Squirrels, take note: Acorn production is up across southern Missouri for the second year in a row.
Hunters, be warned: Well-fed deer may stick to the forests this fall and winter, making them as elusive as they were last year.
Across the state, red oaks produced about 2 percent more acorns in 2006 than in 2005, while white oaks produced about 9 percent more, according to an oak mast survey released last week by the Missouri Department of Conservation.
The term “mast” refers to the nuts and fruits, produced by trees, that are eaten by animals. It includes acorns, hickory nuts, walnuts and maple seeds.
In 2005, red oaks produced about 33 percent more acorns than in 2004, while white oaks produced about 30 percent more.
Acorn production declined for both species of oaks over the past year in the region encompassing Boone and Callaway counties, according to the report. Both oaks went from having a “good” yield in 2005 to a “fair” yield in 2006, according to a numerical index provided by David Gwaze, a resource scientist for the Conservation Department.
Typically, researchers see statewide acorn production rise one year and decline the next, Gwaze said. The decline in the region’s figures was not dramatic enough to pull down statewide figures, he said, and statewide yields are still relatively high.
Statewide increases in red and white oak acorn production are important for both wildlife researchers and hunters. Gwaze said researchers predict an increase in reproduction rates among deer and other wildlife because those animals will have a greater supply of food this fall and winter.
On the other hand, Gwaze said, hunters may have more difficulty finding deer because the animals won’t need to leave the forest regularly to find food. “In terms of hunter success, it’s possible that it might be low again, just as it was low last year,” Gwaze said.
Such an increase in acorn production over two consecutive years is rare, Gwaze said. The last time such an increase took place was 1986.
It’s impossible to predict mast yield from one year to the next, and scientists have a number of theories as to why it changes, said Tim French, central region forestry supervisor for the department.
One theory holds that trees produce higher quantities of mast in some years because of stress that results from drought-like conditions, French said. Missouri has experienced those kinds of conditions for the past two years.
Some trees may be genetically predisposed to producing more acorns, he said, while the fertility of the soil could also be important.
But French said that right now, no one theory is better than another.
“It is variable,” he said. “It’s variable between species of trees; it’s variable because of the environmental factors, such as drought.”
Many kinds of wildlife rely on mast for food, said Mike Schroer, the department’s central region wildlife supervisor.
“It really runs from small mammals up through big birds and the turkeys,” he said.
Schroer said increased breeding among wildlife wouldn’t be immediately seen unless there is a harsh winter. In the case of a harsh winter combined with a large supply of acorns, Schroer said, animals will have good fat reserves that will sustain them until spring, when they should be able to produce more offspring. Last year’s winter was mild, he said, but he hasn’t heard forecasts for this year.
The 2006 Conservation Department study, released last week, was conducted beginning in early September.
Researchers looked at 50 trees in multiple counties across southern Missouri, which is more heavily forested and hunted than the north, Gwaze said. Each tree was identified as having a low, moderate or heavy yield of acorns, he said. Data from each county was then combined and converted into a numerical index, where the greatest possible acorn yield is equivalent to 300 points. A poor year yields from zero to 75 points, a fair year from 76 to 150, a good year from 151 to 225 and an excellent year from 226 to 300.
The Conservation Department has been performing this kind of research since 1959, Gwaze said.