Abstract
There is a globally accepted need for environmental water management (EWM) to help address the threats and stressors on rivers, wetlands and floodplains. Given the socialecological context of river-floodplain systems, enunciating ‘what is good’ is critical to effective EWM. In this thesis I argue that ‘what is good’ is not well established for nonwoody vegetation (NWV) and that the notion of condition (aka ‘what is good’) needs a rethink. My PhD explores ‘success’ and ‘what is good’ in terms of characterising the condition of NWV in dynamic, cyclic and variable floodplain-wetland systems. In this PhD I use a variety of approaches such as online surveys, literature review, conceptualisation, and data analysis, to explore how condition is characterised and provide insights into the management of environmental flows for NWV outcomes. The intended outcome of this is a better understanding of how condition may be incorporated into ecological restoration, specifically with regards to using EWM to target values associated with NWV.The construct of condition for NWV needs to be viewed as part of an adaptively managed social-ecological system to tackle some of the challenges of evaluating NWV outcomes. Condition needs to reflect: i) what is trying to be achieved, ii) why it is trying to be achieved, and iii) how to know if it is on track. Further, NWV condition needs to consider: i) hierarchical biodiversity, ii) social-ecological functions and values, and iii) resilience. These themes are further explored in this thesis.
I gained practitioners’ perspectives to better understand the complexity in the adaptive management of environmental water for NWV with regards to: i) desirable outcomes and benefits; ii) influencing factors and risks; iii) challenges of monitoring and evaluation, and iv) improving outcomes. Survey participants indicated that EWM aims to achieve outcomes by improving or maintaining vegetation attributes and the functions and values these provide. Survey responses highlighted six areas to improve EWM for NWV outcomes: (1) flow regimes, (2) vegetation attributes, (3) non-flow drivers, (4) management-governance considerations, (5) functions and values, and (6) monitoring, evaluation and research. These suggest a need for more than ‘just water’ when it comes to the restoration and management of NWV. Findings indicate more integrated land-water governance and management is required to address the impacts of non-flow drivers such as pest species, land-use change and climate change. Building societal understanding of EWM is important to help tackle social-ecological constraints to improve EWM outcomes.
A review of published literature identified a diverse range of response metrics, associated flow components and co-variates have been used to describe NWV responses to flow across multiple levels of ecological organisation and across a range of different spatial and temporal scales. A recommendation arising from the review is the importance of articulating a ‘theory of change’ to enable observed patterns in vegetation responses to be placed within a perspective of ecological variability and management context. The ability to articulate a ‘theory of change’ relies, in part, on our ability to generalise vegetation responses to a suite of drivers, which also relies, in part, on structuring data in ecologically meaningly ways. Translating observed patterns into perspectives that inform management decisions would be a helpful progression in the science-management interface.
Throughout my thesis chapters, functions and values emerge as a factor, linked strongly to the notion of ‘why it is [NWV outcome] trying to be achieved’. The survey of practitioners found that participants valued NWV for their provision of a range of ecosystem functions and services, with strong emphasis on ecological aspects such as regulation functions, habitat provision and biodiversity. However, the inclusion of a question in the survey framed to focus on stories or narratives resulted in a different emphasis. Responses indicated that NWV, and rivers, wetlands and floodplains were valued for the way they made people feel through lived experiences such as recreational activities, personal interactions with nature, educational and research experiences. This highlights the important role of storytelling in navigating complex natural resource management challenges and ascertaining a deeper understanding of values that moves beyond provision of function to feeling.
In the framing of my thesis, I contend that resilience is one of the core components of ‘condition’, however clear framings of resilience for NWV are lacking. I applied framings of resilience and ideas from panarchy theory to conceptualise NWV community dynamics and resilience in arid and semi-arid floodplain-wetlands. I highlight key considerations and identify generalised models for i) resistance and ii) recovery mechanisms considering composition, structure and processes, through different phases of hydrological cycles underdifferent hydrological scenarios. I conceptualise resilience in terms of resilient variability (‘acceptable’) versus a loss of resilience (‘unacceptable’) along with degradation, restoration and transition pathways. I extend these generalised models to five broad NWV types and present a case study to explore the validity of hypothesises using data collected from floodplain-wetlands in the Murray-Darling Basin, Australia. This conceptualisation helps frame resilience and articulates a theory of change for NWV communities in floodplain-wetland systems in response to changes in wet-dry cycles.
River-floodplain systems are social-ecological systems, therefore defining ‘what is good’ has both social and ecological components. In this thesis I present a framing of NWV condition that considers hierarchical biodiversity, social-ecological functions and values, and resilience. I argue that managing for NWV outcomes requires more than just water. In addition, I argue that given the diversity and hierarchical structure of NWV, evaluating outcomes at levels of governance such as the Basin, requires a structured narrative to frame findings from multiple projects. Evaluating NWV outcomes should place stronger emphasis on the impact of EWM and to what degree outcomes are likely to represent resilience. Conceptual models developed in this thesis helps define resilience and articulate a theory of change for NWV communities in floodplain-wetland systems in response to changes in wetdry cycles. Constraints to EWM remain a major challenge to achieving NWV outcomes that will require social-ecological solutions.
| Date of Award | 2024 |
|---|---|
| Original language | English |
| Supervisor | Ross THOMPSON (Supervisor), Fiona DYER (Supervisor) & Samantha CAPON (Supervisor) |