Index of Estuarine Condition Estuarine Fringing Vegetation

Brief description

IEC2021_ FRINGING _VEG is the spatial representation of fringing vegetation used in the calculation of Index of Estuarine Condition (IEC) scores. In the context of the IEC, 'fringing vegetation' refers to the vegetation which grows above the permanently inundated portion of the estuary but within the zone of influence of the more-or-less saline estuarine waters. It includes vegetation in intertidal areas and riparian areas in the estuary but not subtidal vegetation (see Sinclair and Kohout 2018 for more precise working definitions of vegetation zones). In the field, the extent of the fringing vegetation and any built structures that impinge on it were mapped (by annotating an aerial photograph). Fringing vegetation was mapped according to Ecological Vegetation Classes (EVC) (https://www.environment.vic.gov.au/biodiversity/bioregions-and-evc-benchmarks) and subjectively classified into areas of different condition with reference to vegetation structure, weediness and land use. Each patch of vegetation that could be accessed was scored for its degree of invasion by perennial weeds and its structural resemblance to a relevant benchmark (https://www.environment.vic.gov.au/biodiversity/bioregions-and-evc-benchmarks). Additional observations were recorded on the score sheet, relating to `Health of the dominant plant species¿ and `Extent of engineered hydrological modifications¿. Scores were estimated for the areas that could not be observed. These estimated scores were based on the areas that were observed. The areas of all relevant polygons were calculated, and a score produced for each metric (IEC Report 2021).