This text is presented in Spanish and English. This book on the Chilchos Valley in the north-eastern slopes of the Andes in Peru attempts to understand how human activities have changed the landscape in the montane forests during the last 500 years. Settlements and terraces from the Chachapoya and Inca cultures in the Ceja de Selva witness of an ample use un pre-Hispanic times. Later after a drastic declination of the population in the colonial period the Chilchos Valley was forgotten in hundreds of years and then rediscovered and revisited in 1900. Within the stage of rediscovering the valley new socio-cultural processes of adaptation to the environment began with migrations from the Sierra. This book is about historical ecology and environmental studies carried out in 2000-2001 by a team of archaeologists, anthropologists, botanists and geographers in north-eastern Peru. During the last five hundred years the montane forest landscapes in the Huambo valley and La meseta, the provinces of Rodriguez de Mendoza and Huallaga were modified by tribal groups, the Chachapoyas and the Inca cultures and later by the invasion of the Spaniards. Today population pressure from the highlands is the cause of the transformations of the biologically diverse cloud forest.