Shrubland ambivalent in its syndromes of dissemination by animals: a base-rich littoral site at Fitzgerald River National Park, southwestern Australia

@peterslingsby @arthur_chapman

Under mesic, temperate climates in Australia and southern Africa, vegetation tends to contain either myrmecochorous plants ( and and, disseminated by ants, or endozoochorous plants, disseminated by birds.

Vegetation types emphasising myrmecochorous plants include kwongan (, wallum (, heathland, and mallee-heath ( in Australia, and fynbos ( in South Africa.

Vegetation types emphasising endozoochorous plants include vine-thicket ( and rainforest (in the loose sense) in Australia, and strandveld (, various forms of thicket (, and southern afrotemperate forest ( in South Africa.

In this Post I document a plant community in Australia that happens to be exactly intermediate, in the sense that the two syndromes of dissemination are equally balanced.

The following may explain how I came to focus on the shrubland in question.

Vine-thicket is latitudinally widespread in Australia, but is everywhere restricted to small patches.

This restriction is because vine-thicket depends on a combination of

  • relatively nutrient-rich soils, and
  • relative freedom from wildfires by virtue of slight topographic barriers.

The southwestern region of Western Australia ( lacks vine-thicket, despite the fact that such vegetation occurs at similar latitudes in eastern Australia. This seems to be because the land is so flat, and intense wildfires so extensive, that not a single hectare of this vast area - apart from saline or semi-saline sites - of nearly 50 million hectares has been exempt from the tyranny of a regime that perpetuates flammable vegetation types: kwongan, mallee-heath, mallee, and eucalypt forest/woodland.

In the late seventies I became curious as to what kind of shrubland might occur in the situations most edaphically suited to vine-thicket in southwestern Western Australia, i.e. situated at the very threshold of eligibility.

The following is the composition of a particular plant community that - I suspect - would be vine-thicket were the surrounding conditions slightly more protective. It is one of the two study sites reported in, and happens nearly to correspond to the location of

The study site is just southeast of Culham Inlet ( and and adjacent to the southeastern corner of the unusually hilly Fitzgerald River National Park ( and

The study site has since been spoiled by roadworks (

The soil in this site was:

  • base-rich ( because it combined calcareous littoral sand with alluvium, the site perhaps being somewhat topographically protected from wildfires, and
  • relatively rich in phosphorus for southwestern Western Australia, but also rather sodic because of proximity to a semi-saline inlet in a landscape devoid of perennial streams.

My floristic list is based on six visits made between 1978 and 1983, at various times of year. * indicates non-indigenous species, FF indicates species with fleshy fruits, E indicates species with elaiosomes attractive to ants, and FF/E indicates species with diaspores of intermediate structure such as fleshy fruits so small that they are as attractive to ants as to birds.

The number of myrmecochorous species is similar to that of bird-disseminated species, because elaiosomes/small arils occur on the seeds of more than ten of the species and some of the fleshy fruits are smaller and duller-hued than those typically attractive to birds.

The commonest of the myrmecochorous species is Acacia rostellifera in stunted form, which forms clumped (clonal) shrubs about 1.2 meters high.

There are up to 15 indigenous species bearing fleshy fruits in this plant community, which is an unusually large number for southwestern Australia. This would somewhat emulate vine-thicket were it not for the fact that many of the present species have halophytic affinities rather than the affinities with rainforests expected in vine-thicket.

The commonest of the non-halophytic species with fleshy fruits is Billardiera heterophylla. This is fairly common in the site and, although liane-like, effectively forms domed shrubs with dense crowns, one meter high.

The overall result:
In this plant community, the approximately 30 species disseminated by animals are about evenly balanced between myrmecochorous and endozoochorous, with ambivalent diaspores in members of Amaranthaceae, Epacridaceae, Lauraceae, Mimosaceae and Polygonaceae.

The following list is arranged in alphabetical order by families/genera/species.

Carpobrotus virescens FF
Tetragonia implexicoma FF and

Atriplex paludosa ssp. baudinii
Chenopodium baccatum FF and
Chenopodium wilsonii FF and
Enchylaena tomentosa small FF
Suaeda australis
Threlkeldia diffusa FF/E and and

Daucus glochidiatus
Trachymene pilosa

*Asparagus asparagoides FF
Thysanotus patersonii E? and

Dianella revoluta FF and

Olearia axillaris
Senecio lautus ssp. dissectifolius
Sonchus oleraceus

*Brassica tournefortii

Crassula colorata

Acrotriche cordata FF/E and

Pultenaea barbata E

Pelargonium littorale

Scaevola crassifolia E?

Westringia dampieri E

Cassytha melantha FF and
Cassytha filiformis FF/E

Guichenotia ledifolia E
Lasiopetalum discolor E

Acacia cochlearis E
Acacia cyclops large aril functionally similar to fleshy fruit
Acacia rostellifera E

Eucalyptus angulosa
Melaleuca lanceolata
Melaleuca quadrifida

Oxalis corniculata

Phyllanthus calycinus E?

Billardiera heterophylla FF

Plantago varia

*Avena sativa
Austrostipa variabilis

Muehlenbeckia adpressa FF/E

Calandrinia calyptrata

*Lysimachia arvensis

Clematis pubescens
Clematis linearifolia

Spyridium globulosum E

*Galium murale

Boronia tetrandra E

Santalum spicatum (FF)

Solanum symonii FF and

Pimelea clavata? E
Pimelea ferruginea E

Roepera apiculata E

Publicado el febrero 28, 2022 04:59 MAÑANA por milewski milewski


The flora of Fitzgerald River National Park is rich (1748 species,,within%20the%20park%27s%20297%2C244%20hectares.), but contains remarkably few lianes: Billardiera spp., Convolvulus erubescens, Cassytha spp., Glycine clandestina, Kennedia nigricans, Hardenbergia comptoniana, Comesperma volubile, C. integerrima, Muehlenbeckia adpressa, and Clematis spp. It is noteworthy that at least six of these occur in the site described above.

Publicado por milewski hace alrededor de 2 años

I recorded the following bird species in this site:
Cracticus torquatus
Pomatostomus supercilosus
Phylidonyris novaehollandiae
Lichenostomus virescens
Lichmera indistincta
Colluricincla harmonica
Zosterops lateralis
Malurus pulchellus
Stipiturus malachurus
Sericornis frontalis
Emblema oculata

Publicado por milewski hace alrededor de 2 años

Jerome Patrick Bull 2006

The ecological significance of frugivorous animals as seed vectors of fleshy-fruited plants in High diversity ecosystems of south-western Australia

Publicado por milewski hace casi 2 años

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