Brewer talks about conservation easements and perpetuity. Although conservation easements have many appealing features, their drawbacks have caused some observers to see the heavy reliance on them by land trusts as a weakness with possibly serious consequences. The protection provided may be fragile or, at least, of unproven dependability.
Conservation Easements and Perpetuity: Till Legislation Do Us Part,
74 Law and Contemporary Problems
Available at: http://scholarship.law.duke.edu/lcp/vol74/iss4/11