Funmurphys: the Blog

Forest Management

My backyard would appear to have a remnant of the primeval Missouri Forest: Oak, Ash, Hickory, and Dogwood. The previous owner had marked several trees for removal by putting a big red paint blotch on them. I have removed a trio of live trees (oddly enough none had a big red splotch) and a bunch of dead trees - two white pines and the remainder dogwoods. I didn't try to change the variety, however, but had other concerns. But in the larger forest outside my backyard, Oaks and Hickories are on the decline. Researchers at Case Western University surmise that fires caused by lightning help the Oaks compete against more shade tolerant trees:

Paul Drewa, assistant professor in Case's biology department, and graduate student Sheryl Petersen, suspect that these kinds of fires may provide a natural mechanism to deter encroachment of shade tolerant hardwoods, especially red maples that are crowding out oaks and other plants on the ground floors of numerous forests throughout the eastern United States.

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"Human alterations to the natural fire regime, especially decades of fire suppression, have changed oak-dominated ecosystems in southern Ohio and throughout the eastern US," reported Petersen. "As a result, there is a preponderance of shade tolerant hardwoods that are preventing oaks and other native species from regenerating."

The oak canopies of remaining forest fragments are deceptive, according to the researchers, who found that oaks are not thriving well beyond the seedling stage, with few developing into older life history stages, including juveniles, saplings, and poles.

"Eventually this means the demise of oak trees and other less shade tolerant plant species in future years," said Drewa

This isn't any new idea though -- as a 2004 article in Missouri Conservationist Magazine makes clear:

In the fall, the hills adjacent to the Missouri and Mississippi rivers seem ablaze with brilliant orange sugar maples. Few trees are as attractive as a sugar maple in autumn, but there is something haunting in all that orange.

Not long ago, these same hills contained a lot more of the reds, purples and yellows of oak and hickory. Slowly but surely, the oranges are taking over, indicating that the river hill forests are changing, and not for the better.

We have long had some sugar maple in our woods. In the last 50 years, however, the amount of sugar maple has increased dramatically. This is especially true in counties adjacent to the Missouri and Mississippi rivers, where land is especially productive because of loess, or wind blown silt. Loess is blown from the river bottoms and deposited on nearby slopes. In some areas, loess is more than 100 feet deep. In areas like these, sugar maples are overtaking most other forest vegetation.

The primary reason for the maple takeover is that over the last 50 or so years, we have stopped fires from burning our woods. Native Americans commonly used fire as a tool in Missouri. They burned the landscape to aid in hunting and fighting wars. They also used fire to improve wildlife habitat, which helped ensure an abundance of game. The first European settlers also used fire, primarily to create and improve pasture lands.

Fire played a huge role in shaping the composition of our woods. Oaks and hickories are relatively tolerant of fire. Their thick bark helps protect them from intense heat. Smaller seedlings and trees may be "top-killed," but their deep root crown allows them to resprout quickly and vigorously.

Fighting forest fires is done with the best of intentions, but not always smartly (just like the new model, prescribed burns). The problem with the old zero tolerance policy is that it allows fuel to build up and huge conflagrations to occur. And if it weren't for the obvious fact that the longer we fought forest fires, the worse they got, we would still have a zero tolerance policy.

The problem is how to transition back to way forests were prior to zero tolerance without burning the forests down in the process. And another thing to consider is that prior to zero tolerance, the policy was not just let natural fires burn, but set our own. For millenia, the Indians set fires across North America. So to get back to what we consider virgin forest, we have to realize that in fact there has been nothing virgin about North American forests for millenia. What we really want is to go back to actively managed forests with fire as the primary tool.

Prescribed burns seem to be the favored way for the Forest Service to manage forest fires and an immediate return to older practices, but as Mike at SOS forest points out:

So the New Plan is to destroy America’s priceless, heritage forests (whoops, we mean worthless wildlands) in catastrophic fires. The idea is to burn them down sooner so they don’t burn down later.
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Does this make sense? Burn our forests down so they don’t burn down? It makes sense to the Dale Bosworth, Chief of the FS, because he signed onto all the recommendations in the Audit.

The trouble with prescribed burns is that they are hard to control - they result in both not enough fuel removal, and far too much -- causing the inferno that fire fighting was supposed to stop in the first place. The sad thing is, we already know a better way - mechanical removal of fuel. Of course, that brings up the dreaded L word - logging. But the science is clear:

Our findings indicate that fuel treatments do mitigate fire severity. Treatments provide a window of opportunity for effective fire suppression and protecting high-value areas. Although topography and weather may play a more important role than fuels in governing fire behavior (Bessie and Johnson 1995), topography and weather cannot be realistically manipulated to reduce fire severity. Fuels are the leg of the fire environment triangle (Countryman 1972) that land managers can change to achieve desired post-fire condition. However, in extreme weather conditions, such as drought and high winds, fuel treatments may do little to mitigate fire spread or severity.
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There are at least three ways to reduce tree densities and accomplish fuel treatments: wildfire, prescribed fire and mechanical thinning. The first, natural fires, are often impractical. Letting natural fires play their historical role may have unwanted effects in forests that have undergone major stand structural changes over the past years of fire exclusion. Any fire started may result in historically uncharacteristic high severity. In many ponderosa pine forests choked with dense, small-diameter trees, or encroached by shade-tolerant trees, natural fires may no longer play a strategic role.

The second strategy for restoring these forests is large-scale prescribed burning. This is likely to be effective in stands that have moderate or low tree densities, little encroachment of ladder fuels, moderate to steep slopes which preclude mechanical treatment, and expertise in personnel to plan and implement such large prescribed burns. Large-scale implementation of this strategy will require funding for the planning and implementation over current expenditures and may require modifications to current air quality legislation. Future results of such expenditures may be seen down the road in lessened wildfire suppression costs, reduced fire severity, and reduced air quality impacts.

Mechanical tree removal, the third strategy, works best on forests that are too densely packed to burn, that have nearby markets for small-diameter trees, and areas where expertise and personnel are not available for prescribed burning programs. Mechanical tree removal may be accomplished by many different types of harvest, including precommercial thinning, selection or shelterwood harvest coupled with small-diameter tree removal, and thinning from below (Fiedler 1996). The goal is to manage forests for much lower tree densities leaving larger residual trees. Harvests to reduce wildfire hazard will remove small-diameter trees in contrast to traditional timber harvests. Mechanical fuel treatments can be very labor intensive, especially on steep slopes and in remote areas, and may not be commercially attractive due to the small diameter trees that need removal. To make fuel treatments more cost-effective for small-diameter trees, consistent markets are necessary (Nakamura 1996). Fiedler et al. (1997) assert that mechanized tree harvest on moderately-steep terrain coupled with removal of large amounts of biomass can generate considerable revenue. Periodic underburns and programs for restoring natural fire are critical to maintain these post-harvest stands.

In other words, go in and remove the undergrowth mechanically (i.e. logging, but not clear cutting), then use fire afterwards for maintanence. This was essentially the goal behind the Healthy Forests Initiative, but the logging (i.e. mechanical removal) aspects were controversial and unpopular with a lot of people. Another problem is that the trees and underbrush to be removed isn't what timber companies are really after. So it looks like will be mainly using fire to fight fire for a while longer.

BTW, if you aren't getting Missouri Conservationist Magazine, you should be if you have any interest in the Midwestern Great Outdoors.