As a potential buyer of rural land I avoid conservation easements like the plague. If you are considering selling the property, ever, you would do well to avoid making one.
Think about it. If you want to have land for farming or forestry or something, why would you ever allow restrictions on how you could use it, FOREVER? Making a living farming is hard enough. Think of the boards, faceless government entities, land trust managers or bureaucrats who have no idea how to make a living from the land telling you how to run your business or what you can grow or animals(ie. type, or how many) you can raise on your own property.
The conservation easements I am familiar with are designed more for the tourist or already land-owning neighbors or the wealthy who want to preserve the view from the road or pretty vistas from their McMansions. They love the idea of farming and not the reality. This results, at least in my area, in land sitting idle on the market for years with inflated prices that is wonderful and useful but impossible to make a living from.
-fixie.