bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of lime (CaCO3) application on soil structural stability of a red earth
Authors: Chan K. Y. , Heenan D. P.
Published: August 2004

Changes in soil structural stability as a result of lime application
(1·5 t/ha) were monitored over 3 years in a red earth with
contrasting initial pH, organic carbon, and structural stability conditions at
Wagga Wagga, NSW. The lime was applied to the surface of the direct
drilled-soil without any incorporation, but in the case of the cultivated
soils, the lime was incorporated into the top 10 cm by scarifying.
After liming, an initial temporary reduction in macroaggregate (>2
µm) stability was detected in the immediate surface (0-2·5 cm) of
the direct-drilled soil where the highest increases in pH, losses in soil
organic carbon, and increases in microbial biomass were also observed. The
decrease in structural stability was attributed to lime-induced increases in
biological decomposition and the resulting soil organic carbon losses.
Subsequent samplings did not detect any difference in either macro- or micro-
(<50 µm) aggregate stability of this soil as a result of lime
treatment.
In contrast, for the 2 cultivated soils which had lower initial structural
stability and organic carbon levels, a decline in stability was not observed.
Instead, significant increases in macroaggregate and microaggregate stability
were detected 1·5 years after lime application. By the end of 3 years,
macroaggregate stability of the limed cultivated soils approached that of the
direct-drilled soil. The improvement in structural stability extended to
7·5 cm depth 3 years after lime application. Wet-sieving experiments
using prolonged periods of shaking indicated enhanced stability of the
water-stable aggregates of the limed cultivated soils but not the
direct-drilled soils.
Influence of plants and cropping on microbiological characteristics of some New Caledonian ultramafic soils
Authors: Amir H. , Pineau R.
Published: August 2004

Five New Caledonian ultramafic soils were compared for their bacterial and
fungal population densities and for their microbial activity estimated by
fluorescein diacetate (FDA) hydrolysis. The low microbial numbers and
activities were related to the organic matter content and to metallic
toxicity. Actinomycetes were found to be dominant among bacterial populations.
The effect of soil colonisation by plants on the microflora was studied and
appeared to be very favourable. The rhizosphere effect of 2 plant species
(Grevillea gillivrayi and
Costularia comosa) was estimated. The influence of
cropping on the development of microflora in one soil was also investigated
and a qualitative study of the fungal populations and their variation in
relation to the cropping was reported. The fungal flora was dominated by
Moniliaceae, and
Tuberculariaceaeand Dematiaceae
were absent in natural ultramafic soils. Cropping enhanced the diversity of
these fungal populations.
Inverse method to estimate mineralisation rate constants for nitrogen simulation models: interaction between sampling strategy and quality of parameter estimates
Authors: Snow V. O. , Bond W. J.
Published: August 2004

Sustainable agricultural practices and land application of wastes require that
the accession of nitrate to groundwater be within acceptable limits.
Simulation modelling is a valuable aid to the development and testing of
management practices that achieve this goal, but requires unbiased and precise
parameter estimates. Here we consider the role of simple lysimeter-based
techniques, which may yield only a single integral observation in the form of
total solute leached or total drainage, in supplementing infrequent
concentration data for the purposes of parameter optimisation.
The utility of such techniques was evaluated using a simulation model to
create a ‘no-error data set’ of nitrate concentration values and
summary observations of the total mass of nitrate leached and total drainage
over a 182-day period. From that no-error data set a more realistic data set
incorporating random error was created. By using those concentrations, the
value of the mass of nitrate leached or total drainage was evaluated by their
effect on the unbias and precision of optimised mineralisation or evaporation
parameters. The effects of observation weight, error in the observations, and
2 other experimental strategies involving a higher intensity of solute
sampling were also tested.
It was found that the summary observations, such as those obtainable from
simple lysimeter-based techniques, had the potential to reduce bias and
improve the precision of the optimised parameters. The consequence of this
effectiveness was that error in the summary observations led to considerable
error in the optimised parameters.
Geomorphic controls on aluminium in acid soils of the Axe Creek catchment, Victoria
Authors: Ruth A. , Johnson B. B. , Fowler T. J.
Published: August 2004

This study investigates the influence of terrain, including steepness and
position in slope, on soil pH, extractable aluminium (Al), and organic carbon
(OC) in the Axe Creek catchment, Victoria. Both soil pH and Al were determined
by use of 1 : 5 soil : 0·01 M CaCl2 extracts,
with Al measured colorimetrically using a modified pyrocatechol violet method.
Although all soils were acidic, the Al concentration was highest on the
hilltops (>10 mg/kg) and lowest at base-of-slope sites (<1
mg/kg). The concentration of Al was generally inversely related to soil
pH. However, on average, a lower Al concentration was found in the top 10 cm
than in the interval from 10 to 30 cm, even though the soil pH remained
relatively constant throughout the top 30 cm. The lower Al concentration in
the surface layer corresponded to a substantially higher level of OC near the
surface, suggesting the formation of Al-organic matter complexes.
Monitoring salinity of the soil solution in a citrus orchard: the 4P technique revisited
Authors: Nadler Arie , Erner Yair
Published: August 2004

During a 6-year salinity experiment in a citrus (Shamouti) grove, 3 salinity
levels of irrigation water (0· 8, 1· 3, and 1 ·7
dS/m) were used. Measured salinity levels depended on the monitoring
technique, aqueous extract (Ext) v. electrical
resistance (4 electrode method, 4P), and consistently differed by up to
50%. The main advantages of the resistivity method over sampling are:
specific consideration of the actual water content at time of measurement,
minimal disturbance of the natural soil structure and chemical composition,
and a reduced spatial variability due to the possibility of repeated
measurements at one spot. Despite massive salt inputs
(12×103 -36×103 mmol
charge(+)/ha), the final salinity levels, even according to the
higher estimating resistivity method, were moderate, and during the 6 years
had no significant effect on yield. It could thus be categorised as being
either below or above the yield-reducing threshold value, depending on the
measuring technique.
A rainsplash component analysis to define mechanisms of soil detachment and transportation
Authors: Terry James P.
Published: August 2004

Rainsplash is a term that has been used to describe a wide variety of effects
caused by the impact of raindrops on soils. This is because rainsplash, even
by individual drops, is not a single process but a combination of several
discrete but interacting soil particle detachment and transport mechanisms.
Because there are a number of possible rainsplash sub-processes that may
operate on soils, some of the terminology used in splash studies is
inconsistent. In response, this paper reviews some of the past research on
raindrop{soil interactions, as well as incorporating observations by the
author, in order to clarify the definitions used to describe soil dispersal
mechanisms during drop impact. Five main mechanisms are identified, and
defined as (1) aggregate breakdown, (2) cratering, (3) splashing, (4) splash
saltation, and (5) splash creep, several of which are illustrated with
photographic and video techniques under laboratory splash tests. For rainfall
in field conditions, an integrated ‘component approach’ introduces
a more expansive and flexible approach to rainsplash on soils than is
currently available, by considering this geomorphological process as a suite
of discrete but interacting mechanisms, varying with changing rainfall and
soil characteristics during storms. Some implications of this concept for
erosion studies in splash-prone areas are examined.
Effect of forms of nitrogen supply on mobilisation of phosphorus from a phosphate rock and acidification in the rhizosphere of tea
Authors: Zoysa A. K. N. , Loganathan P. , Hedley M. J.
Published: August 2004

Nitrogen (N) is the main fertiliser input to tea plantations because of the
large removal of this element with regular harvests of young shoots in the
field. The form of N supply is known to influence the uptake of other plant
nutrients, notably phosphorus (P), through its effect on soil pH in the
rhizosphere. A glasshouse study was conducted to test the effect of N form (NH
+4,
NO-3 , or both) on the
transformation of soil P in the rhizosphere and its availability to tea
(Camellia sinensis L.) plants fertilised with sparingly soluble Eppawala
phosphate rock (EPR). Four-month-old tea (TRI 2025) plants were grown in
rhizosphere study containers containing an Ultisol from Sri Lanka (pH 4
·5 in water) amended with EPR and KCl at 200 g P or K/g soil, and
mixed with
(NH4)2SO4
(100% NH+4 -N),
NH4NO3 (50%
NH+4 -N and 50%
NO-3 -N), and
Ca(NO3)2 (100%
NO-3 -N) at the rate of 200 g
N/g soil, with a control (no N fertiliser), as treatments.
Rhizosphere pH decreased compared with the bulk soil when N was supplied as
NH+4 or
NH+4
+NO-3 forms, and increased
when N was supplied as NO-3. The
cation{anion balance estimations in the plants showed that the plants had
taken up more NO-3 than
NH+4 even in
(NH4)2SO4
treated soil, suggesting high nitrification rates, especially in the
rhizosphere, in spite of using a nitrification inhibitor. More EPR dissolved
in the rhizosphere compared with that in the bulk soil, regardless of the N
form applied. The
(NH4)2SO4
treatment had the highest dissolution rate of EPR in the rhizosphere, whereas
Ca(NO3)2 treatment had the lowest,
reflecting the degree of acidification in the rhizosphere.
Resin-P and NaOH-Pi (inorganic P) concentrations were
lower and NaOH-Po (organic P) concentration was higher
in the rhizosphere than in the bulk soil. Plant and possible microbial uptake
of P is the main reason for the decrease in resin-P and
NaOH-Pi. The increase in NaOH-Po
concentration in the rhizosphere is believed to be due to transformation of
Pi to Po by the high microbial
activity in the rhizosphere. The
(NH4)2SO4
treatment caused the highest depletion of resin-P but lowest depletion of
NaOH-Pi, probably due to the fixation of P by the soils
at the low pH in the rhizosphere.
The study revealed that the use of the
NH+4 form of fertiliser can
increase acidification in tea rhizosphere compared with bulk soil and this can
enhance the effectiveness of PR fertiliser utilisation by tea plants.
Soil erodibility (Km) values for some Australian soils
Authors: Loch R. J. , Slater B. K. , Devoil C.
Published: August 2004

This paper reports calculated soil erodibility (Km)
values for the universal soil loss equation (USLE) for a range of surface
soils, and for some subsoils. The calculation of erodibility values was based
on laboratory measurements of water-stable sizes at the soil surface following
wetting by rain and on the wet density of coarse sediment. Also included are
erodibility data derived from field studies of erosion for 5 soils from New
South Wales and Queensland. The erodibility values obtained indicate
reasonable consistency in erodibility values for Vertosols and Ferrosols, but
considerable variation in the erodibility of soils lower in clay.
Soil factors best correlated with the calculated Km
factors were identified, and the potential to use such information to estimate
Km factors was evaluated.
Evaluating drainage responses in duplex soils in a Mediterranean environment
Authors: Ward P. R. , Dunin F. X. , Micin S. F. , Williamson D. R.
Published: August 2004

Deep drainage below 0 ·5 m from a sloping duplex soil under a pasture
in south-western Australia was evaluated by water balance determinations over
durations of a few days. Soil water dynamics were measured with time domain
reflectometry, and evapotranspiration with the Bowen ratio technique. These
near-continuous measurements enabled accurate determinations of deep drainage
to be made at a time scale that was consistent in duration with deep drainage
events. From 15 June 1994 to 16 October 1994 at Narrogin (with below average
rainfall of 350 mm), deep drainage accounted for 11-21 mm, and occurred
entirely within days of one particular rainfall event. This was associated
with the only period of prolonged waterlogging at the site, and its occurrence
was supported by a rise in the deeper groundwater. Water balance calculations
from experimental data at monthly intervals could not detect drainage
accurately, due to the large uncertainty associated with ET determinations.
The SWIM model predicted 15-25 mm deep drainage, depending on saturated
hydraulic conductivity of the B horizon, for the same rainfall event. When
errors in rainfall and evapotranspiration measurement were included in the
simulation, the range in predicted drainage was 6-31 mm.
Relationship between clay mineralogy and exchangeable Al in red and yellow soils from the Islands of Okinawa and Java
Authors: Nurcholis Mohammad , Tokashiki Yoshihiro , Oya Kazuhiro , Shimo Moritaka , Miyauchi Nobofumi
Published: August 2004

Red and yellow soils from tropical regions are generally more mature than
their subtropical counterparts. Most of these soils contain kaolin as the
dominant clay mineral. Exchangeable aluminium (Al) generally balances
permanent negative charges and occupies strongly acidic exchange sites of the
soil clay. The objective of this study was to identify those clay minerals
that are most highly implicated in contributing exchangeable Al to red and
yellow soils collected from the Islands of Okinawa and Java.
All soils exhibited an acid reaction but varied in their exchangeable Al
content and clay mineralogy. Clay content was high in all Javan soils but
varied in those from Okinawa. Javan soils were dominated by kaolinite, and
Okinawan soils by an association of illite and halloysite. However, 2 : 1-2 :
1 : 1 intergrades were significant components in both the Oku red soils
(Okinawa Island) and the Pamagersari red soils (Java Island). Javan soils were
characterised by a more mature (advanced) state of weathering than those from
Okinawa. The source of exchangeable Al was halloysite in Okinawan soils and 2
: 1-2 : 1 : 1 intergrades in Javan soils.
Effects of metsulfuron-methyl on amylase, urease, and protease activities in two soils
Authors: Ismail B. S. , Yapp K. F. , Omar O.
Published: August 2004

Effects of metsulfuron-methyl on the activities of amylase, urease, and
protease in loamy sand (Sungai Buluh series) and clay loam soil (Lating
series) were evaluated for up to 28 days. Metsulfuron-methyl at 5· 0
µg/g caused a reduction in amylase and urease activities for the
entire period of study, especially at 28 days of incubation. A similar trend
was observed in Lating series soil where the lowest activities of amylase and
urease were attained at Day 28 in the presence of 5 ·0 µg/g
of metsulfuron-methyl. The protease activity in either Sungai Buluh or Lating
series soil decreased during the 7 days of incubation compared with that of
the control, but a recovery trend was obvious at all concentrations from Day
14 onwards.
Effect of ammonium, organic amendments, and plant growth on soil pH stratification
Authors: Evans C. M. , Conyers M. K. , Black A. S. , Poile G. J.
Published: August 2004

We studied the development of soil layers of different pH (strata) within the
surface 10 cm of soil. Substrates which affect nitrogen transformations
(ammonium sulfate, sucrose, and lucerne hay) were added to the soil to
determine the effect of amendment on the development of pH stratification.
A glasshouse experiment used soils of 3 different initial pH(0·01
CaCl2; pHCa) values: 4, 5, and 6.
At the end of the experiment, soil was sampled in depth intervals of
0·5 cm between 0 and 2 cm depth and then 1-cm intervals between 2 and
10 cm depth. Soil pHCa decreased over time and
pHCa changes could be explained by variations in the
concentration of ammonium and nitrate, which were brought about by changes in
the rate of mineralisation, nitrification, and plant uptake of nitrogen.
Little stratification in soil pHCa was found within the
0–10 cm layer. This minimal stratification was considered to be due to
the soil in the pots being a closed system where nitrate was not lost through
leaching.
A field trial was rotary hoed to a depth of approximately 10 cm to achieve
adequate mixing of soil and amendments. Soil pHCa
decreased over the 6 months of the growing season, ranging from 0·1
pHCa units in the control to 0·4
pHCa units in the hay amendment. Between the initial and
final sampling times there was little change in soil
pHCa in the surface 0–2 cm. The
pHCa decreased in the layers between 2 and 10 cm, thus
producing the stratification of soil pHCa. The growth of
oats had little effect on the development of pHCa
stratification. Decreases in the soil pHCa from the
0–2 cm to the 8–10 cm layer in the absence of plants were
0·22, 0·27, 0·30, and 0·51 for the control, added
sucrose, added ammonium sulfate, and added hay amendments, respectively. The
processes of mineralisation and nitrification were considered to be the major
causes of change in soil pHCa. Stratification of
pHCa in the field trial was attributed to nitrification
followed by nitrate leaching in the open system.
Pesticide fate and behaviour in Australian soils in relation to contamination and management of soil and water: a review
Authors: Kookana R. S. , Baskaran S. , Naidu R.
Published: August 2004

Pesticides, if used as recommended, are generally expected to cause little
adverse impact on the environment. However, it is evident that trace levels of
pesticide residues present in soil, water, air, and sometimes food, may result
in harmful effects on human and environmental health. Pesticides can pose
health risks through several exposure pathways including direct occupational
related exposure, through food, or through the residues present in the
environment. This paper reviews available information on the nature and extent
of pesticide contamination of Australian soils, surface water, and
groundwaters. Published studies on the fate and behaviour of pesticides in
Australian soils have also been reviewed, covering the key processes
controlling the fate and behaviour of pesticides in soils, namely
sorption-desorption, degradation (biological and abiotic), and volatilisation
in soil and their off-site transport into surface and groundwaters. Some
management options for minimising the diffuse source pollution of soils and
waters by pesticides and remediation of contaminated soils and water have also
been discussed. The review concludes that contamination of soils and water
with pesticides has occurred in Australia and there is a need to understand
the behaviour of pesticides in the soil environment in order to develop
management practices to minimise any adverse impact on our environment in
future.
Mineralisation of low concentrations of organic compounds and microbial biomass in surface and vadose zone soils from the Swan Coastal Plain, Western Australia
Authors: Franzmann P. D. , Zappia L. R. , Patterson B. M. , Rayner J.L. , Davis G. B.
Published: August 2004

Mineralisation rates for ring-labelled 14C-atrazine,
benzene, and toluene were determined for a number of Swan Coastal Plain soils
which had not been previously in contact with these contaminants. Microbial
biomass was estimated by phospholipid techniques in soil samples from the same
sites.
Mineralisation rates for the volatile aromatic hydrocarbons in the thin (up to
30 cm) surface soils (23·4-42·6 µmol/kg · day
when fitted to zeroth-order rate kinetics) were appreciably faster than the
mineralisation rates measured in soils collected from a depth of 1 m
(0·11-3·0 µmol/kg · day).
The pesticide atrazine was degraded slowly, with degradation rates in surface
soils ranging from 1·22×10-3 to
2·78×10-4 µmol/kg · day,
and those in soils at 1 m ranging from 5·
13×10-4 to
3·16×10-4 mol/kg
· day. When mineralisation data were fitted to first-order kinetics
then half-lives for atrazine mineralisation ranged from about 1 year in
surface soils to 3·1-5·1 years in soils at 1 m. These rates were
comparable to atrazine mineralisation rates measured in soils that had not
been previously in contact with atrazine, as reported by others. The extent of
mineralisation of the organic compounds v. time
generally fitted better to zeroth-order kinetics than to first-order kinetics.
Confidence in the determination of the mineralisation rate at slow rates of
mineralisation was low (r2 as low
as 0·2 in plots of the extent of mineralisation
v. time in zeroth-order and first-order plots for
samples that showed slow mineralisation).
Biomass, expressed as stationary phase Escherichia coli
equivalents (SPEE), ranged from 1·4 ×107 to
1·2×108 SPEE/g dry weight for surface
soils, and from 8·6×105 to
7·3×106 SPEE/g dry weight for soils at
1 m. The phospholipids extracted from surface soils tended to contain higher
proportions of unsaturated and hydroxy fatty acids than soils at 1 m, which
contained higher relative concentrations of branched fatty acids, which is
consistent with the microbiota moving, with greater depth, from a
Gram-negative to a more Gram-positive dominated population. Biomass correlated
well with mineralisation rates of the volatile aromatic compounds
(r2 = 0·96) but less
so with atrazine mineralisation rates
(r2 = 0·86),
although further experiments would be required to determine if biomass was
consistently a good predictor of mineralisation rate for these organic
contaminants.
The results suggest that it is important to maintain a fertile,
‘microbially rich’ soil in order to maximise the potential for
mineralisation of organic contaminants above groundwater resources. The
mineralisation rate measurements for atrazine obtained in this study should be
useful in models for the prediction of the contamination threat to groundwater
resources.
Effluent irrigation—an environmental challenge for soil science
Authors: Bond W. J.
Published: August 2004

With the growth of concern for the impact of humankind on the environment,
soil scientists have increasingly shifted the emphasis of their work towards
the effect of agricultural and other land management practices on the
environment. This shift has required some changes to the way soil science is
practised. The example of land application of wastes, an increasingly popular
practice, is used to illustrate the role of soil science in the complex web of
scientific, social, and economic aspects of environmental issues, and the need
to influence community thinking and the policy debate. The issues often most
likely to be limiting to effluent irrigation are excessive nitrate leaching,
poor salt management, and the effects of increasing soil sodicity on current
and future land uses. The scientific challenges that these pose are discussed,
together with some broader issues including those associated with
implementation of effluent irrigation, and socioeconomic and environmental
considerations that should influence the decision to select effluent
irrigation as the means for disposal or reuse.
Soil carbon changes resulting from sugarcane trash management at two locations in Queensland, Australia, and in North-East Brazil
Authors: Blair Graeme J. , Chapman Les , Whitbread A. M. , Ball-Coelho B. , Larsen P. , Tiessen H.
Published: August 2004

Sugarcane cropping produces a large amount of crop residues, which offers
considerable scope for residue management. Soil samples, collected from 2
long-term experiments in Australia and an experiment in Pernambuco State,
Brazil, were analysed for total carbon (CT) and for
labile carbon (CL) by oxidation with 333 mM
KMnO4.
At the 2 locations in Australia, CT and
CL concentrations were lower in the surface layer (0-1
cm) of the cropped soil compared with a nearby uncropped reference soil.
Burning resulted in a greater loss in CT and
CL at a depth of 0-1 cm than green cane trash
management. At one of the sites, sugarcane cropping resulted in a decline in
CT relative to the reference in the green trash
management treatment but an increase in CL.
In Brazil, trash management from one cane crop did not change
CT over a 12-month period but green cane trash return
increased CL. Sustainable sugarcane cropping systems
must include crop residue return without burning in order to maintain an
active C cycle in the system to drive nutrient cycles.
Change in soil infiltration associated with leys in south-eastern Queensland
Authors: Connolly R. D. , Freebairn D. M. , Bell M. J.
Published: August 2004

Cropping systems in south-eastern Queensland have led to degradation of soil
physical properties and loss of infiltration capacity. Pasture leys are
favoured for ameliorating soil physical properties because they add organic
matter to the soil, create macroporosity, and help to re-aggregate soil. We
measured change in hydraulic conductivity with period of ley for 5 major soil
groups in south-eastern Queensland (Sodosols, light and heavy Vertosols, Red
Ferrosols, and Red Chromosols/Kandosols). We characterised 2 soil layers
that are susceptible to degradation when cropped: surface soil exposed to
raindrop impact, and the layer immediately below the cultivated layer
(0·1-0·2 m deep). A rainfall simulator was used to measure
hydraulic conductivity of surface seals under high intensity rainfall. Disc
permeameters and pressure plate apparatus were used to measure hydraulic
conductivity of the soil matrix in the 0·1-0·2 m layer.
Hydraulic conductivity of both soil layers improved with period of pasture for
all but the light-textured Red Chromosols/Kandosols. The estimated period
of pasture required to return hydraulic conductivity to pre-cultivated levels
ranged from 5 to 40 years, depending on soil type and layer. This is about 2-3
times the period of cultivation that caused the degradation. Grazing reduced
the effectiveness of pasture in ameliorating surface sealing on Sodosols.
Beneficial effects of a 2·5-4·5 year, ungrazed ley pasture on
surface soil persisted for up to 5 years after recultivation, but were lost in
the 0·1-0·2 m layer within 1 year. These rates of decline in
hydraulic conductivity were faster than observed on previously uncultivated
soils.
The APSIM model was used to predict the effect of measured improvements in
soil hydraulic conductivity on average runoff from summer fallows. The model
predicted that most benefits for fallow runoff would be achieved with 2-5
years of ley. The surface seal was the major limitation to infiltration when
the soil was bare. Subsurface soil layers limited infiltration if surface
sealing was reduced by ameliorating soil properties or maintaining cover on
the soil surface. The results suggest that despite amelioration of soil
structure with leys, appropriate tillage and cover management is still
required to maintain high infiltration rates.
Procedures for characterising denitrification rates in a wastewater-irrigated forest soil
Authors: Barton L. , McLay C. D. A. , Schipper L. A. , Smith C. T.
Published: August 2004

In land-based wastewater treatment systems, soil denitrification can remove
sufficient added nitrogen to decrease leaching and the threat of water
pollution. To establish a suitable sampling strategy for measuring
in situdenitrification rates, we investigated the
importance of spatial and temporal variability of denitrification in a forest
soil regularly irrigated with wastewater. To determine appropriate sampling
depths and locations in a catchment, denitrifying enzyme activity (DEA) was
measured at 5 sampling depths (litter, 0-5, 5-10, 10-20, 20-40 cm), and 3
topographic positions (ridge, midslope, toeslope) in irrigated and
nonirrigated sites. To determine appropriate times for sampling after
irrigation, in situ denitrification rates were measured
at time intervals before and after irrigation for 1 week, using soil cores and
acetylene inhibition.
DEA was greatest in the litter layer and decreased with depth. In irrigated
soils, DEA was greater than zero in the upper 20 cm of toeslopes, and the
upper 10 cm of midslopes and ridge positions. In situ
denitrification rates increased immediately after wastewater irrigation,
peaking at 24 h, and then decreased to pre-irrigation rates after 3 days,
unless it rained. We concluded that soil cores need to be collected from at
least the upper 10 cm soil (including the litter layer), and on a daily basis
between irrigation events, to quantify denitrification losses from soil
regularly irrigated with wastewater.
Relationships and Generic Concepts within Styphelieae (Epacridaceae)
Authors: Powell Jocelyn M. , Morrison David A. , Gadek Paul A. , Crayn Darren M. , Quinn Christopher J.
Published: August 2004

A morphological data base of 30 characters has been assembled for 33 terminal
taxa in the tribe Styphelieae sensu Powell et al.
(1996), as well as four outgroup taxa representing the other major affinity
groups previously identified within the Epacridaceae on morphological and
molecular data. Heuristic and bootstrap analyses provided strong support for
the tribe, but indicated a need to modify several long-established generic
concepts. Four genera are shown here to be polyphyletic. Six new monotypic
genera should be segregated from Astroloma.
Brachyloma should be divided into three segregates. Two
distinct affinity groups warranting generic status were identified within
Cyathodes. The separation of the monotypic Western
Australian genus, Croninia, from
Leucopogon s.l. is supported, and four other separate
entities are here recognised: four species from section
Heteranthus Benth. should be united with
Lissanthe, and the other three segregates warrant
generic status. In addition, Monotoca is paraphyletic,
and should be redefined to incorporate Oligarrhena,
while a new genus, ‘Pseudactinia’, is required to accommodate two
new species from Western Australia. There seems little justification for
maintaining the distinction between Trochocarpa and
Decatoca. The pattern of intergeneric relationships
resolved suggests that Astroloma s.l.,
Coleanthera, Conostephium,
Croninia, Melichrus,
Styphelia and much of Leucopogon
s.l. constitute an affinity group, and that Brachyloma
s. str. and B. scortechinii are basal within the tribe,
but there is only weak support for these aspects of the topology within the
data.
A Revision of Eragrostis (Eragrostideae, Eleusininae, Poaceae) in Australia
Authors: Lazarides M.
Published: August 2004

Based on characters of gross morphology, a taxonomic revision is presented of
the Australian taxa of Eragrostis Wolf, comprising 69
endemic and exotic species distributed in six groups. Seventeen species are
proposed as new. Ten taxa are hereby reduced to synonymy. Lectotypes are
designated for 11 species. New distribution records include
E. atrovirens for Australia,
E. schultzii for Western Australia,
E. leptocarpa and E. pergracilis
for Victoria, E. minor for New South Wales, and
E. sterilis for New South Wales and the Northern
Territory. Polymorphy and interspecific gradation are inherent problems in the
taxonomy of the genus. Also, apparent evolutionary characters such as mode of
spikelet disarticulation can be inconsistent and difficult to interpret.
Features of the caryopsis relating to 3-dimensional shapes, compression,
surface markings, and an adnate or free pericarp are among the most useful
characters for identification purposes. Cleistogamy occurs in many species,
but is not reflected in spikelet morphology.
Eragrostis curvula is recorded as an apomict.
Seiridium papillatum, a New Species (Mitosporic Fungus) Described on Stems of Eucalypts in Australia
Authors: Yuan Zi Qing , Mohammed Caroline
Published: August 2004

A second species of Seiridium is described on
Eucalyptus spp. in Australia as
S. papillatum sp. nov. It is distinguished from the
known species of the genus by its short papillate conidium appendages and
large, ellipsoid to sub-cylindrical, striate, 5- (4–7-) septate conidia.
A key to S. papillatum and closely related
Seiridium species is provided and morphological
differences are discussed. Colony morphology and growth rate of
S. papillatum at different temperatures are compared
with those of S. eucalypti and a
Seiridium isolate from Callitris.
A Revision of Triodia including Plectrachne (Poaceae, Eragrostideae, Triodiinae)
Authors: Lazarides M.
Published: August 2004

On the basis of morphological data presented herein,
Plectrachne Henr. is included in
Triodia R.Br. This congeneric change requires 15 new
combinations and three new nominations. In Triodia R.Br.
sens. lat., 11 new species are proposed, one subspecies
is raised to specific rank, while three species and six varieties are reduced
to synonyms. For the first time, Triodia melvillei and
T. schinzii are recorded for South Australia,
T. bunicola for Victoria,
T. mollis for Queensland and
T. marginata for New South Wales. Although probably
monophyletic, Triodia as here interpreted is widely
variable. Thus, a classification of nine informal infrageneric groups is
proposed.
Early Tertiary Macrofossils of Proteaceae from Tasmania
Authors: Carpenter Raymond J. , Jordan Gregory J.
Published: August 2004

Proteaceous leaves from two Early Tertiary sites in Tasmania are described and
discussed. Based on gross leaf morphological and cuticular characters, 15
species are recognised from Oligocene lacustrine sediments at Cethana.
Specimens of two taxa are not distinguishable from the extant species
Telopea truncata from Tasmania and
Lomatia fraxinifolia from north-eastern Queensland, and
are therefore assigned to these species. Two new species of
Banksieaephyllum are recognised. Ten other taxa are
difficult to identify to existing genera, and are therefore referred to a new
genus Proteaciphyllum. They all possess features typical
of subfamily Grevilleoideae. Other, less well preserved, but probable
Proteaceae from Cethana are also described. Specimens from the Leven River
deposit, probably also of Oligocene age, are assigned to a new species of
Orites, O. excelsoides. This
species is closely related to extant O. excelsa from
rainforests of north-eastern New South Wales and north-eastern Queensland.
Cethana has by far the highest diversity of Proteaceae of any fossil flora
described to date. The fossils also demonstrate the past association of now
geographically remote taxa, and the prevalence of sclero- and xero-morphy in
the family by the Oligocene.
On the Classification of the Chloridoideae (Poaceae)
Authors: Borre An Van den , Watson Leslie
Published: August 2004

A series of phenetic and cladistic analyses (using ISS-flexible, NJTREE and
HENNIG86) has been conducted on 166 generic descriptions of Chloridoideae,
using 120 selected morphological and leaf anatomical characters. The results
are emphatically not supportive of the traditional main division into the
tribes Eragrosteae and Chlorideae, but instead indicate five quite different
high level groups. By contrast, they afford strong support for the small
tribes Pappophoreae, Orcuttieae, and Triodieae. They also highlight the
special problems posed by polymorphic taxa (represented here by
Eragrostis) in planning and interpreting taxonomic and
phylogenetic studies. Based on these findings a new classification model for
the subfamily is proposed.
A Reappraisal of Acacia cowleana and Allied Taxa, Including the Description of a New Species, A. elachantha, from the Tropical Dry-zone of Australia
Authors: McDonald M. W. , Maslin B. R.
Published: August 2004

The taxonomy of Acacia cowleana Tate is reviewed. In thepast this name had been applied to a broadly circumscribed entity which is nowtreated as two species, A. cowleana sensu typico andA. elachantha M.W.McDonald & Maslin, sp. nov. Fullbotanical descriptions, illustrations and distribution maps are given.Acacia oligophleba Pedley is treated as conspecific withA. cowleana. A lectotype is selected forA. cowleana.Acacia cowleana andA. elachantha along with A. coleiMaslin & L.Thomson, A. leptocarpa A.Cunn. ex Benth.,A. longispicata Benth.,A. thomsonii Maslin & M.W.McDonald and anundescribed species from Wetar, Indonesia, constitute the informalA. cowleana group. The main distinguishing charactersfor the six described species in the group are given.
Geographic Variation in Eucalyptus diversifolia (Myrtaceae) and the Recognition of New Subspecies E. diversifolia subsp. hesperia and E. diversifolia subsp. megacarpa
Authors: Wright Ian J. , Ladiges Pauline Y.
Published: August 2004

Patterns of geographic variation in morphological and chemical characters are
documented in Eucalyptus diversifolia Bonpl. (soap
mallee, white coastal mallee). This species is found in coastal and subcoastal
Australia from southern Western Australia to Cape Nelson (western Victoria),
with a number of disjunctions in the intervening region. Morphological data
from adult plants collected at field localities and seedlings grown under
uniform conditions were analysed using univariate and multivariate methods,
including oneway ANOVA, multiple comparison tests, non-metric multidimensional
scaling (NMDS), nearest neighbour networks, and minimum spanning trees.
Seedling material was tested for isozyme polymorphism, and adult leaf
flavonoids were analysed using liquid chromatography. Morphological and
chemical characters are also documented in E. aff.
diversifolia, a closely related but unnamed taxon
restricted to ironstone outcrops near Norseman (WA), and putative
E. diversifolia- E. baxteri
hybrids from Cape Nelson. Congruent patterns in data sets distinguish three
groups of E. diversifolia adults and progeny: (1) those
to the west of the Nullarbor disjunction; (2) South Australian populations to
the east of this disjunction; and (3) those from Cape Nelson. Formal taxonomic
recognition of the three forms at subspecific level is established, namely
E. diversifolia subsp.
diversifolia, E. diversifolia
subsp. hesperia, and
E. diversifolia subsp. megacarpa.
Patterns of geographic affinity between populations are consistent with a
hypothesis of genetic exchange between normally disjunct regional populations
of E. diversifolia via coastal land-bridges exposed
during periodic times of low sea level since the mid Tertiary.
A Taxonomic Revision of Gomphrena (Amaranthaceae) in Australia
Authors: Palmer Joanne
Published: August 2004

A taxonomic revision of the genus Gomphrena L.
(Amaranthaceae) in Australia is presented. Of the 33 species recognised, 12
species are described as new: G. arida,
G. atrorubra, G. connata,
G. cucullata, G. eichleri,
G. floribunda, G. humifusa,
G. kanisii, G. lacinulata,
G. magentitepala, G. occulta,
G. rosula; as are five subspecies:
G. affinis F.Muell. ex Benth. subsp.
pilbarensis, G. brachystylis
F.Muell. subsp. pindanensis,
G. canescens R.Br. subsp.
erythrina, G. diffusa R.Br. subsp.
arenicola, G. leptoclada Benth.
subsp. saxosa. One new combination has been made:
G. leptophylla (Benth.) J. Palmer, and
G. breviflora F.Muell. has been reinstated. A key,
descriptions, distribution maps, and notes are provided for all taxa and
photographs of type specimens are provided for new taxa. Lectotypes have been
chosen where necessary and comments are made on the present infra-generic
classification in the genus.
Batrachospermum (Batrachospermales, Rhodophyta) in Australia and New Zealand: new taxa and emended circumscriptions in sections Aristata, Batrachospermum, Turfosa and Virescentia
Authors: Entwisle Timothy J. , Foard Helen J.
Published: August 2004

Fifteen species of Batrachospermum from Australia and
New Zealand are documented, including (except for the recently described
B. antipodites Entwisle) descriptions, photomicrographs,
maps and keys. The temperate region particularly boasts many intriguing and
endemic taxa. Ten species are described as being new to science:
B. discorum, B. kraftii,
B. ranuliferum, B. antiquum,
B. theaquum, B. debilis,
B. campyloclonum, B. prominens,
B. terawhiticum and B. wattsii.
Diagnostic characters include trichogyne shape, carpogonium morphology and
disposition, carposporophyte morphology (including the presence of
indeterminate gonimoblast filaments), carposporangia morphology and some
vegetative features such as fascicle cell shape.
Batrachospermum cayennense Mont. ex KÜtz.,
B. arcuatum Kylin, B. anatinum
Sirodot are reported for the first time from the Australia–New Zealand
region, and the circumscription of the cosmopolitan
B. gelatinosum (L.) DC. is expanded. All species have
‘well-developed’ whorls, more or less straight carpogonial
branches, and carpogonia with a symmetrical base. Thus they are referable to
section Aristata, Batrachospermum,
Turfosa or Virescentia. However,
many of the new taxa are difficult to allocate in the existing sectional
system.
Anatomical studies in West Malaysian Icacinaceae
Authors: Teo Stephen P. , Haron Noorma Wati
Published: August 2004

On the basis of a comparative anatomical study of the leaf lamina and petiole
of six genera of Icacinaceae in West Malaysia, these genera can be classified
into four closely knit groups by virtue of their many shared characters: Group
I comprises Cantleya, Gomphandra
and Stemonurus whereas Groups II and III are made up of
Gonocaryum and Sarcostigma,
respectively. The climber genus Iodes is classified into
Group IV. Taxonomically useful characters include the shape of the vascular
bundles in both the midrib and petiole, the presence of funnel-shaped palisade
cells, foliar sclereids, tannin crystals, hypodermis layer and accessory or
wing bundles in the petiole. A key to the genera and the descriptions of each
species and variety based on anatomy are given. Phylogenetic relationship
among the genera are also discussed based on the study with data supplemented
from other taxonomic sources.
Physalis micrantha (Solanaceae) recorded from the Northern Territory
Authors: Symon D. E.
Published: August 2004

Physalis micrantha Link may be added to the flora of the Northern Territory
with five collections recorded from the Gulf of Carpentaria coastline.
Tragia finalis (Euphorbiaceae), a new species from northern Queensland
Authors: Forster Paul I.
Published: August 2004

Tragia finalis P.I.Forst. sp.nov. is described and
illustrated. Information is provided on its affinities, distribution, habitat
and conservation status. A key to the Australia species of
Tragia is presented.
Archerieae: a new tribe in Epacridaceae
Authors: Crayn D. M. , Quinn C. J.
Published: August 2004

Recent cladistic analyses based on both morphology and nucleotide sequencedata have demonstrated that Archeria Hook. f. is anisolated and relatively basal taxon within Epacridaceae. It is here assignedto a new monotypic tribe, Archerieae Crayn & Quinn, trib. nov.
Before the floras—Monographs
Authors: Grimes James W.
Published: August 2004

The proposal is made that writing of national or regional floras is premature,
and that systematic resources should be directed toward the preparation of
monographs with cladistic analyses. This proposal results from one major
consideration: that the preparation of floras does not require rigorous
analysis of species definition and delimitation, and therefore the basic data
(i.e. the species circumscriptions) are more unreliable than that in
monographs. Furthermore, contrary to some published arguments, the data in
floras are not presented and summarised in a format compatible with other
areas of comparative and applied biology, whereas it is otherwise in a
monograph with cladistic analysis. This proposition is based on the
author’s experience in preparing both monographs and floristic
treatments.
Biogeography after Burbidge
Authors: Ladiges Pauline Y.
Published: August 2004

The contributions of Nancy Burbidge and Leon Croizat to an understanding of
Australian phytogeography are summarised and compared. The focus of
systematics on relationship and nodes of cladograms is outlined as the basis
of modern cladistic biogeography. It is argued that development of explicit
analytical methods for the discovery of general area cladograms has been
hindered by lack of recognition of geographic paralogy—evidenced by
duplication or overlap in geographic distribution of taxa related at a node in
a cladogram. A new method, subtree analysis, which recognises and eliminates
paralagous nodes, and often inconsistencies, is illustrated with examples from
the Australian flora. General patterns are congruent with conclusions of
Burbidge and Croizat.
Paper Presented as the 1996 Nancy Burbridge Memorial Lecture.
The santonian through paleogene record of Proteaceae in the southern South America - Antarctic peninsula region
Authors: Askin Rosemary A. , Baldoni Alicia M.
Published: August 2004

Proteaceous plants were an important component of the high-latitude Late
Cretaceous–Paleogene podocarpaceous conifer and
Nothofagus forest vegetation growing in high-rainfall
temperate conditions. In the southern South America–Antarctic Peninsula
region the fossil record of the Proteaceae comprises pollen, leaves, fruits
and wood with affinities to the extant subfamilies Grevilleoideae,
Proteoideae, and possibly Carnarvonioideae and Persoonioideae. The oldest
reported occurrences of Proteaceae in this region are in the middle–late
Santonian of the Antarctic Peninsula and include pollen of
Proteacidites subscabratus Couper, with the addition in
the Campanian of other species of Proteacidites and
Propylipollis, Cranwellipollis
spp. and Peninsulapollis spp. Diversity of proteaceous
pollen increased through the Campanian and Maastrichtian, reflecting the
spread of Proteaceae along the Antarctic Peninsula and into South America.
Both endemic species and species derived from the Australian region are
represented. Compared to coeval Australian assemblages, however, proteaceous
diversity remained relatively low. Interestingly,
Beauprea-type species
(Beaupreaidites spp.,
Peninsulapollis spp.) are common and varied in the
Antarctic Peninsula from Campanian into the Eocene, yet the South American
pollen record does not include these forms, except for rare
Peninsulapollis gillii. Possibly drier conditions may
have discouraged northward migration of this group. South American fossil
proteaceous taxa are primarily related to Grevilleoideae, a trend that
continues into the modern flora on that continent.