Red Oak Acorn Production Data, Eastern United States 1968-2000

These data are time series of annual acorn of production from 34 sites in the Eastern United States between 1968 and 2000. The data originate from four studies: Fearer, T. M., Norman, G. W., Pack, J. C., Bittner, S. & Healy, W. M. 2008 Influence of physiographic and climatic factors on spatial patterns of acorn production in Maryland and Virginia, USA. J. Biogeogr. 35, 2012–2025. (doi:10.1111/j.1365-2699.2008.01960.x); Sork, V. L. 1993 Ecology of mast fruiting in three species of North Amierican deciduous oaks. Ecology 74, 528–541; Drake, W. E. 1995 Evaluation of an approach to improve acorn production during thinning. In Proceedings of the Eighth Biennial Southern Silvicultural Research Conference. General Technical Report SRS-1, Washington, D.C.: U.S. Department of Agriculture, Forest Service; Palmer, W. L. 1998 Acorn production in a mixed-oak stand in Pennsylvania: twenty-seven years of data. Harrisburg, Pennsylvania, USA: Pennsylvannia Game Commission. Please refer to these source publications for methodological details.

The data were combined and analyzed in Haynes et al. Geographical variation in the spatial synchrony of a forest-defoliating insect: isolation of environmental and spatial drivers. In press. Proceedings of the Royal Society B. Because Haynes et al. were interested in the spatial synchrony of acorns of the red oak species group (Erythrobalanus subgenus), data from the source citations on acorns of the white oak species group are not provided here. Furthermore, as in Haynes et al., we only provide data from sites with strong temporal overlap of observations across sites.

The acorn abundance variable in this data set was measured differently among studies. The Fearer et al. 2008 data are mean numbers of red oak acorns per tree across 40 trees at each site. The Sork 1993 data are mean numbers of acorns per tree. The Drake 1995 data are kg of acorns per hectare. The Palmer data are pounds of acorns per acre.