bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes with time of zinc forms in an acid, a neutral, and a calcareous soil amended with three organic zinc complexes
Authors: Obrador A. , Alvarez J. M. , Fernández M. D. , López-Valdivia L. M.
Published: September 2002

Three zinc (Zn) fertilisers were added as soluble organic salts
(Zn-ethylenediaminetetraacetate plus fulvic and humic acids, Zn-lignosulfonate
plus ethylenediaminetetraacetate, and
Zn-2-hydroxy-1,2,3-propanetricarboxilate) at several levels, to 3
representative types of soils, to study the behaviour of Zn applied. Samples
of treated and untreated soils were incubated for 15, 30, and 60 days at
22˚C and field capacity. A selective sequential dissolution procedure and
DTPA extraction were employed to determine the changes in Zn distribution. The
distribution and the percentage conversion into different forms of the added
metal were dependent on soil type, Zn sources, and Zn loading level. After an
initial increase in all forms of Zn in the treated soils, Zn concentration in
the water-soluble plus exchangeable fraction and the amounts extracted with
DTPA began to decrease. At the end of the experiment, Zn in the most labile
fraction was detected in the calcareous soil (pHw 8.3)
only when the mixture of fulvic and humic acids with Zn-EDTA chelate was
applied (e.g. 1.59 mg/kg of Zn in the 20 mg/kg treatment). The highest
conversion values of Zn applied in this calcareous soil occurred in the
amorphous Fe-oxide bound and residual fractions of all fertilisation
treatments and a low conversion value occurred in the carbonate-bound
fraction.
fulvic acid, humic acid, Zn-EDTA, Zn-lignosulfonate,
Zn-2-hydroxy-1,2,3-propanetricarboxilate, Zn extractability.
Measuring transient solute transport through the vadoze zone using time domain reflectometry
Authors: Vogeler I. , Green S. , Nadler A. , Duwig C.
Published: September 2002

Time domain reflectometry (TDR) was used to monitor the transport of
conservative tracers in the field under transient water flow in a controlled
experiment under a kiwifruit vine. A mixed pulse of chloride and bromide was
applied to the soil surface of a 16 m2 plot that had
been isolated from the surrounding orchard soil. The movement of this solute
pulse was monitored by TDR. A total of 63 TDR probes were installed into the
plot for daily measurements of both the volumetric water content (θ) and
the bulk soil electrical conductivity (σa). These
TDR-measured σa were converted into pore water
electrical conductivities (σw) and solute
concentrations using various
θ–σa–σw
relationships that were established in the laboratory on repacked soil. The
depth-wise field TDR measurements were compared with destructive measurement
of the solute concentrations at the end of the experiment. These results were
also compared with predictions using a deterministic model of water and solute
transport based on Richards’ equation, and the
convection–dispersion equation. TDR was found to give a good indication
of the shape of the solute profile with depth, but the concentration of solute
was under- or over-estimated by up to 50%, depending on the
θ–σa–σw
relationships used. Thus TDR can be used to monitor
in situ transport of contaminants. However, only rough
estimates of the electrical conductivity of the soil solution can so far be
obtained by TDR.
Reclamation of steeply sloping coal spoil banks under Mediterranean semi-arid climate
Authors: Salazar M. , Poch R. M. , Bosch A. D.
Published: September 2002

Deep coal mining activities in the Ebro Valley, north-eastern Spain, are important elements of the economy. A method for reclamation of high slope (30-56%) spoil banks under semi-arid Mediterranean conditions was assayed using amended mine spoils (with pig slurry and straw) as substrate due to the lack of topsoil. Sixteen experimental plots, divided into 4 sets according to slope aspect, gradient, and length, were established in October 1998. Two types of substrate and 4 types of seed mixes were used. Substrate, runoff, and vegetation properties were monitored.
Carbon turnover in two soils with contrasting mineralogy under long-term maize and pasture
Authors: Parfitt R. L. , Parshotam A. , Salt G. J.
Published: September 2002

Total organic carbon (C) and natural 13C abundance were
measured in adjacent allophanic soils (Andisols) and non-allophanic soils
(Inceptisols) under maize (Zea mays L.) and ryegrass
pasture (Lolium perenne L.) to assess the C turnover
rate in soils of contrasting mineralogy and specific surface area. The
allophanic soil contained more total C than the non-allophanic soil (139
v. 101 t C/ha in the upper 0–35 cm) but
neither soil showed a significant difference in C content between pasture and
maize, provided maize residue was retained and incorporated. The gross annual
inputs under maize and pasture were both estimated to be about 9 t C/ha,
consistent with the similar soil total C contents. Since the soil total C
content did not appear to change with time, the gross C mineralisation was
about 9 t C/ha each year. The proportion of old pasture C remaining in the
soil after maize cropping for 25 years was about 78% in the allophanic
soils and about 69% in the non-allophanic soils, reflecting the
influence of both Al and allophane, with its high specific surface area, on
the retention of old C. The maize C retained in 25 years was similar in both
the allophanic soil and the non-allophanic soil (29 t/ha). Therefore, the
higher total C content of the allophanic soil would appear to arise from
stabilisation of old pasture and forest C by Al and allophane.
clover, grass, New Zealand soils.
Nitrate leaching and pasture production from different nitrogen sources on a shallow stoney soil under flood-irrigated dairy pasture
Authors: Di H. J. , Cameron K. C.
Published: September 2002

The leaching of nitrate
(NO3–) in intensive
agricultural production systems, e.g. dairy pastures, is a major environmental
concern in many countries. In this lysimeter study we determined the amount of
NO3– leached following the
application of urea, dairy effluent, urine returns, and pasture renovation to
a freedraining Lismore stony silt loam (Udic Haplustept loamy skeletal)
growing a mixture of perennial ryegrass (Lolium perenne)
and white clover (Trifolium repens) pasture. The study
showed that NO3–-N leaching
losses ranged from 112 to 162 kg N/ha per year, depending on the amount
and forms of N applied and pasture conditions. Nitrate leaching under the
urine patches was the main contributor to the N leaching loss in a grazed
paddock. Nitrate leaching losses were lower for urine applied in the spring
(29% of N applied) than for urine applied in the autumn
(38–58%). The application of urea or dairy effluent only
contributed a small proportion to the total
NO3– leaching loss in a
grazed paddock. Pasture renovation by direct-drilling may also have caused an
increase in NO3– leaching
(c. 31 kg N/ha) in the first year. Modelled annual average
NO3–-N concentrations in the
mixed recharge water in the acquifer were significantly lower than those
measured under the rooting zone due to dilution effects by recharge water from
other sources (3.9 v. 13–27 mg N/L). Herbage
nitrogen offtake and dry matter yield were higher in the urine treatments than
in the non-urine treatments.
groundwater, denitrification, mineralisation, grazing, forage.
Risk mapping of soil acidification under Stylosanthes in northern Australian rangelands
Authors: Noble A. D. , Middleton C. , Nelson P. N. , Rogers L. G.
Published: September 2002

The inclusion of Stylosanthes into pastures and cropping
systems has proved to be a low cost method of improving product quality in
Asia, Africa, South America, and northern Australia. However, there is recent
evidence that accelerated soil acidification has occurred under these
production systems, questioning their long-term sustainability. In an effort
to assist producers and extension officers in identifying soils that are
predisposed to accelerated acidification, an acidity risk map of the Dalrymple
Shire in Queensland, Australia, was developed using information from a
recently completed land resource survey. Validation of a previously derived
pedotransfer function that predicts pH buffering capacity was undertaken using
an independent set of soil samples collected from the Shire. Excellent
agreement between measured and predicted pH buffering capacity was obtained.
The pedotransfer function was used to estimate the pH buffering capacity of 44
soil associations in the Shire. These values were used to predict the number
of years that it would take for soils to acidify from their current pH to 5.0
assuming a constant net acid addition rate of 2.1 kmol
H+/ha.year. Approximately 62% of the
total area of the Shire is predisposed to accelerated acidification and would
take between 10–20 years to acidify to pH 5.0. In contrast, a relatively
minor proportion of the total area of the Shire (17%) had significant
internal buffering capacity. However, the degree of uncertainty associated
with these estimations on certain soil associations may be too high to be of
relevance. In order to overcome this limitation a field test designed to
assess the risk of accelerated acidification on a paddock basis is proposed
and outlined in the paper.
pH, buffer capacity, pedotransfer function.
Seasonal changes in hydrochemistry along a toposequence of texture-contrast soils
Authors: Cox J. W. , Chittleborough D. J. , Brown H. J. , Pitman A. , Varcoe J. C. R.
Published: September 2002

Ameliorative strategies are urgently required in some agricultural catchments in southern Australia to reduce the loss of potential contaminants to streams. However, a better understanding of where the contaminants are generated on hillslopes, their forms, and the pathways through which they are transported were required. Thus, seasonal changes in the quantities and forms of several chemical species were measured in both vertical and lateral flow pathways at 4 sites along a toposequence in the Mt Lofty Ranges, South Australia. Instrumentation was installed to measure and quantify overland flow and throughflow, and porous-wick samplers were installed at 2 depths to study the chemistry of leachate. Neutron moisture meter access tubes were installed to measure seasonal changes in soil water content with depth as this influences chemical concentrations and mobility.

In years of average to below average annual rainfall, throughflow was the most important transport pathway for contaminants. However, it was expected that overland flow will be the dominant transport pathway when annual rainfall is above about 550 mm. Changes in water content of the texture-contrast soils was caused by seasonal rainfall causing periodic saturation, by waterlogging, groundwater, or both. This affected the type and form of contaminant. For example, Na and Cl concentrations were generally only large (800 and 1500 mg/L, respectively) on the lower slopes but in the wettest seasons their concentrations increased at depth on mid-slopes due to the influence of shallow saline groundwater. These chemicals then leached when groundwater levels subsided. The results suggest that ameliorative strategies to reduce agricultural contaminants should target the transport pathways specific to each chemical species, at the point (or points) in the landscape where they are generated.
Nitrification in a Vertisol subsoil and its relationship to the accumulation of ammonium-nitrogen at depth
Authors: Page K. L. , Strong W. M. , Dalal R. C. , Menzies N. W.
Published: September 2002

Unusually high concentrations of ammonium have been observed in a Vertisol below 1 m depth in south-east Queensland. This study investigated the possibility that an absence of nitrification is allowing this ammonium to accumulate and persist over time, and examined the soil environmental characteristics that may be responsible for limiting nitrifying organisms. The possibility that anaerobiosis, soil acidity, soil salinity, low organic carbon concentrations, and/or an absence of active nitrifying microorganisms were responsible for limiting nitrification was examined in laboratory and field studies. The presence/absence of anaerobic conditions was determined qualitatively using a field test to give an indication of electron lability. In addition, an incubation study was conducted and soil environmental conditions were improved for nitrifying organisms by adjusting the pH from 4.4 to 7, adjusting the electrical conductivity from 1.6 to 0.5 dS/m, amending with a soluble carbon substrate at a rate of 500 mg/kg, and using microorganisms from the surface horizon to inoculate to the subsoil. Over a 180-day period no nitrification was detected in the control samples from the incubation study, indicating that an extremely low rate of nitrification is likely to be responsible for allowing ammonium to accumulate in this soil. Analysis of the effect of soil environmental conditions on nitrification revealed that anaerobic conditions did not exist at depth and that pH, EC, organic carbon, and inoculation treatments added in isolation had no effect on nitrification. However, when inoculum was added to the soil in combination with pH, a significant increase in nitrification was observed, and the greatest amount of nitrification was observed when inoculum, pH, and EC treatments were added in combination. It was concluded that the reason for the low rate of nitrification in this soil is primarily the absence of a significant population of active nitrifying microorganisms, which may have been unable to colonise the subsoil environment due to its acidic, and to a lesser extent, its saline environment.
Effects of management practice on properties of a Victorian red-brown earth. 2. Wheat root distribution and grain yield
Authors: Lorimer M. S. , Douglas L. A.
Published: September 2002

The effects of 5 management practices (native forest, native pasture, phalaris
pasture, crop-pasture rotation, and continuous cropping), applied prior to
sowing wheat seeds, on the distribution of wheat roots and associated grain
yields were studied. The grain yield from the 5 treatments decreased in the
following order: crop-pasture rotation > native pasture > phalaris
pasture > native forest > continuous cropping, and this was directly
related to the distribution of the wheat roots in the respective treatment
plots. A high incidence of root disease in the phalaris pasture plots severely
restricted root distribution and grain yield despite the apparent
‘ideal’ soil conditions for plant growth. The implications of
current land management practices, which lead to the formation of plough-pans
and reduced root penetration into the subsoil, are discussed in terms of
future wheat production on this soil type.
Chemical and mineralogical composition of Fe-Mn concretions and calcretes occurring in sodic soils of Eastern Uttar Pradesh, India
Authors: Ram H. , Singh R. P. , Prasad Jagdish
Published: September 2002

The chemical and mineralogical composition of iron–manganese
(Fe–Mn) concretions, calcretes (lime nodules), and soil matrix in sodic
soils (Typic Halaquepts) from Mirzapur, Faizabad, Ghazipur, and Ballia
districts of Uttar Pradesh have been investigated. The data show enrichment of
iron and manganese oxides in Fe–Mn concretions,
CaCO3 in calcretes, and insoluble constituents in the
soil matrix. Hydrochloric acid-insoluble fractions were higher in soil than in
concretions and calcretes. Sodium content was also higher in soils than in
concretions and calcretes, and it increased with depth. The concretions had
haematite and limonite in high proportion, while calcretes predominantly
contained calcite and lesser amounts of quartz, mica, and fieldspars. The thin
section study indicated that staining of calcretes was caused by gradual
replacement by iron oxides. The calcretes and Fe–Mn concretions were
formed by pedogenic processes and modified by subsequent environmental
changes.
Modelling current parna distribution in a local area
Authors: Summerell G. K. , Dowling T. I. , Richardson D. P. , Walker J. , Lees B.
Published: September 2002

Parna is a wind-blown clay, mobilised from inland Australia as the result of a
series of intermittent high wind events during the Quaternary. Parna can be
recognised on the basis of colour, texture, distributional patterns, and
pedology. Parna deposits have been recorded across a wide area of south
eastern Australia and have influenced the local pedology and hydrology. In
some cases parna has increased soil sodicity and the potential for dryland
salinisation. Predicting its spatial distribution is useful when considering
agricultural potential and in assessing the risk and spatial spread of dryland
salinity. Here we present the results of modelling to predict its local
distribution in an area covering 291 km2 in the Young
district of NSW. Two conceptual models of parna deposition and subsequent
redistribution were used to develop a current parna distribution map:
(a) deposition =
f(topography, aspect) after assuming that interactions
of rainfall, vegetation, and wind speed were relatively the same at the local
scale; (b) removal or retention =
f (slope angle, catchment size, slope length) as a
representation of the erosive energy of gravity. Five landscape variables,
elevation, aspect, slope, flow accumulation, and flow length, were derived
from a 20 m digital elevation model (DEM). A training set of parna deposits
was established using air photos and field survey from limited exposures in
the Young district of NSW. These areas were digitised and converted to a grid
of areas of parna and no-parna. This training set for parna and the 5
landscape variable grids were processed in the IDRISI for WINDOWS Geographic
Information System (GIS). Spatial relationships between the parna and no-parna
deposits and the 5 landscape variables were extracted from this training set.
This information was imported into an inductive learning program called
KnowledgeSEEKER. A decision tree was built by recursive partitioning of the
data set using Chi-squares to categorise variables, and an
F test for continuous variables to best replicate the
training data classification of ‘parna’ and
‘no-parna’. The rules derived from this process were applied to
the study area to predict the occurrence of parna in the broader landscape.
Predictions were field checked and the rules adjusted until they best
represented the occurrence of parna in the field. The final model showed
predictions of parna deposits as follows: (i) higher
elevations in the Young landscape were the dominant sites of parna deposits;
(ii) thicker deposits of parna occurred on the windward
south-west and north-west; (iii) thinner deposits
occurred on the leeward side of a central ridge feature;
(iv) because the training set concentrated around the
major central ridge feature, poorer predictions were obtained on gently
undulating country.
Waste jarosite and alunite will be ineffective sulfur and potassium fertilisers
Authors: Williams S. N. , Gilkes R. J. , Bernard N. G.
Published: September 2002

The processing of ilmenite to synthetic rutile produces an acidic sulfate- and
iron-rich solution from which the mineral jarosite [KFe
3 (OH)6 (SO
4 ) 2 ] can be precipitated.
Jarosite and isostructural alunite [KAl 3
(OH)6 (SO 4 )
2 ], which may also be precipitated from processing
waste, have the potential to be effective slow-release fertilisers on sandy
soils. A glasshouse experiment was conducted on a very sandy soil in which the
effectiveness of these two compounds as sulfur and potassium fertilisers was
compared with that of control fertilisers (gypsum and KCl). Neither compound
proved to be an effective fertiliser. Equilibrium solubilities of sulfate (63
mM, 173 mM) and potassium (60 mM, 70 mM) for jarosite and alunite,
respectively, were very low, which is consistent with the relative
ineffectiveness of these compounds as fertilisers.
Soil development on rehabilitated bauxite mines in south-west Australia
Authors: Ward S. C.
Published: September 2002

Rehabilitation after bauxite mining in the jarrah forest aims to re-establish
a self-sustaining forest. This implies that ecosystem processes will be
re-established and soil nutrient stores will be similar to those of the
unmined forest. This study determined the baseline levels of a number of soil
properties in areas of jarrah forest typically cleared and mined for bauxite,
and the effect of mining and rehabilitation processes on the vertical
distribution of soil nitrogen. In addition, the changes in soil nitrogen,
extractable phosphorus, extractable potassium, and pH that occurred up to 8.5
years after rehabilitation were investigated.
The values of the soil properties in unmined forest found in this study were
similar to those previously measured in the jarrah forest. Values of all
parameters varied significantly with depth. Considerable mixing of soil
horizons occurred when the topsoil was stripped, placed on an area undergoing
rehabilitation, and ripped. Many soil parameters showed significant changes in
the period 3.5–8.5 years after rehabilitation. Levels of total nitrogen
in the top 10 cm of soil in rehabilitated areas increased from around
0.04–0.05% initially to levels approaching those found in
good-quality jarrah forest (0.10–0.30%) after 8.5 years. Soil pH
declined in the surface layer after rehabilitation. The rate of acidification
is likely to decrease in future years. The levels of the soil chemical
parameters were mostly within or moving towards the range of values found in
areas typically mined for bauxite.
The results indicate that ecosystem processes have been re-established on the
rehabilitated areas and that there is no obvious soil chemical impediment to
the establishment of a self-sustaining forest ecosystem on rehabilitated
bauxite mines.
Soil stripping and replacement for the rehabilitation of bauxite-mined land at Weipa. III. Simulated long-term soil organic matter development
Authors: Schwenke G. D. , Mulligan D. R. , Bell L. C.
Published: September 2002

Long-term trends in soil organic carbon (C) and nitrogen (N) under current and
alternative rehabilitation practices at Weipa were simulated using the CENTURY
model. After 100 years, predicted organic C in the surface soils (0–20
cm) of each treatment had risen to new dynamic equiliPbria. Since the
‘passive’ pool of recalcitrant organic C, which occupied
47% of organic C, changed little over the simulation period, the new
equilibria differed according to initial organic C content. Most organic
matter recovery occurred in the ‘slow’ fraction, although the
greatest rate of change occurred in the ‘active’ C pool, which
stabilised within 50 years at levels similar to the native forest. Similarly,
‘slow’ C accumulated in all treatments to new equilibria which
were similar to that in undisturbed forest soil. The main difference between
treatments was in the predicted time until a stable equilibrium in the
‘slow’ pool was reached: between 90 and 160 years depending on the
soil stripping and replacement operation used. Successful development of new
equilibria was highly sensitive to the amount of legume
N2 fixation in the system and also to the severity of C
and N losses during fire events. Reasonable agreement was found between
simulated organic C accumulation and that observed in surveyed rehabilitation
of up to 15 years of age (r2
= 0.67 for freshly replaced soils,
r2 = 0.72 for soils
stockpiled before respreading).
Mineralisation of nitrogen in a chronosequence of rehabilitated bauxite mines
Authors: Todd M. C. L. , Adams M. A. , Grierson P. F.
Published: September 2002

Mine site rehabilitation should aim to establish quickly and maintain the
processes of nutrient cycling at rates comparable with, or approaching, those
of native forests. Current management strategies for rehabilitating bauxite
mines and other mine sites in Australia usually include planting fast-growing
understorey species at high densities and applying fertiliser. We provide the
first detailed study of nitrogen (N) availability and N transformations
(mineralisation/immobilisation) in such rehabilitated mine sites. Mean
concentrations of NO3–
(0–5 cm) in a chronosequence (7, 13, 22, and 27 years old) of
rehabilitated mine sites ranged from 0.5 to 1.3 kg/ha, and
NH4+ from 4.0 to 9.5
kg/ha. In burnt and unburnt native jarrah
(E. marginata Donn ex. Smith) forests adjacent to the
mine site, mean NO3–
concentrations in surface soil (0–5 cm) were 0.8 kg/ha (burnt) and
1.1 kg/ha (unburnt), and mean
NH4+ concentrations were 6.8
kg/ha (burnt) and 7.8 kg/ha (unburnt). Concentration of
NH4+ at 0–5 cm was
strongly related to soil water content
(R2 = 0.69,
P < 0.05) in rehabilitation sites, but not at
5–10 cm depth. Rates of N mineralisation (0–5 cm) in
rehabilitation sites ranged from 34 to 52 kg/ha.year, of the same order as
rates in native forest soil. In all rehabilitation and native forest sites,
rates of N mineralisation were significantly related to rates of N-uptake at
both 0–5 and 5–10 cm depth
(R2 > 0.63,
P < 0.05). Soil C/N ratios (0–5 cm) in
rehabilitation sites ranged from 22.4 to 38.8, and in native forests from 35.6
(burnt) to 40.3 (unburnt). Soil C/N ratios increased with depth in both
rehabilitation and native forest sites (ranged from 31.2 to 51.6).
Availability of water was the major determinant of nitrogen availability in
this strongly Mediterranean climate.
Comparison of pyrocatechol violet and aluminon for the determination of 'reactive' aluminium in the presence of organic acids
Authors: Ginting Sahta , Johnson Bruce B. , Wilkens Sabine
Published: September 2002

The effect of 5 organic anions (citrate, malate, malonate, oxalate, and
tartrate) on the concentration of Al measured with 2 colorimetric reagents
[pyrocatechol violet (PCV) and aluminon] was determined as a
function of reaction time. The results are compared with concentrations of
reactive Al [Al3+ +
AlOH2+ +
Al(OH)2+ ] predicted
from stability constants. The PCV reagent was found to overestimate this
fraction, i.e. to underestimate the extent of complexation by oxalate,
malonate, and malate, even when the shortest reaction time of 30 s was
applied. However, the aluminon reagent provided a good estimate of
‘reactive’ Al at the 30 s reaction time in the presence of all
organic anions studied. At a citrate and tartrate to Al ratio of 1 : 2, the
‘reactive’ Al concentration, determined from stability constant
data, underestimated the extent of Al complexation. These deviations could be
modelled by the addition of a further complex, with the composition
Al2 (OH)L2+ for citrate and
Al2(OH)2L2+
for tartrate. Tentative equilibrium constants for these species are presented.
Pedogenic destruction of ferrimagnetics in Alaskan loess deposits
Authors: Liu X. M. , Hesse P. , Begét J. , Rolph T.
Published: September 2002

The positive correlation between magnetic susceptibility and pedogenic degree
or weathering intensity, observed in the loess-palaeosol sequences from China
and central Europe, has been widely used by Quaternary scientists for
palaeoclimatic studies. The in-situ pedogenic
enhancement of ferrimagnetic content is normally believed to be the main
reason for the increase of susceptibility in soil units. However, this pattern
of high magnetic susceptibility in palaeosols, and lower values in loess, is
not replicated in some loess deposits. Alaskan and Siberian loess deposits
display a completely opposite susceptibility behaviour: high values in loess
and low values in palaeosols. This inverse relationship has been explained by
the idea that magnetic susceptibility is reflecting the magnitude of an
aeolian ferrimagnetic component of consistent mineralogy, the grain size of
which is related to average wind velocity. Our magnetic study of Alaskan
samples in this paper suggests that there are notable differences in magnetic
properties between Alaskan loess and developed palaeosols, not only in
magnetic grain-size and concentration but also in magnetic mineralogy. This
evidence is difficult to explain fully through variation in wind strength
alone, but implies that the low magnetic susceptibility values in the Alaskan
palaeosol units are a reflection, at least in part, of the alteration of the
ferrimagnetic content by post-depositional processes. Magnetic susceptibility
has variable behaviour corresponding to different temperature–moisture
environments. Ferrimagnetic minerals are produced (positive correlation) under
pedogenic conditions resulting from low precipitation and high evaporation but
will be destroyed (negative correlation) under high moisture (waterlogged)
pedogenic conditions. If pedogenic development occurs under conditions which
oscillate between ferrimagnet formation and destruction then it may be
difficult to find a correlation between them. Therefore, great care should be
taken when using susceptibility values for palaeoclimatic reconstruction.
Spatial prediction of topsoil salinity in the Chelif Valley, Algeria, using local ordinary kriging with local variograms versus whole-area variogram
Authors: Walter Christian , McBratney Alex B. , Douaoui Abdelkader , Minasny Budiman
Published: September 2002

A novel form of ordinary kriging, involving the local estimation and modelling
of the variogram at each prediction site (OKLV), is tested at a regional scale
on a large data set, in order to adapt to non-uniform spatial structures and
improve the assessment of the salinity hazard in the lower Chelif Valley,
Algeria. The spatial variability study was carried out on a 38000 ha area
using 5141 topsoil electrical conductivity (EC) measurements systematically
sampled on a 250 m by 250 m grid. Variography analysis confirmed the existence
of large trends in the EC variability with differing spatial structures
between sub-areas.
OKLV performed better than ordinary kriging with a whole-area variogram (OKWV)
in predicting the proportion of high saline soils in large blocks, but the
predictions appeared mostly similar. In contrast, the estimation variance maps
revealing the uncertainties of the spatial predictions were markedly different
between the 2 methods. OKLV integrates the local spatial structure in the
uncertainty assessment, whereas kriging with a whole-area variogram only
considers the sampling intensity. Comparison with prediction errors on a
validation set confirmed the consistency of the OKLV prediction variance. This
appears to be a major improvement for decision-making procedures such as
delineating areas where remediation should take place.
Laboratory experiments and modelling studies of leaching of intermittently drained columns
Authors: Rose D. A. , Adey M. A. , Al-Sibai M.
Published: September 2002

This paper examines the intermittent leaching of columns of porous ceramic
spheres, as analogues of soil aggregates, in 3 ways: theoretically, by
laboratory experiments, and by simulation. The work extends earlier
investigations of continuously saturated columns to the case where columns
drain during breaks in the leaching process.Solute movement during
displacement is described by the mobile–immobile
convection–dispersion equation but, because air replaces solution as the
soil drains, it is considered to be immiscible rather than miscible
displacement. During the rest period solute redistributes within the
aggregates with the concentration at the surface of aggregates increasing.
During the next leaching period transfer of solute into macropores is
consequently faster. This results in a greater leaching efficiency.
The intermittent drained leaching is less efficient than the continuously
saturated intermittent leaching (by 16% under the conditions of our
experiment) as, in the latter system, solute can diffuse from within
aggregates into macropores during rest periods.
Nevertheless there is a benefit compared with continuous leaching.
Modelling reveals (i) that the first-order mass-transfer
rate coefficient increases as the number of leaching cycles increases,
(ii) that the concentration profiles of solute down the
column of aggregates differ substantially between the saturated and drained
situations, and (iii) that the concentrations in the
mobile and immobile solutions at the base of the column converge towards the
end of each leaching cycle.
Spatial interpolation and simulation of post-burn duff thickness after prescribed fire
Authors: Robichaud P. R. , Miller S. M.
Published: September 2002

Prescribed fire is used as a site treatment after timber harvesting. These
fires result in spatial patterns with some portions consuming all of the
forest floor material (duff) and others consuming little. Prior to the burn,
spatial sampling of duff thickness and duff water content can be used to
generate geostatistical spatial simulations of these characteristics. Results
from field studies indicated that spatial patterns of duff characteristics
occurred, and they were then modeled by kriging, simulation and a
trend-surface modeling techniques. The higher elevations of the study unit
burned more severely than the lower portion. This is believed to be due to the
heat generated by the fire drying out the upper portions of the units, thus
consuming more duff material and thinner pre-burn duff thickness due to
ground-based harvesting techniques. Attempts to predict duff consumption and
subsequent post-burn duff thickness were successful using a trend-surface
model developed for this site and a general duff consumption model. Knowledge
of spatial patterns of duff remaining may help land managers adjust
prescriptions and alter ignition patterns to reduce areas where total
consumption of duff might occur.
Occurrence of wildfire in the northern Great Lakes Region: Effects of land cover and land ownership assessed at multiple scales
Authors: Cardille Jeffrey A. , Ventura Stephen J.
Published: September 2002

Risk of wildfire has become a major concern for forest managers, particularly
where humans live in close proximity to forests. To date, there has been no
comprehensive analysis of contemporary wildfire patterns or the influence of
landscape-level factors in the northern, largely forested parts of Minnesota,
Wisconsin and Michigan, USA.
Using electronic archives from the USDA Forest Service and from the
Departments of Natural Resources of Minnesota, Wisconsin, and Michigan, we
created and analysed a new, spatially explicit data set: the Lake States Fire
Database. Most of the 18 514 fires during 1985—1995 were smaller
than 4 ha, although there were 746 fires larger than 41 ha. Most fires were
caused by debris burning and incendiary activity. There was considerable
interannual variability in fire counts; over 80% of fires occurred in
March, April, or May.
We analysed the relationship of land cover and ownership to fires at two
different fire size thresholds across four gridded spatial scales. Fires were
more likely on non-forest than within forests; this was also true if
considering only fires larger than 41 ha. An area of National or State Forest
was less likely to have experienced a fire during the study period than was a
forest of equal size outside National or State Forest boundaries. Large fires
were less likely in State Forests, although they were neither more nor less
likely to have occurred on National Forests. Fire frequency also varied
significantly by forest type. All results were extremely consistent across
analysis resolutions, indicating robust relationships.
A prescription for controlling the air pollution resulting from the use of prescribed biomass fire: clouds
Authors: Radke Lawrence F. , Ward Darold E. , Riggan Philip J.
Published: September 2002

Forestry, conservation, wildfire risk reduction, and agricultural uses of
planned or prescribed fires as a tool for meeting the needs of wildland
managers are increasingly in collision at the air pollution control and
climate change cross-roads. The inevitable conflict resulting from the
disparate goals of users has long been the subject of a combination of both
systems and ecologically integrated analysis attempting to minimize the
environmental impact and maximize the economic and societal benefits of this
land management technique. We offer here experimental evidence for the
viability of implementing a pollution control option that could substantially
reduce the particulate emissions from prescribed fires in biomass and explore
some of the logical implications of these concepts.
In nature, clouds and precipitation are the principal mechanisms by which the
atmosphere is cleansed of particulate pollution, aerosols and smokes. We
propose here, for consideration, using clouds as a part of the prescription
for scheduling biomass fires.
Since in most areas biomass fire is already carried out within a detailed
prescriptive plan which includes meteorological forecasts, the addition of
additional meteorological scheduling constraints should be acceptable to most
users providing that the benefits are correspondingly large. Reducing
particulate smoke emissions in all size classes by at least 50% seems
practicable.
Fire modelling in Tasmanian buttongrass moorlands. III. Dead fuel moisture
Authors: Marsden-Smedley Jon B. , Catchpole Wendy R.
Published: September 2002

An experimental program was carried out in Tasmanian buttongrass moorlands to
develop fire behaviour prediction models for improving fire management. This
paper describes the results of the fuel moisture modelling section of this
project. A range of previously developed fuel moisture prediction models are
examined and three empirical dead fuel moisture prediction models are
developed. McArthur’s grassland fuel moisture model gave equally good
predictions as a linear regression model using humidity and dew-point
temperature. The regression model was preferred as a prediction model as it is
inherently more robust. A prediction model based on hazard sticks was found to
have strong seasonal effects which need further investigation before hazard
sticks can be used operationally.
A primer on mapping vegetation using remote sensing
Authors: Bobbe Tom , Lachowski Henry , Maus Paul , Greer Jerry , Dull Chuck
Published: September 2002

This paper was presented at the conference ‘Integrating spatial technologies and ecological principles for a new age in fire management’, Boise, Idaho, USA, June 1999
The use of information based upon remotely sensed data is a central factor in
our 21st Century society. Scientists in land management agencies especially
require accurate and current geospatial information to effectively implement
ecosystem management. The increasing need to collect data across diverse
landscapes, scales, and ownerships has resulted in a wider application of
remote sensing, Geographic Information Systems (GIS) and associated geospatial
technologies for natural resource applications. This paper summarizes the use
of digital remotely sensed data for vegetation mapping. Key steps in preparing
vegetation maps are described. These steps include defining project
requirements and classification schemes, use of reference data, classification
procedures, and assessing accuracy. The role of field personnel and inventory
data is described. Case studies and applications of vegetation mapping on
national forest land are also included.
remote sensing, GIS, mapping, geospatial,
project planning.
The new smoke management
Authors: Riebau Allen R. , Fox Douglas
Published: September 2002

This paper was presented at the conference ‘Integrating spatial technologies and ecological principles for a new age in fire management’, Boise, Idaho, USA, June 1999
The United States Environmental Protection Agency (EPA) will implement new
regulations for the management of atmospheric particulate matter 2.5 µm
and less in diameter (PM2.5), tropospheric ozone, and
regional haze in the next few years. These three air quality issues relate
directly to forest and agriculture burning. Fire generates
PM2.5 and ozone precursor gases that reduce visibility.
Hence, wild and agricultural land managers will be subject to these air
quality regulations much as industrial and mobile sources have been for the
past 25 years. In addition, these new regulations come at a time when private
as well as public land managers throughout the United States are developing
plans to increase their application of fire as a management tool. Prescribed
fire will remain viable as a tool for land managers with these new regulations
but only under a responsible smoke management paradigm. This paradigm will
include formal ‘state-approved’ Smoke Management Programs and will
require the use of new and ‘approved’ technologies that have been
subjected to public and stakeholder scrutiny as regulatory tools. These
programs will acknowledge that wildland fire is different from conventional
human-caused air pollution sources. They will recognize that the managed use
of fire is a superior option to wildfire from public safety and health
perspectives. But they will also require greater utilization of non-burning
alternatives in all circumstances, especially where fire is used for economic
rather than ecological reasons. Through better smoke management and greater
use of non-burning alternatives, steadily reduced smoke emissions will likely
result.
Betula glandulosa Michx. Response to burning and postfire growth temperature and implications of climate change
Authors: de Groot W. J. , Wein Ross W.
Published: September 2002

Plants collected from eight fire-prone sites in western and northern Canada
were tested in a greenhouse experiment for response to low fire severity and
growing temperatures of 14-24˚C. The combined data showed that burning
interacted with growth temperature during the first 42 days after treatment to
significantly reduce sprout height at low temperatures and increase sprout
height at the highest temperature. Burning significantly increased sprout
height growth at all temperature treatments after 84 days although this effect
was most apparent at the highest growth temperature. Burning significantly
reduced sprout production after 42 days and had no significant influence on
sprout production or aboveground biomass production after 84 days. Separate
analysis of individual site data showed two populations with significant
fire-stimulated sprout height growth and two other populations with similar,
but slightly less significant response. The populations showed no geographic
or topographic trend in fire response. The warmer growing conditions of
postfire microsites appear to provide this shade intolerant plant with a
competitive advantage over other invading pioneer and resprouting species by
enhancing fire-stimulated height growth response. Due to its fire ecology,
Betula glandulosa populations are expected to expand and
thrive in this region under future climate change conditions.
The distribution and roost habitat of the orange leaf-nosed bat, Rhinonicteris aurantius, in the Pilbara region of Western Australia
Authors: Armstrong K. N.
Published: September 2002

The endemic orange leaf-nosed bat,
Rhinonicteris aurantius, is a relict both in a
phylogenetic and a geographic sense. Prior to this study, two colonies in
disused mines and seven other records of single animals were known from the
disjunct Pilbara population of Western Australia. Cave roosts were located in
the region for the first time, five new roosts were found in disused mines and
the species was recorded in five new localities. Cave roosts were discovered
in sandstone bedding. Free-flying R. aurantius were
located in a diverse range of landscapes composed of banded iron formation,
Cleaverville Formation geology and granite. Mines utilised as roosts were
structurally complex and in some cases breached the watertable. This study
revealed that while the species is widespread throughout the region, it is
restricted to certain landform units, the number of suitable roosts within
landform units is limited and the population appears to be subdivided within
the region. Dispersal and connectivity within the population may be dependent
on the availability of roosts in intervening areas, which may be a function of
the availability of groundwater to subterranean formations for the control of
roost microclimate. Currently, the known breeding range is one gorge at Barlee
Range Nature Reserve and one mine at Bamboo Creek.
A comparison of population estimates and abundance indices for house mice inhabiting beech forests in New Zealand
Authors: Ruscoe Wendy A. , Goldsmith Ruth , Choquenot David
Published: September 2002

Populations of house mice were sampled on nine grids in Fiordland National
Park between May and November 1999, using live-capture and footprint-tracking
tunnel methods. Trapped mice were removed from three grids (approximately 3.24
ha each), and marked and released on the other six. Density estimates were
obtained using recapture data from the grids where mice were released
(Mh (jackknife) model from program CAPTURE), and
rate-of-capture data from grids where mice were removed
(Mbh (removal) CAPTURE model). Density estimates were
used to evaluate the performance of 4 indices of mouse abundance by
contrasting R2-values of their
regression on estimated mouse density. Indices evaluated were:
minimum number of individuals known to be alive (MNA)
(total number of individual mice caught over the course of a trapping
session), one-night trap catch (number of mice caught on
first night of each trapping session expressed as captures per 100
trap-nights), three-night trap catch (same index
estimated from number of mice caught over the first three nights), and
tracking-tunnel index (proportion of nine tunnels that
had mouse tracks). While MNA,
one-night trap catch, and
three-night trap catch were all significantly correlated
with estimated density, MNA was most strongly
correlated, with R2 varying
between 0.67 to 0.87 depending on whether 3, 4 or 5 nights’ capture data
were used. Variation in tracking-tunnel index was
unrelated to mouse density on our grids.
The record of fauna, and accumulating agents of hair and bone, found in middens of stick-nest rats (Genus Leporillus) (Rodentia : Muridae)
Authors: Pearson S. G. , Baynes A. , Triggs B. E.
Published: September 2002

Middens built by stick-nest rats (Leporillus apicalis
and/or Leporillus conditor) contain information
relating to the animals that lived in the arid areas of Australia. The hair
and bones recovered from stick-nest rat middens in the Northern Territory,
South Australia and Western Australia provide information about the former
distribution and community composition of species in arid Australia. Some of
the species recorded from the middens are no longer present in the surrounding
areas. The bone and hair materials appear to have been derived from the scats
of small carnivorous mammals and incorporated into middens by stick-nest rats.
The material has been radiocarbon dated and, in some cases, represents over
2000 years of accumulation in the middens of stick-nest rats.
Dispersal of southern elephant seals (Mirounga leonina L.) marked at Macquarie Island
Authors: van den Hoff John
Published: September 2002

Southern elephant seals marked at Macquarie Island disperse to distant
locations where they are sometimes seen during their moult and, for juveniles,
a mid-year haul-out period (July–August). Most (87%) of these
resighted seals were within 1000 km of Macquarie Island, and most commonly at
Campbell Island (700 km to the north-east). The sex and age classes most
likely to disperse there were males less than two years old. Male elephant
seals of all ages were resighted significantly more often than females, the
ratio being 2 : 1 (P > 0.05). Migration duration
tended to increase with the seals’ age but migration distance was
underestimated from resight observations when compared with known telemetry
records. Emigration from the Macquarie Island population appears limited. From
the resight effort at Campbell Island during 1995 the maximum proportion of
the juvenile population from Macquarie Island to haul-out at Campbell Island
was in the order of 0.0053.