Conservation planning in the Anthropocene: Reconciling biodiversity needs with philanthropic constraints
Caught between ongoing habitat destruction and funding shortfalls, conservation organizations are turning to systematic planning approaches to identify places that offer the highest biodiversity return for each dollar invested. However, available planning tools do not account for the landscape of funding for conservation or quantify the constraints it imposes on conservation outcomes. We use state-level data on philanthropic giving and investments in land conservation by a large nonprofit (The Nature Conservancy; TNC) to evaluate the extent to which the landscape of philanthropy explains expenditures on conservation relative to biodiversity priorities. Further, we use a species area curve-based return on investment (ROI) approach to investigate the biodiversity conservation gains possible with increases in flexibility to reallocate funding across space.
Philanthropic fundraising at the state-level better explains TNC conservation expenditures (r2 = 0.64) than two separate systematic conservation planning approaches (r2 = 0.08 to 0.21). These results emphasize that the distribution of philanthropic support to TNC state chapters is the dominant constraint over where this organization works in the US. We estimate that over a recent decade, TNC could have protected between 8.5% to 80.2% more endemic species by implementing a 1% to 10% tax on each individual state chapter and redistributing funding optimally according to an ROI on endemic species richness, accounting for land prices and existing protected areas. To improve the returns in biodiversity gains per dollar invested, conservation organizations need to develop mechanisms to increase their flexibility to reallocate funding across space. Rather than continuing to focus on some hypothetical situation where conservation organizations are assumed to have complete liberty to move funds around, conservation planning tools might be more useful if they were to quantify and incorporate the institutional constraints within which conservation organizations operate.