Conserving ecosystem services and biodiversity: Measuring the tradeoffs involved in splitting conservation budgets

Conservation organizations increasingly target ecosystem services alongside biodiversity, yet it remains unclear whether ecosystem service goals reinforce or detract from those for biodiversity. We assess tradeoffs between biodiversity and ecosystem services and test the hypothesis that the severity of this tradeoff is a function the breadth of taxa and ecosystem services targeted. We identify optimal conserved lands networks for four taxa, four ecosystem services, and all possible combinations of each. We then assess the amount of biodiversity and ecosystem service contained within each network, its conservation cost, and its overlap with every other network. We find that overlap varies widely across individual ecosystem services and taxa, and that networks targeting multiple services contain more biodiversity than networks targeting a single service. Safeguarding a given amount of ecosystem service and biodiversity through joint optimization requires a 13% increase in conservation budgets relative to achieving targets for biodiversity alone, and results in a 22% budget savings relative to achieving targets for each though separate efforts. We conclude that including ecosystem services goals alongside those for biodiversity is likely have a net positive impact on biodiversity, especially when a broad suite of services are targeted.