Symposium 1 (PT 1). Tree rings from national forest inventories: a timely opportunity to assess tree growth across space and through time
My Session Status
Tree-ring time series provide long-term, annually resolved information on the growth of individual trees. However, public tree-ring archives contain a considerable portion of data collected from trees that have been selected with specific research questions in mind (e.g., for climate reconstruction). This makes these archives a biased representation of the sensitivity of forest ecosystems to ongoing climate variation (e.g. temperature, precipitation), including non-stationarity (i.e., global warming and associated changes to Earth’s climate). Many public collections also lack the tree and forest information needed to quantify forest-level growth, making it very difficult to scale-up tree-level information to ecosystem estimates of biomass accumulation and carbon sequestration. National forest inventories (NFIs), by comparison, are systematic observatories of forest ecosystems designed specifically for large-scale inference. Yet, this spatial information comes at relatively low temporal (e.g. decadal) resolution and hampers the investigation of forest responses to annual climate variability as well as seasonal and climate extremes. When tree-ring data are collected in NFIs (or other statistically designed) forest plot networks, multiple influences on tree growth can be captured in an unbiased and representative way—not just climate, but also competition, disturbance processes, and other environmental factors (atmospheric CO2 concentration, N deposition)—which is critical to parse their effects and understand how they may interact. A systematic effort to sample tree rings in NFIs can yield unprecedented temporal and spatial resolution of the drivers of forest and carbon dynamics. This symposium aims to showcase the latest work on the development and applications of tree rings collected from NFIs and forest plot networks. Applications of NFI tree-ring data may include retrospective analyses of spatial variations in productivity and climate sensitivity, efforts to improve carbon accounting, examinations of climate change impacts, and assessments of mitigation potential critical for Earth’s habitability.
Sub Sessions
Tree-ring research studies depend heavily on samples, but the connection to the sampling theory remains loose. Tree-ring studies need to be based on samples of restrained size for several reasons: measuring tree-ring features remains labour-intensive, costly, and sampling cannot be seen as totally free of consequences for trees. Sampling, the art of selecting observational units to produce population-level estimates, comes with constraints that, when not respected, lead to biases and loss ...
Forest responses to climate change are highly uncertain, but critical for forecasting and managing forest carbon dynamics. Tree-ring time series data provide annually resolved growth responses to climate, but often lack the stand-level information needed to scale growth up to carbon uptake. In contrast, the U. S. Forest Service Forest Inventory and Analysis (FIA) Program is an exceptional spatial network to estimate forest carbon, but lacks the annual resolution needed to determine how tre...
Past forest mortality after disturbances creates one source of uncertainty that needs to be taken into account to reconstruct biomass dynamics. Additionally, using unitless normalized data from tree-ring records to calibrate stand productivity in vegetation models constitutes another source of uncertainty for model calibration. In this presentation I would assess these two sources of uncertainty and discuss the influence of calibration technique in model-data fusion. I combined data from p...
Tree-ring time series provide long-term, annually resolved information on the growth of individual trees. When sampled in a systematic context, tree-ring data can be scaled to estimate the forest carbon capture and storage of landscapes, biomes, and ultimately the globe. A systematic effort to sample tree rings in national forest inventories would yield unprecedented temporal and spatial resolution of forest carbon dynamics, and help resolve key scientific uncertainties, which we highlight...