A biodiversity intactness index.
The nations of the world have set themselves a target of reducing the rate of biodiversity loss by 2010. Here, we propose a biodiversity intactness index (BII) for assessing progress towards this target that is simple and practical--but sensitive to important factors that influence biodiversity status--and which satisfies the criteria for policy relevance set by the Convention on Biological Diversity. Application of the BII is demonstrated on a large region (4 x 10(6) km2) of southern Africa. The BII score in the year 2000 is about 84%: in other words, averaged across all plant and vertebrate species in the region, populations have declined to 84% of their presumed pre-modern levels. The taxonomic group with the greatest loss is mammals, at 71% of pre-modern levels, and the ecosystem type with the greatest loss is grassland, with 74% of its former populations remaining. During the 1990s, a population decline of 0.8% is estimated to have occurred.
Scholes
R J
RJ
CSIR Environmentek, PO Box 395, Pretoria, 0001, South Africa. bscholes@csir.co.za
Biggs
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D000353:Africa, Southern; D000465:Algorithms; D000818:Animals; D044822:Biodiversity; D003247:Conservation of Natural Resources / Q000379:methods*; D003625:Data Collection; D004463:Ecology / Q000379:methods*; D005843:Geography; D007391:International Cooperation; D008322:Mammals / Q000502:physiology; D018521:Plant Physiological Phenomena; D011157:Population Dynamics; D012680:Sensitivity and Specificity; D013997:Time Factors