NATN (North American Treeline Network)

The North American Treeline Network (NATN)
Coordinators: David M. Cairns1, Lara M. Kueppers2, and Connie I. Millar3

1Texas A&M University, College Station, Texas, cairns[at]
2University of California Merced, Merced, California, lkueppers[at]
3USDA Forest Service, PSW Research Station, Albany, California, cmillar[at]

Photo: Treeline from the Kenai Peninsula, Alaska. Treeline from the Kenai Peninsula, Alaska; Photo: D. Cairns

In spring 2012, the Director of the international Mountain Research Initiative approached CIRMOUNT regarding interest in developing a research effort in North America to parallel a similar program launching in Europe. The proposed focus would be on interdisciplinary dynamics of the upper treeline in mountains as a zone sensitive to climate. A group of interested mountain scientists met after the MtnClim 2012 conference in Estes Park, Colorado in early October 2012 to discuss scope and next steps, which include assembling an advisory board and developing a proposal for a research coordination network. An initial description of NATN's intent follows:

The treeline ecotone is the boundary zone between forest and arctic or alpine environments and is potentially a bellwether for responses of cold-adapted ecosystems to climate change. Although presence and structure of trees define the treeline ecotone, this system includes complex interactions among vegetation, soils, animals, climate, topography, and disturbance regimes. As such, treelines serve as a focal system for disciplines across the natural sciences, yet cross-disciplinary integration of theory and methods is lacking, which prevents holistic understanding of this sensitive ecosystem. Historic divisions in treeline research have been drawn along pattern and process boundaries. The NATN will promote collaboration between these groups, building a comprehensive systems framework and identifying gaps in both theory and data. The goal of the North American Treeline Network (NATN) is to integrate research efforts across disciplines, scales, and methodologies. Specifically, we aim to catalyze efforts to characterize and understand past and present treeline dynamics, and to facilitate projections of future changes in treeline ecotones across North America.

To do this, NATN will bring together ecologists, ecosystem scientists, geographers, ecophysiologists, climatologists, hydrologists, and others to solidify our understanding of treeline dynamics across domains of time and space. NATN will sponsor regional and international meetings of treeline scientists that will enhance communication and collaboration across disciplinary boundaries. The network will place an emphasis on the professional development of students and early career scientists, including through student exchanges and a series of topical webinars, to promote new lines of inquiry and collaboration. We will involve early career scientists in all aspects of network development and provide travel grants for participation in workshops and synthesis activities. In addition to bringing diverse scientists together, our approach will include the development of common experimental and observational protocols that encompass elements of both pattern and process, as well as design of a georeferenced database that can synthesize, archive and provide wide access to diverse treeline related data for North America.

Establishment of NATN corresponds with a companion activity in Europe that seeks to integrate treeline research across disciplinary and national boundaries, and leverages recent support for study of arctic treeline as part of the International Polar Year. The time is ripe for the North American treeline community to coalesce around a common effort that will involve significant synergies with our European colleagues.

The legacy of NATN will be a set of common protocols for experimental and observational studies, an extensible treeline database, a robust communications network among treeline scientist both in North America and Europe, and a cohort of interdisciplinary researchers prepared to advance treeline science into the future. It is only through these integrated efforts that sound projections of a future treeline system will be possible.