School of Agriculture, Food and Ecosystem Sciences - Research Publications
Permanent URI for this collection
Search Results
1 - 10 of 55
-
ItemPlant and soil biodiversity is essential for supporting highly multifunctional forests during Mediterranean rewilding(Wiley, 2023-02-01)1. The multidimensional dynamics of biodiversity and ecosystem function during the rewilding of Mediterranean forests remain poorly understood, limiting our capacity to predict how future restoration efforts may help mitigate climate change. 2. Here, we investigated the changes in multiple dimensions of biodiversity and ecosystem services in a 120-year forest succession after harvest to identify potential trade-offs in multiple dimensions of ecosystem function, and further assess the link between above and below-ground biodiversity and function. 3. We found a positive influence of successional age on not only multiple dimensions of biodiversity and function but also some important trade-offs. Two ecosystem axes of function explained nearly 75.4% of functional variation during ecosystem rewilding. However, while the first axis increased with successional age promoting plant productivity and element stocks, the second axis followed a hump-shaped relationship with age supporting important reductions in nutrient availability and pathogen control in old forests. Our study further revealed a significant positive relationship between plant and soil biodiversity with multiple elements of multifunctionality as forests develop. Moreover, the influence of plant and soil biodiversity were especially important to support a high number of function working at high levels of functioning. 4. Our work provides new insights on the patterns and functional trade-offs in the multidimensional rewilding of forests and further highlights the importance of biodiversity for long-term Mediterranean rewilding.
-
ItemNo Preview AvailableMicrobial hydrogen cycling in agricultural systems - plant beneficial or detrimental?(WILEY, 2023-08)Hydrogen-oxidising bacteria play a key role in maintaining the composition of gases within the atmosphere and are ubiquitous in agricultural soils. While studies have shown that hydrogen accumulates in soil surrounding legume nodules and the soil surface, soils as a whole act as a net sink for hydrogen, raising questions about how hydrogen is internally recycled by soils. Can the energy derived from hydrogen oxidation be directly funnelled into plants to promote their growth or does it only act as a booster for other plant-growth promoting bacteria? Moreover, while the fertilisation effect of hydrogen on plants has previously been shown to be beneficial, questions remain about the upper limit of hydrogen uptake by plants before it becomes detrimental. Agricultural practices such as fertilisation may impact the balance of hydrogen-oxidisers and hydrogen-producers in these ecosystems, potentially having detrimental effects on not only agricultural land but also global biogeochemical cycles. In this perspectives piece, we highlight the importance of understanding the contribution of hydrogen to agricultural soils and the effects of agricultural practices on the ability for bacteria to cycle hydrogen in agricultural soils. We propose a framework to gain better insights into microbial hydrogen cycling within agroecosystems, which could contribute to the development of new agricultural biotechnologies.
-
ItemPrecipitation seasonality and soil pH drive the large-scale distribution of soil invertebrate communities in agricultural ecosystems(OXFORD UNIV PRESS, 2023-10-17)Soil invertebrates contribute significantly to vital ecosystem functions such as the breakdown of organic matter and cycling of essential nutrients, but our knowledge of their large-scale distribution in agricultural systems is limited, which hinders our ability to robustly predict how they will respond to future global change scenarios. Here, we employed metabarcoding analysis of eukaryotic 18S rRNA genes to examine the diversity and community composition of invertebrates in 528 sorghum rhizosphere and bulk soils, collected from 53 experimental field sites across China. Our results revealed that Nematoda, Arthropoda and Annelida were the dominant soil invertebrate groups in agroecosystems. Among all the climatic and soil parameters we examined, precipitation seasonality (i.e. the irregular distribution of precipitation during a normal year) had the strongest relationship with the richness of soil invertebrates, with an increase in soil invertebrate richness predicted with increasing precipitation seasonality. Mean annual precipitation and soil pH were the most important predictors of soil invertebrate community structure, with numerous invertebrate phylotypes showing either significantly positive or negative relationships with these two variables. Our findings suggest that shifts in precipitation patterns and soil pH, induced by future climate change and agricultural practices, will have important consequences for the distribution of soil invertebrate communities, with implications for agricultural ecosystem sustainability.
-
ItemNo Preview Available
-
ItemNo Preview AvailableImpacts of shelterbelt systems on pasture production and soil bacterial and fungal communities in agricultural fields(Wiley, 2023-09-01)Abstract Introduction Shelterbelts, which provide protection for livestock and crops against severe weather conditions, have been recognised as important contributors to increased crop yields. Soil microorganisms play important roles in nutrient cycling, soil health and plant performance, thereby exerting significant influence on ecological services in terrestrial ecosystems. However, impacts of shelterbelts on soil microbial communities in pasture ecosystems remain poorly studied. Materials and Methods Here, we assessed the effect of shelterbelts (composed of Eucalyptus and native shrubs) on the pasture and nutrient productivity as well as soil bacterial and fungal communities at four distances from the shelterbelts with two different heights in two fields during spring and summer by applying amplicon sequencing, physicochemical and nutritional value analyses. Results The results showed that the shelterbelt height, distances from shelterbelts, seasons and their interactive effects substantially affected pasture yield, neutral detergent fibre, metabolisable energy and crude protein yields, but did not increase the pasture productivity in the rows adjacent to the shelterbelts. We also identified that the alpha diversity of bacteria and fungi did not significantly change across distances from the shelterbelts in both fields, but the community structure of soil bacteria and fungi was significantly influenced by distances from the shelterbelts. Interestingly, soil calcium (Ca) and shelterbelts were identified as top predictors of fungal community while soil pH and Ca was key drivers of bacterial community. Conclusion Our study provides novel knowledge in the impact of shelterbelts on pasture and nutritional production and soil microbial communities, which contributes to appropriate application and strategic management of the windbreak systems in agriculture production.
-
ItemConversion of natural grassland to cropland alters microbial community assembly across northern China(WILEY, 2022-12)To feed the growing human population, natural grasslands are being converted to agricultural use at a massive scale. This conversion may have negative consequences for soil biodiversity, but its impact on the community assembly of differentially microbial groups remains largely unknown. Here, we investigated the diversity and community compositions of bacteria, archaea, fungi and protists, using a paired sampling of grassland and cropland soils across the agro-pastoral ecotone of northern China. Land-use conversion decreased α diversity of bacteria, fungi and protists, and altered the structures of the entire soil microbial community (archaea, bacteria, fungi and protists). The community assembly of archaea and bacteria was dominated by stochastic processes, and that of protists dominated by deterministic processes in both land-use types. By contrast, the fungal community was governed more strongly by stochastic processes in grassland soil, than by deterministic processes in cropland soil. Our findings support the 'size-plasticity' hypothesis that smaller body-sized microorganisms (archaea and bacteria) are more structured by stochastic processes, and larger one (protist) is more influenced by deterministic processes. Our study demonstrates that distinct ecological processes govern microbial community assembly, and land-use change regulates the balance between determinism and stochasticity.
-
ItemProtistan predation selects for antibiotic resistance in soil bacterial communities(Oxford University Press, 2023-12)Understanding how antibiotic resistance emerges and evolves in natural habitats is critical for predicting and mitigating antibiotic resistance in the context of global change. Bacteria have evolved antibiotic production as a strategy to fight competitors, predators and other stressors, but how predation pressure of their most important consumers (i.e., protists) affects soil antibiotic resistance genes (ARGs) profiles is still poorly understood. To address this gap, we investigated responses of soil resistome to varying levels of protistan predation by inoculating low, medium and high concentrations of indigenous soil protist suspensions in soil microcosms. We found that an increase in protistan predation pressure was strongly associated with higher abundance and diversity of soil ARGs. High protist concentrations significantly enhanced the abundances of ARGs encoding multidrug (oprJ and ttgB genes) and tetracycline (tetV) efflux pump by 608%, 724% and 3052%, respectively. Additionally, we observed an increase in the abundance of numerous bacterial genera under high protistan pressure. Our findings provide empirical evidence that protistan predation significantly promotes antibiotic resistance in soil bacterial communities and advances our understanding of the biological driving forces behind the evolution and development of environmental antibiotic resistance.
-
ItemNo Preview Available
-
ItemNo Preview AvailableTrophic interrelationships of bacteria are important for shaping soil protist communities(WILEY, 2023-08)Protists occupy multiple trophic positions in soil food webs and significantly contribute to organic matter decomposition and biogeochemical cycling. Protists can ingest bacteria and fungi as main food sources while being subjected to predation of invertebrates, but our understanding of how bottom-up and top-down regulations structure protists in natural soil habitats is limited. Here, we disentangle the effects of trophic regulations to the diversity and structure of soil protists in natural settings across northern and eastern Australia. Bacterial and invertebrate diversity were identified as important drivers of the diversity of functional groups of protists. Moreover, the compositions of protistan taxonomic and functional groups were better predicted by bacteria and fungi, than by soil invertebrates. There were strong trophic interconnections between protists and bacteria in multiple organismic network analysis. Altogether, the study provided new evidence that, bottom-up control of bacteria played an important role in shaping the soil protist community structure, which can be derived from feeding preferences of protists on microbial prey, and their intimate relationships in soil functioning or environmental adaptation. Our findings advance our knowledge about the impacts of different trophic groups on key soil organismic communities, with implications for ecosystem functions and services.
-
ItemNo Preview AvailableEngineering biodegradable coatings for sustainable fertilisers(CSIRO PUBLISHING, 2023)With the pressures of a changing global climate and ever-growing population, the need for sustainable agricultural practices that increase crop yields while decreasing greenhouse gas emissions are critical. Currently used practices to increase yields can often be problematic due to low nitrogen use efficiency or a potential overreliance on agrichemicals that can alter the community composition of a given ecosystem, although this is typically system and situation dependent. As such, the next generation of enhanced efficiency fertilisers that combine chemical, materials engineering and biological components are likely to be a game changer. Integral to their success is a better understanding of how plant–soil microbiomes interact with the new enhanced efficiency fertilisers, and how we can best tailor the fertilisers to suit different plant–soil combinations. In particular, the biodegradation properties of new fertiliser coatings must be given careful consideration so as to not further burden agricultural soils with microplastics or cause ecotoxicity problems. This perspective proposes novel, interdisciplinary strategies to generate highly efficient, biodegradable fertiliser coatings for use in the agricultural sector.