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

Tanya M. Doody*, Susan L. Gehrig, R. Willem Vervoort, Matthew J. Colloff, Rebecca Doble

*Corresponding author for this work

    Research output: Contribution to journalArticlepeer-review

    7 Citations (Scopus)

    Abstract

    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 ~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, ~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.

    Original languageEnglish
    Article numbere14291
    JournalHydrological Processes
    Volume35
    Issue number7
    DOIs
    Publication statusPublished - Jul 2021

    Fingerprint

    Dive into the research topics of 'Determining water requirements for Black Box (Eucalyptus largiflorens) floodplain woodlands of high conservation value using drip-irrigation'. Together they form a unique fingerprint.

    Cite this