I've never understood that either, but there has been a pratice going on for decades the involves conservation groups and state/federal governments.

Often times money is granted to a conservation group by either a consortium of large banking institutions or state governments themselves. Zoning laws for particular properties of interest are changed in the name of "conservation". Unable to develop the land and having it severly devalued the owner is forced to sell to one of these "conservation" groups. Many of whom share board members with many of the large banks providing tax free grants to purchase the property in the first place. See where this is going here? After some time zoning laws are changed back to allow development in the area. Land developed and sold to highest bidder. The cycle has been washed, rinsed, and repeated all over the country.