A friend of mine just sent me this. Not sure where it was from.
After last year's middling acorn count, Quantico's oak trees are producing an especially hearty crop of acorns this year. A major source of food for deer, turkeys, rodents and other animals in the area's forests, the acorn supply is an important ecological driver that has implications beyond these animals' populations, even affecting next year's gypsy moth numbers and risks of Lyme disease in 2014.
A count by the Fish, Wildlife and Agronomy Section at the end of August found the overall acorn index value is up to 30.8 from last year's 10. 4. Head of Fish, Wildlife and Agronomy Tim Stamps said the average count is around 20.
The index for white oak acorns, which are the preferred food, is up from 4.1 last year to 25.1, and the red oak acorn count is up from 16.8 to 36.5.
"It will hopefully keep the deer well fed and help keep them off the roads," Stamps said, noting that a plentiful food supply for the winter will mean that in the spring, does should be able to carry more young, and bucks can put more energy into antler production. Looking at the deer as game, he said, "there's potential for quality and quantity to be boosted in 2013."
For trophy hunters, to the extent that more fawns are born next spring, that should mean more antlered deer in the 2015 and 2016 hunting seasons, Stamps said.
William McShea, senior research scientist for the National Zoo facility in Front Royal, said the most immediate consequence of a large acorn crop is that deer are more likely to stay in the deep forest, rather than in roads and gardens.
An increase in the rodent population next year as a result of the increased food supply will not only provide more food for predators, but McShea said the rodents will likely eat more gypsy moth larvae, preventing a gypsy moth infestation next year.
However, he said a boom in white-footed mice could increase risks of Lyme disease in the spring of 2014. These rodents are frequent carriers of Lyme disease and a common food source for ticks, which tend to latch onto the mice shortly after they hatch in the summer. By the following spring, the ticks are in their active nymph stage, the time when they're most likely to transmit Lyme disease.
Stamps said the last time the acorn index value, which is calculated by counting the acorns on 10 randomly selected branch tips on each of 80 oaks across the base, exceeded 30 was when it hit 32.5 in 2007. At that time the count hadn't exceeded 30 since 1985, when it spiked to about 75, Stamps said. "People couldn't even walk up hills that year. It was like walking on marbles. It was phenomenal."
McShea said red and white oak acorn crops rarely line up, in part because the white oak generates acorns every year, while red oak acorns take two years to mature. He said meager crops often result from events in the spring, such as freezes that kill the trees' flowers or severe winds that blow them off. Droughts and gypsy moth infestations can also stifle acorn production.
"We know what makes for a small crop, but what makes a big acorn crop, we can't tell you," McShea said.
But he noted that oaks can't produce a large acorn crop two years in a row, and the inconsistency in the number of acorns produced from year to year is a survival strategy for the trees, preventing animal populations from reaching a level where they consume nearly all the acorns.
"The whole variable acorn crop is a way of killing off what's eating your babies," he said.
With the region's burgeoning deer population eating not just acorns but almost every oak sapling that takes root, though, McShea said future acorn crops could be a lot slimmer.