Cross-site studies "by design:" Experiments and observations that provide new insights

TitleCross-site studies "by design:" Experiments and observations that provide new insights
Publication TypeBook Chapter
Year of Publication2013
AuthorsYao J, Sala O.E, Peters DC
Book TitleLong-Term Trends in Ecological Systems: A Basis for Understanding Responses to Global Change
PublisherNational Technical Information Services
CitySpringfield, Virginia
Accession NumberJRN52668
ARIS Log Number256307
Keywordsatmospheric chemistry, climate change, cross-site comparisons, disturbance, ecological response, ecology, ecosystem, EcoTrends, experimental forests, global change, human demography, human population growth, Long Term Ecological Research (LTER), long-term datasets, precipitation, rangeland, rangeland research stations, surface water chemistry

The cross-site comparisons presented in the previous chapters are all conducted after the individual studies are completed.  The differences in experimental design in individual studies in a posteriori cross-site studies limit the scope of questions that can be addressed, and the powerfulness and confidence in the conclusions.  This chapter describes cross-site studies that are “by design” where the questions, experimental layout, methods, and measurements included multiple sites from the beginning. These a priori cross-site studies provide powerful tools to understand the phenomenon of global change and to predict its impacts on ecosystems and society. Two types of a priori cross-site studies are described: (1) experimental manipulations of drivers or system properties, and (2) observations or monitoring of natural or managed ecosystems located along environmental gradients. Within each type, examples of both on-going or completed experiments and new or developing experiments are presented.  For each example, insights that would not have been obtained with other approaches are also presented. The limitations and difficulties of this type of studies are listed.