Changing spatial patterns of conservation investment by a major land trust

While numerous scientific publications have used biological data and sometimes decision theory to identify where conservation funds should be invested, studies that examine where money for conservation actually has been spent and how investment patterns have changed through time are scarce. We analyze changing spatial patterns of spending on land protection, using investments by a major conservation organization, The Nature Conservancy (TNC), in the conterminous United States as a case study. We focus on investments in land protection made by TNC in four decades (1970–2009) using fee simple and easement acquisitions. During this period, TNC expanded and accelerated its investments in land conservation. We compare patterns of conservation investment in different states via two metrics: (1) the amount TNC spent to acquire land for protection, and (2) the overall area protected. The two metrics, while correlated, reveal different information about TNC’s investment patterns. The amount of conservation activity TNC undertook in different states shows pronounced variation when measured either by the overall area protected or the cost of acquiring that area. We used a regression approach to relate variation in investment levels across states in each decade to a suite of biological and socioeconomic factors relevant to the effectiveness of conservation resource allocation decisions. Through time, these variables are able to explain greater spatial variation in the levels of investment into different states. The richness of native species per state showed the strongest association with overall investment levels. However, land costs also influenced investment patterns in recent decades but in ways that differed when measured by the overall area protected and by the money spent to protect it.