Dr Kirstie Fryirs - Research
My research interests span seven areas:
- River evolution and post European disturbance studies;
- Geomorphic river condition and recovery potential;
- Sedimentary budgets, cascades and (dis)connectivity;
- The River Styles framework; (www.riverstyles.com)
- Catchment based river management;
- Links to river ecology;
- River sensitivity and biophysial fluxes.
River evolution and post-European disturbance studies
My research in this area has documented the evolution of rivers and their floodplains during the Late Quaternary, but in particular the impact of European settlement and associated forms of physical disturbance on the structure and function of river systems. This research has focused on a number of different river systems in various landscape settings. I have worked in the Bega catchment, upper Hunter catchment and various north coast river systems on upland swamps, bedrock-controlled coastal rivers, alluvial coastal rivers. I have also examined how antecedent landscape character dictates contemporary river character and behaviour. This work on river evolution provides the foundations for examining river sensitivity to change and to forecast river recovery potential.
Geomorphic river condition and recovery potential
In the geomorphological community there has been an emphasis on studying the processes of, and responses to, river degradation. Very little research has been undertaken on how to assess river condition and geomorphic river recovery. Significant conceptual work had been undertaken overseas, but no framework for assessing geomorphic river condition and recovery potential in the field had been developed. This research form the core of my PhD. Such a framework must be grounded in solid science before it can form the basis for river management prioritorisation and development of sustainable rehabilitation strategies. These frameworks now form part of the River Styles framework.
Sedimentary budgets, cascades and (dis)connectivity
In this area of research there are effectively two types of work undertaken, sediment movement on slopes and sediment movement along valley floors. Very few researchers have incorporated both and assessed the link between the two, i.e. mechanisms of sediment movement from hillslopes to the valley floor and along the channel network. I have undertaken research on catchment-wide sediment budgets which assess the distribution and controls on sediment storage and movement through catchments. I have undertaken numerous sediment budgets in individual subcatchments and assessed the distribution, and changing nature of sediment storage and delivery at the catchment scale. Given that sediment movement and storage drives geomorphic change, such information is needed before any assessment of river recovery, or implementation of river rehabilitation strategies can occur. My current research is examining landscape (dis)connectivity by assessing the distribution of "blockages" in the fluvial system (termed buffers, barriers and blankets) and how they affect landscape sensitivity to change.
The River Styles® framework www.riverstyles.com
The River Styles® framework is a multiscalar framework that has four stages:
- catchment-wide assessment of river character and behaviour;
- assessments of river condition based on the evolution of river reaches;
- assessing the trajectory of change and river recovery potential; and
- identification of target conditions and prioritisation of river management practices.
Uptake of the River Styles framework now forms a template for many State agency river rehabilitation and management initiatives.
Catchment based river management
Field-based understanding of river structure and function forms a critical baseline upon which river management strategies must be based. The research I have undertaken to date, has been effectively linked with State agencies and industry. In recent times river management and river rehabilitation has become a focal point for my research.
Geomorphology and river ecology
An area of emerging research, for me, is in the field of river geoecology. In recent research I have collaborated with a number of colleagues in developing a framework for linking geomorphology and ecology in assessments of habitat availability. Given that geomorphology provides a way of summarising and interpreting the structure and function of rivers, it can be used as a basis for assessing how the ecology of rivers has changed over time. My research, in collaboration with ecologists in DWE has liked geomorphology and ecology in an approach for assessing the geoecological condition of rivers. I am currently examining seed bank dynamics in Wollombi catchment, north of Sydney.
River sensitivity and biophysical fluxes
I worked on large-scale river rehabilitation program, the Upper Hunter River Rehabilitation Initiative (UHRRI). This large scale rehabilitation program occured along an 8-10 km study reach of the Hunter River near Muswellbrook. It aimed to,
- test theories of directed ecosystem change,
- understand catchment scale drivers of reach-scale change,
- predict and determine the interactions and feedbacks emerging from manipulating a complex system and,
- better understand the processes determining the success of riverine rehabilitation involving native vegetation restoration and LWD replacement.
A multi-disciplinary team worked on different aspects of ecosystem function including geomorphic processes, vegetation interactions, organic matter processing and nutrient fluxing. My research focussed on analysis of catchment-scale geomorphic, hydrological and vegetation patterns and processes that drive the reach-scale structure and functioning of the Upper Hunter River. This provides the physical template to link biotic-abiotic patterns, processes and interactions at a range of spatial and temporal scales. Explanation of biophysical linkages, and associated water and sediment fluxes and their relations to riparian vegetation cover and LWD loading, provides the catchment-framed basis to determine the current inputs and drivers of change within the system. Using this information, predictions can be made of how catchment inputs will drive the future character and behaviour of the Hunter River study reach.