Summary - City of Gosnells

Methods 28Part IV: Supplementary QuestionsThese questions concern the occurrence of rare, but ungazetted, flora and fauna species, the effect of wetlands on nearby landvalues, the frequency of human use of wetlands and the importance of the wetland to the owner. This section is usually onlyevaluated if the management category obtained by the uses of Parts I, II and III falls in one of the transitional zones betweencategories on the EPA (1993) graph.In Bulletin 686, wetlands that have gazetted rare species are automatically allocated to the HighConservation Category (=CCW in the wetland management categories currently in use by the EPA, 2008). Ifa wetland includes gazetted rare species, it is recommended that the questions in Part I and Part II of thequestionnaire should still be answered to provide additional management information. However, the scoresarrived at in Parts II and III of the Bulletin 686 questionnaire for a wetland that includes rare species do notalter the allocation of the CCW category to such wetlands.If the wetland undergoing the evaluation does not include gazetted rare species, two graphs are provided atthe end of the Bulletin 686 questionnaire to determine management category. These graphs display the totalPart II scores received by the wetlands that were evaluated in the process of designing this evaluationinstrument versus their total Part III scores. The first graph applies to ‘permanent and seasonal wetlands withwell defined boundaries’. The second graph applies to ‘seasonal and episodic wetlands with poorly definedboundaries’. The two dimensional space in both of the graphs provided in Bulletin 686 is divided up in bothgraphs into five areas. Each of these areas delineates one of the five wetland management categoriesrecognised by the EPA in 1993.The appropriate graph from Bulletin 686 is used to plot Part I scores versus Part II scores for each wetlandthat is evaluated by this method to arrive at a final management category for the wetland.3.3.3.3 Vegetation condition in the evaluation of wetland management categoryThe extent and condition of remnant native vegetation in a wetland is a good guide to which managementcategory is appropriate for the wetland (Hill et al. 1996; EPA, 2008). In the survey of the MKSEA, theevaluation of wetland vegetation condition is of particular relevance due to the very high conservationsignificance of any remnant vegetation of the Guildford Vegetation Complex.For extensive wetlands over 70 ha in area (usually palusplains and damplands on the eastern SCP) all areaswith remnant vegetation were assigned to the management category of Conservation Category Wetland(EPA, 2008) in recognition of the widespread clearing that has occurred in the past in this type of wetland.The assessment by Hill et al. (1996) of what constituted wetland vegetation for extensive wetlands over 70ha in area differed from the bushland condition scale used in Government of Western Australia (2000). Thedefinition of remnant vegetation for this process in Hill et al. (1996) includes:• Complete native vegetation cover;• Partial disturbance of either canopy or understorey; or• Canopy (tree or shrub) cover with understorey removed.For lakes, sumplands and damplands under 70 ha in area, an assessment was made as to the ‘naturalness’ ofthe wetland (EPA, 2008), i.e. the percentage of vegetation that remains undisturbed in a wetland. Thismeasure provided a second tier assessment method of determining the management category for a wetland(Table 3.12).Table 3.12: Vegetation status assessment in the evaluation of the management category of wetlands (adapted from Hillet al. 1996, Table 3)Management Category General Description Vegetation Status AssessmentC – ConservationR – Resource EnhancementM – Multiple UseWetlands which support a high level of attributes andfunctions.Wetlands which may have been partly modified but stillsupport substantial attributes and functions.Wetlands with few attributes which still provide importantwetland functions.>50% vegetation undisturbed10-50% vegetation undisturbed