Annona glabra L.

Title: Annona glabra L.

Scientific name:

Annona glabra L.

Common name(s):

pond apple

Habitat: In Australia it occurs on creek and river banks and farm drainage systems, wetlands and mangrove swamps, and the high tide area of the littoral zone on beaches (Land Protection, 2001).

Distribution:

Original source via CABI

Invasiveness Assessment

ESTABLISHMENT

1. Germination requirements? Germination can occur throughout the year, though germination rates are highest after periods of rainfall (ARMCANZ 2000).

2. Establishment requirements? “Seedlings require moist to wet, generally well lit conditions.” Low light levels restrict seedling growth as does waterlogging. Requires access to light and moisture, but does not tolerate inundation (ARMCANZ 2000).

3. How much disturbance is required? “Disturbance can play an important part in encouraging infestations of pond apple.” Canopy openings due to severe storms can stimulate germination and seedling growth. Unlikely to establish under deep rainforest canopy; favours estuaries and floodplains where plenty of light and moisture occur (ARMCANZ 2000).

GROWTH / COMPETITIVE

4. Life form? Small semi-deciduous tree to 6 metres (15 under optimal conditions) (ARMCANZ 2000). Other lifeform.

5. Allelopathic properties? None described in ARMCANZ (2000).

6. Tolerates herb pressure? The plant is not documented as eaten by fauna or domesticated stock. Animals such as pigs and birds eatthe fruit (ARMCANZ 2000). No herbivory pressure.

7. Normal growth rate? ‘Seedlings grow rapidly to form dense stands that shade out native grasses and sedges’( NRM 2001). Moderately rapid growth equal to similar competitive spp.

8. Stress tolerance to frost, drought, w/logg, sal. etc? Commonly found in estuarine situationsÞsalt tolerant. Will withstand seasonal or tidal inundation, but not permanent waterlogging (e.g. wetlands, mangroves). Larger trees tolerate low intensity fires and, “[d]ense stands of pond apple lack sufficient fuel loads to sustain a fire.” (WTMT 2004). It has a high requirement for soil moisture, which limits its occurrence away from water sources. Unlikely to tolerate drought. Tolerant to salt and temporary inundation; tolerates low intensity fire.

REPRODUCTION

9. Reproductive system? Sexual reproduction; cross-pollination only (possibly by beetles)(ARMCANZ 2000).

10. Number of propagules produced? Each fruit contains » 140 seeds; no of fruit produced not documented. However, it is estimated that seed banks of, “several thousand seeds m-2/year,” are common (ARMCANZ 2000). Assume 1000–2000 seeds per plant.

11. Propagule longevity? Not known.

12. Reproductive period? Not documented. Plants reach reproductive maturity after two years and typically grow to 6 metres in height (WTMT 2004). Assume plants to live at least 3 to 10 years.

13. Time to reproductive maturity? Plants reach reproductive maturity after 2 years (WTMT 2004).

DISPERSAL

14. Number of mechanisms? Propagules spread by water, humans and native and feral animals. “Water is the main dispersal agent for both pond apple fruit and seed. Spread of seed by animals vectors is very minor compared to its dispersal by water (WTMT 2004).

15. How far do they disperse? Under tidal influence, seed can be spread both up and downstream within a river. However, the major movement of seed is due to floodwater. It is also noted that ocean currents play a role in seed dispersal along the coast (WTMT 2004). Under these conditions seeds will be spread more than 1 kilometre.

Impact Assessment

RECREATION

1. Restrict human access? A semi-deciduous tree 12 – 15 metres tall, occurring on creek banks, wetlands, mangrove communities & high tide litter zones on beaches (NRM 2001). ‘Thickets of pond apple restrict access’ (ARMCANZ 2000).

2. Reduce tourism? ‘Thickets of pond apple restrict access and impair outlooks and the general variety of the coastal recreational experience’ (ARMCANZ 2000).

3. Injurious to people? “…pond apple was introduced to Australia as grafting stock for custard apple. In its native America pond apple fruit has some commercial use” (NRM 2001). No toxic principle or physical properties likely to cause injury.

4. Damage to cultural sites? Occurs mostly in riparian or wetland areas subjected to regular natural disturbance. Not documented to occur in areas of cultural significance (WTMT 2004). Where it may occur, dense infestations (approaching a monoculture) it would present a moderate negative visual impact.

ABIOTIC

5. Impact flow? Terrestrial species. “It grows in fresh, brackish and even saline waters. The plant will not survive, however, in areas that are permanently inundated” (ARMCANZ 2000). Due to its dependence on a high water supply, it is found in riparian areas, floodplains and the margins of wetland areas. In such areas a dense infestation may affect the watercourse by narrowing the channel or reducing the size of the waterbody (WTMT 2004).

6. Impact water quality? Not documented to affect water quality. Does not withstand permanent inundation (ARMCANZ 2000).

7. Increase soil erosion? A semi-deciduous tree that in open areas forms dense stands (NRM 2001). Unlikely to contribute to soil erosion.

8. Reduce biomass? “Pond apple can establish as a dense understorey that suppresses other growth and under favourable conditions can replace mature stands of paperbark with a monoculture forest of pond apple” (NRM 2001). Suppression of other species may result in slight reduction of biomass.

9. Change fire regime? “Time between fires is lengthened due to the reduction in understorey in infested areas” (ARMCANZ 2000). Does not contribute to an increase in fire risk.

COMMUNITY HABITAT

10(a) Impact on composition of high value EVC? Basin=South Gippsland (ISC=very poor-moderate); CMA=West Gippsland; CLIMATE potential=L. Therefore no high value EVC exists.

10(b) Impact on medium value EVC? All Victorian waterbodies are presumed to be high value EVCs.

10(c) Impact on low value EVC? All Victorian waterbodies are presumed to be high value EVCs.

11. Impact on structure? “Pond apple forms a dense understorey/sub-canopy, replacing ferns, grasses, shrubs and sedges and prevents tree regeneration” (ARMCANZ 2000). “Creeks may become muddy monocultures” (NRM 2001). Major effect on all strata in some situations.

12. Effect on threatened flora? This species is not documented as posing an additional risk to threatened flora.

FAUNA

13. Effect on threatened fauna? This species is not documented as posing an additional risk to threatened fauna.

14. Effect on non-threatened fauna? Dense infestations would alter the habitat for native fauna. The plant may provide suitable shelter/nestingsites, but food source is radically altered due to impacts on plant diversity (NRM 2001). Possible serious reduction in local faunal populations.

15. Benefits fauna? The fruit is a food source to some fruit-eating animals such as the cassowary and flying foxes (ARMCANZ 2000).

16. Injurious to fauna? Not known to be harmful.

PEST ANIMAL

17. Food source to pests? The fruit is known as a food source to native fauna. In Queensland feral pigs spread the seed (ARMCANZ 2000).

18. Provides harbor? May provide harbour to minor pest species such as birds (NRM 2001).

AGRICULTURE

19. Impact yield? Not known as a weed of agriculture (ARMCANZ 2000).

20. Impact quality? Not known as a weed of agriculture (ARMCANZ 2000).

21. Affect land values? Not known as a weed of agriculture (ARMCANZ 2000).

22. Change land use? Not known as a weed of agriculture (ARMCANZ 2000).

23. Increase harvest costs? Not known as a weed of agriculture (ARMCANZ 2000).

24. Disease host/vector? Not known to be a host or vector of disease for agriculture (ARMCANZ 2000).

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 an anonymous donor.

Attachments:

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referenced by (1)

wra1029: Common Name - P (via pond apple)

Article: wra5118 (permalink)
Categories: :wra:a, :wra:inv1, :wra:invh, :wra:inv2, :wra:invmh, :wra:inv3, :wra:invml, :wra:inv4, :wra:invl, :wra:inv5, :wra:inv6, :wra:impmh, :wra:inv7, :wra:inv8, :wra:inv9, :wra:inv10, :wra:inv11, :wra:invm, :wra:inv12, :wra:inv13, :wra:inv14, :wra:inv15, :wra:imp1, :wra:imp2, :wra:imph, :wra:imp3, :wra:impl, :wra:imp4, :wra:impml, :wra:imp5, :wra:imp6, :wra:imp7, :wra:imp8, :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: 23 November 2009; 9:51:43 am Australian Eastern Daylight Time

Author Name: Jessica Mackay
Author ID: mackayj