A. Balmford et al., USING HIGHER-TAXON RICHNESS AS A SURROGATE FOR SPECIES RICHNESS .2. LOCAL APPLICATIONS, Proceedings - Royal Society. Biological Sciences, 263(1376), 1996, pp. 1571-1575
Recent analyses confirm that urgent attempts to catalogue the distribu
tion of biological diversity may be facilitated by focusing at the lev
el of genera or families rather than species. However, questions remai
n over the application of higher-taxon surveys to identify networks of
priority areas for conservation action. Is the close spatial match be
tween species and higher-taxon richness at global and regional scales
reiterated when sites are locally distributed? How much money is saved
by the higher-taxon approach? And how does using genus or family info
rmation affect the efficiency with which spatial priorities for conser
vation are identified? We examined these issues using data on the dive
rsity of woody plants in Sri Lankan forests. We found that at this loc
al scale, the family and particularly generic richness of sites was cl
osely linked to their species richness, independently of variation in
site size. Moreover, fieldwork in an additional forest showed that tar
geting woody plant genera and families rather than species reduced sur
vey costs by a minimum of 60% and 85% respectively. Most importantly,
while using family data in site-selection algorithms led to the loss f
rom reserve networks of around 7-10% of woody plant species, using gen
era rather than species had virtually no effect on the representation
of species in priority sites. These results thus confirm that judiciou
s use of the higher-taxon approach is indeed a valuable technique for
improving the cost effectiveness of field surveys for local conservati
on planning in the tropics.