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Forest Management

As a forester, it is always disturbing to hear people talk about letting wildland fires burn with the possible loss of life and property. Many seem to think that burning down a forest is preferable to logging it. This point of view shows a serious lack of understanding about the dynamics of how forest ecosystems function.

Disturbance is normal in forests. The NPS has finally figured this out. Using the example of Yosemite, for years Park Service scientists seemed baffled by the forest colonization of the meadows in Yosemite Valley. They have believed for decades that the way to preserve the Park was to put a fence around it and protect. Research of historical land use patterns show that sheep were grazed in the Valley, the local Native tribes set fires every fall, and that there were at least two sawmills operating on the edge of the Park in the late 1800s and early 1900s and later. This is the mechanism that maintained the meadows.

Many people that care about Nature and outdoor recreational pursuits have very strong emotional feelings about land use policies and forest management. They may have strong feelings, but do not necessarily go to the trouble to educate themselves about these issues.  This is an ongoing battle between federal management agencies and the lay public.

Forests are impacted primarily by fire and logging. Other disturbances like grazing, landslides, and other natural disasters tend to be minor in comparison. Because of the potential loss of life and property and timber, from uncontrolled wildland fires, we as a Nation began forest firefighting in earnest around the time of the Conservation Movement in 1900. At that time, forest suppression was by hand crews supported by strings of pack animals. Smoke jumpers, helitack crews, and hotshot crews came later.

As long as timber harvesting continued somewhere near sustainable levels, this system worked pretty well. By the 1960s and 1970s many different types of state and federal legislation were in place to protect forests from over-harvesting. We had to learn some difficult lessons before that time. Concurrent with ever increasingly more efficient fire suppression, the US Forest Service in 1991, made a landmark decision to decrease cutting on National Forest lands below the annual allowable  (AAC). This is the amount of wood that can be removed on each Forest District without affecting sustainability.

In the last two and half decades the combination of reduced logging and fire suppression has created critical levels of built up brush, overstocked stands of timber, and dangerous fire conditions. A warming climate and drought have made the situation even worse. So have outbreaks of insects and pathogens.

From the perspective of forest management (or lack of it), the obvious solution going forward is timber harvesting, timber stand improvement, thinning and fuel reduction programs. The chainsaw is society's best friend. All of these activities can be prioritized near where people live first. Much of the wood removal will not include commercially valuable wood products and in will cost money. By our lack of action in the last 25 years large, more catastrophic fires have been the main way that fuels have been reduced. Our last two fires locally were stopped when the fire front over ran areas that were recently burned. This has been our de facto management policy, wild fire.

The USFS operates with large losses every year, when they should be turning a modest profit. Their budgets are increasingly taken up by fire suppression costs. They have a little left for fire rehab, and little for timber sale administration. These trends can be changed.

Pogo was right "We have seen the enemy, and it is us."

Ppine, you have many excellent points on how are forests could be better managed and understory control of fire hazards is a valid endeavor. 

But I have to ask a couple of questions in relation to that. There is a definitive progression in the way the forests grow after a fire, aspen to lodgepole and then the appearance of the Ponderosa's and other large overstay "at least here in CO." The decomposition of biomass on the forest floor, aided by natural fires largely contributed to the health of the forests and their growth cycles. Ponderosa seeds disperse when they have reached a certain temperature due to brush fires, etc. 

Are you proposing to keep the current state of the forests more static allowing for better timber production, or maintaining a more natural state with ebbs and flows for the public lands? 

Also considering that the damaging factors of most recent forest fires are property loss from urban sprawl, LA being a heavy reference point. Would you actually consider that worth the expenditure of fighting the fire or an acceptance of natural forces, such as a tornado or hurricane?


We have not used rational methods for forest management in North America. In eastern Canada, for example we have usually swung between clearcutting and no cutting. After the clearcutting, they plant only spruce, spraying with broadleaf herbicides, thus creating a monoculture which is attractive to spruce budworm, which they then must eliminate with toxic pesticides. Never a thought of allowing the natural softwood/hardwood cycle.

Single-tree selective harvest is not of value if you let the loggers do the selecting. Obviously, it will be more economical for a logger to take the good trees and leave the wolf trees, thus seeding the next generation with inferior specimens.

The Seedtree system has merit, but I don't know how much it is utilized. 

If we could use one of the selective methods of harvesting which would also eliminate excessive undergrowth (through skidders weaving between trees), our fire situation would be somewhat aleviated, the forests would be healthier, and the industry could be sustainable (at a lower rate of harvest). 

Which systems have you seen in use?

This sounds like practical common sense and experience vs. naive idealism though I could be wrong. Is there some real world practical experience behind your talking points marmot?

Dale, I have a bit more on the plant and wildlife biology side. Mapping populations and other forms of biological surveying, though I am still relatively new to the workforce on that side of things. I have been on the idealistic side before, and then once at that point quickly figured out that naive idealism isn't reality. 

The seed dispersal for conifers is actually triggered by fires, once the cones reach a certain temperature, they release their seeds, and the seeds disperse, this would normally be triggered by a brush fire (I'm defining that as a fire, natural or man-made, burning the shrubs and undergrowth in the forest without ever reaching heats that would damage the larger trees), flash fires might actually be a better term. But you get the idea. 

There is also a recovery pattern that forests have, out west, the most common one is when large aspen or lodge-pole pine groves covering a mountainside, it is an indication either of a prior fire in the area, or in the case for many areas of Colorado the entire mountainsides were clear-cut for charcoal production. Leadville would be a good place for evidence for the lodgepole, and Vallecito Reservoir near Durango would be a good area for indication of the aspen. 

My references to an ebb and flow, would be the process over decades of fires occurring, letting new trees come up, other trees would eventually overtake those, and you'd have a sequenced progression of growth patterns in the tree types over a period of thirty or so years.

The first point, I do have background on.

The second, I am a little more idealistic, on. Which is why I raised the question, concern Ppines reference to the cost of forest fires. I was basing that off of the loss of properties that burned due to a forest fire, and whether it might be better to conceive of the idea more as a force of Nature versus giving it the gravity of a house fire in an urban setting. 

Thanks for the comments.

I will address the western coniferous forest only, since I have no professional experience in the East although I grew up there.

Forest harvest methods include selection cuts, shelterwood, seed tree and clear cuts. I have experience with all of them and all are viable. The commercial native species require different methods. For illustrative purposes we will consider Douglas fir and ponderosa pine. Doug fir is shade intolerant and grows in wetter habitats. It requires direct sunlight for reproduction and lives in places like the west side of the Cascades. It requires clearcuts.  That always gets people excited, but that is the harvest system that works.

Ppine is also shade intolerant, but grows in drier habitats right above sagebrush and pinion/juniper communities. It can be harvested by selection cuts.

In the Rockies, aspens reproduce where there is sufficient moisture. They are a pioneer species which reproduces rapidly and is short lived. Lodgepole pine is one of the few species that has serotinous cones and is fire dependent for reproduction. Many other species reproduce after fires like ppine, but it is not a requirement.

The notion of monocultures and lack of diversity tend to be exaggerated. The concept of a static forest rarely happens in nature. Sometimes there are stagnant overstocked stand that usually occur after fires. Otherwise forests are a highly dynamic system with fierce competition between individuals and  species. The species that belong there are in the seed bank, left over after logging and freely invade. Some forests like the large ppine forest of AZ and NM is dominated by one species of tree, with a large understory and herbaceous component. This has nothing to do with logging practices and that is how that forest evolved. It was like that pre European contact. 

The loss of forest land to urban development is a relatively minor problem, especially in the West.

We have used a logical approach to forestry in North America for a long time until recently. We learned everything from the Germans at first. We were too heavy handed and did not realize that the big trees were going to run out after the harvesting in New England, the Upper Midwest and then the Pacific Northwest.  Forest management was really starting to pay off in the 1960s until 1991. Public opinion spooked the USFS and they got very conservative in their harvest practices. Now we have a mess on our hands.

I do not want to bore anyone with long answers. There is a lot of mis-information out there and plenty of propaganda. Forests are the ultimate renewable resource. We should think of them as a resource to be used by managed harvests. If you live in a wood frame house, use paper, eat beef, like to drink really fresh water, or enjoy oxygen charged air, thank a forest. Not to mention outdoor re-creation.

Thanks for clarifying, also learned a few new things!

Cool stuff. Though in truth, nobody wants to go hiking, fishing, camping, or anything else, in a burned out forest. While people who are educated in this say the forests grow back after a fire, folks like me look at an area that burned 30 years or more ago and there are still no trees. Pine, you'll know a couple of the places I'm talking about like Dog Valley, or Peavine Mountain. For a simple boots in the dirt guy like me fire suppression seems like a great idea. Otherwise we risk running short of interesting places to hike, don't we? 

About 20 years ago I was living in the Carson Valley just south of Carson City Nevada. Got tired of shoeing horses seven days a week so I decided to cut firewood two days a week and sell it. In that process was looking at some huge commercial firewood sales up near Tahoe somewhere, I don't remember the exact location. The paperwork I had indicated that these were large areas of several square miles where there were no more than two or three live trees. The rest was standing dead timber. The surrounding healthy forests had all been logged to provide timbers for the mines on the  Comstock Lode in Virginia City. The dead areas where the places that could not be logged at the time because they lacked the technology to build roads into the steep rocky country. Mining on the Comstock ran roughly from about 1859 to about 1874. So, the healthy forest had been logged, the dead forest had not. And logging is bad because????? Always been curious about that.

Anyone with common sense knows that all logging does not look anything like the photo shown here a day or so ago so no need to refer back to that.

I just read the book Fire Season by Phillip Connors, who spent eight or nine summers manning a mountaintop fire tower in New Mexico. He writes about USFS managers making decisions about when to let a natural fire burn and when to call in the cavalry. I think basically a cool ground fire is doing free brush removal/TSI so why not let it go? But if wind, wind and fuel conditions look like they'll make it crown so that you lose your crop, better get it under control.

Makes sense to me anyway.


As you noted, you are not aware of the conditions in the East. You said 

The notion of monocultures and lack of diversity tend to be exaggerated. The concept of a static forest rarely happens in nature. 

Nature is not allowed to interfere with forestry in Maritime Canada. Jim Irving oversees much of the forests of the Maritimes and well into Maine. JD Irving brags of their tree planting

Planting as many as 25 million trees a year and nearly 1 billion trees since 1957, today it is the largest private tree improvement program in Canada.

see Irving Woodlands

When Irving clearcuts in NB, a displaced squirrel would need to pack a week's worth of nuts to find his next tree. After the slash has settled, teams are sent in to plant spruce and pull any naturally occurring oak, maple, butternut, alder, etc. growth. Sometimes they also spray herbicides. "Only pulpwood need apply." Of course, the spruce barely grows, because the land had already been depleted of the nutrients necessary for spruce; it is fine for mixed hardwoods however. 

Ah, well. 

It is true that some sites have problems after fires, and can be taken over by dense stands of shrubs like Ceanothus. Trees have trouble regenerating in those. Fortunately many states like OR and WA have state forestry practices acts that require tree planting. Standing dead trees after a fire can be very problematic because of the amount of dead fuel available for the next fire. Really hot fires consume most of the woody material and convert it to readily available nutrients. A fast moving crown fire may kill all the trees but leave the boles and branches intact.

I live in Carson Valley and hike a lot in the Sierra. I have spent time with archaeologists up near Spooner Summit with metal detectors in mature Jeffrey pine, white fir, incense cedar forests. There is plenty of metal buried in the duff layer of pine needles, draft horse and mule shoes, old misery whips, old stove parts, etc. It is obvious that these areas were logged completely during the Mining Era, but they have a mature forest on them now. It is unusual to see sites that have been clearcut that do not reproduce.

A site with standing dead, is almost always a recent fire scar. Even a severe outbreak of bark beetles or mistletoe, will not kill all of the trees.

It is very interesting to look at historical photo pairs of sites with an old photo and new one from the same location. The Union Pacific RR has a large library of photos in the West. Nearly 100 % of the time the new photos have more and denser vegetation than the old ones.

If the rotation age is 100 years, then only 1 % of the forest is being harvested each year. Newly harvested sites are planted within a year. Many people are upset by clearcuts, but that is the best wildlife habitat, the young forest with enough light to support a dense shrub layer and grasses and forbs. Clearcuts are now carefully limited in size and tend to be rectangular maximizing the "edge effect." The population of elk in western WA took a major upturn when several profs at the U of WA convinced the USFS to decrease the maximum size of allowable clearcuts.

I don't like to see the slash left behind.  While proper logging can reduce fire risks, not when the loggers leave the slash behind.

Slash needs to be left in the woods, because it has 90 percent of the nutrients that exist in a tree. If you remove it, then the forest soil needs to be fertilized. Some nutrients in forest soils like N are deficient because it is tied up in decomposition. Slash is normally burned in the woods, but recent droughts have made that very difficult. In some areas, air quality regulations make slash burning impractical. Fine materials decompose relatively quickly when they can't be burned.

If you have ever noticed, eastern Canada and New England have few of the wildfires that plague the Western states. This may be due in part to much less duff and understory plants. Invasive earthworms can take the blame for that.

In our area we had no native earthworms, however, once earthworms were introduced they were incredibly destructive. The upper photo below is without earthworms, the lower photo is after earthworm introduction.


The hardwood forests of the East, have few fires because they are supported by a wet climate with frequent summer rains. They have little understory when the canopy is closed and little sunlight reaches the forest floor. The duff layer decomposes more rapidly in the East because of the amount of moisture in it and the relatively warm temperatures, especially at night compared to the mountainous forests in the West.

The presence of earthworms probably has nothing to do with the different conditions shown in your photographs.

There is no doubt that many people in the East, especially in the southern pine forests practice "incendiary fires". There is a long history of setting fires in the fall to remove understory plants and release nutrients. Native Americans did the same thing, the original prescribed burning.


Before you make statements regarding the role of earthworms in altering the forest ecosystem, why don't you read

Which is worth the read and contains images like this:

also which states in the Abstract "European earthworms are invading previously worm-free hardwood forests across Minnesota and the Great Lakes region. In many of these forests, earthworm invasions have been associated with the loss of a previously thick forest floor. The ability of earthworms to alter and control ecosystem processes has been demonstrated in agricultural systems, but the dynamics and impact of these invasions in native forest ecosystems is largely unknown... Over four years earthworm populations and forest floor thickness were sampled across all transects, thus providing both a space-for-time assessment of decadal scale successional dynamics and a four-year window into shorter time changes. We found a succession of earthworm species across the visible leading edge due to different patterns of colonization by different earthworm species. Marked increases in space and time in earthworm biomass were associated with the development of discrete transition zones where forest floor thickness decreases to zero in as little as 75 m from areas that have forest floor layers up to 10 cm thick with advancement of the visible leading edge of up to 30 m in four years at three of the study sites."

The following article gives a good overview of the ecological changes due to earthworms in forests --

OMW, you didn't mention how the Euro earthworms got to North America. When the sailing ships arrived to load cargo for Europe, they unloaded the ballast that had filled the cargo holds to provide stability. This ballast included a lot of dirt, which harbored the earthworms. Indications are that either North America did not have earthworms prior to the European immigration, or the Euro earthworms crowded the native species of worms out.

Much as I am skeptical of much of what is wandering the internet in wikipedia, here is a summary that covers what OMW posted. The West Coast has a similar situation with Asian earthworms.


The study you cited looks like a credible source. I am not familiar with the effects of earthworms on forest soils. The study concludes that invasions of European earthworms can reduce the duff layer in hardwood forest types in Minnesota.  There is no conclusion about how that affects a forest ecosystem.

If we use the analogous case of the effect of earthworms on agricultural soils, most would agree that they are beneficial. Detrivores break down the duff layer by digesting it. Forest soils have an inherent limitation of nitrogen cycling that gets tied up in the nitrication of decaying organic material. Earthworms may be an asset to speeding the process, thereby making more N available to forest trees.

There have been some experiments in the past by companies like Weyehauser, in the PNW that used aerial fertilization, spreading of sludge, and other means to improve forest fertility. It is usually not an economically viable alternative, even on the best and most productive sites.

Healthy forest soils have very high numbers of organisms in the form of bacteria, Nematodes, Ascarids, and countless other critters.

Thanks for bringing up the subject. I suspect that we have many more pressing problems when it comes to forest management.


You said "There is no conclusion about how that affects a forest ecosystem."

The three sources I linked do speak of the effect of earthworms on the forest ecosystem. Earthworms reduce the mite population, which is responsible for spreading fungi spores.

Earthworms shift the soil system from a slower cycling, fungal-dominated system to a faster cycling, bacterial-dominated system, or at least one that is less fungus dominated (Wardle 2002).

Earthworms also dramatically alter the Carbon, Nitrogen, and Phosphorus available in the duff, leaching these into the soil. 

Earthworm invasion also affects phosphorus (P) cycling in soil, which is strongly influenced by physical and chemical modifications. Trees in areas with an intact forest floor concentrate a large proportion of their fine roots in this layer, where up to 80% of their annual P requirement is met by the tight linking of organic P mineralization and uptake (Wood et al. 1984; Yanai 1992). By eliminating the forest floor and mixing it with the underlying soil, earthworms can greatly alter P cycling by increasing P fixation by soil minerals and by altering the mineralization of organic P. For example, a study of sugar maple stands in Quebec showed that all stands that had forest floors mixed with mineral soil had lower concentrations of available P than did stands with intact forest floors, undisturbed by earthworm activity (Pare and Bemier 1989 a, b).

"Our objectives were to assess the influence of exotic earthworm invasion on (a) the amount and depth distribution of soil C and N, (b) soil δ13C and δ15N, and (c) soil solution chemistry and leaching of C and N in forests with different land-use histories. At a relatively undisturbed forest site (Arnot Forest), earthworms eliminated the thick forest floor, decreased soil C storage in the upper 12 cm by 28%, and reduced soil C:N ratios from 19.2 to 15.3." from Influence of Earthworm Invasion on Redistribution and Retention of Soil Carbon and Nitrogen in Northern Temperate Forests Patrick J. Bohlen, Ecology 

Overall, ppine, there is nothing that can be done at present in stopping the spread of invasive earthworms. I mentioned it in the context of how our eastern forests have lost most of their duff and understory plants, thus being less likely to build up a dry biomass susceptible to fire. 

You said

I suspect that we have many more pressing problems when it comes to forest management.

Perhaps there are more pressing problems, but if you don't understand, or at least acknowledge, all the pressures upon a forest ecology, any decisions you make are less than optimum; as the input for decision-making may be lacking important variables. 


Duly noted.

In the West many forests probably have a soil mantle that is too dry in summer to support large populations of earthworms. Maybe that is why I have never heard of this phenomenon.

This has been a lot of fun so far.

Maybe we should talk a little about succession before this thread dies. We mentioned before that disturbance in forests is normal.  Fire or logging can reset succession to year zero. It is relatively unusual for trees to have lifespans beyond say 250 years or so. Many pioneer species like aspens and cottonwoods don't live much past 80-90 years. In the past, ecologists talked about pioneer species and the natural succession to "climax species."  There is really a continuum of succession and there may not be an end point. Forest ecologists now speak in terms of early versus late seral stages.

Shade tolerance has a lot to do with which species show up first. Common species in the West, are lodgepole pine, ponderosa pine and Douglas fir which are all shade intolerant and need direct sunlight to grow well. Keep in mind that forest trees grow where they compete best, not where they necessarily grow best.

If we hike through a series of ppine forest sites in the West, say after a fire, we will see repetition in the move from early towards later seral stage.  Over time the canopy will start to close, but there will be an herbaceous layer of grasses and forbs, and a shrub layer.  As the stands mature the shading will create cooler mirco-environments. Species like white fir, incense cedar, grand fir, and others will grow under the canopy of ppine depending on the location. In later seral stages, the shade tolerant species will continue to increase but never really overtaking or crowding out the dominant large old ppines.

The next time you are out hiking in a forest, try to learn the major species, and observe how they interact with each other. It adds a lot to most peoples' experiences. It is a big deal to me to find some really old Shasta red fir, western white pine and sugar pine trees out in the middle of nowhere.




October 24, 2020
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