Biodiversity Conservation and Phylogenetic Systematics

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to identify a subset of ktaxathatmaximizesPDonaphylogenetictreeofntaxa
(2 ≤ k < n).ForreserveselectionwedefinePDonasubsetofareasasthePDofthe
uniontaxonsetoftheareas.Thesimplestreserveselectionproblemisanalogously
to identify a subset of kareasthatmaximizesPDoverallsubsetsofkareas.Inthe
following, we reformulate these problems using SD and further integrate economi-
calandecologicalconstraintsintotheextensions.

Taxon Selection Problems

Westartwiththesimplesttaxonselectionproblemformallydefinedas:

Asanillustration,giventhesplitsetfortenpheasants(Fig. 2 ) we want to select
fourtaxamaximizingSD.Bydoingsoweyieldanoptimalsubset(highlightedin

Problem 1 (Taxon Selection)

Given a phylogenetic split set for ntaxa,findasubsetofktaxathatmaximizes

SD over all subsets of ktaxa.

Taxa Areas

Conservation targets

1. Taxon
   selection

Conservation Constraints

Ecology Economy

3. Viable
   taxon
   selection


4. Budgeted
   taxon
   selection


5. Reserve
   selection


6. Budgeted
   reserve
   selection

Fig. 3 The“network”ofbiodiversityoptimizationproblems

O. Chernomor et al.