Dendrochronology in Motion: Visualizing Cottonwood Tree Growth across Space and Time

Cottonwood (Populus deltoides subsp. Monilifera) tree rings have been shown to faithfully record river discharge through time (Meko et al. 2015). What is less understood, however, is 1) how a tree's position on the floodplain influences its growth and its relationship to climate, and 2) how this influence changes through time. Taking advantage of the existing tree ring, hydrologic, and remote sensing datasets, we can watch the growth and development of a centuries-old riparian forest in a 10-minute video. I used tree ring data from cottonwoods growing on the floodplain of the Little Missouri River in Theodore Roosevelt National Park, North Dakota to visually explore spatial patterns in annual tree growth. Identifying spatial relationships can help scientists and land managers determine which trees are most susceptible to changes in climate and water availability. Animating annual growth is also an alternative way to present tree rings to a general audience. It is my hope that these types of visualizations can generate new insights and interest from researchers and the public alike.