Determining water requirements for Black Box (Eucalyptus largiflorens) floodplain woodlands of high conservation value using drip-irrigation

Black Box (Eucalyptus largiflorens F. Muell.), is a keystone tree species of lowland semi-arid floodplain ecosystems in south-eastern Australia. E. largiflorens woodlands are of high conservation value and threatened by climate change-induced drought and irrigation water diversions due to their location on upper floodplain areas where flood frequency has declined. Water requirements of E. largiflorens have not been well quantified using empirical data. Accordingly, knowledge gaps exist in relation to volumes of environmental water required to maintain and improve ecological condition for disconnected floodplain woodlands. To further assist conservation and water resource management, we tested the use of drip irrigation to provide a variety of water regimes to experimental plots in order to monitor tree responses. Water was provided via irrigation delivery across four regimes representing known volumes of water, referred to as an environmental water provision, applied over a 22-week period for two Austral summers. Benefits to trees were identified by measuring transpiration and plant water status using sap flow sensors and a Scholander pressure chamber, respectively. Results indicate that volumes of 0.3, 0.4, 0.7 and 0.8 ML increased transpiration and improved plant water status in comparison to a control, with delivery recommended to commence early autumn. Greater volumes (1.4 ML), substantially increased transpiration and improved water status, especially when delivered at a rate of similar to 25 mm week(-1) compared to a monthly 'burst' which broadly represented natural, sporadic summer rainfall in the region. For an environmental watering provision of 25 mm week(-1), similar to 178 ha of E. largiflorens woodland can be watered with a 1 GL environmental water allocation. The study methods presented are relevant worldwide and our results further the collective understanding of the benefits environmental water provides to E. largiflorens.The authors gratefully acknowledge funding from the BiodiversityFund of the South Australian Murray-Darling Basin Natural ResourceManagement Board. We thank Riverland West Landcare and RebeccaTurner for their support and assistance; Treasury Wine Estates PtyLtd for provision of environmental water and for establishing andmaintaining the drip irrigation, led by Brendan Turner; Kelly Marsland(MDBA) and Kate Holland (CSIRO Land and Water, Adelaide) foradvice on experimental design; Kate Frahn (SARDI) and JodiePritchard (CSIRO) for field assistance; Martin Nolan and Sultan Umoru(CSIRO Land and Water, Adelaide) for GIS assistanc

Bringing the margin to the focus: 10 challenges for riparian vegetation science and management

[EN] Riparian zones are the paragon of transitional ecosystems, providing critical habitat and ecosystem services that are especially threatened by global change. Following consultation with experts, 10 key challenges were identified to be addressed for riparian vegetation science and management improvement: (1) Create a distinct scientific community by establishing stronger bridges between disciplines; (2) Make riparian vegetation more visible and appreciated in society and policies; (3) Improve knowledge regarding biodiversity¿ ecosystem functioning links; (4) Manage spatial scale and context-based issues; (5) Improve knowledge on social dimensions of riparian vegetation; (6) Anticipate responses to emergent issues and future trajectories; (7) Enhance tools to quantify and prioritize ecosystem services; (8) Improve numerical modeling and simulation tools; (9) Calibrate methods and increase data availability for better indicators and monitoring practices and transferability; and (10) Undertake scientific validation of best management practices. These challenges are discussed and critiqued here, to guide future research into riparian vegetation.COST Action CONVERGES, Grant/Award Number: CA16208; Horizon 2020 Framework Programme of the European Union; Portuguese Foundation for Science and Technology, Grant/Award Number: 2020/03356/CEECIND;PTDC/ASP-SIL/28593/2017;UIDB/00239/2020; CSIC: PTIECOBIODIVRodríguez-González, PM.; Abraham, E.; Aguiar, F.; Andreoli, A.; Bale Entiene, L.; Berisha, N.; Bernez, I.... (2022). Bringing the margin to the focus: 10 challenges for riparian vegetation science and management. Wiley Interdisciplinary Reviews Water. 9(5):1-14. https://doi.org/10.1002/wat2.16041149

Bringing the margin to the focus: 10 challenges for riparian vegetation science and management

Riparian zones are the paragon of transitional ecosystems, providing critical habitat and ecosystem services that are especially threatened by global change. Following consultation with experts, 10 key challenges were identified to be addressed for riparian vegetation science and management improvement: (1) Create a distinct scientific community by establishing stronger bridges between disciplines; (2) Make riparian vegetation more visible and appreciated in society and policies; (3) Improve knowledge regarding biodiversity—ecosystem functioning links; (4) Manage spatial scale and context-based issues; (5) Improve knowledge on social dimensions of riparian vegetation; (6) Anticipate responses to emergent issues and future trajectories; (7) Enhance tools to quantify and prioritize ecosystem services; (8) Improve numerical modeling and simulation tools; (9) Calibrate methods and increase data availability for better indicators and monitoring practices and transferability; and (10) Undertake scientific validation of best management practices. These challenges are discussed and critiqued here, to guide future research into riparian vegetation

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

Quantifying water savings from willow removal in Southeastern Australia.

Two global issues are brought together in this thesis to address a facet of both water resource and weed management in Australia. Water resource security is of global concern as human need for water increases and uncertainty in future water availability associated with climate change continues to evolve, particularly in arid and semi-arid regions. Furthermore, invasive species modify landscapes around the globe in response to anthropogenic ecosystem alterations, with significant impacts within aquatic systems. Water savings projects are under investigation in Australia in response to resource over-allocation and impacts of a prolonged drought from 1997 to 2009 (‘The Millennium Drought’). An overarching aim of such investigations is to return water to the environment to meet future consumptive and environmental water requirements. In southeast Australia, invasive willows (Salicaceae: Salix spp.) have been identified as naturalized weeds which invade stream beds. In natural systems, stream beds are generally unoccupied and willow establishment increases total riparian leaf area and therefore total evaporative losses. Anecdotal evidence suggested water could be returned to creeks and streams if willows were removed, creating water saving. Strategies exist within State and Commonwealth agencies in Australia to monitor willow invasion, reduce environmental impacts and establish programs to reduce further spread. However, current methods to identify and monitor willow distribution are costly and time consuming. In this dissertation, field investigations were undertaken to quantify water use of willows and to determine the potential water savings associated with removal of willows from creeks and streams within the Murray-Darling Basin. Methods are described which can potentially be applied across riparian zones worldwide, to aid water accounting and water resource management. Three years of sap flow and water balance measurements, undertaken to determine willow evapotranspiration, indicate that removal of Salix babylonica located within stream beds with permanent access to water (‘in-stream’ willows) in semi-arid areas will potentially return 5.5 ML ha⁻¹ year⁻¹ of willow crown projected area to the stream when removed. A similar yearlong study undertaken in a cooler temperate region established potential water savings of 3.9 ML ha⁻¹ year⁻¹ if Salix fragilis stands were removed from stream beds. Evapotranspiration of willow and endemic woody species were compared, establishing that removal of willows from water limited environments is unlikely to return a water saving. Two Penman-Monteith models (a model for S. babylonica and S. fragilis) were calibrated using field measurements of leaf area index and stomatal conductance. Each model was validated using field measured evapotranspiration and then run to calculate monthly pan coefficients (the ratio of evapotranspiration to pan evaporation) for each species across broad climatic ranges in Australia. Derived monthly pan coefficients and monthly pan evaporation predict evapotranspiration of willows across various climatic zones to assist accounting and management of water resources at broader scales. Furthermore, development of a simple open water evaporation model coupled with evapotranspiration pan factors provides a means to estimate potential water savings from willow removal across broader climatic zones. The pan coefficient method presented has broader application across riparian systems worldwide providing a method to scale woody vegetation evapotranspiration across climatic zones using validated evapotranspiration models. To further enhance and improve willow management practices, an economical remote sensing technique was developed to discriminate canopy area of willows located within stream beds from native vegetation and willows situated on banks which are generally water limited environments. A method is described using very high resolution WorldView-2 imagery (2x2 m) to identify and calculate total canopy area of both in-stream and water-limited willow infestations within a target region. Delineating willow canopy area provides a method to scale willow evapotranspiration and water savings predictions associated with removal of in-stream willows to catchment scale, to account for catchment evaporative losses, thus providing essential information to catchment managers. As intensive and science-based resource management policies are required to address predicted future water scarcity in Australia, the knowledge delivered from this research addresses some important knowledge gaps. For example, current and future water availability is predicted within catchments using hydrological models, while vegetation evapotranspiration is predicted from remote sensing. Direct measurement of riparian evapotranspiration strengthens water availability estimates and addresses some ‘unspecified losses’ associated with Murray-Darling Basin water balance estimates. Estimates of potential water savings related to removal of willows also assists with catchment water accounting. Tools derived within this dissertation provide methods to scale willow and native riparian evaporative losses and water savings estimates from local to regional scales, further improving efforts to account for and manage water resources in Australia and worldwide. This thesis provides evidence that water savings can potentially be achieved by removing willows located within stream beds which have permanent access to water and inhabit an otherwise unoccupied niche, increasing both total canopy leaf area and riparian evaporative losses. Methods are also provided to scale willow water use information from local to regional catchment scales.Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 201

Quantifying water savings from willow removal in Australian streams

Tanya Doody and Richard Benyonhttp://www.elsevier.com/wps/find/journaldescription.cws_home/622871/description#descriptio

Women advancing research on hydrological processes: Preface

Peer Reviewe