2007 Vegetation Monitoring – Swan Coastal Plain 2007 Vegetation Monitoring - Swan Coastal Plain (Bunbury, Busselton-Capel Groundwater Areas) A Report to the DoW R. Loomes, J. Wilson & R. Froend Centre for Ecosystem Management ECU Joondalup CEM report no. 2007- 15 February 2008 Centre for Ecosystem Management 1 2007 Vegetation Monitoring – Swan Coastal Plain Table of Contents SUMMARY .................................................................................................................................................. 3 PROJECT CONTEXT ................................................................................................................................4 PROPOSED MONITORING PROGRAM................................................................................................ 5 BACKGROUND............................................................................................................................................ 5 MONITORING OBJECTIVES AND HYPOTHESES ............................................................................................ 6 PARAMETERS ........................................................................................................................................... 10 MONITORING FREQUENCY AND APPROACH ............................................................................................. 15 Transect establishment ....................................................................................................................... 15 Baseline Monitoring ........................................................................................................................... 15 TRIGGER LEVELS...................................................................................................................................... 17 REPORTING .............................................................................................................................................. 19 2007 VEGETATION MONITORING & HYDROLOGICAL CONDITIONS.................................... 20 APPROACH ............................................................................................................................................... 20 RESULTS .................................................................................................................................................. 20 DISCUSSION ............................................................................................................................................. 71 CONCLUSION............................................................................................................................................ 72 APPENDICES ............................................................................................................................................ 73 APPENDIX 1: OVERSTOREY DATA............................................................................................................. 73 APPENDIX 2: UNDERSTOREY SPECIES DATA ........................................................................................... 105 REFERENCES......................................................................................................................................... 124 Centre for Ecosystem Management 2 2007 Vegetation Monitoring – Swan Coastal Plain Summary The Department of Water is undertaking groundwater allocation planning work in the Busselton-Capel and Bunbury groundwater areas. As part of the allocation process, the groundwater-dependent ecosystems (GDEs) of high ecological and social value have been identified and work undertaken to establish vegetation monitoring transects and groundwater bores to support the future development of ecological water requirements (EWRs). The 2007 report is divided into two sections. The first outlines a proposed monitoring program, the second presents the results of the second round of annual monitoring. The monitoring program incorporates the following: • Monitoring objectives and the hypotheses being tested; • Rationalization of parameters to be measured as indicators of wetland and terrestrial vegetation health; • Monitoring approach and frequency; • Vegetation condition trigger values; and • Reporting. The program will be further developed during 2008 in consultation with DoW staff. The chief focus will be the determination of ecological and hydrological trigger levels and refinement of the current monitoring and reporting approach. Baseline monitoring was undertaken in spring 2006. Field methods were designed to capture measurements relevant to all parameters outlined in the monitoring program. The second round of monitoring occurred in late spring 2007. Results of the 2007 vegetation monitoring indicated that although a general decline in mean tree health was noted across the majority of transects the greatest decline occurred at Hay Park which had experienced a fire during 2007. Marked improvement in canopy condition was noted at Manea Park and Spanish Settlers Reserve which continued to recover from 2006 fires. Changes were also noted in exotic species richness however, this appeared to mostly relate to fires and/ or seasonal variations in the presence/ absence of annual species. A similar finding was recorded for overall composition change. At this stage there is insufficient water level data to support any relationship between changes in water regime and vegetation condition. Therefore it is not possible to reject or accept of any of the hypotheses postulated within the monitoring program. Centre for Ecosystem Management 3 2007 Vegetation Monitoring – Swan Coastal Plain Project Context The Department of Water is undertaking groundwater allocation planning work in the Busselton-Capel and Bunbury groundwater areas. As part of the allocation process, the groundwater-dependent ecosystems (GDEs) of high ecological and social value have been identified and work undertaken to establish vegetation monitoring transects and groundwater bores to support the future development of ecological water requirements (EWRs). During 2006, 15 transects were established in 14 locations supporting intact wetland or phreatophytic vegetation on the southern Swan Coastal Plain (Loomes, Ogden and Froend, 2006). The aim of monitoring is to provide a greater understanding of whether groundwater quality, groundwater abstraction and climatic impacts are having an impact on GDEs. Groundwater monitoring bores have been established at each transect. The tasks associated with this project are: • Development of a vegetation monitoring program for established transects. • Conduct monitoring at existing transects. • Report on the monitoring results. Under a separate contract a transect established within the Ruabon Nature Reserve and deemed inaccessible to bore contractors, was replaced and baseline monitoring undertaken. Centre for Ecosystem Management 4 2007 Vegetation Monitoring – Swan Coastal Plain Proposed Monitoring Program Background The National Framework for the Management and Monitoring of Australia’s Native Vegetation defined monitoring as ‘sampling and analysis designed to ascertain the extent of compliance with a predetermined standard or the degree of deviation from an accepted norm’ (Department of Environment and Heritage, 2000). The Framework further states that ‘the development of a monitoring program should be an iterative process that establishes feedback between management planning and its consequences’. This section of the report proposes a vegetation monitoring program for the 15 identified ‘criteria sites’. The program incorporates the following: • Monitoring objectives and the hypotheses being tested; • Rationalization of parameters to be measured as indicators of wetland and terrestrial vegetation health; • Monitoring approach and frequency; • Vegetation condition trigger values; and • Reporting. Centre for Ecosystem Management 5 2007 Vegetation Monitoring – Swan Coastal Plain Monitoring Objectives and Hypotheses Monitoring is underpinned by the assumption that there is a specific objective for the collection of data (Finlayson & Mitchell, 1999). Without objectives, the success or otherwise of a policy or plan cannot be assessed and conflict may arise between groups that have different expectations regarding outcomes (Adam, 1998). The very design of a monitoring program should be led by the objectives as they will influence the variables chosen as indicators of ecosystem health, the spatial and temporal scales of monitoring, as well as the management response to monitoring outcomes (Downes et al., 2002; Pettit, 1997). Monitoring objectives should reflect the ecological values of a GDE thereby allowing monitoring to focus on the important ecological characteristics of each site. Objectives should be clearly stated and presented as hypotheses, which can be subsequently tested and the information assessed and fed back into the management process (Finlayson & Mitchell, 1999). In turn, hypotheses should relate the loss of environmental values of a specific ecosystem to the groundwater regime and incorporate monitoring variables or parameters as compliance criteria. The ecological values of the 15 monitored criteria sites were determined through searches of CALM Rare Flora and Threatened Ecological Communities databases, review of published and grey literature and baseline monitoring undertaken in 2006 (Table 1). Although ecological values of GDEs generally encompass biotic, functional and land/ waterscape values (Horwitz & Rogan, 2003), as this