Pauline Mele

La Trobe University · AgriBio Centre for AgriBioscience

Here we describe the potential for sediment microbial nitrogen-cycling gene (DNA) and activity (RNA) abundances to spatially resolve coastal areas impacted by seasonal variability in external nutrient inputs. Three sites were chosen within a nitrogen-limited embayment, Port Phillip Bay (PPB), Australia that reflect variability in both proximity to...

The compound nitrapyrin can act as a potential nitrification inhibitor (NI) when applied with ammonium (NH4+)-based N fertiliser. The efficacy of nitrapyrin applications may be soil dependent however, being influenced by soil texture, organic carbon (C), and moisture. The objective of this study was to assess the effects of nitrapyrin on the nitrif...

Actinobacteria play key roles in terrestrial ecosystem functioning. They contribute to global carbon cycling through the decomposition of soil organic matter, they increase plant productivity and are widely known as prolific producers of bioactive compounds essential for human and animal health. The almost century-old search for new members of the...

Soil fungi play essential roles in many terrestrial processes, but our knowledge of the forces governing fungal distribution and community composition along broad-scale environmental gradients is still limited. In this study, we explored biogeographic distribution and composition of soil fungal communities associated with 62 tussock grasslands acro...

The current theoretical framework suggests that tripartite positive feedback relationships between soil biodiversity, fertility and plant productivity are universal. However, empirical evidence for these relationships at the continental scale and across different soil depths is lacking. We investigate the continental-scale relationships between the...

In recent years, identification of the microbial sources responsible for soil N2O production has substantially advanced with the development of isotope enrichment techniques, selective inhibitors, mathematical models, and the discoveries of specific N-cycling functional genes. However, little information is available to effectively quantify the N2O...

Background Microbial inhabitants of soils are important to ecosystem and planetary functions, yet there are large gaps in our knowledge of their diversity and ecology. The ‘Biomes of Australian Soil Environments’ (BASE) project has generated a database of microbial diversity with associated metadata across extensive environmental gradients at conti...

Most studies on soil N2O emissions have focused either on the quantifying of agricultural N2O fluxes or on the effect of environmental factors on N2O emissions. However, very limited information is available on how land-use will affect N2O production, and nitrifiers involved in N2O emissions in agricultural soil ecosystems. Therefore, this study ai...

Key messages • Soil is an important habitat for thousand millions of organisms. • Soil biodiversity is extremely diverse in shapes, colours, sizes and functions. • Soil biodiversity is globally distributed, from deserts to polar regions through grasslands, forests, urban and agricultural areas. • Soil biodiversity supports many services essential t...

SPE EA Pôle BIOME The Atlas is divided in 8 chapters covering all the aspects of soil biodiversity: - Chapter I: The soil habitat - Chapter II: Diversity of soil organisms - Chapter III: Geographical and temporal distribution - Chapter IV: Ecosystem functions and services - Chapter V: Threats - Chapter VI: Interventions - Chapter VII: Policy, educa...

Our interests in soil change are moving away from soil properties and increasingly towards changes in the processes and functioning of soils. Soil organisms are fundamental to dynamics and change in soils through their fundamental role in soil processes [1]. However it is only with recent technical and theoretical advances that we have started to e...

The present study was designed to analyse soils by different methodologies to determine the range of traits that could be investigated for the study of environmental soil samples. Proton nuclear magnetic resonance spectroscopy (1H NMR) was employed for metametabolomic analysis of soils from agricultural systems (managed) or from soils in a native s...

Two fosmid libraries, totaling 13,200 clones, were obtained from bioreactor sludge of petroleum refinery wastewater treatment system. The library screening based on PCR and biological activity assays revealed more than 400 positive clones for phenol degradation. From these, 100 clones were randomly selected for pyrosequencing in order to evaluate t...

Top hits selected in Blastn searches, comparing the fosmid sequence with bacterial genomes deposited in GenBank. (DOC)

Plant growth promoting pseudomonads play an important role in disease suppression and there is considerable interest in development of biomarker genes that can be used to monitor these bacteria in agricultural soils. Here, we report the application of a PCR primer sets targeting genes encoding the main antibiotic groups. Distribution of the genes w...

The microbial community structure of bacteria, archaea and fungi is described in an Australian native grassland soil after more than 5 years exposure to different atmospheric CO(2) concentrations ([CO(2) ]) (ambient, + 550 ppm) and temperatures (ambient, + 2°C) under different plant functional types (C (3) and C (4) grasses) and at two soil depths...

In petrochemical refinery wastewater treatment plants (WWTP), different concentrations of pollutant compounds are received daily in the influent stream, including significant amounts of phenolic compounds, creating propitious conditions for the development of particular microorganisms that can rapidly adapt to such environment. In the present work,...

Soil biota is responsible for the majority of ecosystem functions in soil, in particular carbon transformations, nutrient cycling, soil structure maintenance, and biological population regulation. An environmental microarray was designed to study key functional genes that facilitate soil processes required for sustainable and productive management...

The aim of this study was to assess the long-term changes in some key soil chemical properties at the completion of three long-term trials in south-eastern Australia and the relationship between those soil properties. From a soil organic matter perspective, the build-up of carbon (%C) requires an accumulation of nitrogen (%N), and the build-up of %...

This report shows that there is good evidence from scientific research that the land management practices adopted by farmers have a direct impact on soil condition. Improving soil condition benefits production as well as providing a range of ecosystem services to the broader community; including water purification, breakdown of wastes and toxins, r...

The management of soil health under various global change scenarios requires clear iteration of the links between soil health and soil biota and the elucidation of the multitude of ways in which soil biota contributes to and is impacted by global change. Because of the enormity of the topic, the major focus of this chapter will be on the most funct...

Management of soil health for sustainable agricultural productivity can be achieved if appropriate knowledge and tools are in the hands of land managers. A review of available tools for soil assessment, development of training modules in aspects of soil health, and a pilot for a soil health management planning process, formed the principal elements...

Public expectations of soil management are gradually expanding beyond traditional primary production requirements to include diverse ecosystem services. In Australia, as in many other countries, the accommodation of these new expectations will require shifts in the practice of private land managers. In turn, this may require public intervention and...

Nitrogen is a critical nutrient in plant-based primary production systems, therefore measurements of N cycling by microorganisms may add value to agricultural soil monitoring programs. Bacterial-mediated nitrogen cycling was investigated in soils from two broad land-uses (managed and remnant vegetation) across different Soil Orders from three geomo...

Agricultural ecosystems can be described by many different variables that include soil chemical, physical, and biological data. Whilst most of the chemical and physical properties variables that are relevant to soil quality are well understood, measures of soil biological properties so far have been much more difficult to use as decision support to...

Several sampling methods were investigated for the quantification of organic anions in the rhizosphere of Al-tolerant (ET8) and Al-sensitive (ES8) wheat plants in soil systems. Controlled environment studies used anion exchange membranes to collect rhizosphere organic anions (from root tips and mature regions of nodal roots) from ET8 and ES8 plants...

Two of the major constraints to grain production in large areas of South-East Australia and cropping soils worldwide are high levels of subsoil boron (B) and excessive salinity (NaCl). Although the effect of these constraints is often studied in plants, the effect on microbially mediated plant-beneficial processes is unclear. To that end, we invest...

Crop management practices can affect the soil microbial community, but it is not clear whether the effect of these practices is measurable at the wheat root-soil interface, where the plant exerts significant influence through root exudation. In this study, wheat plants were grown in soil amended with milled canola, lucerne, lupin, pea, and wheat re...

Development of legume-based farming systems has resulted in Australian agriculture being globally competitive. There is now political pressure for agriculture to become accountable for ‘off-site’ environmental consequences. Farming systems relying on annual species are unsustainable because of a mismatch between the supply and demand of water and N...

Roots modify the environment in which they grow and can be tactically used to condition the soil for the benefit of following generations of plants. In this study, we evaluated changes in selected nutritional and biological properties of the soil after growing a range of plant types as treatments that modified soil structure through creation of bio...

Impermeable subsoil is a major constraint to root growth and water infiltration in most duplex soils of Australia, but can be ameliorated by channels or biopores created by dead and decomposed roots of plant species that are adapted to these soils. In the current study, we evaluated whether a 6-year phase of native woody species planted in belts cr...

Pastures in southern Australia are dominated by endogeic earthworms such as Aporrectodea caliginosa (Sav.). Introductions of the anecic earthworm, A. longa (Ude), which is mostly restricted to Tasmania at present, are likely to increase the functional diversity of local communities and thereby enhance plant production and agricultural sustainabilit...

A field study was carried out in the high rainfall zone (HRZ, >600 mm p.a.) of southern Australia from March 1994 to August 1997 to test the hypothesis that sown perennial grasses and liming could make the existing pastures more sustainable through better use of water and nitrogen. The site, on an acid duplex soil at Book Book near Wagga Wagga in s...

Earthworms play an important role in soil ecology and can serve as practical indicators in land quality evaluation. The abundance and distribution of earthworms were determined in 84 cropping and pasture soils in north-east Victoria and southern New South Wales (NSW), Australia. Overall, an average density of 89 earthworms m−2 was found, with an av...

Cropping practices commonly used in conservation tillage can potentially impact on earthworm abundance and distribution. Management practices associated with conservation tillage farming for cereals such as stubble retention and management, greater utilization of herbicides, and soil acidity amelioration were assessed for their influence on earthwo...

The accumulation of mineral-nitrogen (N) in the top 10 cm of soil during the summer fallow was measured in 2 replicated field experiments following a range of crops including wheat, oats, canola, peas and lupins. At the first site, mineral-N was measured following harvest and in autumn before sowing subsequent crops across 3 seasons (1994–96). Crop...

Water infiltration and movement into soil are important factors for cropping systems in texture contrast soils subject to runoff and erosion under unsteady rainfall. This study considers the effects of 10 years of direct drilled (with stubble retained) wheat, in a duplex soil (luvisolic type soil with sandy clay loam A horizon and clay subsoil) in...

Microarray technology provides a tool for assessing the transcriptional response or abundance of thousands of microbial functional or structural genes concurrently. Two new microarrays have been designed to detect a range of microbial functional gene targets for enzymes associated with the cycling of soil C, N, P and in antibiotic production, biode...