Widespread concern over the state of the environment and the impacts of anthropogenic activities on ecosystem services and functions has highlighted the need for high-quality, long-term datasets for detecting and understanding environmental change. In July 2001, an international conference reviewed progress in the field of long-term ecosystem research and monitoring (LTERM). Examples are given which demonstrate the need for long-termenvironmentalmonitoring and research, for palaeoecological reconstructions of past environments and for applied use of historical records that inform us of past environmental conditions. LTERM approaches are needed to provide measures of baseline conditions and for informing decisions on ecosystem management and environmental policy formulation. They are also valuable in aiding the understanding of the processes of environmental change, including the integrated effects of natural and anthropogenic drivers and pressures, recovery from stress and resilience of species, populations, communities and ecosystems. Keywords: LTER, Ecosystems, Management, Indicators, Environmental governance, Public awareness, Review.