Tree Ring Data from the Harvard Tract in Pisgah State Forest NH 1675-2015

Is it possible to reconstruct aboveground carbon/biomass from tree rings? If so, how far back in time can researchers go when using tree-ring data in the reconstruction of past biomass? Answers to these questions will have a significant impact on our understanding of dynamics in the terrestrial carbon sink. Long tree-ring records of biomass can reveal intra-annual to annual to multidecadal variations that cannot be resolved by forest census data that is not conducted at annual time steps. Additionally, while these dynamics might be resolved using remote sensing, most remotely-sensed products are only two decades or less in length. By having long records of carbon biomass, we can then identify not only the dominant drivers of biomass, but how the importance of these drivers might change during different eras as environmental factors change (e.g., climate, air pollution, disturbance). To test these and other questions, we collected tree-ring records from two 30m radius plots set within Harvard’s Pisgah Tract in Pisgah State Forest, New Hampshire. We can convert these data to biomass using allometric equations and compare tree-ring inferred aboveground biomass to the census data going back in time. Famously, 80% of this tract was knocked down in September 1938 by a strong hurricane. The forest has sine regrown and the plots we installed can be used to understand forest recovery and carbon dynamics in a heavily disturbance forest. Given that this was a known/decently documented event, these data were used by Trotsiuk et al. (2018) to test various growth release methods as applied to tree-ring data. Trotsiuk, V., Pederson, N., Druckenbrod, D. L., Orwig, D. A., Bishop, D. A., Barker Plotkin, A., Fraver, S., Martin-Benito, D. 2018. Testing the efficacy of tree-ring methods for detecting past disturbances. Forest Ecology and Management 425: 59-67.