Virginia Tech Forestry Outreach Program

Acorn Study

Introduction

Acorn production has long fascinated wildlife biologists and forest ecologists. Acorns are a critically important wildlife food in the eastern deciduous forest, contributing a large percentage of the diet for gray squirrel, wild turkey, white-tailed deer, blue jay, black bear, raccoon, and many other species.

Acorn crops vary greatly from year to year. Some ecologists believe acorn crops are influenced by late spring frosts that kill oak flowers that would otherwise develop into acorns. Other ecologists believe that summer drought reduces the size of acorn crops. Finally some believe that acorns are produced on a cycle intended to overwhelm predators in heavy production years. This cycle, called mast production, is considered an adaptation.

Methods

During the first two weeks in October of each year, selected trees on the Virginia Tech campus and nearby Blacksburg were investigated for acorn production. Nine or ten hula-hoops were randomly thrown beneath the tree canopy and all acorns were counted within the hula-hoop. The diameter of the hula-hoop was measured to determine the area sampled. The Virginia Tech data collection sheet was used to record data.

Results

Three tree species were investigated: black oak, northern red oak and white oak. No data was collected for black and northern red oak in 1999.

Table 1. Acorn Production of trees on the VA Tech campus and nearby Blacksburg
Acorns per square meter
Species	1999	2000	2001	2002
black oak	No data	9	5	23
northern red oak	No data	156	2	33
white oak	156	0	0	105

Click here to see graphs of the data

Discussion

 

If you would like to participate in the study next year, please request a tree tag from Jeff Kirwan, jkirwan@vt.edu. We will use this to mark your tree for future reference.