bluuebunny/crossref_metadata_2025 huggingface dataset:
Interactions Between Iron and Phosphorus in the Nutrition of Banksia ericifolia L.f var ericifolia (Proteaceae) in Soil-Less Potting Media
Authors: Handreck KA
Published: December 2005

Interactive effects of iron and phosphorus on the growth and appearance of Banksia ericifolia L.f. var. ericifolia seedlings were investigated. The seedlings were grown in a pinebark-based soil-less potting medium amended with 0-40 mg L-1 P added as single superphosphate and with Fe supplied either as FeSO4.7H2O (at 0-3 g L-1) or FeEDDHA (at 0-430 mg L-1). Fe deficiency was the dominant visual effect on shoots; its severity increased as P supply increased. Classic symptoms of P toxicity (death of oldest leaves) were produced in plants at the highest levels of P supply and low Fe supply. At each level of added P, Fe tended to lower %P in the shoots, mainly by allowing increased production of dry matter as Fe deficiency was overcome. The highest rate of FeSO4.7H2O addition reduced accumulation of P in the leaves and increased it in the stems. High P additions reduced accumulation of Fe into leaves. At non-toxic additions of P, young leaves had higher concentrations of P than did old leaves, but the reverse applied as P supply became excessive. The leaves of high quality plants contained less than about 0-14% P and more than 30 mg kg-1 Fe. P:Fe ratios for the leaves of such plants were in the range 14-53 (mean 23). Numbers of proteoid root clusters were greatest on plants in media of high Fe supply and low P and declined rapidly as P supply increased above the adequate range. No evidence was found for Fe stress leading to greater development of proteoid roots. Quality scores of at least 85% of maximum were mainly confined to media giving < 3 mg L-1 P in 2 mM DTPA (1:1.5 volume) extracts and amended with at least 1.5 g L-1 FeSO4.7H2O or 215 mg L-1 FeEDDHA. Response in ferrous sulfate treatments was better correlated with extractable P and Fe than with totals added, but there was no difference with FeEDDHA treatments, because additions of FeEDDHA did not decrease extractable P and ferrous sulfate did.
Seed Bank Dynamics of Three Co-Occurring Banksias in South Coastal Western Australia: the Role of Plant Age, Cockatoos, Senescence and Interfire Establishment.
Authors: Witkowski ETF , Lamont BB , Connell SJ
Published: December 2005

Seed bank dynamics of three co-occurring, non-sprouting Banksia species (B. baxteri, B. speciosa and
B. coccinea) in patch-burnt scrub-heath (aged 10 and 21 years) were studied in the southern sandplains
of Western Australia. In the younger plants, canopy seed storage was highest in B. coccinea. However,
21-year-old B. coccinea stored an order of magnitude fewer seeds than the other species and no more
than young B. coccinea. Seed storage per year increased exponentially with plant age in B. speciosa
and B. baxteri, whereas a quadratic function, peaking at 16 years, best described seed storage in B.
Coccinea. Degree of serotiny was lowest in B. coccinea. Seed abortion did not vary between age cohorts
but was highest in B. coccinea. Granivory ranged from 18 to 42% and was highest in the older plants
and in B. baxteri. Cockatoos removed about 20% of cones in B. baxteri and B. coccinea and 10%
in B. speciosa. Experimental cone removal accelerated follicle opening, especially in B. coccinea, irrespective of whether cones were placed on the ground (simulating cockatoo removal) or reattached to
the plant (simulating plant death). Half the 21-year-old B. coccinea were dead and the remainder were
considered senescent, as most branches showed dieback and cone fertility had fallen to 8%. Death
of the other species was negligible, with cone fertility rising to a mean of 45% (B. speciosa) and 66%
(B. baxteri). Interfire establishment was significant only in B. coccinea. The build-up of a viable seed
bank with time occurred at a slower rate than for non-sprouting banksias in the northern sandplains.
Restriction Fragment Length Polymorphisms in Chloroplast DNA From Six Species of Eucalyptus
Authors: Steane DA , West AK , Potts BM , Ovenden JR , Reid JB
Published: December 2005

Chloroplast DNA was extracted from six species of Eucalyptus (E. perriniana, E. nitens, E. ovata, E. regnans, E. amygdalina and E. risdonii). Digests with four restriction enzymes (Hind III, Xho I, Nco I and Eco RV) revealed restriction fragment length polymorphisms (RFLPs) between subgenera, between species and within species. However, no variation in fragment pattern was detected with Sac II or Pst I. The subgenera Monocalyptus and Symphyomyrtus were clearly differentiated by their RFLP patterns where, with the exception of one outlying specimen of E. amygdalina, 45% of all polymorphic fragments were specific to one or other subgenus. While species from different subgenera and series were well differentiated, it was more difficult to differentiate species within series with the low sample sizes used. However, the average net divergence between species increased with increasing taxonomic distance between species, from 0.02% within series and 0.20% between species from different series within subgenera, to 0.99% of nucleotides per nucleotide site for species from different subgenera. Based on Eco RV digests, the eucalypt chloroplast genome was estimated at 143 kb.
Inheritance of Selected Traits in Accessions of Vigna vexillata (L) a Rich of Australian and African Origin
Authors: James AT , Lawn RJ
Published: December 2005

The inheritance of several traits in Vigna vexillata was studied for crosses involving accessions of African and Australian origin. Anthocyanin stem pigmentation, silver leaflet midrib, leaflet hirsuteness, presence of long hairs on the calyx lobes, black pod colour, speckled seed testa and twining stem habit all appeared to be conditioned by single completely dominant gene action, as was apparent resistance to powdery mildew. Width of the floral standard, peduncle length, number of seeds per pod, weight of 100 seeds, tuberous root dry weight, total plant dry weight and harvest indices for seed and tuberous roots all appeared to be quantitatively inherited, with moderate broad sense heritabilities. Leaflet shape, the primary distinguishing attribute between the varieties occurring in Australia, angustifolia and youngiana, appeared to be simply inherited. No difficulties were encountered in obtaining F1 and backcross progenies in any crosses. Further, the inheritance of traits in progeny of Australian × African crosses appeared normal and, in the several instances where direct comparison was possible, similar to that observed in crosses within the Australian material.
Effects of Edaphic Factors and Flood Frequency on the Abundance of Lignum (Muehlenbeckia florulenta Meissner) (Polygonaceae) on the River Murray Floodplain, South Australia
Authors: Craig AE , Walker KF , Boulton AJ
Published: December 2005

Lignum is a native woody perennial which forms extensive thickets in low-lying areas of the floodplain of the lower River Murray, although its range and abundance have been affected by land clearance, salinisation, flow regulation and possibly grazing on seedlings. Comparisons between lignum cover and edaphic data for three sites (Chowilla, Morgan and Overland Comer) showed a negative correlation with soil hardness. Cover was also correlated positively with soil moisture and negatively with time since last flooded, but not correlated with flood recurrence interval. Principal Components Analysis revealed a complex component, loaded by moisture, salinity, pH and organic content, that explained most of the variation in lignum cover. A greenhouse experiment indicated that the salinity and volume of water supplied to plants have significant effects on stem growth. Stands of lignum may be best maintained by flooding low-lying areas every 3-10 years or areas with saline soils more frequently.
Roots of Jarrah Forest Plants .I. Mycorrhizal Associations of Shrubs and Herbaceous Plants
Authors: Brundrett MC , Abbott LK
Published: December 2005

This survey included 109 plants native to the jarrah forest (a mediterranean eucalypt woodland in south-western Australia dominated by Eucalyptus marginata and E. calophylla). Mycorrhizal formation by seedlings of these plants was examined after inoculation with isolates of vesicular-arbuscular mycorrhizal (VAM) fungi, or after growth in intact cores of natural habitat soil containing VAM and ectomycorrhizal (ECM) fungi. These methods were supplemented by examining roots from mature forest-grown plants, so that different methods and criteria for designating mycorrhizal association types could be considered. Most plants had one of the following types of mycorrhizal association: VAM only (56% of species); both ECM and VAM (16% of species); or non-mycorrhizal roots (25% of species, which also had long root hairs and/or cluster roots). Plants with dual ECM/VAM associations often formed ECM more readily than VAM. With the exception of the large and diverse families, Papilionaceae, Myrtaceae and Anthericaceae, plants within a family had consistent mycorrhizal relations, as did the members of most genera.
Postfire Demography of the Wet-Mallee Eucalyptus luehmanniana F Muell (Myrtaceae)
Authors: Davies SJ , Myerscough PJ
Published: December 2005

The post-fire demography of Eucalyptus luehmanniana, a wet-mallee eucalypt restricted to the Sydney region, was studied by descriptive and experimental methods. Patterns of growth and reproduction were related to time since the last fire for 15 populations burned from 2 to 24 years previously. After fire, mature individuals (clumps) resprout from subterranean lignotuberous buds producing numerous narrow stems. Resprouted clumps flower within 2-4 years and fruit within 5-6 years of the last fire. Fruits accumulate in the canopy with increasing time, up to at least 24 years since fire. Measurements from one reproductively mature population showed that there is a low level of seed-fall below the canopy (0.98 seeds m-2 day-1) in the absence of fire. Recruitment without fire appears unlikely due to a combination of factors: low seed viability (34.9%, s.e. = 5.3), low levels of field emergence, no soil-stored seed, and a high proportion (86.9%, s.e. = 3.4) of seed failing enclosed in capsules. Canopy-stored seed is released en masse following fire. Three factors potentially influencing the recruitment of E. luehmanniana seedlings, fire-related effects, water availability and protection of developing seedlings from animals, were investigated experimentally in the field. Seedling emergence was uniformly low (2.2-2.6%), and not significantly increased on burned plots, caged plots, or water-added plots alone. In one experiment, plots both burned and caged had significantly higher emergence. Mortality in all experimental plots was 100% within 6 months. Seedling recruitment of E. luehmanniana will not occur following all fires, and will depend on the coincidence of fire with suitable post-fire conditions.
The Cytology of Brachyscome Cass. (Asteraceae: Astereae). II. Hybridisation Between B. goniocarpa (N = 4) and B. dichromosomatica (N = 2)
Authors: Watanabe K , Short PS , Kosuge K , Smith-White S
Published: December 2005

Artificial hybrids between the inbreeding species B. goniocarpa Sond. & F. Muell.(n = 4) and outbreeding B. dichromosomatica C. R. Carter var. dichromosomatica (n = 2) have been produced. Morphologically, the hybrids were essentially intermediate between the parental species. Cytological
investigations showed that the total length of mitotic metaphase chromosomes for the B. dichromosomatica
haploid set was 1.33 times that of the B. goniocarpa set. Chromosomes derived from the parental
species showed similar condensation behaviour. Meiotic pairing involved both the B. dichromosomatica
chromosomes and two of the four B. goniocarpa chromosomes; the other two B. goniocarpa chromosomes
formed univalents. The results suggest that the current placement of the two taxa in different superspecies
is not warranted.
Self-Incompatibility, Protandry, Pollen Production and Pollen Longevity in Banksia menziesii
Authors: Ramsey M , Vaughton G
Published: December 2005

Controlled self- and cross-pollination indicated that a natural population of Banksia menziesii (Proteaceae) was self-incompatible. Flowers were protandrous. Deposition of pollen into the stigmatic cavity was regulated by opening of the stigmatic groove. Stigmatic grooves opened 24-48 h after the flowers opened. Pollen production was high and the pollen:ovule ratio was approximately 10000. Over 90% of pollen grains were viable when flowers first opened. Viability decreased rapidly with time and most pollen was inviable within 24 h. These results indicate that B. menziesii requires pollen vectors to produce seed and suggest that pollinators may have influenced the evolution of the reproductive traits that were examined.
Contrasting Growth and Morphological Characteristics of Fire-Sensitive (Obligate Seeder) and Fire-Resistant (Resprouter) Species of Restionaceae (S Hemisphere Restiads) From South-Western Western-Australia
Authors: Pate JS , Meney KA , Dixon KW
Published: December 2005

Populations of south-western Australian members of the Restionaceae were examined in a wide range of wetland, seasonally inundated and dryland habitats over 4 years and the behaviour of 82 of the species authenticated according to whether they survived (resprouter strategy) or were killed (obligate seeder strategy) by fire. Material of the same seeder and resprouter species collected during summer or early autumn from habitats not burnt for at least 5 years was then used for morphometric measurements, observations on rhizome morphology, determinations of culm: rhizome dry weight (DW) ratios and assays of starch and sugars in rhizomes. Rhizome diameters of all 37 resprouters exceeded 2.3 mm while 28 of the 45 seeder species had narrow rhizomes in the range 0.2-2.1 mm. Culm : rhizome DW ratios of seeders (mean 12.3 ± s.e. 1.2) were much higher than those of resprouters (mean 2.9 ± s.e. 0.4). Mean ± position of perennating buds of seeders was mostly at or close to soil surface (-0.6 ± 0.2 cm), while that of resprouters was more deeply buried ( 2.8 ± s.e. 0.5 cm), Seven categories of rhizome morphology were recognised. Three of these (essentially tufted habit, rhizome growth ascending or erect) were much more typical of seeders (n = 37) than resprouters (n = 5). The other four categories included rhizomes of basically horizontal growth and a loosely tufted or widely spreading habit, and were collectively associated more with resprouters (n = 32) than seeders (n = 8). Starch was present at detectable levels in rhizomes of 23 species of resprouters (mean concentration ± s.e. DW for these positive species was 7.13 ± 1.62%) and only 3 seeders (0.16 ± 0.11%). Levels of total soluble sugars (mean ± s.e. DW) (predominantly sucrose, fructose and glucose) were 3.39 ± 0.59% in resprouters compared with 1.06 ± 0.19% in seeders. Data are discussed in relation to previous studies on seeder and resprouter representatives from other plant families.
Crown Assessments Improve Regression Estimates of Leaf Area in Jarrah Trees (Eucalyptus marginata)
Authors: Whitford KR
Published: December 2005

Regression equations for estimating the single-sided leaf area of individual jarrah trees (Eucalyptus marginata Donn ex Smith) are presented. The destructive measurement of 96 trees on five sites and over three seasons provided the data that were used to relate leaf areas to crown dimensions and assessments. Substantial variation in jarrah leaf area across sites and between seasons weakens normal allometric relationships. Combining crown dimensions with assessments of the foliage density and crown size produced substantial improvements in the estimate of leaf area, raising the r² from 0.48 for a model based on crown depth to 0.92 for a model that included assessments of crown development and foliage density. Because the expanded equations consider the foliage density, they avoid the site and seasonal dependence found in simple allometric relationships based only on stem diameter, sapwood area or crown dimensions.
A Paedomorphocline in Eucalyptus: Natural Variation in the E. risdonii/E. tenuiramis Complex
Authors: Wiltshire RJE , Potts BM , Reid JB
Published: December 2005

Ontogenetic and morphological variation in 40 natural populations of the closely related species, E. risdonii and E. tenuiramis, were assessed in a multivariate study of juvenile and adult leaf and fruit characters. The present taxonomic separation of the two taxa is based mainly on ontogenetic differences, but this study reveals that the variation between the two taxa in the retention of the juvenile leaf habit is continuous and may represent a paedomorphocline. The morphological data suggest that at least four phenetic groups are required to summarise the morphological variation in the E. risdonii/ E. tenuiramis complex. When ontogenetic variation is removed, the morphological variation between some E. risdonii and some E. tenuiramis populations is also continuous and much smaller than the morphological differences within E. tenuiramis. This suggests that E. risdonii may be the product of relatively recent changes in developmental timing (heterochrony) from E. tenuiramis.
Environmental Determinants of Allosyncarpia ternata Forests That Are Endemic to Western Arnhem Land, Northern Australia
Authors: Bowman DMJS
Published: December 2005

Allosyncarpia ternata S. T. Blake dominates closed forests on rugged sandstone escarpments on the
western edge of the Arnhem Land Plateau, northern Australia. The forests occur in a floristic continuum
between fire-protected wet monsoon forests in the base of canyons and frequently burnt, eucalyptdominated
savannas that occur in all other topographic positions. An indirect gradient analysis of
69 quadrats from these three vegetation types at six different localities showed that no measured edaphic
variable was correlated with this floristic transition.
A detailed study of a single patch of Allosyncarpia on level terrain with rock-free, sandy soils showed
that Allosyncarpia trees occur on sites with significantly deeper soils and higher concentrations of available
K in the surface soil compared to surrounding eucalypt savannas. However, there was no significant
difference in dry season surface soil moisture content between these communities. There is also evidence
that there is no significant difference in subsoil moisture supply. Xylem pressure potential of Callitris
intratropica (which is equally abundant in both Allosyncarpia and eucalypt communities) was found
to be statistically similar at the beginning and end of the dry season. The Allosyncarpia forest was
made up of a mosaic ranging from stands co-dominated by savanna species with grassy understoreys
to stands co-dominated by monsoon forest species with dense understoreys. No measured environmental
factors were significantly related to the patterning of these stands within the forest.
Seed throw of Allosyncarpia is limited to several metres from the canopy edge and seedlings were
only observed beneath the canopy. Field experiments demonstrated that seedling survival in the savanna
can be enhanced by the provision of shade, and nursery experiments demonstrated that the growth
of seedlings provided with ample water is suppressed by full sunlight. Dry season fires in grass fuels
ranging from 2 to 8 t ha-1 were found to be lethal to seedlings <100 mm tall.
Although most Allosyncarpia trees recover following fire damage, the present distribution of the
species may be best explained as a consequence of wildfires. However, there is need for confirmation
that the species range is contracting under current fire regimes. This is probably best derived by analysis
of existing remote sensing data.
Acclimation to a Change in Light Regime in Seedlings of Six Australian Rainforest Tree Species
Authors: Osunkoya OO , Ash JE
Published: December 2005

Acclimation potential of seedlings of six non-pioneer, North Queensland rainforest tree species
(Diploglottis diphyllostegia, Flindersia brayleyana, Dysoxylum schgneri, Prunus turnerana, Neisosperma
poweri and Castanospora alphandii) were evaluated in three different light regimes. The seedlings were
grown from seeds and raised in 37, 10 and 2.5% photosynthetically active radiation (PAR) of full
sunlight in a shade house. Plants were harvested at 1, 4, and 15 months after germination. At 4 months,
for each species, one-third of the seedlings in each light environment were transferred to each of the
two other light environments. The remaining one-third stayed in the same light environment and formed
the control. The control seedlings of all species showed a marked response to increasing PAR: relative
growth rate (RGR) and total biomass were low in the 2.5% PAR level, increased in the 10% PAR
level and were maximal in the 37% PAR level, except for Neisosperma. The seedlings in the 25%
PAR level showed a typical shade plant morphology with a high leaf area ratio, low root-shoot ratio
and low specific leaf weight. For seedlings of Dysoxylum and Prunus, a change in light regime from
37% PAR to 2.5% PAR resulted in negative relative growth rates. Eleven months after transfer, many
growth characteristics still showed significant initial × final light environment interactions, an indication
of incomplete adjustment. Acclimation to increasing light availability was faster than acclimation to
decreasing light availability. On the basis of biomass allocation patterns (root-shoot ratio, leaf area
ratio and specific leaf weight), the six species could not be differentiated under the three light regimes
and their dynamics. However, using RGR as a relative measure of carbon economy, it was possible
to differentiate the species in their acclimation ability to decreased but not to increased irradiance.
It was concluded that, for non-pioneer species, acclimation potential may be more related to physiological
than to morphological plasticity.
Growth and Carbon Partitioning in Rainforest and Eucalypt Forest Species of South Coastal New South Wales, Australia
Authors: Barrett DJ , Ash JE
Published: December 2005

Rainforest, ecotone and eucalypt forest species were grown for 22 weeks in glasshouse conditions under light, water and nutrient treatments. Plant biomass, leaf area and leaf biomass per plant increased in Eucalyptus sieberi, Eucalyptus fastigata, Pittosporum undulatum, Callicoma serratifolia, Elaeocarpus reticulatus, Backhousia myrtifolia and Ceratopetalum apetalum at high irradiance (1230-1670 μ-mol PAR m-2 s-1). Both E. sieberi and E. fastigata inhabit the relatively high light environments of northern aspects, upper southern aspects and ridge tops in the gully systems of south coastal New South Wales. Callicoma serratifolia, P. undulatum and E reticulatus are pioneer species of the ecotone around rainforest patches, and B. myrtifolia and C. apetalum are rainforest canopy species. Mean plant biomass under high irradiance was ranked: eucalypt species > ecotone species and B. myrtifolia > C. apetalum. At low irradiance (200-530 μ-mol PAR m-2 s-1) the trend observed was reversed where rainforest canopy and ecotone species produced greater plant biomass. Plant response to different water and nutrient treatments under glasshouse conditions showed that, while the light environment primarily governed plant response, interaction between treatments occurred which resulted in maximum plant biomass at relatively high levels of soil moisture and nutrients. Carbon partitioning was used as an indication of relative response to light treatments. The proportion of plant mass partitioned to leaves did not change between experimental treatments. The magnitude of the response of leaf area ratio and specific leaf weight to light treatment, however, was ranked: eucalypt species > ecotone species > rainforest canopy species. This suggested that species naturally growing outside the rainforest canopy maximised leaf area in proportion to plant mass for a given irradiance, presumably to maintain high growth rates.
Reproductive-Biology and Interspecific Hybridization of Acacia mangium and Acacia auriculiformis A. Cunn. ex Benth (Leguminosae, Mimosoideae)
Authors: Sedgley M , Harbard J , Smith RMM , Wickneswari R , Griffin AR
Published: December 2005

Acacia mangium and A. auriculiformis flowered between February and May, producing mature pods between October and April. The flowers of both species were similar in structure and showed weak protogyny and variable levels of andromonoecy. Male flowers either lacked pistils completely or had small sterile pistils. Controlled hand pollination resulted in pollen tubes in the pistil and penetration of the ovules following self and cross intraspecific and interspecific pollination. The cross A. auriculiformis × A. mangium was more successful than the reciprocal, but fertile seed was produced following interspecific pollination in both directions and all seedlings were shown to be hybrid by isozyme analysis of parents and seedlings. There were relatively few insect visitors to the flowering branches, but the same suite of insects was observed foraging for pollen on both species. Native bees belonging to the Halictidae carried most polyads on their hairy bodies and may act as pollinating agents. There appeared to be no major fertility barriers to interspecific hybridisation between Acacia mangium and A. auriculiformis, and hybrids could occur spontaneously via synchronous flowering and common insect visitors.
Determination of Fire-Residence Time, and Its Role in the Survival of Eucalypts After a Bushfire
Authors: Bennett AJR
Published: December 2005

Bushfires occur frequently in drought-prone eucalypt forests of Australia, and their intensity can vary within very wide limits. Permanent damage is caused when a tree's vascular cambium layer is heated above 60°C, but this may be prevented in eucalypts by a thick layer of bark. It can take several minutes of flaming combustion during a bushfire for sufficient heat to penetrate the bark and kill the cambium. By heating some small sections of wood or bark in an oven to temperatures between 300°C and 600°C, then grinding and polishing a transverse section, reflectance measurements have been made in vertical incident light through a microscope fitted with a photomultiplier. These readings show a linear correlation between the logarithm of reflectance and temperature. Using this correlation, some maximum temperature profiles were obtained across transverse bark sections cut from trees subjected to a low-intensity bushfire. These have been compared with some graphs which relate the maximum temperatures reached within bark to the distance from the outer surface after progressively longer periods. By using reflectance measurements made on sections of charred bark or, more simply, by measuring the thickness of the black outer layer of charred bark an estimate of the fire residence time of a bushfire can be obtained.
Population Genetics of an African Acacia, Acacia albida. I. Genetic Diversity of Populations From West Africa
Authors: Joly HI , Zeh-Nlo M , Danthu P , Aygalent C
Published: December 2005

Acacia albida (Faidherbia albida) is an important species for agroforestry and widely distributed in
Africa. This paper proposes a genetic control for 14 enzymatic systems. The eight more reliable ones,
involving 10 loci, have been used to study the genetic diversity of 22 populations, mostly from west
Africa.
A. albida exhibits a high level of genetic diversity (H = 0.45) compared with that found in Australian
acacias studied so far. Most populations exhibited a deficit in heterozygotes (FIS = 0.21). All analyses
showed large differences between western and eastern populations.
Simulation of the Effect of Season of Fire on Post-Fire Seedling Emergence of Two Banksia Species Based on Long-Term Rainfall Records
Authors: Bradstock RA , Bedward M
Published: December 2005

Simulations were used to investigate the effect of season of fire on seedling emergence in Banksia ericifolia and B. serrata in the Sydney region, New South Wales. The simulations were based on models of soil-surface moisture in response to rainfall, seedling emergence response to soil moisture and post-fire seed release from fruits as determined by fire intensity, derived from field and laboratory studies. Fires were modelled on the first day of each calendar month for a 50-year period. Levels of post-fire seedling emergence were calculated using rainfall data from the Sydney Observatory for the corresponding period (1931-1980). Trends in seedling emergence as a function of month of fire were examined. Alternative sets of simulations were performed to assess the effect of variations in post-dispersal seed mortality, fire intensity and induced summer dormancy. In both species, mean emergence was affected by season of fire only when a 10% per month level of post-dispersal seed mortality was simulated (there was no fire-season effect at lower mortality levels). Highest predicted emergence occurred after summer fires and lowest emergence after winter fires. A reduction in rate of seed release (lower intensity fire) and induced seed dormancy in summer also had a minor effect with respect to fire-season in B. ericifolia. Reported levels of post-dispersal seed mortality in Banksia species are often high, and therefore, the simulations suggested that there will be an effect of fire season on seedling emergence. However, given the high level of year to year variation in seasonal rainfall in the Sydney region, fire-season effects are not predictable in the short term. In the longer term, the timing of fire relative to sequences of wet and dry years may be of equal importance to season of fire in its effect on populations of these species.
Monsoon Forests in North-Western Australia. II. Forest-Savanna Transitions
Authors: Bowman DMJS
Published: December 2005

Presence-absence data for tree species in over 1000 quadrats, 10 ° 20m, on 144 transects were analysed
by the divisive classificatory program TWINSPAN in order to define wet or dry monsoon forest, ecotone
and savanna assemblages. A sorted table revealed that there was continuous floristic variation among
these six vegetation types, although the abundance of tree species varied highly significantly between
assemblages.
Both wet and dry monsoon forests have higher stem densities, greater basal area, more tree species,
higher litter cover and lower grass cover than surrounding savannas. Wet monsoon forest soils have
significantly more moisture than surrounding savanna, but on the dry monsoon forest-savanna boundary
there is no significant difference in soil moisture. Both wet and dry monsoon forest soils are more
fertile than those in surrounding savannas, although there is considerable variation in the concentration
of nutrients within and between the two forest formations. The greater fertility of the forest probably
reflects superior nutrient accretion compared with the savanna, rather than indicating that monsoon
forests are restricted to inherently fertile sites.
Half the wet monsoon forest boundaries sampled had ecotonal quadrats separating forest from
savanna, while only 18% of the dry monsoon forest boundaries had such structurally and floristically
intermediate quadrats. A limited number of tree species was found to dominate both wet and dry
forest ecotones. Wet forest ecotones are overall environmentally more similar to the surrounding savanna
than the adjoining forests. Dry forest ecotones are environmentally intermediate between the dry forest
and savanna.
Both wet and dry forests have less fire damage than surrounding savannas. In contrast to the edaphic
control of most wet monsoon forests, dry forests are typically restricted to fire protected niches. The
distribution of both wet and dry forest, ecotone and savanna on boundaries with no edaphic or topographic
discontinuities is thought to reflect a dynamic relationship between these assemblages.
Seed Weights and Numbers as a Function of Fruit Size and Subgenus in Some Eucalyptus Species From South-Western Australia
Authors: Gill AM , Brooker MIH , Moore PHR
Published: December 2005

The woody fruits of 21 species belonging to four different subgeneric groups in Eucalyptus held contents which consisted of 'particles' that were either fertile or sterile, i.e. 'seeds' or 'ovulodes' respectively. The biggest fruits were 9 times wider than the smallest and more than 200 times heavier. Mean numbers of particles per fruit varied from 49 to 953; mean numbers of seeds per fruit varied from 0.8 to 108. Rising trends against mean oven-dry wall weight of fruits (i.e. fruits minus contents) were found for mean numbers of particles per fruit, mean particle weight and total weight of fruit contents. Using oven-dry weights of components as an index of the energetic costs of their production, costs per particle rose as fruit weights increased. Costs per seed rose to a maximum for fruits up to a dry weight of nearly 10 g but the four largest-fruited species had a relatively low cost for seeds per unit of wall weight. Species of Monocalyptus had fewer but bigger particles than species of Symphyomyrtus. Species of Eudesmia occupied an intermediate position.
Root Depth, Leaf Area and Daytime Water Relations of Jarrah (Eucalyptus marginata) Forest Overstorey and Understorey During Summer Drought
Authors: Crombie DS
Published: December 2005

Foliage projective cover of trees on high and low rainfall jarrah forest sites was 1.6 and 1.2 times
that of their understorey respectively. Corresponding leaf area index ratios were 7.2 and 3.4 times.
Tree and understorey species developed substantial water deficits on both sites during the summer
drought, although water deficits developed more rapidly and became more severe on the site receiving
less rainfall. Stornatal conductances and midday water potentials of deeply rooted trees (root depth
> 10m) remained higher than those of less deeply rooted understorey plants for 1-2 months in the
absence of rain. Daily cycling of water potential and stomatal conductance was detected in most plants
throughout the summer. This is interpreted as indicating that the plants did not become dormant
during summer drought.
Relationship Between Soil Nitrogen and Floristic Variation in Late Snow Areas of the Koscinsko Alpine Region [Australia].
Authors: Atkin OK , Collier DE
Published: December 2005

We studied soil and vegetation patterns of two late snow areas in the Kosciusko alpine region of New
South Wales, Australia. Marked floristic differences were found between the lower, central and upper
regions of each area. The distributions of six selected species, and the spatial variation in total vegetation
cover, were related to the spatial variation in total and exchangeable soil nitrogen concentrations. To
test whether variations in soil nitrogen were controlling the spatial separation of late snow area plant
species six selected species were subsequently grown at 12-15°C, over a range of increasing nitrogen
concentrations. Five of the six selected species (Luzula oldfieldii subsp. dura, Epilobium tasmanicum,
Plantago glacialis, Luzula acutifolia subsp. nana and Ranunculus niphophilus) showed similar responses
to increasing nitrogen levels, both in terms of relative dry weight production and shoot nitrogen
concentrations. Only in one species (Colobanthus nivicola) did responses suggest that it may have
been more suited to growth on nitrogen-deficient soils. We concluded, however, that variations in
nitrogen availability alone are not responsible for the floristic variation in late snow areas. Possible
factors responsible for the variation in floristic composition of the late snow areas are discussed.
Cretaceous Macrofloras of Eastern Otago, New-Zealand: Angiosperms
Authors: Pole M
Published: December 2005

Twenty-one taxa of plant megafossils are described from the mid Cretaceous Matakaea Group (Horse Range and Pukehiwitahi localities) and the Upper Cretaceous of the Taratu Formation (Shag Point, Cameron's Pit, and Clutha Mouth localities). One new species, Nothofagus melanoides, is formally described. The vegetation is interpreted as having been mixed deciduous angiosperm-conifer forest, with Araucariaceae the dominant gymnosperms. It grew at high southern latitudes which would have experienced several months of darkness during the winter.
Cell-Wall Histochemistry and Anatomy of Taro (Colocasia esculenta.)
Authors: Harris PJ , Ferguson LR , Robertson AM , Mckenzie RJ , White JB
Published: December 2005

The cell-wall histochemistry and anatomy of the corm, petiole and leaf blade of taro [Colocasia esculenta (L.) Schott], an important South Pacific food plant, are described. The results are discussed in relation
to the possible protective action of taro cell walls (dietary fibre) against a range of diseases, including
colorectal cancer. Cell walls may protect against colorectal cancer by adsorbing carcinogens, and lignified,
suberised, and possibly cutinised walls adsorb hydrophobic carcinogens more than walls lacking these
substances. The only cells in taro with lignified walls are xylem tracheary elements. The corm is covered
with a thick periderm, and the histochemistry of the walls of the phellem indicates the presence of
suberin and associated waxes. The leaf blade and petiole are covered by a cuticle, and the presence
of cutin and associated waxes is also shown histochemically. Parenchyma is the most abundant cell
type with unlignified walls and occurs as aerenchyma in the cortex of the corm and in the petiole
and midrib of the leaf blade. Mucilage ducts occur throughout the corm and their contents stain with
a reagent (β-glucosyl Yariv reagent) specific for arabinogalactan-proteins (a soluble dietary fibre). Large
numbers of starch granules occur in the cortex and central cylinder of the corm, but few occur in
the leaf.
Mycorrhizas and Other Specialized Nutrient-Acquisition Strategies: Their Occurrence in Woodland Plants From Kakadu and Their Role in Rehabilitation of Waste Rock Dumps at a Local Uranium Mine
Authors: Reddell P , Milnes AR
Published: December 2005

The presence of mycorrhizas, proteoid roots and leguminous nodules was determined in a range of
woodland species (from a variety of habitats in soils formed on different parent materials) in the Kakadu
area in the monsoonal tropics of northern Australia. In addition, the chemical fertility and the occurrence
of mycorrhizal fungi and rhizobia in rudimentary soils ('minesoils') forming in situ on waste rock dumps
at a mine site in the region were compared with stockpiled topsoils from the mine area and undisturbed
topsoils collected from the surrounding native woodland. A major aim of these investigations was
to assess the feasibility of rehabilitating the waste rock dumps without spreading topsoils.
More than 90% of the woodland flora examined had one or more specialised nutrient-gathering
mechanism. Mycorrhizas were found on 82% of the species, with some 16% of species having both
ecto and VA mycorrhizas, often on the same individual plant. Many of these observations are the
first records of mycorrhizal infection in the particular genera and species involved. Soil baiting and
dilution experiments showed that rhizobia and mycorrhizal fungi were ubiquitous components of the
soil biota in all undisturbed woodland soils. However, they were absent or poorly represented in the
stockpiled topsoils and in some of the rudimentary soils formed in waste rock at the mine site. The
diversity of spore types and/or numbers of infective propagules of VAM fungi was lower in stockpiled
topsoils and in minesoils than in the undisturbed woodland soils. Nutrient omission experiments identified
that acute deficiency of P, and to a lesser extent N, was a limitation to growth of seedlings on all
soils. Zn deficiency was detected in the only soil for which this was examined. A glasshouse experiment,
using a young minesoil and application of basal nutrients, demonstrated that inoculation of Acacia
holosericea seedlings with rhizobium could completely alleviate the effects of N deficiency. Under
conditions of both N and P deficiency, dual inoculation of A. holosericea with rhizobium and spores
of the VAM fungus, Glomus, only partly overcame the limitations of P deficiency on seedling growth.
Induction of deficiencies of P and Zn in a second minesoil (through application of basal nutrients),
demonstrated that inoculation of seedlings of Eucalyptus pellita with spores of the ectomycorrhizal
fungus, Scleroderma, partly alleviated the effects of both deficiencies.
Rehabilitation strategies implemented at the mine site using either soils forming in situ on the waste
rock dumps, or by spreading stockpiled topsoils, will need to ensure deficiencies of P and other nutrients
are alleviated and that viable populations of mycorrhizal fungi and rhizobia are introduced and maintained
during early phases of vegetation establishment.
Chromosome-Pairing and Pollen Viability in Desmodium ovalifolium Wall × Desmodium heterocarpon (L) DC. Hybrids
Authors: Mckellar MA , Quesenberry KH
Published: December 2005

Lack of genetic compatibility can result in low viable seed production in wide crosses. One year of an ongoing hybridisation program, during which 1333 Desmodium ovalifolium × Desmodium heterocarpon crosses were made, resulted in only two F1 plants. An examination of four stages of microsporogenesis (metaphase I, first division segregation, late tetrad microspore production, and pollen shed) was conducted for two lines of D. ovalifolium, three lines of D. heterocarpon and five D. ovalifolium × D. heterocarpon F1 hybrids made over a 2- year period. Both parental lines and hybrids had low levels of metaphase I univalents, anaphase I laggards, abnormal tetrad microspore production, and had high percentages of pollen stainability. Lack of chromosome homology does not appear to be the reason for low hybrid production in controlled crosses between D. ovalifolium and D. heterocarpon.
Floral Morphology and Breeding System of Three Species of Eucalyptus, Section Bisectaria (Myrtaceae)
Authors: Ellis MF , Sedgley M
Published: December 2005

Aspects of the breeding system, floral morphology and pistil cytology were studied in three trees each
of E. spathulata, E. cladocalyx and E. leptophylla. E. spathulata and E. leptophylla were found to be
highly self incompatible, setting very low levels of seed from controlled self pollination. E. cladocalyx
trees ranged from self compatible to self incompatible. Reductions were seen in both the number of
capsules and the numbers of seeds per capsule, from self pollination. The mechanism of self
incompatibility was investigated in the pistil by following the success of cross and self pollinations with
fluorescence microscopy. In E. cladocalyx and E. leptophylla no reduction in ovule penetration was
seen from self pollination while in E. spathulata a significant reduction was seen in two trees but not
the third, indicating that the post-zygotic mechanism of self incompatibility operates in all three species,
and with mixed pre-zygotic and post-zygotic mechanisms in E. spathulata.
Floral architecture differed between the three species in the structure of the inflorescence units,
flower morphology, and anther, pollen and ovule numbers per flower. Pistil cytology was similar for all
three species but differed in the length of the stylar canal, degree of sclerotinisation, stigma morphology
and volume of transmitting tissue. The implications of floral structure and of the location and extent of
outcrossing control are discussed in relation to seed genotypes and seed output.
Formation and Structure of Mycorrhizas of Seedlings of Coachwood (Ceratopetalum apetalum)
Authors: Mcgee PA , Furby JH
Published: December 2005

The mycorrhizas of seedlings of coachwood (Ceratopetalum apetalum) were examined. When the host was grown under increased photon flux density infections of both vesicular-arbuscular (VA) and a sheathing association were extended. Paris type VA mycorrhizas were observed, though arbuscules and vesicles were rare. Hyphae of VA mycorrhizal fungi appeared to degenerate when under the sheathing association. The sheathing association was characterised by thin mantles and no Hartig net. An electron-dense bilayer formed over hyphae in the sheath and hyphae were surrounded by a fibrillar matrix. Beneath the sheath, the walls of the epidermis were thickened and fibrillar. Lignin and suberin were present in the walls of cells of the hypodermis and absent in the epidermis. No evidence was found that the fungal associations induced a negative response from the host. While the structure of the mycorrhizas was unusual, the sheathing association was believed to be a variant of typical ectomycorrhizas.
Cryopreservation of Shoot-Tips of Grevillea scapigera (Proteaceae): a Rare and Endangered Plant From Western Australia
Authors: Touchell DH , Dixon KW , Tan B
Published: December 2005

Cryopreservation of leaf, petiole, stem pieces and shoot-tips was investigated as a means for long-term maintenance of germplasm of the rare and endangered species, Grevillea scapigera A.S. George. Crypreservation was only achieved using shoot-tips or axillary buds and a slow-cooling regime with the aid of an improvised freezing device. The highest survival of thawed explants (20%) was obtained with 4-week-old in vitro shoot-tips cultured for 48 h in a prefreezing liquid culture medium supplemented with 5% dimethylsulfoxide. The pretreated shoot-tips were frozen in a liquid medium containing 10% dimethylsulfoxide cooled at a rate of 0.5°C/min to -40°C and held at this temperature for 30 min before being plunged into liquid nitrogen. Shoot-tips that survived the freeze-thaw cycle produced callus followed by shoot production 22 weeks after thawing. All shoots regenerated from thawed tissues and transferred to soil appeared phenotypically identical to untreated control shoots and plants. Rapid methods for assessing post-thaw tissue viability and explant recovery using triphenyltetrazolium chloride were tried but these methods were inadequate for determining the capacity of thawed tissues to recover from freeze damage.
Stand Structure and the Influence of Overwood on Regeneration in Tropical Eucalypt Forest on Melville-Island
Authors: Fensham RJ , Bowman DMJS
Published: December 2005

The stand structure of tree species in tropical eucalypt forest on Melville Island reveals a mass of short woody sprouts in the ground layer and low numbers of sapling eucalypts. The growth of the woody sprouts showed no significant response in the first 2 years after release from overwood competition. However, eucalypts are released in response to overwood removal, after 2-5 years, although investigations of old clear-felled blocks indicated that this response is not consistent. The initiation of saplings may be related to the size of the lignotuber and the presence of a tap root for some species. It is suggested that the accession of saplings may be limited by the degradation of root systems by termite herbivory. Using assumptions regarding longevity of life stages, it is demonstrated that the forest structure of the study site can be perpetuated undercurrent conditions despite indications that the relative dominance of the forest eucalypt species will shift.
Control of Growth and Flowering in Two Western Australian Species of Pimelea
Authors: King RW , Dawson IA , Speer SS
Published: December 2005

Pimelea ferruginea and P. rosea both show an obligate requirement for exposure to mean temperatures
below 15°C for more than 5 weeks for induction of flowering. Subsequently, floral primordia develop
slowly in these cool conditions or rapidly if the average temperature is raised to 21°C. Plants held
at 21°C or warmer remained vegetative for over 1 year. P. rosea was found to be daylength neutral,
whereas flowering of P. ferruginea was enhanced, slightly, by a short day photoperiod of 10 h. Plant
height was greater for both species in long days. Benzylaminopurine (BA) was effective for increasing
branching. Gibberellin A3 (GA3) and paclobutrazol were effective in controlling plant height in P.
ferruginea. Flower life was not altered by application of silver thiosulfate and BA, and was greatest
when plants were grown in high photosynthetic photon flux density and at lower temperatures (15/
10°C v. 24/19°C).