dataset: EFG_EVD

This layer shows Ecological Fire Groups (EFG) and Ecological Vegetation Divisions (EVDs) on Victorian public land, as defined in Cheal (2010). EFGs are groupings of EVCs for the purpose of fire management. They are similar to EVDs, except that they enable for finer scale classification of vegetation based on fire response characteristics. It is recommended that fire ecology analyses are carried out in terms of EFGs rather than EVDs. For a full understanding of the concepts on which this dataset is based, please see DSE Fire and adaptive management report no. 84, "Growth stages and tolerable fire intervals for Victoria's native vegetation data sets", David Cheal, 2010. The relevant terms are explained in more detail below. An EVC is a native vegetation classification unit that is described through a commonality of its floristic, life form, and ecological characteristics, and through an inferred fidelity to particular environmental attributes. There are approximately 600 EVCs statewide. An EVD is a native vegetation classification unit based on grouping multiple EVC units that share similar ecological responses and relationships (including fire responses). There are 32 EVDs as of 2010. An EFG is a native vegetation classification unit which provides for the recoding and updating of more specific fire response characteristics for EVDs. For example particular EVCs within an EVD grouping may be known to exhibit different fire response characteristics, such as minimum tolerable fire intervals (see below). There are 37 EFGs as of 2010. Tolerable fire intervals are the minimum and maximum recommended time intervals between fire events for a particular vegetation community. The time interval is derived from the vital attributes of plant and animal species that occupy the vegetation community. Maximum TFI describes the maximum time required between two successive fire events at a site in order that a vegetation community or its constituent species can persist in the absence of fire. Expressed in years. A minimum TFI may be assigned for both low severity fire and high severity fire. Minimum low severity TFI describes the minimum time required between two successive fire events at a site, the first of which is a low-severity fire with a high proportion of unburnt landscape scattered within the fire perimeter, in order that a vegetation community or its constituent species can persist and have every reasonable chance of reaching maturity and setting seed. Minimum high severity TFI describes the minimum time interval required between two successive fire events at a site, the first of which is a high-severity fire, in order that a vegetation community or its constituent species can persist and have every reasonable chance of reaching maturity and producing propagules before the following fire event. Expressed in years. The dataset was compiled November 2010.