Ilex aquifolium L.

Title: Ilex aquifolium L.

Scientific Name: Ilex aquifolium L.

Common Name: holly

Source & more images (via ALA)

Habitat: Preferring cool, moist climates and deep fertile soils the species is reported to invade woodlands, scrubland, damp to wet schlerophyll forest, riparian vegetation, the edges of cool temperate rainforest and pasture (Blood 2001; Carr, Yugovic & Robinson 1992; Muyt 2001; Webb, Sykes & Garnock-Jones 1988; Weber 2003). In Europe the species is reported to normally occur in the understorey of woodland however in areas with mild winters it can occur in open areas (Groom, Baker & Long 1991). At the northern and eastern extremes of the species range of it’s native Europe it is reported to be restricted to coastal areas (Groom, Baker & Long 1991).

Distribution:

Original source via GBIF

Invasiveness Assessment

ESTABLISHMENT

1. Germination requirements? In Spain germination is reported to occur from Spring to Autumn, with the highest proportion germinating in late spring (Arrieta & Suárez 2005). Therefore the species germinates under seasonal conditions.

2. Establishment requirements? Can establish in the dense shade underneath mature holly trees, which is reported to be 1% of sunlight, however survival rates are low (Arrieta & Suárez 2005; Peterken 1966). Reported to invade the edges of cool temperate rainforest (Muyt 2001). Survival of holly seedling through their first year is reported to be effected by the summer drought period and grazing (Arrieta & Suárez 2006). The species can therefore establish under a moderate canopy but does require other additional factors such adequate moisture through the summer period.

3. How much disturbance is required? Reported to invade wet sclerophyll forest and riparian vegetation (Carr, Yugovic & Robinson 1992).

GROWTH / COMPETITIVE

4. Life form? Other; Holly is a “dioecious broad-leaved evergreen tree” (Obeso 1998).

5. Allelopathic properties? No reported evidence of allelopathy in Holly.

6. Tolerates herb pressure? Holly is noted as being browsed by ungulates including cattle, goats and deer. A plant exposed to heavy grazing form establishment can persist as a low gnarled mounded shrub and the more a plant is browsed the spinier the leaves of the regrowth become (Obeso 1997; Perrin, Kelly & Mitchell 2006). The species is affected by a leaf-miner (Phytomyza ilicis) in Europe (Eber 2001). A study where individual branches were artificially girdled or defoliated showed little impact on fruit production and therefore sexual reproduction (Obeso 1998). Therefore the species can persist under gazing and is capable of flowering and producing seed under moderate grazing.

7. Normal growth rate? The species is reported to be slow growing laying down very hard wood also seedling growth is reportedly slow, taking five or more years to reach maturity (Blood 2001). Therefore the growth rate of holly is considered to be less than many other tree species.

8. Stress tolerance to frost, drought, w/logg, sal. etc? Tolerance to frost varies with time of the year from -9ºC in summer to -24ºC in mid-winter (Rütten & Santarius 1988). Tolerates frost to -15ºC for short periods (Blood 2001). Prolonged severe frosts can damage trees, the species is reported to be limited to areas in Europe where the mean January temperature is above -4.6ºC (Peterken & Loyd 1967). Therefore the species is considered to be tolerant of frost.

Drought can kill seedlings within their first year (Blood 2001). Holly leaves are sclerophyllous which can be an advantage under moderate drought conditions (Salleo, Nardini & Lo Gullo 1997). Therefore while mature plants may be able to persist through a period of drought, the species is unlikely to establish in a drought prone area and therefore is not considered tolerant to drought. The species shows some tolerance of heavy metals (Samecka-Cymerman & Kempers 1999). Fire can kill the stem, but the plant can then resprout from the base (Peterken & Loyd 1967). Reported to be reduced after forest fires (Tinner et al 1999). Therefore the species is considered to have some tolerance to fire. Considered intolerant to very wet soils, but is reported growing in waterlogged soils (Peterken & Loyd 1967). Therefore the species is considered to have some tolerance to waterlogging.

REPRODUCTION

9. Reproductive system? Holly is a dioecious tree which reproduces sexually by flowering and producing fruit and vegetatively through suckering (Obeso 1998).

10. Number of propagules produced? Each fruit normally contains between 4 and 5 seeds (Blood 2001). In Spain average fruit production per tree over a ten year period has been estimated in the range of 10,000 (Guitián & Bermejo 2006).

11. Propagule longevity? After a three year experiment the initial seed bank was diminished by 80-90% and therefore holly is considered to have a short persistent seed bank (Arrieta & Suárez 2004).

12. Reproductive period? Long lived (Blood 2001). An individual has been reported to be 254 years old (Peterken & Loyd 1967).

13. Time to reproductive maturity? Under good conditions plants can reach maturity in 5 years (Blood 2001).

DISPERSAL

14. Number of mechanisms? Seed dispersed by birds and possibly by possums and foxes (Muyt 2001). Intact seeds have been reported to be excreted from captive possums in New Zealand (Williams et al 2000). Dispersed by bird species including blackbirds and to a minor extent by foxes (Garcia, Martinez & Obeso 2007). Seeds from Ilex sp. have been reported in regurgitated pellets of pied currawongs (Bass 1996).

15. How far do they disperse? Reported to be dispersed by pied currawongs and by foxes which have been reported to have a dispersal range of 20 km and 5 km respectively (Bass 1996; Garcia, Martinez & Obeso 2007; Muyt 2001; Spennemann & Allen 2000).

Impact Assessment

RECREATION

1. Restrict human access? Forms dense thickets (Weber 2003). Has spiny leaves, therefore holly could be of high nuisance value restricting people and vehicles, however due to its slow growing nature it would be unlikely to cause tracks to become impassable.

2. Reduce tourism? Unknown

3. Injurious to people? Has poisonous berries, and leaves have spines (Blood 2001). The berries and leaves of the species are toxic, especially to children. Reported symptoms included nausea, vomiting, diarrhoea, collapsing and unconsciousness (Shepherd 2004). The spines on the leaves of holly are not however considered large and while toxic the fruit is not considered fatal and does not occur year round.

4. Damage to cultural sites? The species is reported to be valued in some historical situations (Blood 2001). Unknown if the species has any negative impact on infrastructure, cultural or heritage sites.

ABIOTIC

5. Impact flow? Terrestrial species, not reported to occur in flowing water.

6. Impact water quality? Terrestrial species not reported to impact on water quality.

7. Increase soil erosion? Unknown; The species is reported as strong rooted and from an early age develop a tap root (Muyt 2001).

8. Reduce biomass? Can create a taller shrub layer, therefore invasion by holly could increase biomass or result in direct replacement (Weber 2003).

9. Change fire regime? Unknown; After an intense fire damaged plants can regrow from the root stock (Peterken & Loyd 1967).

COMMUNITY HABITAT

10(a) Impact on composition of high value EVC? EVC= Creekline Herb-rich Woodland (V); CMA= Corangamite; Bioreg= Central Victorian Uplands; VH CLIMATE potential. Holly can form dense thickets, creating a tall species poor shrub layer which also impacts upon the lower strata (Weber 2003). Therefore the species is capable of causing major displacement within a layer.

10(b) Impact on medium value EVC? EVC= Lowland Forest (D); CMA= Corangamite; Bioreg= Otway Plain; VH CLIMATE potential. Holly can form dense thickets, creating a tall species poor shrub layer which also impacts upon the lower strata (Weber 2003). Therefore the species is capable of causing major displacement within a layer.

10(c) Impact on low value EVC? EVC= Wet Forest (LC); CMA= Corangamite; Bioreg= Otway Plain; VH CLIMATE potential. Holly can form dense thickets, creating a tall species poor shrub layer which also impacts upon the lower strata (Weber 2003). Therefore the species is capable of causing major displacement within a layer.

11. Impact on structure? Holly can form dense thickets, creating a tall species poor shrub layer which also impacts upon the lower strata and can prevent regeneration (Muyt 2001; Weber 2003). Therefore the species is capable of causing major displacement within the shrub layer and possibly the lower strata and prevent the regeneration of canopy species.

12. Effect on threatened flora? Unknown.

FAUNA

13. Effect on threatened fauna? Unknown.

14. Effect on non-threatened fauna? Unknown; The impact the species has on the vegetation of the invaded ecosystem could effect available habitat and alter food supply; however this is not specifically reported.

15. Benefits fauna? Fruits eaten by birds and possibly possums (Muyt 2001; Williams et al 2000). Forms thickets which may be used for shelter (Weber 2003). Unknown how important this can be to desirable species.

16. Injurious to fauna? The leaves are spiny, the fruit is toxic to people not reported to effect birds or animals (Blood 2001).

PEST ANIMAL

17. Food source to pests? Fruit eaten to some extent by foxes (Garcia, Martinez & Obeso 2007). Browsed by goats and deer (Obeso 1997).

18. Provides harbor? Forms thickets which may be used for shelter (Weber 2003). It is not specifically reported to shelter pest species.

AGRICULTURE

19. Impact yield? It is reported to invade pasture and could occur in Forestry (Blood 2001). As grazing limits the species growth and it is reported to be slow growing it is unlikely to have significant impacts on product yield.

20. Impact quality? It is reported to invade pasture and could occur in Forestry (Blood 2001). As grazing limits the species growth and it is reported to be slow growing it is unlikely to have significant impacts on product quality.

21. Affect land values? Unknown.

22. Change land use? It is reported to invade pasture and could occur in Forestry (Blood 2001). As grazing limits the species growth and it is reported to be slow growing it is unlikely to cause a change in land use.

23. Increase harvest costs? The species could occur in forestry and while it’s slow growing it is reported to form thickets (Blood 2001; Weber 2003). This may restrict access to plantations and slightly increase the time taken for maintenance. It is reported to invade pasture (Blood 2001). However as grazing limits the species growth it is unlikely to impact upon the cost of production.

24. Disease host/vector? Not reported to be a host or vector of pest species of agricultural crops.

Feedback

Do you have additional information about this plant that will improve the quality of the assessment? If so, we would value your contribution.

Assessment ratings originally made by the Victorian Department of Primary Industries.

The entry of this assessment was made possible through the generous support of The Weed's Network.

Attachments:

urn_lsid_biodiversity.org.au_apni.taxon_53754.png
holly via ala.JPG
Capture.JPG

referenced by (2)

wra1002: Common Name - H wra1002: Common Name - H (via holly)

Article: wra6898 (permalink)
Categories: :wra:i, :wra:inv1, :wra:invmh, :wra:inv2, :wra:inv3, :wra:inv4, :wra:invl, :wra:inv5, :wra:inv6, :wra:inv7, :wra:invml, :wra:inv8, :wra:inv9, :wra:invh, :wra:inv10, :wra:inv11, :wra:inv12, :wra:inv13, :wra:inv14, :wra:inv15, :wra:imp1, :wra:impmh, :wra:imp2, :wra:impm, :wra:imp3, :wra:imp4, :wra:imp5, :wra:impl, :wra:imp6, :wra:imp7, :wra:imp8, :wra:impml, :wra:imp9, :wra:imp10a, :wra:imp10b, :wra:imp10c, :wra:imp11, :wra:imp12, :wra:imp13, :wra:imp14, :wra:imp15, :wra:imp16, :wra:imp17, :wra:imp18, :wra:imp19, :wra:imp20, :wra:imp21, :wra:imp22, :wra:imp23, :wra:imp24
Date: 21 December 2011; 10:24:19 AM AEDT

Author Name: Zheljana Peric
Author ID: zper12