The year 2020 is the 40th anniversary of the U.S.National Science Foundation's LTER Program, which has grown from a remote vision, to a loosely organized set of research projects, to a dynamic network of 28 sustained research programs across 18 major biomes. Hypothesis-driven, place-based research has been the Network's bread and butter throughout its 40-year history. Integrating that science across sites and biomes has always been seen as important, but the approaches to synthesis have varied and the availability of resources has waxed and waned. Yet collaborative synthesis is essential for understanding the generality of site-based insights, scaling the results, and making them useful for modeling.
Results/Conclusions
A recent update of the LTER Network bibliography makes it possible to approach the question of "what works" to facilitate collaboration at both the site- and the network-level. Between 1980 and 2019, the average number of LTER-based publications per site per year grew from 6 to more than 30. For the first 10-15 years of the Network's history, the number of authors and institutions per publication was similar to a comparable sample of non-LTER publications. But the pace of collaboration accelerated rapidly between 1995 and 2019. Today, LTER papers involve nearly twice as many authors and institutions as comparable non-LTER publications. Site tenure and ecosystem type are predictably strong drivers of collaboration in the LTER Network. Researcher mobility emerged as an unexpected source of collaboration that merits further investigation.