In many cases, these purchase a large volume of low value-added output either in advance or in the initial stages of each productive cycle, and, in some cases, they also provide transport services to the community concessions. Nonetheless, there are conflicting opinions on the management of Peten's forests, based mainly on environmentalist positions or reflecting points of view that focus exclusively on the economic interest represented by the zone's forestry resources. A joint study performed in 2008 by USAID and the Rainforest Alliance compares the forest cover of concessions included in the RBM in 1985 with the situation existing in 2005.