Detecting Change in Belowground Carbon Stocks: Statistical Feasibility and Future Opportunities from Loblolly Pine Forests

The substantial magnitude of belowground carbon (C) stocks suggests that even minor proportional changes in soil C concentrations could significantly affect global carbon budgets. However, measuring stock changes with sufficient statistical confidence proves difficult due to soil C heterogeneity. In the southeastern United States, planted loblolly pine forests have extensive potential to modify C flows under intentional management regimes. To understand feasibility of estimating belowground C stocks, we evaluated current knowledge of and ability to detect change in belowground C subpools (i.e., coarse woody material, O horizon, mineral soil, detritus, fine roots) in planted loblolly pine stands by compiling statistical distributions from existing databases. We performed power analyses to quantify minimum detectable change in each subpool given current sample sizes, as well as minimum sample sizes required to detect desired magnitudes of change with adequate statistical confidence. The mineral soil subpool could report the smallest magnitude of change (12.9%, power=0.8, α=0.05), and smaller changes could be detectable at individual depth increments. No subpool had enough measures to detect change <10% across the region (power=0.8, α<0.2). At minimum, tens of thousands more samples (>2200% increase, power=0.8, α≤0.2) would be needed to detect the smaller stock changes (i.e., 2%) across the species' native range in which current monitoring and market frameworks are interested. Measurement gaps highlight pools for prioritized monitoring. Lack of statistical power associated with all pools necessitates greater data collection or a reconsideration of statistical conventions.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Forestry

Department dc:contributor.department

Forest Resources and Environmental Conservation

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2025

Author dc:creator

• Vickery, Caroline Elizabeth

Chair dc:contributor.committeechair

• Strahm, Brian

Committee members dc:contributor.committeemember

• Munro, Holly
• Green, Patrick Corey

• sample size
• power analysis
• carbon storage
• soil organic matter
• forest soils

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

vt_gsexam:43123

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/131419