ORCID Profile
0000-0002-1655-1478
Current Organisations
UNSW Sydney
,
Mississippi State University
,
University of Southern Mississippi
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Publisher: Wiley
Date: 04-2022
DOI: 10.1002/ECS2.4021
Abstract: Habitat interactions play key roles in regulating bio ersity and ecosystem functions. This is particularly important in aquatic ecosystems, where the flow of water facilitates exchanges of energy and matter. Oyster reefs, a highly degraded habitat globally and a key focus for restoration efforts, can reduce water movement and facilitate the deposition of particles around them, affecting nutrient cycling in surrounding sediments. The effects of these reefs on sediment infauna taxonomic and functional bio ersity, however, remain unknown. We s led sediments at increasing distances from reefs at three estuaries to evaluate the relationships between proximity to oyster reefs and composition and functionality of infaunal communities and explored the potential mechanisms behind those relationships. Sediments close to oyster reefs had consistently greater amounts of labile organic matter, which in turn was positively related to the number of taxa and total abundance of infauna. Also, the functional traits of infauna, such as bioturbation and feeding modes, were related to proximity to reefs, but they were variable between estuaries indicating the importance of background estuarine environmental conditions. These results suggest that habitat linkages between oyster reefs and sediments are important in regulating taxonomic bio ersity, while functional bio ersity seems to be driven by processes operating at larger scales. Given burgeoning restoration initiatives worldwide, particularly those of oyster reefs, incorporating seascape interactions can help inform recovery of bio ersity and functions beyond the target habitat at the seascape level, which is often overlooked.
Publisher: Wiley
Date: 31-05-2022
Abstract: Many important ecosystem functions are underpinned by below‐ground bio ersity and processes. Marine sediments, one of the most abundant habitats on earth, are essential to the mineralisation of organic matter. However, they are increasingly polluted by urban activities leading to the loss of bio ersity and the functions they provide. While traditional sediment remediation strategies are focussed on microbial and engineering solutions, we propose that the reintroduction of below‐ground ecosystem engineers (bioturbators) is important to rehabilitate polluted sediments and drive recovery of their functions in urban coastal ecosystems. We tested this notion by introducing bioturbators to nutrient polluted sediments to assess their survival, as well as their capacity to drive bio ersity and oxygenation and their potential to remediate nutrient pollution. Polychaete worms Diopatra aciculata and clams Katelysia sp. were added to mesocosms (ex‐situ), and the worms also added to experimental plots in‐situ. Potential for remediation was assessed with measures of nutrient content. All animals survived when introduced to polluted sediments and showed no evidence of sub‐lethal effects. Worms oxygenated sediments and reduced organic matter content by up to 50% in‐situ. The worms also drove shifts in the receiving communities at all locations and increased the number of taxa at one location. On the other hand, the effects of clams were variable, showing opposite effects in organic matter content at different sites and levels of pollution. Synthesis and applications . Global seafloor habitats are becoming increasingly degraded and novel strategies that combine bio ersity restoration with remediation are urgently needed to return function. Tube‐building bioturbators can stimulate nutrient processing in sediments proving multiple functional outcomes, but these effects are dependent on the receiving environment. In areas with medium levels of pollution, they can kick‐start recovery in a feedback loop whereby bioturbation increases oxygenation and nutrient remediation, shifting sediment bio ersity and contributing to further recovery. This can drive long‐term changes in sediment communities, particularly in urban areas where unvegetated sediments are conspicuous.
Publisher: Wiley
Date: 18-05-2022
DOI: 10.1111/REC.13670
Abstract: Population characteristics (e.g. density and body sizes) of foundation species can affect their own persistence and provisioning of ecosystem functions. Understanding the drivers of population characteristics of foundation species at multiple spatial scales is therefore critical for maximizing ecosystem functions of restored habitats. We analyzed variation in population characteristics (densities, 95th percentile, and median lengths of live oysters) of the Sydney rock oyster, Saccostrea glomerata , on remnant oyster reefs at regional scales (among three estuaries) along an approximately 250 km of coastline in New South Wales, Australia. We then analyzed how population characteristics were further related to spatial attributes at smaller spatial scales including within‐patches (rugosity, distance to patch‐edge, and elevation), whole‐patches (size and shape), and among‐patch (connectivity) within each estuary. The densities and body sizes of S. glomerata were related to spatial attributes occurring within‐patch (e.g. elevation), whole‐patch (e.g. shape), and landscape (i.e. connectivity) scales, but these relationships varied among estuaries. The greatest variation in oyster density and size occurred at regional scales, suggesting that processes acting at larger spatial scales (e.g. water quality and/or climate) set the context for smaller scale influences on oyster characteristics. Our results highlight the potential importance of incorporating site‐specific, spatial attributes in the design of restored oyster reefs to maximize ecosystem services and functions provided by restoration efforts.
Publisher: Cold Spring Harbor Laboratory
Date: 09-01-2021
DOI: 10.1101/2021.01.08.425997
Abstract: Plants live in association with microorganisms that positively influence plant development, vigor, and fitness in response to pathogens and abiotic stressors. The bulk of the plant microbiome is concentrated belowground at the plant root-soil interface. Plant roots secrete carbon-rich rhizodeposits containing primary and secondary low molecular-weight metabolites, lysates, and mucilages. These exudates provide nutrients for soil microorganisms and modulate their affinity to host plants, but molecular details of this process are largely unresolved. We addressed this gap by focusing on the molecular dialogue between eight well-characterized beneficial strains of the Pseudomonas fluorescens group and Brachypodium distachyon , a model for economically important food, feed, forage, and biomass crops of the grass family. We collected and analyzed root exudates of B. distachyon and demonstrated the presence of multiple carbohydrates, amino acids, organic acids and phenolic compounds. The subsequent screening of bacteria by Biolog Phenotype MicroArrays revealed that many of these metabolites provide carbon and energy for the Pseudomonas strains. RNA-seq profiling of bacterial cultures amended with root exudates revealed changes in the expression of genes encoding numerous catabolic and anabolic enzymes, transporters, transcriptional regulators, stress response, and conserved hypothetical proteins. Almost half of the differentially expressed genes mapped to the variable part of the strains’ pangenome, reflecting the importance of the variable gene content in the adaptation of P. fluorescens to the rhizosphere lifestyle. Our results collectively reveal the ersity of cellular pathways and physiological responses underlying the establishment of mutualistic interactions between these beneficial rhizobacteria and their plant hosts.
Publisher: Elsevier BV
Date: 05-2023
Publisher: PeerJ
Date: 22-05-2023
DOI: 10.7717/PEERJ.15426
Abstract: Assessing fish assemblages in subtidal and intertidal habitats is challenging due to the structural complexity of many of these systems. Trapping and collecting are regarded as optimal ways to s le these assemblages, but this method is costly and destructive, so researchers also use video techniques. Underwater visual census and baited remote underwater video stations are commonly used to characterise fish communities in these systems. More passive techniques such as remote underwater video (RUV) may be more appropriate for behavioural studies, or for comparing proximal habitats where the broad attraction caused by bait plumes could be an issue. However, data processing for RUVs can be time consuming and create processing bottlenecks. Here, we identified the optimal subs ling method to assess fish assemblages on intertidal oyster reefs using RUV footage and bootstrapping techniques. We quantified how video subs ling effort and method (systematic vs random) affect the accuracy and precision of three different fish assemblage metrics species richness and two proxies for the total abundance of fish, MaxN T and MeanCount T , which have not been evaluated previously for complex intertidal habitats. Results suggest that MaxN T and species richness should be recorded in real time, whereas optimal s ling for MeanCount T is every 60 s. Systematic s ling proved to be more accurate and precise than random s ling. This study provides valuable methodology recommendations which are relevant for the use of RUV to assess fish assemblages in a variety of shallow intertidal habitats.
Location: United States of America
No related grants have been discovered for Olga Mavrodi.