Sensitivity of seedling growth to phosphorus supply in six tree species of the Australian Great Western Woodlands

Many Australian native plants from regions with ancient, highly weathered soils have specialised adaptations for acquiring phosphorus (P) and can exhibit negative effects of excess P supply on growth and survival. Despite this, fertiliser (including P) is routinely applied in post-mining and other restoration schemes. In this study we investigated the effect of a range of applied P on the growth and tissue P concentrations for six woody species from the Great Western Woodlands (GWW) of Western Australia, a region that it not only biodiverse, but that has experienced significant levels of mining related activities. Our data from a pot-based experiment show that all six species exhibited greater growth with increased P application up to 15 mg kg sand-1. However, at P concentrations in excess of 15 mg kg-1, dry mass accumulation did not increase further for three of the species tested. For the other three species, dry mass accumulation declined as the P concentration increased above 15 mg kg-1. For all of the study species, root and shoot P concentrations increased as the concentration of applied P increased. The internal shoot P concentration, at which dry matter accumulation either plateaued or started to decline, was in the range 1.95 to 3.2 mg P g-1 DM. This was approximately 2 to 4 times the concentration found in natural vegetation. These data suggest that in a restoration context, there is a potential risk that, excess P applcation may decrease plant growth rates for some species. Consequently, the addition of fertiliser to restored sites may have unpredictable impacts on the plant community by directly reducing the growth of some species while increasing the growth of others. We suggest that careful consideration should be given to designing appropriate fertiliser regimes for land restoration schemes in ancient P deplete landscapes to avoid the risk that fertiliser addition has the unwanted outcome of decreasing growth and survival of the target native species whilst increasing the abundance of unwanted weeds or aggressive pioneer species

Characterizing the Metabolic Fingerprint and Anti-inflammatory Activity of Hypericum gentianoides

In this paper we characterize the metabolic fingerprint and first reported anti-inflammatory activity of Hypericum gentianoides. H. gentianoides has a history of medical use by Native Americans, but it has been studied very little for biological activity. High-performance liquid chromatography (HPLC) and liquid chromatography−electrospray ionization−mass spectrometry (LC-ESI-MS) analyses of a methanol extract show that H. gentianoides contains a family of over nine related compounds that have retention times, mass spectra, and a distinctive UV absorption spectra characteristic of certain acyl-phloroglucinols. These metabolites are abundant relative to other secondary products present in H. gentianoides, accounting for approximately 0.2 g per gram of dry plant tissue. H. gentianoides methanol extracts and a specific semipreparative HPLC fraction from these extracts containing the putative acyl-phloroglucinols reduce prostaglandin E2 synthesis in mammalian macrophages

A large-scale experiment finds no evidence that a seismic survey impacts a demersal fish fauna

Seismic surveys are used to locate oil and gas reserves below the seabed and can be a major source of noise in marine environments. Their effects on commercial fisheries are a subject of debate, with experimental studies often producing results that are difficult to interpret. We overcame these issues in a large-scale experiment that quantified the impacts of exposure to a commercial seismic source on an assemblage of tropical demersal fishes targeted by commercial fisheries on the North West Shelf of Western Australia. We show that there were no short-term (days) or long-term (months) effects of exposure on the composition, abundance, size structure, behavior, or movement of this fauna. These multiple lines of evidence suggest that seismic surveys have little impact on demersal fishes in this environment

A field and video-annotation guide for baited remote underwater stereo-video surveys of demersal fish assemblages

Researchers TL, BG, JW, NB and JM were supported by the Marine Biodiversity Hub through funding from the Australian Government's National Environmental Science Program. Data validation scripts and GlobalArchive.org were supported by the Australian Research Data Commons, the Gorgon-Barrow Island Gorgon Barrow Island Net Conservation Benefits Fund, administered by the Government of Western Australia and the BHP/UWA Biodiversity and Societal Benefits of Restricted Access Areas collaboration.1. Baited remote underwater stereo-video systems (stereo-BRUVs) are a popular tool to sample demersal fish assemblages and gather data on their relative abundance and body-size structure in a robust, cost-effective, and non-invasive manner. Given the rapid uptake of the method, subtle differences have emerged in the way stereo-BRUVs are deployed and how the resulting imagery are annotated. These disparities limit the interoperability of datasets obtained across studies, preventing broad-scale insights into the dynamics of ecological systems. 2. We provide the first globally accepted guide for using stereo-BRUVs to survey demersal fish assemblages and associated benthic habitats. 3. Information on stereo-BRUV design, camera settings, field operations, and image annotation are outlined. Additionally, we provide links to protocols for data validation, archiving, and sharing. 4. Globally, the use of stereo-BRUVs is spreading rapidly. We provide a standardised protocol that will reduce methodological variation among researchers and encourage the use of Findable, Accessible, Interoperable, and Reproducible (FAIR) workflows to increase the ability to synthesise global datasets and answer a broad suite of ecological questions.Publisher PDFPeer reviewe