Jcz. Woinarski et al., APPLICATION OF A TAXON PRIORITY SYSTEM FOR CONSERVATION PLANNING BY SELECTING AREAS WHICH ARE MOST DISTINCT FROM ENVIRONMENTS ALREADY RESERVED, Biological Conservation, 76(2), 1996, pp. 147-159
Measures of phylogenetic diversity have been used to establish conserv
ation priorities amongst groups of taxa. We adapt one such measure ('P
hylogenetic Diversity' or 'PD') to a hierarchical environmental classi
fication and use its algorithm to design a conservation reserve system
(using the Northern Territory of Australia as a case study). This app
roach accords priority selection to sites which are most dissimilar to
the environments already secured in the existing conservation network
, and hence rapidly increased equitability in reservation percentage a
t higher levels of the hierarchy (broad environmental groups). Variati
on within these broad classes (i.e. environmental classes defined at a
lower level of the hierarchy) is included in selections, but this inc
lusion tends to occur later in the selection process. This approach re
sults in an eventual complete solution (to the goal of 5% reservation
of all recognised environmental classes), which is 18% more expensive
than a minimum-set solution which treats all environmental classes as
equally distinct, but its advantage of rapid securement of main-enviro
nments would be compelling where only a limited number (less than the
minimum set) of additions to the existing conservation network is achi
evable in the forseeable future. The approach is further contrasted wi
th a prioritisation mechanism ('irreplaceability') associated with min
imum-set approaches. Irreplaceability is largely a measure of limited
distribution, and we argue that this may not be an important ranking c
riterion if the limited environment is defined at a low classification
level and closely related environments are already well-represented i
n the existing conservation network. Copyright (C) 1996 Elsevier Scien
ce Limited.