A tree-ring perspective on the terrestrial carbon cycle

Abstract

Tree-ring records can provide valuable information to advance our understanding of contemporary terrestrial carbon cycling and to reconstruct key metrics in the decades preceding monitoring data. The growing use of tree rings in carbon-cycle research is being facilitated by increasing recognition of reciprocal benefits among research communities. Yet, basic questions persist regarding what tree rings represent at the ecosystem level, how to optimally integrate them with other data streams, and what related challenges need to be overcome. It is also apparent that considerable unexplored potential exists for tree rings to refine assessments of terrestrial carbon cycling across a range of temporal and spatial domains. Here, we summarize recent advances and highlight promising paths of investigation with respect to (1) growth phenology, (2) forest productivity trends and variability, (3) CO2 fertilization and water-use efficiency, (4) forest disturbances, and (5) comparisons between observational and computational forest productivity estimates. We encourage the integration of tree-ring data: with eddy-covariance measurements to investigate carbon allocation patterns and water-use efficiency; with remotely sensed observations to distinguish the timing of cambial growth and leaf phenology; and with forest inventories to develop continuous, annually-resolved and long-term carbon budgets. In addition, we note the potential of tree-ring records and derivatives thereof to help evaluate the performance of earth system models regarding the simulated magnitude and dynamics of forest carbon uptake, and inform these models about growth responses to (non-)climatic drivers. Such efforts are expected to improve our understanding of forest carbon cycling and place current developments into a long-term perspective.

Evaluation of Whole Tree Growth Increment Derived from Tree-Ring Series for Use in Assessments of Changes in Forest Productivity across Various Spatial Scales

“…Supplementary Materials: The following are available online at www.mdpi.com/1999-4907/7/12/303/s1, Table S1: Height-diameter model parameters [1,2], Table S2: National taper model parameters [3], Table S3: Regional taper model parameters [1,[4][5][6] , Table S4: Number of annual increment observations available for comparison by species and diameter class. Values in the diameter class column represent the largest diameter of tree in that class.…”

“…However, the temporal resolution of these data is limited, typically only 5 to 10 years, so they may not provide the annual scale data required for analyzing tree response to annual climate fluctuations. Recent studies have noted the potential utility of tree ring data in terrestrial carbon cycle research [5], as it can lengthen the available time series of annually resolved estimates of ecosystem production or growth increment [3,[6][7][8]. In these applications, ring width measurements are instead used to generate various tree or forest level estimates of annual growth increment.…”

Environmental determinants of the old oaks in wood-pastures from a changing traditional social–ecological system of Romania

“…A typical example for such a recognition of the social-emotional value of the old trees is the various terms (e.g., 'veterans' or 'working trees' in UK), names or stories associated with them (e.g., Read 2000;Butler 2014;Sherren et al 2012). Finally, large, old trees are information bearers about the past climatic and environmental conditions, ecosystem functions, and human management interventions on the tree, such as pollarding, coppicing (Rackham 1986;Babst et al 2014).…”

Fusing tree-ring and forest inventory data to infer influences on tree growth

“…Here, we offer a model that folds the strength of treering data into a mensurational context. As new uses for tree-ring data emerge, including carbon accounting (Babst et al 2014a, b, 2017, Dye et al ( Fig. 4.…”