Legacy Effects of Human Land Use: Ecosystems as Time-Lagged Systems

Today, most ecosystems show some degree of human modification, ranging from subtle influences to complete remodeling and reshaping into anthropogenic ecosystems. In the first issue of the journal Ecosystems, the field of historical ecology, which focuses on the historical development of ecosystems, was prominently positioned with the papers of Foster and others (Ecosystems 1:96-119, 1998) and Fuller and others (Ecosystems 1:76-95, 1998). Starting from these two contributions, we (1) discuss how anthropogenic activities affect ecosystems and their development, (2) outline how land use can be assessed in ecosystem research, and we (3) discuss what the consequences of a historical perspective for our understanding of ecosystems are. We conclude by stating that whereas land-use intensity over time is an ecologically highly relevant parameter to grasp, the availability, quality, and characteristics of historical sources often restrict the analyses. In order to make optimal use of the sources and methods available and to strengthen this field of research and also increase its societal relevance, we suggest building interdisciplinary teams from a very early project phase on. Core task for these teams will be to jointly define research questions considering source availability, and including and merging modeling and experimental approaches in the study design. We propose that adopting a landscape perspective in historical ecology would provide a helpful framework and valuable background for such novel integrated analyses.