What effect do U.S. federal land programs have on private conservation? A new paper by PERC fellows Nick Parker and Wally Thurman examines how private land trusts respond to changes in the federal estate and federal conservation programs. In particular, the authors ask whether increases in government land conservation "crowd out" private land trust conservation.
Parker and Thurman compare the amount of land held by the Land Trust Alliance and Nature Conservancy with changes to the amount of land held by the federal government and in federal conservation programs such as the Conservation Reserve Program. While the results vary, they provide interesting insights into the determinants of private land conservation.
First, the observed effect differs between the Land Trust Alliance (LTA) and the Nature Conservancy (TNC). This is likely due to the different goals of the two trusts. The LTA is made up of many small, local trusts that solicit donations of conservation easements, primarily for open space. TNC, on the hand, actively purchases land and easements, with an emphasis on protecting plant and wildlife habitat.
The Conservation Reserve Program (CRP) is found to slightly crowd out land held by LTA trusts and, to a larger extent, “crowd in” TNC land holdings. In other words, an additional acre of CRP acreage slightly decreases the amount of LTA land and increases the amount of TNC land (see paper for magnitudes). This is plausible because CRP land preserves open space and is a substitute for LTA easements, so crowding out occurs. TNC land increases on adjacent land, likely because wildlife habitat and open space preservation are complements. TNC may also enroll its own land in the CRP.
Increases in the federal estate also have different effects on LTA and TNC conservation. The authors find no reliable effect on LTA trusts, but observe a slight crowding-out effect on TNC land from federal land. This is also plausible because LTA easements are mostly held in perpetuity and cannot be reduced in response to government conservation. TNC-owned land can be sold, or more likely, transferred to the federal government.
The paper contains other insights into understanding private land conservation, including the effect of income and population on land trust growth, and contributes to a growing literature on private land trust conservation.