Chase National Park Research Articles

Removal Rates of Seeds Adapted for Dispersal by Ants

To learn what scope there may be for a mother plant to modify whether her seeds are removed by ants, and how quickly, we investigated (1) how initial seed removal by ants may vary in times (years, season, time of day) and space (within and between sites, and (2) how large these sources of variation are. We focused on seed of two common ant—dispersed species in a field experiment on 20 x 20 m plots at each o three sites in Kuringai Chase National Park in southeast Australia. The most important influence on removal rate over the first 12 h of exposure was the precise location of seeds on the ground (54% of total variation). This variation did not persist over longer periods of time and, except during winter, all seeds had a high probability of being removed within 2—3 d. Time of year also had a strong influence had a strong influence on removal rate (21% of total variation) with the highest rates occurring in summer and the lowest in winter. These changes were mainly attributable to changes in ambient temperature. Differences in removal rates between the two seed species used was the third most important source of variation (4%). There was significant variation in removal rate between the same months in different years, in two of the three between—year comparisons. The effect of year, and of interactions between year and other factors, accounted for between 7 and 18% of total variation. Complementary experiments showed that ants were the only important removers of seed at the study sites and that seed age up to 1 yr did not influence removal rate. Experiments comparing removal rates of clumped seeds to those of single seeds showed no consistence difference. The high probability of removal of elaiosome—bearing seeds within 2—3 d of seedfall means it is unlikely that ant—dispersed plants in this vegetation ever face the problem of their seeds not being encountered and transported by an ant. Instead, the problem may be how to be removed by those ant species whose behavior will give the seed the best chance of survival and establishment.

Suburban development and resultant changes in the vegetation of the bushland of the northern Sydney region

AbstractBushland sites in the northern suburbs of Sydney were compared to sites in Brisbane Waters National Park, Ku‐ring‐gai Chase National Park and Royal National Park which are relatively unaffected by suburban development. Both shale‐derived and sandstone‐derived soil in four physiographical locations were examined, with three replicates of each of the 16 combinations.Phosphorus levels are higher in the soils of suburban sites compared to soils derived from similar rock bases in non‐suburban sites. Phosphorus levels are also higher on shale‐derived than on sandstone‐derived soils, and lower on hilltops than in other physiographic positions. Suburban sandstone sites have soil phosphorus levels similar to those of non‐suburban shale sites.Three major and three minor clusters of species were distinguished using a hierarchical agglomerative clustering. The major clusters consisted of (1) species commonly associated with wet sclerophyll forests and rainforest margins, (2) species directly or indirectly related to the presence of man, and (3) species associated with dry sclerophyll forests and heaths.Using analyses of variance and covariance, and logit models, the abundance of the first main cluster was related to nutrient‐rich soils and the abundance of the third main cluster to low nutrient soils whereas the presence of the second main cluster was almost entirely restricted to sites surrounded by suburbs.The development of suburbs around vegetation patches has led to an increase in the abundance of native and exotic mesomorphic species and the addition of phosphorus to the soils. The data presented in this paper indicates that high phosphorus levels and presence of mesomorphic species are related.

Thesis abstracts

Studies of variation in some Tasmanian species of Plantago L. Michael James Brown. Ecology of the Kangaroo Island wallaby, Macropus eugenii (Desmarest), in Flinders Chase National Park, Kangaroo Island Robert W. Inns. Nutrient effects on intraspecific competition in subterranean clover E. Charles Morris. The ecology of scribbly gums and angophoras Jane Mowatt.

Nematoda (Oxyuroidea: Thelastomatidae) From Australian Passalid Beetles (Coleoptera: Passalidae) With Descriptions of New Species.

Three new genera are proposed for nematodes recovered from the hindgut of Aulacocyclus mastersi, a passalid beetle collected in Ku-ring-gai Chase National Park, N.S.W., Australia. Anuronema (type-species A. kuringa n.sp.) is characterized by the virtual absence of a tail (only a rounded body terminus) in the female. Males are unknown. Phalacronema (type-species P. ardleyi n.sp.) has a conspicuous offset head, annulated cuticle without spines or scales, well developed lateral alae terminating behind the anus, and a didelphic reproductive system. Only females are known. Sprentia (type-species S. australis n.sp.) is characterized by head polymorphism with a conspicuous, campaniform head region in the female, but an inconspicuous, rounded, not offset head in the male; annulated cuticle, without spines; well developed lateral alae in both sexes; posterior oesophageal bulb feebly demarcated; female didelphic, male monorchic with a single thelastomatid spicule and 4 pairs of ventrolateral posterior papillae, 2 pairs precloacal and 2 post-cloacal. [AS]