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Ecologically Sustainable Development

Are We Sustaining Australia? Report Against Headline Sustainabilty Indicators

Environment Australia, 2002
ISBN 0 642 54771 8

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Value 17: Biodiversity and ecological integrity

Rationale for inclusion of issue

Core objective 3 of the NSESD specifies the protection of biological diversity, ecological processes and life support systems. Protection of biological diversity and ecological processes and life support systems is also essential to safeguarding the welfare of future generations (Core Objective 1) and providing for inter-generational equity (Core Objective 2).

Indicator 19 (i)

Rationale for selection of indicator

The agreed headline indicators for biodiversity and ecological integrity are:

• extent and condition of terrestrial habitats;
• extent and condition of freshwater habitats; and
• extent and condition of coastal habitats, estuarine habitats and marine habitats.

However, there is no agreed methodology for assessing condition of habitat in any of the above contexts. For the purposes of this report, vegetation assemblages and habitats are used as a surrogate for ecological systems and ecosystem diversity. While the preservation of flora does not necessarily imply the preservation of the fauna for which it originally provided habitat, original vegetative cover does provide habitat for whatever fauna remains, and is therefore a surrogate indicator for overall biodiversity.

The indicator used in this Report is: number of bio-geographic sub-regions with greater than 30% of original vegetative cover.

The extent and condition of coastal, estuarine, marine and freshwater habitats will, to some extent, be measured by the indicators for coastal and marine health and freshwater health.

Explanatory and elaborative information

The indicator shows that a substantial majority of bio-geographical regions retain a substantial minority of their original vegetative cover. Whether 30% of original vegetative cover per bio-geographical region is adequate for sustaining biodiversity may be subject to ongoing debate. However, the indicator provides a baseline reading on the current state of original vegetative cover, against which future losses and restoration of original habitat may be measured.

Indicator 19 (ii)

Rational for selection of indicator

The agreed headline indicator is the extent to which the above habitats are represented in reserves and non-reserve systems. There is no agreed methodology for assessing the extent to which habitats (of various types and conditions) are represented in reserves and non-reserve systems. The proportion of bio-regions where more than a certain percentage of area is represented in protected areas is the best surrogate we currently have for the extent to which native habitats are represented in reserve systems. For the purposes of this report, the proportion of bio-regions where more than 10% of area is represented in protected areas is used.

Explanatory and elaborative information

As with the previous indicator, whether 26% of bio-geographical sub-regions with greater than 10% of the sub-region's area under protection is an adequate proportion is subject to debate. What the indicator provides is a current reading against which future losses of biodiversity, and the effectiveness of protected area in conserving biodiversity, can be measured.

Indicator 20

Rationale for selection of indicators

Numbers of extinct, endangered and vulnerable species and ecological communities under the Endangered Species Protection Act (1992) (Commonwealth) in 1993 and 2000 is an indicator for loss of biodiversity.

Explanatory and elaborative information

Any apparent increase in the number of species known to be endangered, vulnerable and extinct needs to be treated with caution. Trends in this indicator reflect the number of species which have been legally recognised as threatened or extinct and added to the list since 1993. These changes are therefore as likely to result from increased knowledge/understanding or changes in taxonomy rather than an actual increase in the number of threatened and extinct species.

Having noted this caveat, the total number of species known to be vulnerable, endangered and extinct appears to have increased by 37% since 1993. The main increases have been in the number of vulnerable mammals and vulnerable birds, and the number of endangered vascular plants - although ten vascular plants appear to have moved back from the extinct to the endangered category. Discounting these ten plants, a total of nine animal or plant species appear to have become extinct since 1993.

No time series data are currently available on the number of endangered ecological communities.

Taxon	EN(1993)	EN(2000)	VU(1993)	VU(2000)	PEX(1993)	PEX(2000)
Fish	7	13	6	17
Amphibians	7	15	2	12		4
Invertebrates				4
Reptiles	6	11	15	38
Birds	26	33	25	61	20	23
Mammals	28	29	18	45	21	27
Non Vascular plants		1		1
Vascular Plants	226	516	661	649	74	64
Ecological Communities		23
TOTAL Species	300	618	727	824	115	118
TOTAL Ecological communities		23
	Year			Number
Total Threatened Species (Endangered and Vulnerable)	1993			1027
	2000			1442

Supplementary indicators

• population trends for selected/key species
• number of endangered and vulnerable species where population number have declined/increased since last Report, if available)
• rate of clearing of native vegetation in hectares per annum