It is hereby declared to be in the public interest to encourage the preservation of open space which is potentially subject to development, thus providing a healthful and attractive outdoor environment for work and recreation of the state‘s citizens, maintaining the character of the state’s landscape, and conserving the land, water, forest, agricultural, recreational, and wildlife resources. It is further declared to be in the public interest to prevent the loss of open space due to property taxation at values incompatible with open space usage. The means for encouraging preservation of open space authorized by this chapter is the acquisition of discretionary easements of development rights by town or city governments on such open space land which provides a demonstrated public benefit.