Reconstrucción del paisaje del caldenal pampeano en los últimos 250 a？os

current calden forests (caldenal) in la pampa are understood as derived from pristine savannas. it is also usually accepted that the degradation of these open formations started following two deforestation periods locally known as grandes hachadas and linked to the world war periods. this outline for the landscape history disregard any significant impact during the indian occupation period prior to 1879 and the re-settlement period that took place right afterwards. both assumptions are questioned by modern historical investigations. in this study, we used dendroecological techniques to reconstruct the evolution of the forest landscape in la pampa. our results show that most of the study sites were closed forests at least since the middle the xviiith century, in coincidence with intense indigenous cattle ranging and transhumance activities between the wet pampas in argentina and southern chile. the opening of these formations occurred synchronously at the end of the xixth century together with the introduction of sheep raising activities. the woodlands closed again when cattle supplanted sheep ranching by the 1940s. these results show a high degree of human impact on the caldenal during the last 250 years.