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Abstract
Oaks (Quercus) are economically important, and their seed (acorns) are a valuable food for many animals. Thus, forest managers must consider potential tradeoffs between oak growth and acorn production. I used 13 years of dbh growth and 17 years of acorn trapping data on 195 trees of five common eastern oak species to compare stand-level growth and acorn production between closed canopy mature forest (M) and recent shelterwood with reserves regeneration harvests (SW) (BA 27.3 ± 1.7 m
2/ha in M; 5.1 + 0.8 m
2/ha in SW at study establishment). I also examined treatment differences in dbh growth, crown expansion, and acorns/m
2 crown at the individual tree level, using a subset of paired (by species and dbh) trees. Despite five times more oak trees and oak BA in M, average annual total acorn production/ha was only double (58,199/ha in M) that in SW (27,298/ha), and was statistically greater in M than SW for total oaks and white oak. Stand- and paired individual tree-level analyses indicated that average acorns/m
2 crown and dbh growth was approximately 70% greater in SW than M for total oaks. Crown area increases were greater in SW than M for total oak (66%) and northern red oak (74%), and crown areas in SW expanded disproportionately to increases in dbh alone. In mixed-oak southern Appalachian forests, silvicultural treatments retaining 20–40 mature oaks/ha with fully released crowns will likely yield 50–100% of acorns produced/ha in mature closed canopy stands, as acorn production by residual trees increases. Retention of multiple oak species will reduce the likelihood of stand-level crop failure, as acorn production differs among species and years.
Citation
Greenberg, Cathryn H. 2021. Oak growth and acorn production in southern Appalachian mature forests and shelterwood with reserves regeneration harvests. Forest Ecology and Management. 481: 118691-. https://doi.org/10.1016/j.foreco.2020.118691.
