By Katie Martin/DWR
Acorn production across the state in 2023 can be categorized overall as extremely poor for white oak and average to above average for red oak species (see graphs below). Based on the annual hard mast survey, white oak routes came in at an all-time low since survey data has been recorded in this manner (2007). Conversely, red oaks surveyed right at the long-term median, breaking a two-year low. White oak was generally poor (or nonexistent) across all sites and elevations this year with very limited pockets of average production, found primarily in the north piedmont region.
The lack of white oak acorn production was not unexpected after the above-average year of production in 2022. Interestingly, when viewing hard mast data from a regional perspective, white oak production in more northern states (Pennsylvania, New Hampshire, Vermont) has been rated above average to excellent this year. Red oak production was average or above average in all areas except for the southern Piedmont and Tidewater regions (which both fell well below the long-term average). While red oak acorns are not generally preferred by many wildlife species due to their tannin content (and size), in years of poor white oak production, these acorns will often be readily consumed, especially later in the season.
As with all years, acorn production is highly variable and very site dependent. Many routes had areas of “bumper” mast production even if their overall site average was below average. This variability is due to many reasons (weather, insects, tree species), but for some of our survey sites we are probably approaching the biological end of production due to tree age. Unfortunately, finding “new” stands of mature oak in the 50- to 70-year age range is becoming more and more difficult due to aging forests and lack of sufficient regeneration. Replacing aging trees/survey sites could be quite a challenge moving forward.
The annual hard mast survey has been an ongoing effort between the Virginia Department of Wildlife Resources (DWR) and many partner agencies for many years. Many of the mountain survey sites have been in place since the 1950s. In 2023, staff from DWR, the U.S. Forest Service, U.S. Fish and Wildlife Service, the Virginia Department of Conservation and Recreation (DWR)/Virginia State Parks, Virginia Department of Forestry (DOF), U.S. Department of Defense/Department of Military Affairs, National Park Service, and Smithsonian Conservation Biology Institute surveyed 33 hard mast production sites across Virginia. Sites are located across all regions of the state, although a majority are currently found in the mountains. Continued efforts are being made to add sites to the Northern Piedmont and Tidewater areas.