Ant dispersal and predation affects the availability of seeds for old-field recolonisation in Western Australia

R.J. Harris, Rachel Standish

    Research output: Contribution to journalArticle

    4 Citations (Scopus)

    Abstract

    Seed arrival onto abandoned farmlands (old-fields) in south-western Australia can be limited bytheir proximity to native remnant vegetation. As the major seed-harvesting guild, ants could affectseed availability on old-fields by either: (1) affecting the dispersal of elaiosome-bearing seeds fromadjacent remnants; (2) thieving the elaiosome from seeds without affecting their dispersal onto oldfields;or (3) predating seeds, which reduces the availability of seeds for dispersal. The relativeimportance of these ant-seed interactions will depend on the rates of ant-mediated seed dispersalfrom the remnants onto the old-field, as well as the rates of seed predation across these habitats.We sampled the ant communities within two old-fields, within the adjacent eucalypt woodlandremnants and at the boundaries of these two habitats, using pitfall traps to determine the relativeproportions of seed dispersers, elaiosome thieves and seed harvesters within each zone–ants wereassigned to these groups on the basis of our observations of ant-seed interactions. During theseobservations, we followed the fate of elaiosome-bearing Acacia seeds that were offered to antswithin each zone, primarily to estimate rates of seed dispersal and elaiosome thieving. We alsooffered eucalypt seeds to ants in feeding stations to estimate seed predation within each zone. Wefound that the relative proportions of seed dispersers, elaiosome thieves and seed harvesters weresimilar across zones, despite differences in the species composition between sites and a reductionin species richness in the old-fields. None of the Acacia seeds that we offered were dispersed fromeither remnant into the adjacent old-field. The majority of dispersal events were less than 3.6 mfrom the seed source (61%; n = 74) and dispersal beyond 20 m was rare (4%; maximum 28.1 m).Rates of elaiosome thieving and seed predation were not elevated in the old-fields compared withtheir rates in the other zones. Overall, the data indicate that ant-mediated seed dispersal onto oldfieldswas rare and seed predation by ants was similar across habitats.
    Original languageEnglish
    Pages (from-to)303-313
    JournalRoyal Society of Western Australia, Journal
    Volume91
    Publication statusPublished - 2008

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    Western Australia
    Formicidae
    predation
    seeds
    seed predation
    seed dispersal
    harvesters
    Acacia
    habitats
    species diversity
    pitfall traps
    South Australia
    agricultural land

    Cite this

    @article{1b700d191eeb4e9e9bcd5e64ed82f5e2,
    title = "Ant dispersal and predation affects the availability of seeds for old-field recolonisation in Western Australia",
    abstract = "Seed arrival onto abandoned farmlands (old-fields) in south-western Australia can be limited bytheir proximity to native remnant vegetation. As the major seed-harvesting guild, ants could affectseed availability on old-fields by either: (1) affecting the dispersal of elaiosome-bearing seeds fromadjacent remnants; (2) thieving the elaiosome from seeds without affecting their dispersal onto oldfields;or (3) predating seeds, which reduces the availability of seeds for dispersal. The relativeimportance of these ant-seed interactions will depend on the rates of ant-mediated seed dispersalfrom the remnants onto the old-field, as well as the rates of seed predation across these habitats.We sampled the ant communities within two old-fields, within the adjacent eucalypt woodlandremnants and at the boundaries of these two habitats, using pitfall traps to determine the relativeproportions of seed dispersers, elaiosome thieves and seed harvesters within each zone–ants wereassigned to these groups on the basis of our observations of ant-seed interactions. During theseobservations, we followed the fate of elaiosome-bearing Acacia seeds that were offered to antswithin each zone, primarily to estimate rates of seed dispersal and elaiosome thieving. We alsooffered eucalypt seeds to ants in feeding stations to estimate seed predation within each zone. Wefound that the relative proportions of seed dispersers, elaiosome thieves and seed harvesters weresimilar across zones, despite differences in the species composition between sites and a reductionin species richness in the old-fields. None of the Acacia seeds that we offered were dispersed fromeither remnant into the adjacent old-field. The majority of dispersal events were less than 3.6 mfrom the seed source (61{\%}; n = 74) and dispersal beyond 20 m was rare (4{\%}; maximum 28.1 m).Rates of elaiosome thieving and seed predation were not elevated in the old-fields compared withtheir rates in the other zones. Overall, the data indicate that ant-mediated seed dispersal onto oldfieldswas rare and seed predation by ants was similar across habitats.",
    author = "R.J. Harris and Rachel Standish",
    year = "2008",
    language = "English",
    volume = "91",
    pages = "303--313",
    journal = "Royal Society of Western Australia Journal",
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    Ant dispersal and predation affects the availability of seeds for old-field recolonisation in Western Australia. / Harris, R.J.; Standish, Rachel.

    In: Royal Society of Western Australia, Journal, Vol. 91, 2008, p. 303-313.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Ant dispersal and predation affects the availability of seeds for old-field recolonisation in Western Australia

    AU - Harris, R.J.

    AU - Standish, Rachel

    PY - 2008

    Y1 - 2008

    N2 - Seed arrival onto abandoned farmlands (old-fields) in south-western Australia can be limited bytheir proximity to native remnant vegetation. As the major seed-harvesting guild, ants could affectseed availability on old-fields by either: (1) affecting the dispersal of elaiosome-bearing seeds fromadjacent remnants; (2) thieving the elaiosome from seeds without affecting their dispersal onto oldfields;or (3) predating seeds, which reduces the availability of seeds for dispersal. The relativeimportance of these ant-seed interactions will depend on the rates of ant-mediated seed dispersalfrom the remnants onto the old-field, as well as the rates of seed predation across these habitats.We sampled the ant communities within two old-fields, within the adjacent eucalypt woodlandremnants and at the boundaries of these two habitats, using pitfall traps to determine the relativeproportions of seed dispersers, elaiosome thieves and seed harvesters within each zone–ants wereassigned to these groups on the basis of our observations of ant-seed interactions. During theseobservations, we followed the fate of elaiosome-bearing Acacia seeds that were offered to antswithin each zone, primarily to estimate rates of seed dispersal and elaiosome thieving. We alsooffered eucalypt seeds to ants in feeding stations to estimate seed predation within each zone. Wefound that the relative proportions of seed dispersers, elaiosome thieves and seed harvesters weresimilar across zones, despite differences in the species composition between sites and a reductionin species richness in the old-fields. None of the Acacia seeds that we offered were dispersed fromeither remnant into the adjacent old-field. The majority of dispersal events were less than 3.6 mfrom the seed source (61%; n = 74) and dispersal beyond 20 m was rare (4%; maximum 28.1 m).Rates of elaiosome thieving and seed predation were not elevated in the old-fields compared withtheir rates in the other zones. Overall, the data indicate that ant-mediated seed dispersal onto oldfieldswas rare and seed predation by ants was similar across habitats.

    AB - Seed arrival onto abandoned farmlands (old-fields) in south-western Australia can be limited bytheir proximity to native remnant vegetation. As the major seed-harvesting guild, ants could affectseed availability on old-fields by either: (1) affecting the dispersal of elaiosome-bearing seeds fromadjacent remnants; (2) thieving the elaiosome from seeds without affecting their dispersal onto oldfields;or (3) predating seeds, which reduces the availability of seeds for dispersal. The relativeimportance of these ant-seed interactions will depend on the rates of ant-mediated seed dispersalfrom the remnants onto the old-field, as well as the rates of seed predation across these habitats.We sampled the ant communities within two old-fields, within the adjacent eucalypt woodlandremnants and at the boundaries of these two habitats, using pitfall traps to determine the relativeproportions of seed dispersers, elaiosome thieves and seed harvesters within each zone–ants wereassigned to these groups on the basis of our observations of ant-seed interactions. During theseobservations, we followed the fate of elaiosome-bearing Acacia seeds that were offered to antswithin each zone, primarily to estimate rates of seed dispersal and elaiosome thieving. We alsooffered eucalypt seeds to ants in feeding stations to estimate seed predation within each zone. Wefound that the relative proportions of seed dispersers, elaiosome thieves and seed harvesters weresimilar across zones, despite differences in the species composition between sites and a reductionin species richness in the old-fields. None of the Acacia seeds that we offered were dispersed fromeither remnant into the adjacent old-field. The majority of dispersal events were less than 3.6 mfrom the seed source (61%; n = 74) and dispersal beyond 20 m was rare (4%; maximum 28.1 m).Rates of elaiosome thieving and seed predation were not elevated in the old-fields compared withtheir rates in the other zones. Overall, the data indicate that ant-mediated seed dispersal onto oldfieldswas rare and seed predation by ants was similar across habitats.

    M3 - Article

    VL - 91

    SP - 303

    EP - 313

    JO - Royal Society of Western Australia Journal

    JF - Royal Society of Western Australia Journal

    SN - 0035-922X

    ER -