Extracting coherent tree-ring climatic signals across spatial scales from extensive forest inventory data

Area of Science:

• Dendrochronology
• Forest Ecology
• Climate Science

Background:

• Accessible tree-ring data for climate studies are declining in availability and spatial representativeness.
• National Forest Inventories (NFI) contain extensive, spatially dense tree-ring data not traditionally used in dendrochronology.
• Existing tree-ring chronologies often represent marginal growing environments and are sparsely distributed.

Purpose of the Study:

• To validate tree-ring measurements and dating from National Forest Inventory (NFI) data.
• To assess the potential of NFI data for building reliable tree-ring chronologies at various spatial scales.
• To investigate the utility of NFI tree-ring data for understanding broad-scale tree growth-climate relationships.

Main Methods:

• Developed an a posteriori approach for validating tree-ring measurements and dating from NFI data.
• Selected individual tree-ring width time series from nearly 94,000 black spruce trees in Quebec, Canada.
• Built average chronologies at multiple spatial scales using NFI increment core samples.

Main Results:

• Reliable climate signals were derived from NFI increment cores across spatial scales ranging from 37 to 583,000 km2.
• Chronologies built from NFI data demonstrated spatial coherence and strong correlation with independent reference chronologies.
• Tree-ring data from NFI proved effective for strengthening spatial and temporal coverage in tree-ring studies.

Conclusions:

• National Forest Inventories (NFI) provide a valuable, underutilized resource for dendrochronological research.
• NFI tree-ring data can significantly enhance the spatial and temporal resolution of climate-growth relationship studies.
• Integrating NFI data with other forest measurements offers improved understanding of tree growth across broad scales.