1, n=0

4.03

Parasitic

y=1, n=0

n

4.04

Unpalatable to grazing animals

y=1, n=-1

4.05

Toxic to animals

y=1, n=0

n

4.06

Host for recognized pests and pathogens

y=1, n=0

n

4.07

Causes allergies or is otherwise toxic to humans

y=1, n=0

n

4.08

Creates a fire hazard in natural ecosystems

y=1, n=0

n

4.09

Is a shade tolerant plant at some stage of its life cycle

y=1, n=0

y

4.1

Tolerates a wide range of soil conditions (or limestone conditions if not a volcanic island)

y=1, n=0

y

4.11

Climbing or smothering growth habit

y=1, n=0

n

4.12

Forms dense thickets

y=1, n=0

n

5.01

Aquatic

y=5, n=0

n

5.02

Grass

y=1, n=0

n

5.03

Nitrogen fixing woody plant

y=1, n=0

n

5.04

Geophyte (herbaceous with underground storage organs -- bulbs, corms, or tubers)

y=1, n=0

n

6.01

Evidence of substantial reproductive failure in native habitat

y=1, n=0

n

6.02

Produces viable seed.

y=1, n=-1

y

6.03

Hybridizes naturally

y=1, n=-1

6.04

Self-compatible or apomictic

y=1, n=-1

y

6.05

Requires specialist pollinators

y=-1, n=0

n

6.06

Reproduction by vegetative fragmentation

y=1, n=-1

n

6.07

Minimum generative time (years) 1 year = 1, 2 or 3 years = 0, 4+ years = -1

See left

4

7.01

Propagules likely to be dispersed unintentionally (plants growing in heavily trafficked areas)

y=1, n=-1

n

7.02

Propagules dispersed intentionally by people

y=1, n=-1

y

7.03

Propagules likely to disperse as a produce contaminant

y=1, n=-1

n

7.04

Propagules adapted to wind dispersal

y=1, n=-1

n

7.05

Propagules water dispersed

y=1, n=-1

7.06

Propagules bird dispersed

y=1, n=-1

y

7.07

Propagules dispersed by other animals (externally)

y=1, n=-1

n

7.08

Propagules survive passage through the gut

y=1, n=-1

y

8.01

Prolific seed production (>1000/m2)

y=1, n=-1

n

8.02

Evidence that a persistent propagule bank is formed (>1 yr)

y=1, n=-1

8.03

Well controlled by herbicides

y=-1, n=1

8.04

Tolerates, or benefits from, mutilation, cultivation, or fire

y=1, n=-1

n

8.05

Effective natural enemies present locally (e.g. introduced biocontrol agents)

y=-1, n=1

Total score:

0

Supporting data:

Source

Notes

1.01

no evidence

1.02

Basinger, M. A. (1999) Notes on some naturalized woody plant species new to Illinois. Transactions of the Illinois State Academy of Science, 1999, Vol.92, No.1/2, pp.33-36, 16 ref.

AB: The first known naturalized occurrences of Acer campestre, A. palmatum, Magnolia grandiflora, Phyllostachys aureus [P. aurea] and Viburnum dilatatum in Illinois, USA, are reported from Jackson County. Ilex opaca , a native shrub thought to be extirpated, is reported as an adventive member of the flora. These 6 species have become naturalized from original plantings at Marberry Arboretum and/or Southern Illinois University at Carbondale and several have potential to become future invasive species.

1.03

no evidence

2.01

Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7.

Native Habitat:
Southeastern US to south-central Florida in rich, moist bottomland soils, near swamps, occasionally in dry sandy soil on dunes near the beach. Never above 500 feet elevation. Not able to stand prolonged flooding. Native to the following North American places: Alabama, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee

2.02

2.03

(1)Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7. (2)http://hort.ifas.ufl.edu/trees/MAGGRAA.pdf (3)http://www.floridata.com/ref/m/magno_g.cfm (4)http://plants.gardenbed.com/40/3980_gen.asp (5)http://mgonline.com/magnolia.html

(1)Hardiness Range 6B to 10A
Native Habitat: Southeastern US to south-central Florida in rich, moist bottomland soils, near swamps, occasionally in dry sandy soil on dunes near the beach. Never above 500 feet elevation. Not able to stand prolonged flooding. Native to the following North American places: Alabama, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee (2)USDA hardiness zones: 7 through 10A (3)his native American tree occurs on the coastal plain from North Carolina, south to central Florida, and west to east Texas. It grows best along streams and near swamp margins (4)Hammocks, sand dunes, buffs and sandy bottoms[72].Rich moist soils[227]. Always found in lowland areas, never above 105 metres altitude (5)Magnolia is not really happy in South Florida's zone 10, preferring cooler winter temperatures.

2.04

Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7.

Native Habitat:
Southeastern US to south-central Florida in rich, moist bottomland soils, near swamps, occasionally in dry sandy soil on dunes near the beach. Never above 500 feet elevation. Not able to stand prolonged flooding. Native to the following North American places: Alabama, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee

2.05

(1) Yang, M. H.; Blunden, G.; Patel, A. V.; O'Neill, M. J.; Lewis, J. A. (1994) Coumarins and sesquiterpene lactones from Magnolia grandiflora leaves. Planta Medica, 1994, Vol.60, No.4, p.390, 5 ref.
(2) Luo XiaoDong; Wu ShaoHua; Ma YunBao; Wu DaGang; Zhou Jun (2001) Sesquiterpenoids from Magnolia grandiflora . Planta Medica, 2001, Vol.67, No.4, pp.354-357, 12 ref.
(3) Garg, S. N.; Sushil Kumar (1999) Volatile constituents from the flowers of Magnolia grandiflora L. from Lucknow, India. Journal of Essential Oil Research, 1999, Vol.11, No.5, pp.633-634, 10 ref.
(4) Sesan, T.; Oprea, M. (1991) Fungi involved in decline of some ornamental trees in Romania. [FT: Ciuperci implicate în uscarea unor arbori ornamentali din România.] Studii si Cercetri de Biologie, Biologie Vegetal., 1991, Vol.43, No.1-2, pp.19-21, 6 ref.
(5) Kazimirova, R. N.; Evtushenko, A. P. (1989) Characteristics of the root systems of ground cover plants and transplants of introduced species. Byulleten' Gosudarstvennogo Nikitskogo Botan

(1) UK, (2) China, (3) India, (4) Romania, (5) Ukraine, (6) Spain

3.01

Basinger, M. A. (1999) Notes on some naturalized woody plant species new to Illinois. Transactions of the Illinois State Academy of Science, 1999, Vol.92, No.1/2, pp.33-36, 16 ref.

AB: The first known naturalized occurrences of Acer campestre, A. palmatum, Magnolia grandiflora, Phyllostachys aureus [P. aurea] and Viburnum dilatatum in Illinois, USA, are reported from Jackson County. Ilex opaca , a native shrub thought to be extirpated, is reported as an adventive member of the flora. These 6 species have become naturalized from original plantings at Marberry Arboretum and/or Southern Illinois University at Carbondale and several have potential to become future invasive species.

3.02

no evidence

3.03

no evidence

3.04

no evidence

3.05

no evidence

4.01

Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7.

Trunk has no thorns

4.02

http://johnston.ces.state.nc.us/newsletters/homehort/may99.html

The fallen leaves are very slow to decay. The decaying leaves as

well as the roots are allelopathic. [no evidence provided]

4.03

no evidence

4.04

no evidence

4.05

no evidence

4.06

Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7.

Pests and Diseases
Pests: Scales are common on some trees in the woods and landscape. Borers and weevils can be somewhat troublesome.
Diseases: Magnolia may be subject to leaf spots, blights, scabs and black mildews caused by a large number of fungi, or a bacterium but they rarely require chemical controls. Algae can also cause gray leaf spots. Canker diseases will kill branches. Verticillium wilt may cause death of a few branches or, rarely, may kill the tree.

4.07

no evidence

4.08

unlikely, massive tree, leaves are shiny and green above and brown and hairy on the underside.

4.09

Lin Jie; Harcombe, P. A.; Fulton, M. R. (2001) Characterizing shade tolerance by the relationship between mortality and growth in tree saplings in a southeastern Texas forest. Canadian Journal of Forest Research, 2001, Vol.31, No.2, pp.345-349, 21 ref. (2)http://www.floridata.com/ref/m/magno_g.cfm

(1)We investigated the relationship between shade tolerance and sapling mortality using data collected over 15 years (from 1981) in a mesic forest in southeastern Texas, USA. Seven species representing a range of shade tolerance classes were included in the study. In increasing order of shade tolerance these were: (1) sweetgum (Liquidambar styraciflua ); (2) red maple (Acer rubrum ); (3) blackgum (Nyssa sylvatica ); (4) southern magnolia (Magnolia grandiflora ); (5) flowering dogwood (Cornus florida ); (6) American holly (Ilex opaca ); and (7) American beech (Fagus grandifolia ). We used survival analysis to estimate species-specific sapling mortality risk (hazard) as a function of recent radial growth. We found that shade intolerant species had higher mortality risk at zero growth than shade tolerant species. The results strongly support the point that shade tolerance can be characterized by the relationship between sapling mortality and growth. (2)Full sun to partial shade.

4.1

Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7.

Soil Condition: Loamy, sandy, clay, acidic, neutral, slightly alkaline, tolerates salt, somewhat drought tolerant, tolerates wetness

4.11

Dehgan, B. (1998) Landscape Plants for Subtropical Climates. University Press of Florida., Gainesville, FL. 638pp. p.437

tree

4.12

no evidence

5.01

terrestrial

5.02

tree; Magnoliaceae

5.03

no evidence

5.04

tree

6.01

no evidence

6.02

Shafi Bhat, M.; Jhon, A. Q.; Lone, A. H. (1991) Propagation of Magnolia grandiflora through seed. Progressive Horticulture, 1991, Vol.23, No.1-4, pp.30-33, 6 ref.

AB: M. grandiflora seeds were treated with BA or GA3 at 0, 50, 100 or 200 mg/litre prior to sowing in Nov., Dec., Jan., Feb. or Mar. Growth regulator treatments significantly increased germination compared with the control. Highest germination (51.06%) was obtained with 50 mg BA/litre, followed by 50 mg GA3/litre (45.80%). Of the sowing dates, highest germination (56.92%) was obtained in Jan., followed by Dec. (55.79%). The interaction between growth regulator treatment and sowing date had a significant effect on germination. Highest germination (79.66%) was obtained with seeds treated with 50 mg BA/litre and sown in Dec. followed by the same treatment and a Jan. sowing.

6.03

Kehr, A. E.; Galyon, F. B.; Stansberry, M. (1992) A new hybrid of M. grandiflora x M. sieboldii . Magnolia, 1992, Vol.28, No.1, pp.18-24, 3 ref.

AB: Pollen of Magnolia sieboldii cv. Genesis was applied to stigmas of M. grandiflora cv. Little Gem in 1988. Although the 2 hybrids obtained have not yet flowered, they show distinctive secondary venation on the upper surface of the leaves which is intermediate between the extremely coarse venation of the pollen parent and the extremely fine venation of Little Gem.

6.04

Allain, L. K.; Zavada, M. S.; Matthews, D. G. (1999) The reproductive biology of Magnolia grandiflora . Rhodora, 1999, Vol.101, No.906, pp.143-162, 50 ref.

AB: The reproductive biology of Magnolia grandiflora was investigated at three localities in south Louisiana. Over the 3-4 day flowering period, the flowers of M. grandiflora exhibited changes in sex expression (protogyny), stigmatic receptivity (self- and cross-compatibility to self-incompatibility), UV reflectance (strong reflectance of the stigmas to strong reflectance of the androphore), and pollinator reward (a hexose-dominated stigmatic nectar to pollen). Although beetles were occasional floral visitors and carried pollen, bees (non-native Apis mellifera and indigenous Lasioglossum bruneri ) were frequent floral visitors and were the only floral visitors whose behavior showed any correlation with the array of floral changes that occurred over the 3-4 day flowering period.

6.05

Allain, L. K.; Zavada, M. S.; Matthews, D. G. (1999) The reproductive biology of Magnolia grandiflora . Rhodora, 1999, Vol.101, No.906, pp.143-162, 50 ref.

AB: The reproductive biology of Magnolia grandiflora was investigated at three localities in south Louisiana. Over the 3-4 day flowering period, the flowers of M. grandiflora exhibited changes in sex expression (protogyny), stigmatic receptivity (self- and cross-compatibility to self-incompatibility), UV reflectance (strong reflectance of the stigmas to strong reflectance of the androphore), and pollinator reward (a hexose-dominated stigmatic nectar to pollen). Although beetles were occasional floral visitors and carried pollen, bees (non-native Apis mellifera and indigenous Lasioglossum bruneri ) were frequent floral visitors and were the only floral visitors whose behavior showed any correlation with the array of floral changes that occurred over the 3-4 day flowering period.

6.06

no evidence

6.07

Greene, T. A. (1991) Family differences in growth and flowering in young southern magnolia. HortScience, 1991, Vol.26, No.3, pp.302-304, 9 ref.

AB: Height and caliper (age 3 years) and flower count (age 3.5 years) were evaluated for 36 open-pollinated families of Magnolia grandiflora outplanted in 2 genetic tests in Bexar County, Texas. Significant family differences existed for height, caliper, number of flowers per tree and percentage of trees flowering in both tests. Family heritability estimates for all traits ranged from 0.72 to 0.92. Coefficients of genetic prediction (CGP) between growth and flowering characteristics were small but positive; CGP between height and percentage of trees flowering was 0.28 and 0.24 in the 2 tests. Early growth rate and flowering appeared to be under strong genetic control; thus, improvement through selection would be efficient. However, both traits should be evaluated since the genetic relationship between them was weak. [requires several months for seeds to mature]

7.01

no evidence

7.02

(1) Yang, M. H.; Blunden, G.; Patel, A. V.; O'Neill, M. J.; Lewis, J. A. (1994) Coumarins and sesquiterpene lactones from Magnolia grandiflora leaves. Planta Medica, 1994, Vol.60, No.4, p.390, 5 ref.
(2) Luo XiaoDong; Wu ShaoHua; Ma YunBao; Wu DaGang; Zhou Jun (2001) Sesquiterpenoids from Magnolia grandiflora . Planta Medica, 2001, Vol.67, No.4, pp.354-357, 12 ref.
(3) Garg, S. N.; Sushil Kumar (1999) Volatile constituents from the flowers of Magnolia grandiflora L. from Lucknow, India. Journal of Essential Oil Research, 1999, Vol.11, No.5, pp.633-634, 10 ref.
(4) Sesan, T.; Oprea, M. (1991) Fungi involved in decline of some ornamental trees in Romania. [FT: Ciuperci implicate în uscarea unor arbori ornamentali din România.] Studii si Cercetri de Biologie, Biologie Vegetal., 1991, Vol.43, No.1-2, pp.19-21, 6 ref.
(5) Kazimirova, R. N.; Evtushenko, A. P. (1989) Characteristics of the root systems of ground cover plants and transplants of introduced species. Byulleten' Gosudarstvennogo Nikitskogo Botan

(1) UK, (2) China, (3) India, (4) Romania, (5) Ukraine, (6) Spain

7.03

no evidence

7.04

no evidence

7.05

commonly grows along riverbanks

7.06

Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7.

Fruit is edible by birds

7.07

no evidence

7.08

dispersed by birds

8.01

USDA, NRCS. 2001. The PLANTS Database, Version 3.1 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

Fruit/Seed Abundance: Medium
Seed per Pound: 6450 [large seeds]

8.02

(2) Shafi Bhat, M.; Jhon, A. Q.; Lone, A. H. (1991) Propagation of Magnolia grandiflora through seed. Progressive Horticulture, 1991, Vol.23, No.1-4, pp.30-33, 6 ref.
(3) Misiha, A.; El-Ashry, A. (1991) Seed germination and seedling growth of Magnolia grandiflora L. Bulletin of Faculty of Agriculture, University of Cairo, 1991, Vol.42, No.3, pp.869-879, 18 ref.

(2) AB: M. grandiflora seeds were treated with BA or GA3 at 0, 50, 100 or 200 mg/litre prior to sowing in Nov., Dec., Jan., Feb. or Mar. Growth regulator treatments significantly increased germination compared with the control. Highest germination (51.06%) was obtained with 50 mg BA/litre, followed by 50 mg GA3/litre (45.80%). Of the sowing dates, highest germination (56.92%) was obtained in Jan., followed by Dec. (55.79%). The interaction between growth regulator treatment and sowing date had a significant effect on germination. Highest germination (79.66%) was obtained with seeds treated with 50 mg BA/litre and sown in Dec. followed by the same treatment and a Jan. sowing.
(3) AB: In trials in 1988 and 1989, seeds of M. grandiflora were treated to improve the rate and percentage of germination. Seeds, with testas removed, were soaked for 24 h in tap water or GA3 solutions (250, 500 or 1000 p.p.m.); seeds with intact testas were soaked in 90% sulphuric acid for 15 or 30 min, or stratified in moist sand

8.03

no evidence

8.04

http://hort.ifas.ufl.edu/trees/MAGGRAA.pdf

bark is thin and easily damaged

8.05

no evidence


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