If people started selling their land to government, some wacko history-buff might start raising flags about slavery, or at least fiefdom. However, it is perfectly fine for a Conservation Trust to buy lands from people and donate them to the government, provided there is an understanding that these lands taken off the tax rolls will not be put to productive use.

Why, land is the only thing in the world worth working for worth fighting for, worth dying for, because it’s the only thing that lasts. – Gerald O’Hara