bluuebunny/crossref_metadata_2025 huggingface dataset:
Altitudinal Variation in the Photosynthetic Characteristics of Snow Gum, Eucalyptus pauciflora Sieb. Ex Spreng. I. Seasonal Changes Under Field Conditions in the Snowy Mountains Area of South-Eastern Australia
Authors: Slayter RO , Morrow PA
Published: December 2005

A field study of seasonal changes in the photosynthetic characteristics of three altitudinal populations
of the snow gum (Eucalyptus pauciflora Sieb. ex. Spreng) was conducted at elevations of 915, 1215
and 1645 m in the Snowy Mountains area of south-eastern Australia.
At optimal temperatures in midsummer, peak rates of photosynthesis under CO2-saturating
conditions (Psub) reached levels of 125-135 ng cm-2 sec-1, and under ambient CO2 conditions (Pamb)
reached levels of 45-55 ng cm-2 sec-1. Corresponding values of the intracellular resistance to CO2
transfer (ri) were 5-6 sec cm-1, and of the gas phase resistance to water-vapour transfer (r,)
1.2-2 sec cm-1.
Measured at temperatures of 15, 20 and 25°C, the peak seasonal values of Pmax showed no
significant difference between sites, but at 5° and 10° peak values were highest at the highest elevation
(coldest site), and at 30° and 35° peak values were highest at the lowest elevation (warmest site).
Generally similar patterns applied to Paamb. These features are consistent with the view that E.
Pauciflora shows continuous variation in many physiological characteristics over its altitudinal range.
At each site the temperature optimum for photosynthesis changed markedly during the season,
and was closely correlated both with the long-term maximum air temperature and with the mean
maximum temperature of the 10 days prior to the date of measurement. This appeared to reflect
long-term adaptation of the photosynthetic apparatus of each population to the general temperature
conditions at each site, combined with a short-term acclimation to the prevailing seasonal temperature
regime.
Early Stages of Regeneration After Burning in Dry Sclerophyll Vegetation. I. Regeneration of the Understorey by Vegetative Means
Authors: Purdie RW
Published: December 2005

The dynamics of regeneration by vegetative means were examined during the first 2 years after summer
burning of dry sclerophyll vegetation. Three shrub species were fire-sensitive, and the remaining
perennial shrub and herb species fire-resistant and able to produce vegetative regrowth. The latter
were classified as 'increasers' or 'decreasers' on the basis of their ability to multiply vegetatively.
Of all pre-burn plants, 50-75 % commenced regrowth within 2 months of burning. Vegetative
recovery appeared to be affected most by fire intensity, post-burn soil moisture, plant age and the
origin of the regrowth. The vegetative multiplication of most increaser species was stimulated after
burning.
Regrowth survival was high, and the few observed instances of death were caused by water stress.
The floristic composition of the vegetation remained the same after burning, and although species
dominance appeared to change, it was related to differences in the method of species regeneration.
Seasonal Nutrient Dynamics of Litter in a Subtropical Eucalypt Forest, North Stradbroke Island
Authors: Rogers RW , Westman WE
Published: December 2005

The plant components and chemical composition of litter fall and the litter layer in a forest growing
on deep, nutrient-poor sands were examined on North Stradbroke Island, south-eastern Queensland.
The seasonal distribution of litter fall was examined over a 26-month period. While the total litter
fall was greatest during summer months, the dominant tree species differed in their individual
patterns of litter fall. Eucalyptus signata showed a single summer peak for leaf fall while E. umbra
exhibited one peak in early summer and another in autumn. The possibility is discussed that these
and other temporal differences are evolutionary expressions of niche differentiatibn to reduce
competition between species in the ecosystem. The total litter fall averaged 640 g m-1 yr-1 and
the accumulated forest floor mass totalled 2700 g m-2.
Total nutrient pools and nutrient inputs in litter fall are presented. A litter half-life of 2.9 years
is estimated, a figure close to the half-life of most of the nutrients in the litter. Manganese appears
to be markedly concentrated in eucalypt leaves before they fall. Only sodium, potassium, copper and
chloride appear to be leached easily from leaves slashed from trees and left on the forest floor.
Patterns of litter production and decay in this subtropical forest fit within trends extrapolated from
temperate Eucalyptus-dominated communities studied to date.
Studies of marine algae in the lesser-known families of the Gigartinales (Rhodophyta). I. The Acrotylaceae
Authors: Kraft GT
Published: December 2005

The Acrotylaceae is composed of Acrotylus australis J. Ag., Hennedya crispa Harv., Amphiplexia
hymenocladioides J. Ag. and A. racemosa (J. Ag.) comb, nov. (all endemic to southern Australia),
Reinboldia polyearpa Schmitz from South Africa and Ranavalona duckerae gen. et sp. nov. from
southern Madagascar. The species are multiaxial, zonately tetrasporangiate and monoecious. In
Acrotylus and Ranavalona the tetrasporangia develop in raised nemathecia, whereas they are
scattered in the other species. In Amphiplexia hymenocladioides, tetrasporangia are intercalary in
contrast to the other species with known tetrasporophytes. Acrotylus and Ranavalona are polycarpogonial,
with the carpogonial branches of Ranavalona being additionally nemathecial. The remaining
genera are monocarpogonial, with scattered carpogonial branches. The carpogonia in all species are
directed laterally or thallus-inwardly and provided with reflexed trichogynes. The species are all
procarpic (except possibly Reinboldia), with supporting cells of carpogonial branches functioning as
auxiliary cells. Fusion cells do not form, and several gonimoblast initials arise directly from diploidized
auxiliary cells and enter an adjacent region of 'nutritive' cells. Gonimoblast development is thallus-outward
in Amphiplexia and thallus-inward in Acrotylus, Ranavalona, Hennedya and possibly
Reinboldia, the last genus being known only from a surviving fragment of the type specimen. In all
but Amphiplexia, breakdown of the auxiliary cell, some adjacent cortical cells and some older gonimoblasts
results in a cavity which is lined by gonimoblast derivatives connected to surrounding
nutritive and other vegetative cells. With expansion of the cavity, branched gonimoblast filaments
grow centripetally and produce terminal or short chains of carposporangia that are released through
distinct ostioles. In Amphiplexia, nutritive cells do not completely surround the auxiliary cell, and
most gonimoblast filaments initially cover the interior surface of the pericarp rather than a cavity
lined by specially produced nutritive cells.
The genera are separated on wide differences in habit, vegetative cross section, carpogonial
branches, gonimoblast orientation, carpospore morphology and mature cystocarp cross sections.
The two African genera Ranavalona and Reinboldia appear on vegetative and certain reproductive
grounds to be relatively primitive in the group, with possible links to the less reproductively
complex family Solieriaceae. The most closely related genera within the Acrotylaceae, Acrotylus
and Ranavalona, are also about the most geographically separated. The present-day distinctiveness,
uncommonness and distribution of the genera of the Acrotylaceae perhaps suggest that it is a relict
and isolated group.
Biomass and Structure of a Subtropical Eucalypt Forest, North Stradbroke Island
Authors: Westman WE , Rogers RW
Published: December 2005

The plant biomass of a Eucalyptus signata-dominated forest 15 m tall growing on infertile sands off
the Queensland coast is characterized in detail. The forest has a biomass of 180 t/ha, 90% of which
is found in the nine species achieving > 2.5 m height. Of the total biomass, 42.5 % is below ground.
Pteridium esculentum occupies 41 % of the understorey biomass, with 50 shrub and herb species
partitioning the remainder. Dimension analysis of 10-11 individuals of each of three tree species-
Eucalyptus signata, E. umbra subsp. umbra and Banksia aemula-has served to characterize the
above- and below-ground growth forms of each species, and provide regressions of the mass of tree
components on easily measured plant parts. The size distribution of tree and shrub stems on the
site suggests that the major species have evolved quite different reproductive strategies for main-
taining a steady-state population in the face of recurrent fires.
Sectional reclassification of Drosera subgenus Ergaleium (Droseraceae)
Authors: DeBuhr LE
Published: December 2005

The sectional classification of Drosera subgenus Ergaleium is evaluated as a result of the discovery of D. fimbriata. Stem anatomical features of systematic and evolutionary importance in the subgenus are described and illustrated. The relationships of D. fimbriata and the evolutionary implications of the stem anatomy are discussed, and a new sectional classification is proposed. The new Drosera section Stolonifera is described.
Effect of Seed Treatments on Germination in Acacia
Authors: Clemens J , Jones PG , Gilbert NH
Published: December 2005

The germination of seed of five Acacia spp. was studied following a manual chipping treatment or
exposure to water held at different temperatures for discrete time periods. Response was evaluated
on the basis of the final percentage germination, and estimates of rate of germination and time taken
for germination to commence.
There were differences in response of the species to hot water sufficiently large to be of practical
significance. No single treatment gave optimum germination in all species. Increasing severity of
treatment improved germination rate and percentage germination up to a point where seed mortality
became apparent.
Manual chipping of the seed gave larger improvements in germination rate, and the seeds began to
germinate faster than those given any hot water treatment. However, in some species germination
percentages were lower in chipped seeds than in those treated with hot water.
Volatile oils and the study of natural hybridization between Correa aemula and C. reflexa (Rutaceae)
Authors: Whiffin T
Published: December 2005

A small hybrid swarm between Correa aemula and C. reflexa was located and examined morphologically and chemically, with an emphasis on volatile oils. The hybrid plants were intermediate morphologically between the two parental species. The volatile oil data were subjected to multivariate numerical analysis, the results of which confirmed the general intermediacy of the hybrid plants. In general it was found that ordination is a more useful technique for the study of hybridization than is classification. It would appear that numerical analysis of volatile oil data will prove a useful technique in the study of the complex variation found within the genus Correa.
Raciation in Epacris impressa. I. Corolla colour and corolla length
Authors: Stace HM , Fripp YJ
Published: December 2005

195 populations of Epacris impressa in Victoria, South Australia and Tasmania were surveyed for corolla colour composition. Of these, 75 consisted entirely of plants with white, or pink, or scarlet corollas. These monomorphic populations showed a consistent association between corolla colour, corolla length and anther colour, which suggested that corolla colour is a marker of racial development in this species. Most of the other 120 populations were polymorphic for pink- and white-flowered plants, the content of white-flowered plants ranging from 1 to 99 %. Twenty-six of these polymorphic populations were located in the Grampians and belong to the previously recognized grandiflora race. Four races are distinguished in E. impressa, marked respectively by short white corollas, long pink corollas, long scarlet corollas, and broad pink or white corollas (grandiflora). Corolla colour and length in the genus Epacris, and the potential importance of corolla colour and other differences in successful pollination are discussed.
Raciation in Epacris impressa. III. Polymorphic populations
Authors: Stace HM , Fripp YJ
Published: December 2005

Polymorphic populations occur throughout most of the distribution of E. impressa Labill., in which pink-flowered plants and white-flowered plants grow intermixed in the same locality. Measurements of corolla lengths indicate that these are panmictic populations: there is no difference between the mean lengths of pink and white corollas. In homogeneous populations (the vast majority) there is no seasonal variation in the flowering times of white-flowered bushes and pink-flowered bushes.
At Wilson's Promontory polymorphic scarlet/pink/white populations occur near polymorphic pinklwhite populations and monomorphic scarlet populations. Some of these triple polymorphic populations show heterogeneity of population structure, with seasonal differences of flowering time in the different morphs. Polymorphic populations are generally intermediate between monomorphic populations of the different races of E. impressa. It is likely that they are of hybrid origin. The hypothesis that polymorphic populations form a base for disruptive selection into monomorphic populations is also discussed.
A Revision of Varieties of Stylosanthes guianensis (Aubl.) Sw
Authors: Mannetje LT
Published: December 2005

A key, illustrations, descriptions and areas of distribution are presented for the following 6 varieties recognized in S. guianensis: guianensis, gracilis (Kunth) Vog., intermedia (Vog.) Hassler, robusta
var. nov., dissitiflora (Robins. & Seat.) stat. nov., and longiseta (Mich.) Hassler.
Introduced Australian material has been identified and features of the varieties relating to
flowering, Rhizobium. affinities, genetic barriers, seed protein pattern and morphological-agronomic
relations are presented.
A note on photosynthesis in relatin to water content in liverwarts: Porella platyphylla and Scapania undulata
Authors: Gupta RK
Published: December 2005

Relative water content and photosynthesis were measured after treating two liverworts, the highly drought-resistant Porella platyphylla (L.) Lindb, and the non-resistant Scapania undulata (L.) Dum., at 96.5% RH for various periods., In both species the variation in the relative water content during water stress followed the same pattern, dropping steadily up to 50 hr and then remaining unchanged. Photosynthesis reached a peak during the initial phase of water loss and decreased steadily with further water loss in both species. The maximum photosynthesis occurred after 2 hr of desiccation in Porella and after 6 hr in Scapania.
Experiments on the rate of development of adventitious roots on Sambucus nigra cuttings
Authors: Warren Wilson PM , Warren Wilson J
Published: December 2005

The number of roots emerging daily from Sambucus nigra cuttings was maximal after about 2 weeks and subsequently declined to near zero. If the emerged roots were removed, however, further adventitious roots developed: repeated removal of all roots, or of the rooted base of the cutting, was followed by successive flushes of roots, and removal of every root as it emerged resulted in the initiation of adventitious roots continuing throughout experiments lasting 10 weeks or longer. The results can be interpreted in terms of the initiation rate being related inversely to the number of existing roots, and a quantitative analysis shows that this interpretation can account not only for the time course of root emergence on normal cuttings but also for a damped oscillation observed in the rate of root emergence when emerging roots were continually removed.
Microbial populations of three forest soils: seasonal variations and changes associated with Phytophthora cinnamomi
Authors: Weste G , Vithanage K.
Published: December 2005

Microbial populations of three forest soils were assayed by a dilution plate procedure and compared with garden soil. The forest soils were selected from areas subjected to die-back disease caused by Phytophthora cinnamomi Rands, and were from sites for which pathogen populations, soil temperatures, rainfall and soil water potentials were concurrently recorded. Forest soils showed low microbial populations compared with garden soil. This was associated with low organic content, low nitrogen status and poor water-holding capacity. Areas with severe disease and rapid disease extension had a small soil microbial population, particuarly of actinomycetes, compared with soil from areas with moderate disease and slow disease extension. Microbial populations were lowest in spring and autumn when P. cinnamomi was most active, and zoospore production, dispersal and infection was maximal. Microbial populations of forest soil were reduced following die-back; and the reduction of disease was highly significant (P < 0.01) for the Brisbane Ranges where plant mortality was high and the percentage of bare ground increased.
Pre- and Post-Emergence Damping Off of Seedlings of Pinus Species by Phytophthora cinnamomi and Ph. Drechsleri
Authors: Heather WA , Pratt BH , Chin TU
Published: December 2005

Inoculum of Phytophthora cinnamomi and Ph. Drechsleri incorporated into coarse river sand caused
significant reductions in the survival, height growth, dry weight and root/shoot ratio in seedlings of
most Pinus species tested. Major exceptions were Pinus massoniana, which was not significantly
affected by any treatment, and P. khasya, which was significantly affected by only the northern Ph.
Drechsleri isolate. The significance of these results in relation to nursery and plantation establishment
is discussed.
Variation and Natural Hybridization in the Conostylis aculeata R.Br. Species Group Near Dawesville, Western Australia
Authors: Hopper SD
Published: December 2005

Variation was studied in allopatric and sympatric populations of Conostylis aculeata R.Br.,
C. candicans Endl., and C. pauciflora Hopper near Dawesville, on the Swan River Coastal Plain.
When in allopatry the three species were found to be morphologically similar but distinguishable by
hybrid index analysis. They also showed variable but overlapping habitat preferences. C. paucifora
was morphologically intermediate between C. aculeata and a coastal ecotype of C. candicans.
Sympatric populations of two pairs of species, C. candicans-C. aculeata and C. pauciflora-C. aculeata,
contained intermediate hybrids with slightly reduced pollen fertility relative to the parents. Hybrid
populations were confined to ruderal habitats. Ecological factors appeared to be primary in
maintaining isolation between the species, since indiscriminate pollination occurred in sympatric
populations, and hybrids were abundant and fertile. The taxonomic and evolutionary implications
of natural hybridization in the C. aculeata group, including the possibility of a hybrid origin of
C. pauciflora, are discussed.
The structure and dynamics of a hybrid population of Anigozanthos manglesii D. Don and A. humilis Lindl. (Haemodoraceae)
Authors: Hopper SD
Published: December 2005

The structure of a hybrid kangaroo paw population (Anigozanthos Labill.) in the shire cemetery at Gingin, Western Australia, was analysed from multivariate morphometric, pollen fertility and floral colour data. A. manglesii D. Don. comprised 87% of the population of 9547 flowering individuals in 1976, and occupied the lower, wetter areas of the cemetery to the exclusion of A. humilis Lindl. A. humilis (11 % of the population) occurred at the greatest density on the higher, drier areas. The intervening ecotonal regions were occupied by both species, and by the majority of F1 hybrids (0.5 % of the population) and backcrosses (c. 2%). Census data documented a threefold increase in the number of A. manglesii individuals, a slight increase in the number of F1 hybrids, and a decrease in the number of A. humilis by a third over a 3-year study period. These data suggest the occurrence of a limited amount of introgressive gene exchange in the face of potent barriers to interspecific hybridization.
The reproductive capacity of Anigozanthos manglesii D. Don, A. humilis Lindl. and their hybrids in a wild population
Authors: Hooper SD
Published: December 2005

The flower production, fruit set, seed set and seed germination of parental and hybrid Anigozanthos individuals from the Gingin cemetery, Western Australia, were investigated to establish whether differences in reproductive capacity could have been responsible for observed short-term numerical changes in the population. A. manglesii had a six- to ninefold reproductive advantage over A. humilis due to greater seed set and better germination. F1 hybrids and backcrosses had reproductive capacities equivalent to or slightly better than A. humilis. The agreement between calculated reproductive capacity values and the trend of numerical changes in the cemetery supports the conclusion that differences in reproductive performance have played a significant role in the short-term dynamics of the population.
Diurnal rhythms in stem elongation in Eucalyptus obliqua in relation to temperature and seedling water status
Authors: Blake TJ
Published: December 2005

Diurnal patterns of stem elongation varied with ambient temperature. Stem elongation was more rapid during the day at lower (20-24°C) day/night temperatures. However, the proportion of night growth increased with increasing temperatures from 30% of the daily total at 20� to 100% at 30°. A decline in both the number and duration of growth flushes appeared to explain the low level of shoot elongation at higher (28° and 30°) day/night temperatures. Under the given experimental conditions, diurnal rhythms in stem elongation reflected ambient temperature rather than seedling water potential.
Phytophthora cinnamomi: Population Densities in Forest Soils
Authors: Weste G , Ruppin P
Published: December 2005

Population densities of Phytophthora cinnamomi, associated disease and environmental factors were
studied concurrently during a 2-year period in three different forest ecosystems. Pathogen populations
showed seasonal variation, low values being obtained for winter months associated with soil temperatures
less than 10°C. Populations increased with warmer temperatures for spring and summer,
but declined during dry periods in late summer or early autumn when the soil water potential was
lower than -9 bars, although at that period soil temperatures were favourable. High populations
were recorded in autumn, then declined with decrease in soil temperatures during winter. Correlation
coefficients indicated a highly significant relationship between pathogen populations and soil
temperatures from autumn to early summer, and between soil moisture and pathogen population
for summer and autumn, in the Brisbane Ranges independently of site. The same pattern was evident
in wetter forests at Narbethong and savannah woodlands at Wilson's Promontory, although results
were not significant.
Disease was evident wherever the pathogen occurred among susceptible hosts. The savannah
woodland, the dry shrubby sclerophyll forest and the wetter sclerophyll forest all contained susceptible
dominants; consequently disease was associated with changes in the forest community such as
early death of the understorey, later die-back and death of the trees, and an increase in sedges and
in bare ground. Symptoms and deaths increased with time from invasion. The severity of disease
and its rate of extension, apart from spread by free water, were associated with environmental factors
such as shallow soil, poor drainage and low soil water-holding capacity. These were characteristic of
the Brisbane Ranges, where destruction of the forest community was severe and the rate of disease
extension rapid. In the deep krasnozem at Narbethong and the deep sands of Wilson's Promontory,
destruction was confined to the most susceptible hosts, disease extension was continuous but slow,
and deaths occurred in a mosaic throughout the infected zone.
Root Exudates From Eucalyptus calophylla R.Br. And Eucalyptus marginata Donn. ex Sm. Seedlings and Their Effect on Phytophthora cinnamomi Rands
Authors: Malajczuk N , Mccomb AJ
Published: December 2005

Root exudates from seedling eucalypts were collected aseptically, analysed for sugars, amino acids and organic acids and an examination made of their effect on zoospore chemotaxis, mycelium growth and chlamydospore germination of Phytophthora cinnamomi. Seedlings of root-rot susceptible Eucalyptus marginata produced greater concentrations of sugar and amino acid exudates than the root-rot resistant Eucalyptus calophylla at all sampling times. There was, however, little qualitative difference between the eucalypt root exudates. Both eucalypts attracted zoospores to roots in culture tubes. Infection of the roots followed encystment and germination of the zoospores. Germination of chlamydospores and mycelium growth of P.cinnamomi was significantly increased by the presence of root exudates and no differences were observed between exudates of the two species. Only amino acids and organic acids stimulated germination of chlamydospores. It was concluded that differences in root-rot susceptibility of eucalypts to P.cinnamomi are not attributable to differences in root exudate from eucalypt seedlings.
The Distribution and Abundance of Vesicular Arbuscular Endophytes in Some Western Australian Soils
Authors: Abbott LK , Robson AD
Published: December 2005

The distribution and abundance of large-spored vesicular arbuscular (VA) endophytes was examined at three localities in Western Australia. Within each locality, soil samples were collected from sites with a range of soil properties and superphosphate histories. Vesicular arbuscular endophytes were widespread. Spores were found in all but five of 104 samples. In two of the samples where spores were not found, plants grown in the soils formed VA mycorrhizas. Root infection by a fine endophyte resembling Rhizophagus tenuis was also frequently observed. Five spore types were found. Honey-coloured sessile spores were present in 85% of the samples. The yellow vacuolate spore type was the second most common endophyte, but its distribution was mostly limited to cultivated and fertilized soils. Endophytes other than the yellow vacuolate spore type occurred on both virgin and agricultural soils. The distribution of honey-coloured sessile and yellow vacuolate spores in cultivated soils appeared to be associated with variation in soil pH. The total numbers of spores collected on a 106 μm sieve were not correlated with soil pH, NaHCO3-extractable phosphorus or superphosphate history.
A Comparison of Two Photographic Techniques for Estimating Foliage Angle Distribution
Authors: Smith JA , Oliver RE , Berry JK
Published: December 2005

There is an increasing interest in theoretical models which describe the interaction of solar radiation
with vegetation canopies. Common to these models is a need to describe mathematically the geometric structure of the plant canopy. The amount of radiation reflected or absorbed by the canopy
is primarily determined by the distribution of gaps in the foliage with respect to the radiation source.
A measure of canopy geometry related to gap frequency at various view angles is the distribution of
leaf angles. Two methods for measuring the distribution of leaf angles are discussed. The first
method is to project orthogonally and photograph individual plants and relate the measured leaf
angles in the projections to the canopy distribution of angles. The second method is a rapid in situ
method based on ground level multiple view angle photography. A Fredholm integral equation
relating foliage angles to the proportion of gap in the canopy as a function of view angle is then
solved. Comparisons of the results using the two methods are made for a canopy of Western wheat
grass (Agropyron smithii).
Reversible curvature of style branches of Hibiscus trionum L., a pollination mechanism
Authors: Buttrose MS , Grant WJR , Lott JNA
Published: December 2005

Hibiscus trionum, like several other members of the Malvaceae, has flowers with prominent styles which can reflex during the first few hours after opening so that stigmas make contact with the anthers. This self-pollination mechanism can be interrupted if stigmas are pollinated before or during bending. They then maintain or regain the erect position and selfing cannot occur. Various treatments which can affect this reversal of bending are described.
Phosphorus Uptake and Utilization by Tree Seedlings
Authors: Barrow NJ
Published: December 2005

Seedlings of five native forest species and of Pinus radiata D. Don were grown in pots in a forest soil
at a range of levels of added phosphate for up to 20 weeks. At intervals of 3 weeks, roots were
examined for root hairs and mycorrhizas and the weights of plant parts and their phosphorus contents
were measured. Components of growth and response were calculated from three-dimensional
surfaces which had level of phosphate and time as the independent variables.
Except for Banksia grandis Willd., the species responded to phosphate but the time at which the
response appeared was affected by seed reserves of phosphorus. Thus response appeared much
earlier for the small-seeded Eucalyptus divevsicolor F. Muell. and Acacia pulchella R. Br. than for the
large-seeded Eucalyptus calophylla R. Br. and Eucalyptus marginata Donn. ex Sm. The absence of a
response by the banksia seemed to arise because of a large seed reserve of phosphorus, a low relative
growth rate and a very low concentration of phosphorus in the leaves for maximum photosynthesis.
The rates of uptake of phosphorus per unit weight of roots were generally low but increased at a
time coincident with the development of mycorrhizas. Relative growth rates and the net assimilation
rates were also low and reached maximum values at low concentrations of phosphorus in the leaf.
The outcome was that the level of applied phosphate needed for good early growth did not differ
greatly from that of Trifolium subterraneum L.
Ultrastructure of the Host-Parasite Relationships of Pseudoperonospora humuli on Hops
Authors: Pares RD , Greenwood AD
Published: December 2005

Infected leaf tissue was examined at 3, 4, 5 and 6 days after inoculation, after different fixing and
staining techniques. One example of stomata1 penetration was seen. Examples of cell penetration
and haustorium development were examined in detail. Haustoria penetrate host cells by altering
host cell wall structure, and lomasomes are frequently present in the haustorium neck. Haustoria
do not have nuclei and in early stages have abundant mitochondria that gradually decrease in number
as infection advances.
Early Stages in the Development of Wheat Endosperm. II. Ultrastructural Observations on Cell Wall Formation
Authors: Mares DJ , Stone BA , Jeffrey C , Norstog K
Published: December 2005

In the first 4-5 days after anthesis, the central cell of the wheat embryo sac undergoes transformation
from a multinucleate syncytium to the cellular endosperm. This is accomplished initially by the
centripetal growth of wall projections from the central cell wall and the formation of cylindrical,
highly vacuolate alveoli. Growth is mediated through the production and planar aggregation of
vesicles at the distal tip of the developing projections. The innermost ends of the alveoli are closed
by a thin layer of cytoplasm which is bounded on the inner side by the vacuolar membrane of the
central cell. Cell wall material is not found in this thin layer of cytoplasm and the alveoli therefore
are not complete cells. Following the division of the alveolar nucleus a cross-wall is laid down
between the daughter nuclei by a process which is similar to normal cytokinesis and a layer of
endosperm cells is formed from the peripheral portions of the alveoli. This pattern of centripetal
growth of alveoli and the formation of complete cells from the proximal portions continues until
cellularization is completed by the confluence of alveoli originating from opposite sides of the central
cell. Further growth of the cellular endosperm is accomplished by the meristematic activity of the
peripheral layer of cells.
The ultrastructure of the early stages of partitioning of the central cell is discussed in relation to
current views on the ontogeny of wheat endosperm.
Studies of the status of unburnt Eucalyptus woodland at Ocean Grove, Victoria. I. The structure and regeneration
Authors: Withers J , Ashton DH
Published: December 2005

In a relatively dry maritime environment at Ocean Grove, Vic., an unburnt remnant of vegetation was found to consist of a mosaic of scrub dominated by Casuarina littoralis and C. stricta, and grassy to layered woodland dominated by Eucalyptus ovata, E. viminalis and E. leucoxylon. Evidence from regeneration patterns and local history indicates that eucalypts are dying out and are being replaced by Casuarina species, together with some Acacia pycnantha and Banksia marginata. It is suggested that such scrub may be the terminal stage of a long post-fire secondary succession, since regeneration of eucalypts under existing conditions is negligible. It is unlikely that such vegetation would have remained unburnt under natural conditions before European colonization.
Long-Term Biomass Dynamics in an Arid Chenopod Shrub Community at Koonamore, South Australia
Authors: Noble IR
Published: December 2005

A method for estimating biomass from long-term, non-rigorously controlled photo-points was developed. The method was used to investigate the changes in biomass, from 1926 to 1972, of several important forage species on the Koonamore Vegetation Reserve, South Australia. The changes in biomass are correlated with the rainfall. The biomass dynamics of all the species studied tend to be dominated by large input pulses followed by a slow decline in biomass. The average above-ground biomass and productivity for the community studied is c. 90 gm-2 and 30 gm-2 yr-1 respectively, the major part being due to short-lived plants. Interactions between the short-lived plants and shrubs, and their importance to the grazing industry are discussed.
The history of Ilex (Aquifoliaceae) with special reference to Australia: Evidence from pollen
Authors: Martin HA
Published: December 2005

Ilex is cosmopolitan excluding the arid and arctic areas and consists of some 400 species. Australia has one species, Ilex arnhemensis, which is restricted to the north. The pollen of Ilex is very distinctive and fossil specimens can be related to it with certainty. There is an undescribed fossil species in the Turonian (earliest Upper Cretaceous) of south-eastern Australia, where Ilex predates the first appearance of Nothofagus. Ilexpollenites spp. are usually present from Maastrichtian (latest Upper Cretaceous) to late Miocene. Elsewhere in the world there are three other Cretaceous records and abundant Tertiary occurrences from every geographic region. Ilex was cosmopolitan throughout the Tertiary and it may have been world wide in the Upper Cretaceous also. Ilex grows as a tree or shrub and requires a relatively wet and equable climate (with perhaps a few exceptions). The seeds are dispersed by birds and the embryo undergoes continuous development until germination which may take from 2 to 8 years. Such strategies must be an asset for a wide distribution. Previous works on modern distributions and morphology have implicated south-eastern Asia as the place of origin of Ilex. The fossil record does not support this hypothesis although it is not sufficient to pinpoint its origin. At the time when Ilex evolved, more equable climates extended much further towards the poles than they do today. The south-east Asian region has had one of the most stable climates and is a refuge for ancient angiosperms, regardless of place of origin. No doubt the development of aridity in Australia has restricted Ilex to the north.
Convesion of mevalonic acid by tissue cultures and leaes of Eremophila fraseri F. Muell. (Myoporaceae)
Authors: Dell B
Published: December 2005

Stem calluses of Eremophila fraseri were established on defined media. Resin components secreted by leaf glandular hairs could not be detected in callus extracts. Both calluses and isolated leaves metabolized [2-14C]mevalonic acid but only the leaves incorporated label into resin components. Rates of incorporation in leaf resins were low (1-3 %). These rates varied according to the com- position of the leaf resins.
Studies of the Lignotubers of Eucalyptus gummifera (Gaertn. & Hochr.). I The Nature of the Lignotuber
Authors: Mullette KJ
Published: December 2005

A study has been made of the lignotubers of the mallee form of E. gumrnifera growing in the Hawkesbury sandstone soils of the Sydney region. This form of the species has been found to produce extraordinarily large lignotubers, the largest covering an area of 75 m2; the tree form does not produce large lignotubers. The thicket-like habit of E. gummifera commonly found in the open heath areas of the Sydney region is due to the multiple stems arising from one large lignotuber. It is suggested that large lignotubers are an adaption enabling this species to survive damage to aerial parts.
Studies of the Lignotubers of Eucalyptus gummifera (Gaertn. & Hochr.). II. Anatomy
Authors: Bamber RK , Mullette KJ
Published: December 2005

The anatomy of mallee-type lignotubers of Eucalyptus gummifera has been investigated. The lignotubers contained the following tissues: cambium, phloem, rhytidome, sapwood, heartwood and kino veins. The types and characteristics in lignotubers and stems were generally similar. The lignotuber tissues differed from stem tissues only in quantitative aspects; for example, wood fibres were shorter, the proportion of axial parenchyma of the wood was greater and there was less expansion of the axial parenchyma of the outer phloem. The high proportion of storage tissue in the lignotuber wood in comparison with stem wood suggests that food storage is an important function of lignotubers.
Endogone Spores in a Heathland Area of South-Eastern Australia
Authors: Sward RJ , Hallam ND , Holland AA
Published: December 2005

An area of heath occurring on sandy podzolic soil at Cranbourne in Victoria has been studied. Relative spore numbers of vesicular-arbuscular mycorrhizal fungi have been monitored over a period of 2 years at sites containing disturbed and undisturbed native vegetation, as well as recolonizing areas of mixed indigenous and introduced species. A large number of 'Endogone' spores were found, and some correlation between peak spore numbers and periods of high rainfall was recorded at the disturbed sites. No such correlation was found in undisturbed heath. Many spores of varying morphology were examined, and eight spore types belonging to the non-sporocarpic members of the Endogonaceae have been described in detail. The viability of a white, bulbous-based spore type was investigated following storage in different conditions for varying lengths of time.
Growith of heath vegetation. IV. Effects of temperature on growth of Banksia ornata, B.serrata and B. serratifolia
Authors: Groves RH
Published: December 2005

Established seedlings of three closely related Banksia species (B. ornata, B. serrata and B. serratifolia), with different distributions in southern and eastern Australia, were grown under different day/night temperature regimes in a phytotron for 20 weeks. Results of measurements of shoot elongation and plant productivity show that plants of B. ornata, grown from seed collected in south-eastern South Australia, have a lower temperature optimum for growth than plants of the other two species, which were grown from seed collected at warmer sites in central New South Wales and southern Queensland respectively. This result suggests that in the predominantly winter rainfall areas of southern Australia B. ornata is not necessarily a 'relict' species with a growth pattern typical of a more tropical climate with predominantly summer rainfall.
Effects of Time Since Fire on Heath Floristics at Wilson's Promontory, Southern Australia
Authors: Russell RP , Parsons RF
Published: December 2005

Five stands of heath vegetation were located which were similar in all respects except that their age
since last being burnt ranged from 1 to 21 years. There were no major floristic differences associated
with age since fire. Species richness declined from about 60 species from 1 to 10 years since fire down
to 49 species at 21 years. The essentially self-replacing nature of the vegetation after fire is due to
the high incidence of rootstock regeneration.
Phytogeography of Acacia in Western Australia
Authors: Hopper SD , Maslin BR
Published: December 2005

Distributions of the 373 described and c. 113 undescribed species of Acacia occurring in Western Australia were plotted on state maps divided into 1° latitude by 1.5° longitude grids. The number of species per grid was determined, and species richness was shown to be highest along the inland eastern margin of the South-West Botanical Province. Minor centres of richness were found associated with mountainous areas of the Pilbara Region, Desert Region and Northern Botanical Province. It is proposed that the centres of species richness have been foci of recent evolutionary divergence and also refugia favouring the persistence of some relict forms. It is suggested that recent speciation has been promoted by recurrent migration, extinction and isolation of populations as a result of Pleistocene climatic fluctuations and their erosional consequences in climatically transitional areas. An analysis of the distribution of selected closely related species groups occurring in a range of habitats throughout Western Australia indicates that geographical isolation has played an important role in speciation in the genus.
Altitudinal Variation in the Photosynthetic Characteristics of Snow Gum, Eucalyptus pauciflora Sieb. Ex Spreng. VII. Relationship Between Gradients of Field Temperature and Photosynthetic Temperature Optima in the Snowy Mountains Area
Authors: Slatyer RO
Published: December 2005

Elevational gradients of several field temperature parameters were examined and compared with estimated and observed photosynthetic temperature optima for a range of elevational populations of E. pauciflora.
The gradient of maximum temperature (9.68°km-1) was found to be very close to the dry adiabatic lapse rate, regardless of whether annual, seasonal or monthly conditions were examined. In contrast, the gradient of minimum temperature (2.06°km-1) was much flatter and was affected by topographic location, particularly at sites exposed to nocturnal temperature inversions. The gradient of the square-wave conversion of the day-time temperature curve (Tsqw), found previously to be useful in mediating the photosynthetic temperature response, was intermediate in slope, 7.20°km-1. The gradient of the phytotron-derived preferred temperature for photosynthesis, Tpref (6.26°km-1), was very close to that for Tsqw. The acclimation coefficient, α, showed no apparent change with elevation. Estimates of field photosynthetic temperature optima, based on Tpref, α and Tequiv (which was the value of Tsqw averaged for 10 days prior to the date of measurement) were in close agreement with measured values. The close agreement between the gradients of Tpref and Tsqw, together with the effectiveness of estimation of field temperature optima by means of Tequiv suggested that a temperature function resembling Tsqw may exert effective selection pressure on the photosynthetic temperature response of E. pauciflora in this environment.
Mating Behaviour of Australian Isolates of Phytophthora Species. I. Inter- and Intraspecific Mating
Authors: Shepherd CJ
Published: December 2005

This paper presents the first detailed report on the mating behaviour of isolates of Phytophthora
drechsleri, P. cinnamomi, P. parasitica, P. palmivora, P. cryptogea and P. cambivora from Australia,
Papua New Guinea and New Britain. In all, 97 isolates of Australasian origin and four isolates of
American origin were examined.
Matings between species produced fewer oogonia and more aborted oogonia than occurred in
intraspecific matings. Isolates differed in their abilities to form oogonia in interspecific matings.
Unlike the other species examined, P. drechsleri isolates were unable to form oogonia and
oospores in many of the intraspecific matings attempted. In general, the mating patterns of P.
Cryptogea isolates were similar to those of P. drechsleri, which supports the conclusion that these taxa
are conspecific.
Isolates of P. parasitica mated freely in intraspecific pairings but showed some restrictions in
interspecific matings, with aborted oogonia frequently being produced. The behaviour of single-
zoospore derivatives from seven P.parasitica isolates that exhibited irregular sexual behaviour during
culture showed that three of the field isolates were heterocaryotic, carrying both homothallic and
A1 type nuclei.
Both homogenic and heterogenic incompatibility mechanisms may be operative as barriers to
free sexual reproduction. The present study indicates that determinations of mating competence are
of little taxonomic value.
Effect of Phytophthora cinnamomi on Microbial Populations Associated With the Roots of Forest Flora
Authors: Weste G , Vithanage K
Published: December 2005

The effect of Phytophthora cinnamomi Rands on the microbial populations associated with plant
roots of three forest communities was investigated by the dilution plate method. Rhizosphere and
rhizoplane populations for susceptible and tolerant hosts and soil microflora were compared for
diseased and unaffected areas. Populations of P. cinnamomi were determined concurrently from the
same root and soil material. Samples were collected every three months over a 2-year period from
sites for which rainfall, soil water potentials and soil temperature were continuously recorded.
Independently of the pathogen, microbial numbers from soil, rhizosphere and rhizoplane from
the dry shrubby sclerophyll forest of the Brisbane Ranges were significantly lower than those from
the savannah woodlands of Wilson's Promontory and one-tenth of those from wetter sclerophyll
forests of Narbethong. Microbial populations from soil and roots of the three forest communities
exhibited statistically significant seasonal periodicity with maxima in the autumn-winter period and
minima in the spring-summer seasons. This contrasts with P. cinnamomi populations, which
decreased almost to zero in winter and became maximal in spring-summer. The susceptible roots
examined were associated with smaller populations of microorganisms, particularly aerobic bacteria
and aerobic sporing bacteria in both rhizosphere and rhizoplane compared with tolerant roots.
Disease due to P. cinnamomi did not affect the relative microbial numbers occurring in soil,
rhizosphere and rhizoplane, but was always associated with a reduction in numbers of actinomycetes
on all sites. Severe disease in the Brisbane Ranges was associated with a significant increase in total
microorganisms, particularly aerobic bacteria, in the rhizoplane and rhizosphere of both susceptible
and tolerant plants, coincident with the production of decayed and dead root tissue. Anaerobic
bacteria increased and actinomycetes decreased in number from all rhizospheres sampled from
diseased sites. Finally in areas of severe disease in the Brisbane Ranges there was a subsequent
highly significant reduction in numbers of soil microorganisms associated with a decrease of plant
cover.
Infection of Axenic Eucalyptus Seedlings With Phytophthora cinnamomi Zoospores
Authors: Byrt PN , Holland AA
Published: December 2005

Young Eucalyptus seedlings were raised axenically and infected with small numbers of Phytophthora
cinnamomi zoospores at the root tip. The linear extent of hyphal growth up the root was measured
from 2 to 4 days and shown to be significantly greater in the highly susceptible species of Eucalyptus
when compared with those which are less susceptible in the field. Sporangium production on the
root was observed on both highly susceptible and less susceptible species in the presence of free
water and certain salts.