The Cooperator will collect tree core samples at NCRN vegetation plots at Catoctin Mountain Park (outside 49 monitoring plots) and Monocacy National Battlefield (outside of 15 monitoring plots).
The Cooperator will assemble a team of trained technicians to prepare cores samples for analysis, including
mounting and sanding.
Each core will be scanned alongside a scale bar to provide an image archive of the core.
A Velmex system and Measure J2X software will be used to measure annual increment ( 0. 001 mm precision).
Minimum age will be established for each core and a series of tree-ring chronologies will be developed based on normalized mean annual increment providing a ring width index (RWI).
A SQL database will be created with Plot_Name as the primary key.
Core_ID will relate to Plot_Name and Ring_ID will relate to Core_ID.
Tree species and diameter at breast height (DBH) will be stored in a table with Core_ID.
For each Ring_ID the database will record Ring_width.
Each tree core will be crossdated against all cores within 3km of the focal core in COFECHA.
Crossdating may include the identification of gaps (missing rings) and additions (false rings); the database will be updated with these changes.
Ring_year (related to Ring_ID) will be added to the database following cross dating.Tree growth rate, including basal area increment (BAI) and ring width index (RWI), will be evaluated across sites and species.
The final tree ring database will be approved by the PI before it is released to NCRN staff.