BioCondition
What is condition assessment?
One of the earliest definitions of condition was developed in relation to grazing land management of rangelands, as the “health or productivity of both soil and forage of a given range, in terms of what it could or should be under normal climate and best practicable management” (Society of American Foresters 1944). However, what a condition measure represents is context dependent. That is, the measure will depend upon whether the objective for the assessment of condition is for production, biodiversity or aesthetic purposes. Therefore, it is important that any condition assessment procedure is explicit in defining the aim of the assessment. For example, the primary aim of the Stocktake condition assessment is to provide a measure of land condition relevant to sustainable grazing at the property scale.
BioCondition, however, has been developed with a biodiversity perspective, as a vegetation condition assessment tool to provide a measure of how well a terrestrial ecosystem is functioning for the maintenance of biodiversity values at a local or property scale. It is a site-based, quantitative and repeatable assessment procedure that provides a numeric score that can be summarised as a condition rating of 1, 2, 3 or 4, or functional through to dysfunctional condition for biodiversity. In BioCondition, we refer to vegetation condition as “… how much the attributes of a patch of vegetation differ from the attributes of the same vegetation type in its reference state”. The reference state refers to the natural variability in attributes of a regional ecosystem in ‘Best-on-Offer’ condition, or patches of vegetation that have been least impacted by local disturbances.
It should be noted that the final BioCondition score will not provide an index of habitat suitability for fauna. Habitat suitability depends on many other factors that are not direct indicators of vegetation condition, such as components of habitat that also provide shelter including rock cover and density of dead hollow-bearing trees, or the presence of feral predators. BioCondition is not intended for use in regional planning or assessment of conservation significance, although outputs can contribute to this.
The primary components of BioCondition include:
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BioCondition Benchmarks
Benchmarks are the most practical method of objectively comparing condition for biodiversity within and between regional ecosystems or land types. They are quantitative values for each attribute that is assessed in BioCondition and are based on the average or median values of a mature and long undisturbed ‘reference’ site, or from Best-on-Offer sites. We aim to obtain the quantitative information for attributes during optimal seasonal conditions. Benchmarks are a ‘yardstick’ against which you compare an assessment site (and act as a reference point for comparison).
Benchmark documents have been developed and are available for a subset of regional ecosystems. Where benchmarks are not available, the reference site manual (PDF, 1.5M)* describes a methodology for the derivation of benchmarks.
In rangeland ecosystems, seasonal conditions can account for wide variation in the values obtained for attributes assessed in BioCondition, therefore in these ecosystems a range is expressed instead of a constant benchmark value. When using these benchmarks to score rangeland sites using BioCondition, the lower end of the range should be used, or if you are assessing your site under good seasonal conditions then you could use the average value as the benchmark.
If possible, the recommended approach is to locate and assess a local reference site using the reference site protocol at the same time of the condition assessment. The information obtained from this site can be used to augment and refine the range of benchmark values for each attribute relative to the site being assessed, by accounting for excessive variability that could be caused by seasonal or drought effects, particularly for the attributes:
- Tree canopy cover
- Grass cover
- Species richness
BioCondition manual
BioCondition Manual
The BioCondition manual (PDF, 4.1M)* provides an assessment protocol for the rapid measure of how well an area of vegetation is functioning for the maintenance of biodiversity values. It is based on the notion that vegetation that is ecologically functional is valuable for biodiversity, and that certain attributes of the vegetation can act as surrogates of biodiversity in general. In BioCondition the selected attributes have been tested against detailed measures of biodiversity to ensure their usefulness. A datasheet for use with the manual is provided here (PDF, 52K)*.
Reference site manual
Reference site manual
The reference site manual (PDF, 1.5M)* provides an approach for obtaining Benchmarks when they are not available, or for when sampling needs to occur in non-optimal seasonal conditions. A datasheet for use with the manual is provided here (PDF, 86K)*.
* Requires Adobe Reader
Last updated 16 January 2012