In order to study landscape changes, an interdisciplinary approach that integrates landscape ecology and history is vital. This paper presents two methods to facilitate this integration. The first method aims at improving communication between the two disciplines by defining "interface categories" to talk more specifically about human impact on ecosystems. This procedure is illustrated with an example of forest changes in the Swiss lowlands. In the second method patterns of change in environmental features across regions are compared with regional differences in the importance of human activities with potential impact on the environmental feature under study. This method, referred to as double comparative study, is illustrated with an example of changes in forest composition in the northeastern United States.