Preserving Tree-Ring Datasets for Climate and Hazard Research and Understanding Societal Impacts: Colorado Fire, Climate, Humans

Culebra Range of the Sangre de Cristo Mountains, Colorado. Sample Collection: Ponderosa pine (Pinus ponderosa), Douglas-fir (Pseudotsuga menziesii), Bristlecone pine (Pinus aristate), and Limber pine (Pinus flexilis) living in lower and upper montane slopes of the Culebra Range (~Latitude 37˚N, ~Longitude -105˚W WGS84). The Fire-Climate-Human NGGDPP archive collection was obtained in two separate field campaigns. 1) CSU/USFS-led Bar-NI Fire History (Huckaby and Fornwalt, 2001). Sixty-six fire scar cross-sections were collected using a hand saw or chain saw from living, standing dead, and remnant wood at Bar-NI Ranch (37.15°N, -105.02°W). 2) USGS-led fire history (Brice and Kehrwald, 2023). Twenty-two fire scar cross-sections were collected using a hand saw or chain saw from living, standing dead, and remnant wood at Trinchera Ranch (37.41°N, -105.37°W). Samples were processed following standard dendrochronological methods, including sample surface preparation and visual cross-dating. The annual ring-widths were measured to 0.001mm precision from the digital imagery using Coorecorder measuring software. Visual crossdating was verified statistically using the ring-width measurements in the program COFECHA v.6.06P. Measurement data are not available for cross-sections with tree-growth complacency or hypersensitivity precluding robust statistical crossdating. Ring-width analysis results of these collections have not been published. These tree cross-sections now require preservation. Currently, the physical samples are too large to share outside the project location. To overcome this challenge, we used high resolution digital photography to capture images of each sample using a system custom designed for digitizing tree rings. Digital images obtained for this archive can then be stored and used by researchers, communities and teachers and students at all education levels.