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Factors that influence reproduction in nectar-feeding non-flying mammals are poorly described. We investigated factors that may influence the breeding traits of the eastern pygmy-possum (Cercartetus nanus), a small (25 g) nectar-feeding marsupial from eastern Australia. Females at our coastal site produced 1–3 litters (frequently of 5–6 young) over an 8-month period within the flowering period of the dominant food plant (Banksia ericifolia). The number of lactating females over time was highly correlated (R = 0.9) with the abundance of flowers on B. ericifolia, suggesting that flower availability has a substantial influence on breeding. To assess the generality of these findings and investigate whether elevation or latitude influence breeding in this species, we examined the breeding traits previously described at three other locations. Females on the tableland 70 km away produced one litter of 3–4 young over a 4-month period within the flowering period of B. ericifolia, the dominant food plant. At other coastal and tableland locations 500 km away, coastal females produced larger numbered litters more often than tableland females. A hypothesis relating to minimum temperature appears the most plausible explanation for this pattern that reflects elevation but not latitude. The mean minimum temperature drops below 5 °C for 2–5 months each year at the tableland locations but not at all at the coastal locations. Low temperatures are known to reduce nectar secretion in the dominant food plants. Thus, although the breeding traits of the eastern pygmy-possum are influenced by flowering in their dominant food plants, low temperature appears to impose a constraint on reproductive output.

The Rockwarbler Origma solitaria is restricted to the sedimentary-rock formations around the Sydney region of New South Wales and, like other species in the Acanthizidae, is mainly insectivorous, although its diet is considered poorly known. Here we report on two observations of nectarivory, a food source not previously reported for this species. They involved Rockwarblers feeding at flowers of Heath-leaved Banksia Banksia ericifolia at two locations.

Tap and primary lateral roots of seedlings of the putatively non-mycorrhizal Banksia ericifolia became marginally colonised when grown in an established mycelium of an arbuscular mycorrhizal (AM) fungus in the laboratory. A similar degree of colonisation was found in seedlings from an open woodland. All colonies lacked arbuscules. Two factors influencing colonisation and associated growth of host plants were examined experimentally: concentration of P in the soil and organic energy associated with the fungus. While some inoculated seedlings were slightly smaller when colonised by AM fungi, the results were inconsistent and never statistically significant. Seedlings take up insignificant quantities of soil P during early growth, even in the presence of abundant added P. Though colonisation was minor in all cases, an existing mycelium, whether or not connected to a companion plant, slightly increased the amount of root of B. ericifolia colonised by an AM fungus. All seedlings grew slowly. Shoots were significantly larger than roots, until the initiation of proteoid roots which commenced at about 40 days after germination, with both relatively high and low P supply.

Several features of the phenology and reproductive biology of members of the genus Banksia indicate that these plants either have a high level of mate choice or are obligate outcrossers, with many flowers being functionally male or sterile. These species produce many inflorescences with vast numbers of flowers, yet seed-set is typically very low. Most species studied appear to have at least limited self-compatibility and outcrossing rates close to one. Despite this, pollinators normally deposit a large amount of self-pollen on stigmas. In this study, we used experimental pollinations to test for evidence of preferential outcrossing within populations of Banksia spinulosa and Banksia ericifolia. Our allozyme analysis of progeny arrays indicates that the studied populations of both B. spinulosa from a prior study and B. ericifolia as determined for 27 plants in this study are highly outcrossed. Results from pollinations using applications of self- and cross-pollen and mixtures of the two indicated that, at ...

Several taxa of the Australian Proteaceae have invaded South African fynbos and require costly management programmes to bring under control. Banksia spp. have been introduced only recently to fynbos regions. The invasive potential of Banksia ericifolia (Proteaceae) was investigated by comparing its recruitment potential with that of an indigenous proteaceous shrub, Leucadendron laureolum. Both species are overstorey shrubs that are killed by fire and rely on canopy-stored seeds (serotiny) for recruitment. Eight year old B. ericifolia shrubs produced an average of 16 500 seeds per plant, which is thirty times more than the average of 570 seeds produced by 10 year old L. laureolum shrubs. The seed bank of B. ericifolia was not only larger than that of L. laureolum (1098 vs 525 viable seeds m−2 projected canopy cover), but also considerably larger than that described for the species in its native environment (200–330 seeds m−2 in a 9 year old stand north of Sydney). Leucadendron laureoleum released most of its seed a few days after the cones were burnt, whereas seed release in B. ericifolia was spread over 12 weeks. The seeds of B. ericifolia had lower wingloading and fall rates than L. laureolum and were dispersed over greater distances. The relative seedling growth rates of the two species were very similar (0.03 g per day), but below-ground biomass was greater and proteoid roots were more developed in B. ericifolia seedlings than in L. laureolum after 100 days. Four year old B. ericifolia plants growing in the field had attained over twice the height of indigenous pro-teoids and accumulated up to 10 times the fresh biomass of L. xanthoconus, a species which is ecologically similar to L. laureolum. The Bioclimatic Prediction System (BIOCLIM) was used to create a bioclimatic profile of B. ericifolia and identify climatically suitable areas in the Cape Province. Results show that its potential distribution covers most fynbos areas in the southwestern Cape. It is concluded that B. ericifolia has the potential to be highly invasive in fynbos.

Banksia ericifolia seedlings were grown in a pine bark‐based soilless medium amended with 10, 20, and 40 mg/L P, each combined with 26 Iron sources. Fe deficiency symptoms increased with increases in added P. Only eight Fe sources ‐ three types of ferrous sulfate, two magnetites and three chelates based on EDTA and EDDHA ‐ provided enough Fe to give high quality plants. Among sources based on ferrous sulfate only those that gave at least 15, 22, and 34 mg/L Fe in 2mM DTPA extracts of media amended with 10, 20, and 40 mg/L P, respectively, produced high quality plants. DTPA extracts of media containing magnetites had to contain more than 14, 19, and 25 mg/L Fe at the same P levels. For Fe chelates of EDTA, EDDHA, and lignosulfonate, freedom from Fe deficiency was not related to extractable Fe.

This study examined the water relations of sclerophyllous evergreen vegetation (wallum) on coastal sand barriers in eastern Australia. Many wallum species may be groundwater dependent, although the extent of this dependency is largely unknown. Twenty-six perennial tree, shrub and herb species were investigated in three groundwater habitats (ridge, open depression, closed depression). Pre-dawn and midday shoot xylem water potentials (ψx) were measured monthly between late autumn 2010 and late summer 2011. Pressure–volume curve traits were determined in mid- to late spring 2009, including the osmotic potential at full (π100) and zero (π0) turgor, and bulk modulus of elasticity (ε). Carbon isotope ratios (δ13C) were also determined in mid- to late spring 2009, to measure water-use efficiency (WUE). The species displayed a range of physiological strategies in response to water relations, and these strategies overlapped among contrasting growth forms and habitats. Linear relationships between osmotic and elastic adjustment were significant. A strong correlation between δ13C and distribution along the hydrological gradient was not apparent. Banksia ericifolia subsp. macrantha (A.S.George) A.S.George, Eucalyptus racemosa Cav. subsp. racemosa and Eucalyptus robusta Sm. displayed little seasonal variation in ψx and maintained a comparatively high pre-dawn ψx, and are therefore likely to be phreatophytic. Wetland vegetation in the lowest part of the landscape appeared to tolerate extreme fluctuations in water availability linked to a prevailing climatic pattern of variable and unreliable seasonal rainfall.

We tested the ability to predict plant (and hence population) age for three fire-sensitive obligate-seeder Proteaceae species (Banksia ericifolia, Banksia marginata and Petrophile pulchella) in the heath and woodland vegetation of the Sydney region. To do this we sampled the number of growth whorls, as well as other growth characteristics (stem girth and height measurements, and canopy area and volume estimates), in areas of known time since last fire (TSLF). The average number of growth whorls was a very good predictor of plant age for both Banksia species (R2 = 98%, 99%), but this needed to be corrected for linear underestimation in P. pulchella (R2 = 92%). This technique could successfully be applied to these species in similar habitats across a large spatial scale, and so this information can be used to determine the age of a population in areas of unknown TSLF. A sample size of 15 plants was sufficient for accurate age estimates of all species; however, better estimates of TSLF for a particular plant community were obtained when estimates from two or more of the species were combined. We thus provide empirical evidence for the validity and accuracy of the growth-whorl technique for predicting plant age and hence TSLF. This information will assist in informing the development of appropriate management strategies for plants in relation to fire. Of the other growth characteristics studied, stem girth was the most reliable predictor; however, in general these other characteristics had wide confidence intervals on the predictions for sites greater than 10 years TSLF, owing to a non-linear relationship with age.

The effect of high frequency fire regimes on a coastal heathland north of Sydney was examined. Plant community composition and species frequency and density (of a subset of species) were compared among sites burnt by either one, two or three fires in the period 1988-1990 inclusive. Constrained ordination indicated that number of fires had a significant effect on floristic composition. Site variables also had a significant effect on floristics and frequency and accounted for a larger proportion of variation than did number of fires. Analyses of deviance indicated that frequency in 13 species was unaffected by fire regimes or site factors. Site factors significantly affected frequency in 42 species. Frequency in seven species was significantly affected by fire regimes (no site effect). In six of these, frequency was lower in areas subjected to either two or three fires compared to one fire. Three of these species were obligate seeders. Frequency in the other species (a herbaceous resprouter) was significantly higher in the area subjected to two fires. There was no significant effect of fire on species richness. Densities of seven out of a subset of eight species were also significantly affected by fire (two obligate seeder spp.) and site factors (four spp.), Significantly lower densities were related to multiple fires. The study indicated that regimes of frequent fire can deplete populations of some heathland species with the dominant shrub species, Banksia ericifolia L.f., being most affected.

Plants of Banksia ericifolia and Petrophile pulchella are sensitive to fire. Changes in population size under different fire regimes were estimated, based on measurements of post-fire seedling emergence, seedling survival, survival and seed production in established plants of differing ages, survival of seeds held in serotinous cones and seed-release in the periods between fire. Seeds were first available at 5 years in P. pulchella and 6 years in B. ericifolia. Exact replacement would be possible when burnt at these ages, if seedling establishment were very high. Low establishment would delay replacement to 13 years of age in both species. Late summer/autumn fires of high intensity favour high establishment. Such fires at 8–10 year intervals would be tolerated without any sustained decline in numbers. Fires at 10–15 year intervals could occur regardless of season or intensity with little risk of a population decline. Large increases in numbers and density would follow fires spaced at 15–30 years. Enough seeds would be available for replacement up to about 50 years in both species. Viable seed-release in unburnt conditions was sufficient to compensate for deaths in stands over 20 years old, even with very low levels of establishment. Two variables accounted for the biggest changes in numbers and density between generations interspersed by fires; namely the age at which a stand is burned and the proportion of seeds which emerge as seedlings. A comparison with other similar species showed similarities in controls on emergence and establishment, lengths of primary juvenile periods and life spans.

A non-systemic Insecticide was used to exclude flower and seed predators from Banksia ericifolia and B. oblongifolia Inflorescenses. In B. ericifolia this treatment doubled the number of inflorescences that set seeds, and increased by 40% the number of seeds produced per Inflorescence. Insecticide treatment did not alter either of these components of seed-set in B. oblongifolia partly because the experiment began too late to exclude flower predators In this species. The results obtained for B. ericifolia support the hypothesis that flower and seed predators explain, in part, the low incidence of seed-bearing cones and the low seed:flower ratios reported for many Banksia species. Each Banksia species supports two guilds of Inflorescence predators. Two Lepidopteran species feed on young flowers; one of these causes tunnel damage to the rachis. Each Banksia species also supports five Lepidopteran and two Curcullonid seed-predators. About 40% of these herbivorous Insects are common to both shrubs.

High-density (dense) and low-density (sparse) plots were set up in naturally sown monospecific stands of Banksia ericifolia in coastal heath, 3 years after fire. This was done both in high-growth and low-growth areas. Plant mortality was recorded quarterly, and two harvests were made at 6 and 9 years to sample growth. Density-independent mortality at an exponential rate was observed in the low-growth treatments at both densities, and in the high-growth sparse treatment. Growth level affected mortality, with the half-life of populations in the high-growth sparse plots being double that of populations in the low-growth plots. Density-dependent mortality (self-thinning) was seen only in the high-growth dense plots. Seasonal effects on mortality were slight; maximum mortality was observed in the spring-summer period in plots subject to density-independent mortality, and in the winter-spring quarter in plots that had self-thinned. Yields in the high-growth plots and the low-growth dense plots were high for heath vegetation. The self-thinning populations did not exceed White's (1985) upper boundary for thinning lines of log intercept (K) = 5 on standardized axes. The data suggested a log intercept value in the range 4.8–4.9 in the high-growth stands assuming a thinning-line slope of – 1.5. Banksia ericifolia (a large shrub/small tree) has a high mean plant weight per given thinning density compared with trees, where an upper limit of log K= .4 has been suggested by White (1985). The volume of canopy space per plant in B. ericifolia is not unusual compared with other species. The amount of biomass packed into a given volume of canopy space was high in this Banksia, achieved by having leaves with a low ratio of area to weight (specific leaf area, SLA). For given values of density, leaf area index and proportion of shoot as leaf, plants with a low SLA will be several times heavier than plants with a high SLA. This achieves a high biomass to volume ratio without an erectophile canopy and may explain the high intercept seen for thinning lines of conifers.

Self-thinning B. ericifolia stands were observed to have high mean plant weights for their density, exceeding the upper boundary of the (log mean plant weight = 4.4–1.5 log mean plant density) line of White (1980) by approximately 0.5 units on the y scale (log mean weight per plant (g)). While proportion of shoot as stem and leaf area indices were similar in thinning stands of B. ericifolia and other species, specific leaf area was six to eight times less in the Banksia populations.

Patterns of flowering, levels of fruit set and pollination limitation of fruit set were examined over four years in a group of four co-occurring Banksia species (Proteaceae) in south-eastern Australia