Managing a bottomland hardwood forest has much in common with quality deer management.
Quality deer management emphasizes individual deer health, balancing herd numbers with the habitat's ability to support them. A desirable result is, of course, exceptional male deer specimens, but balanced age structure is an important component as well.
For example, a quality deer herd is not composed of animals that are all the same age. Multiple year classes are present. Exceptional older animals are removed from the herd when they have surpassed or are near to surpassing their physical and reproductive potential. Exceptional animals in the following age class take their places in their hierarchy.
The same principles apply to managing a forest.
Garrick Duggar, assistant chief of the Arkansas Game and Fish Commission's Wildlife Management Division, made the comparison Tuesday during a tour of Dave Donaldson Black River Wildlife Management Area in Northeast Arkansas. The tour's objective was to demonstrate the need to upgrade infrastructure on the WMA and to demonstrate the need for modifying the water management policy not just at Dave Donaldson Black River WMA, but at all 16 wildlife management areas that have green tree reservoirs.
These 16 WMAs house 42 green tree reservoirs containing about 50,000 acres of bottomland hardwood forest. Combined, this acreage is a mere remnant of the millions of acres of bottomland hardwood forest that covered eastern Arkansas before it was cleared, drained and leveled for farming.
The tour began at the Lower Island Green Tree Reservoir at Black River WMA. The terrain and the habitat are remarkably different than at Bayou Meto WMA near Stuttgart, but the management challenges are the same. Both WMAs are at the lowest elevations of their respective watersheds. The only reason the Game and Fish Commission was able to buy them is because they stay too wet for too long, and they are the last acreages to drain when their neighboring rivers drop out. That makes them unsuitable for farming.
The problem at Dave Donaldson Black River WMA is that the Black River takes longer and longer to drop out due to wetter precipitation cycles.
The first thing I noticed walking into the woods at Lower Island GTR is that the forest floor is devoid of understory vegetation except for a smattering of seedling nuttall oaks that will die next fall when the Black River refloods the woods. That means there has been no significant oak regeneration in probably a decade or more. The trees that are present are tall and old, but there are no young trees to replace them.
Within Lower Island GTR, there are about eight nuttall oaks per acre. That's a good density, which means a few trees showing signs of advanced inundation stress can be culled. This will allow sunlight to reach the forest floor, stimulating understory growth that will enable seedling oaks to grow tall enough to survive.
The group stood beside one nuttall oak that Game and Fish personnel estimated to be about 70 years old. It is tall and straight, with moderate evidence of water stress. It is also producing about 50% fewer acorns than it did in its prime. Nearby, however, are other nuttall oaks showing greater evidence of water stress. They exhibit a greater amount of basal swelling, and they exhibit high degrees of epicormic branching, which can best be described as forming one or two separate trunks below the crown. The branch tips in the crown are dead. These are all bad signs that indicate trees that should be culled to benefit the forest at large.
"So, this big, straight tree here is the dominant buck in this herd," I said to Duggar. "For him to put on more body weight and add mass to his antlers, you need to cull these two bucks over here with the spindly, assymetrical racks. Is that an accurate way to hear this?"
"Absolutely!" said Duggar, refining the analogy. This caught the attention of Game and Fish Commissioner Anne Marie Doramus, who leaned in to hear Duggar's expanded thoughts. Other trees with lower wildlife value, like sweet gum, ash and hackberry, must be taken out as well.
For years, duck hunters have complained about the Game and Fish Commission cutting down big trees at Dave Donaldson Black River WMA. Now we know why.
Selective timber harvest is one part of the puzzle. Timber health relies on water management, which depends on water control structures and levees. Water management policy is central to the puzzle, too, to govern water's role in green tree reservoirs. That must change for these woods to continue attracting ducks and providing hunting opportunity. We'll cover that next Sunday.