Is the forest floor a resource?

I'd like to start removing fire ladder material from our zone 5 and putting the detritus underground. While I'm out there it would be nice to rake up some leaf litter to fill the empty spaces. Should I be worried about hurting the forest significantly? Like maybe there's a mass die-off of soil life from the removal of the top mulch layers? Also I imagine the magnitude of damage will depend on the time of harvest in relation to the autumn leaf-drop.

I would say yes I would be worried about significantly harming the forest. It has lived, for its entire evolutionary existence, with a mulch of leaf litter. What all networks of life exist in this mulch are beyond our knowledge and understanding. I think it would be highly unlikely that this mulch layer can be removed without consequence. This soil blanket is not just on an annual cycle, it is comprised of multiple years' worth of leaf litter, in varying stages of decomposition. A complex system that works wonders. How wonderful. Let it be. Just my 2 cents.

yes it will damage the forest. i have a similar situation and i plan to follow a lot of the advice in a book called Firescaping by Douglas Kent and i will end up damaging the forest that is very close to my house but i feel like this will also protect the forest because this will make it so that if my house ever catches on fire it won't set the entire forest i live in on fire. so it feels like it is good for me to protect my home and good for the forest to protect the forest. I will leave most of the forest on my land alone and not take anything from it except for berries.

Hi D.,

Great question, and the fact you would ask it shows that you care, which is a significant step forward in mitigating or correcting any damage you may inadvertently cause. In general (you must consider forest type) any removal of "duff" from the forest is going to change the ecosystem. You will have noted that I did not say damage, destroy or harm. It will all depend on the forest type, your methodologies, and how you maintain the "landscape," you create.

A forest is a living biome, just walking through it on a regular basis changes it, and in some cases dramatically, and harmfully. (It depends on who, how and when the walking is done.) If you are doing this for fire mitigation of your home, I would go right ahead and do it. There is "NO" difference between you doing this work, and a some forest animal building a nest, your just doing it on a larger scale, but I hope just as naturally as they would, and you can. You can also think of it as dramatic landscaping with a purpose.

Japanese "moss" gardens and Desert succulent-rock gardens have a very low "fire load," and would be a wonderful goal to achieve for fire mitigation and tranquil space. You will be displacing some flora and fauna, but others will take advantage of this alteration, that is the way of it. Can you provide more details of your current forest biome, and the radius you are considering?

One example when I WOULD take a "sample": if planting a species that is in the same genus as one growing in your nearby forest, I would take a small bit of soil (top six inches) and use it as an inoculate for the benefitial microbes.

As soon as I bought this place a drought began which lasted nearly 3 years. The leaves in the woods out back were 6 inches deep in places and bone dry. Without the moisture, there was almost no decomposition and the leaves piled up. It was a tinderbox. Fire safety is an issue to be sure. Removing at least some of the deep leaf layer can be prudent to mitigate risk.

The duff layer is a key element to the forest ecosystem, removing all of it will be disruptive. Fortunately, the duff is renewable if the trees are not clear cut, but it takes several years to decades to return to normal, depending on how much of this renewable resource is harvested.

Harvesting the soil of a forest floor was a common practice before the days of chemical fertilizers. Farmers would go into the woods and start digging, filling cart after cart with the top foot or two of soil to spread on their cultivated fields. This is essentially strip mining. A couple of centuries ago, when the continent was covered with forest, space had to be cleared for roads and homes. I can see harvesting the soil under these areas as being acceptable. Nowadays, the trees are gone. Forests have been cut down for timber and fuel, and relegated to nature preserves and low spots on the back 40. Preserving what's left is paramount.

With that said, I think some soil harvesting can be done, but sound judgement is advised.
That 6 inches of leaves I had out back needed attention. Near the house for about 50 feet I gathered up most of the loose material. I did it in the late fall, when the soil would be covered shortly with a fresh, albeit thin, layer of fallen leaves. The idea here was to minimize soil exposure to sun and elements and allow the decomposition cycle to continue. A rake will handle much of the loose material. At times I used a pitchfork. There is a point where the undecomposed top layer becomes partially decomposed litter. This lower layer starts to be mixed with the soil and roots and is not as easy to rake up. I left that in place as much as was practical.

Harvesting the soil from the floor can be done in moderation, but strip mining is not the way to go. This begs the question of how much can be gathered without disruption. If I were putting in a new building, I'd take all of it under the construction area. Looking at the way the forest floor builds with leaves and fallen branches, I think the branches offer a hint of how wide an area can be harvested. I come up with a few feet wide being about as big as I'd want to go, maybe 4-6 feet. Digging a pit 5 feet wide, 5 feet long, a foot deep leaves a good sized scar in the forest. Remediation would need to be part of the project. Filling that gash with logs and branches, leaves, and perhaps some green material would give it a good start towards healing. For the next pit, the height of the trees offers a reference. 50 foot tall trees, give it a 50 foot distance before you dig another pit.

Doing the math, a 50x50 area is 2500 sqft. A 5x5 hole is 25 sqft. The hole is 1% of the area. It would take 100 years to harvest all that soil. If it takes 100 years for that 1 foot deep hole to be replenished, that would be the maximum rate of harvest. Bear in mind, forests are slow, even with remediation efforts in place.

For all the effort and disruption, it would be a shame to waste a bit of that soil.

Well said, Ken {thumbsup}

I have a nitrogen producing tree called Red Alder. They are a pioneer species that thrive on disturbed gravelly soil that is typical of my area after a clear cut. I have some low spots with very nice dark soil that was created by the alder leaf drop. The alder in this area are dying back, while those on gravelly silt are thriving.------ In talking to an old farmer and forester, I learned that these trees don't like the rich soil that they create and they eventually die back and are overtaken by maple and other species that love it. The farmer has been managing a grove for years by regularly clearing little patches and scraping the humus layer away with his front end loader to expose the mineral soil beneath. His wife uses the "muck" leaf mold in their big garden. The exposed soil is quickly colonized by alder which thrive.

Few forests could withstand this sort of harvest but I am utilizing this tree and the soil it produces. I plan to use the excavator to muck out around some of the dying alder. I'll replace this rich soil with gravelly silt left over from road improvements. Young alder have already rooted in the gravel edge of the improved road, so I'm confident that they'll like how I've "improved" their spot. Foresters view this short lived tree as a "trash" tree. I think it's a perfect cover crop. It thrives on neglect, is self seeding and requires no protection from anything. It's only requirement is that it would like someone to take away the rich humus every few years.

There are a few other legume trees that are known to thrive on poor soils. I wonder if they also tend to die back due to the nutrient load in their leaf fall. Luceana is a tropical tree that is used for fuel, fodder and soil improvement. I don't know if it can tolerate humus gathering. I'm going to investigate this further.

Seems to me it's a question of magnitude. Remove one fallen leaf (or ten) and the ecosystem will hardly take notice. I imagine that the method of collection is important too, i.e. 100 one-square meter patches dispersed across the forest is less impactful than one 100-square meter patch.

The way I am inclined to see it, the forest is a powerful, resilient entity that can afford to give up some of its leaf biomass. If anthropomorphized, it may even be happy to contribute to the development of its neighboring soils.

Note that I have no intention of harvesting soil, just lightly raking up the top layer of duff. For clarification the regrowth forest is dominated by white oak, interspersed with pacific madrones. Douglas-firs dominate the climax forest.

it is well known as "duff" and it feeds all your trees and plants and animals of the forest..when you remove it you remove the food that feeds your forest..so yeah..I would say don't do it.

I guess you could "bury" some of it away from tree roots (which would be damaged by digging)..if you have fear of fire..this makes some sense..but the rotting wood feeds a lot of plants and animals. I have heard that a lot of animals and micro organisms will just move out completely and never come back if you start fiddling much with that stuff..so of course it is up to you but that is my opinion only

Quite often, it's possible to acquire this soil when a home is built or a road is cleared. Forests aren't generally sprayed with anything. Check out the history of the land before committing. For a few hundred dollars, you could get more good dirt than a decade of hand gathering would achieve.

I read recently that the biggest factor in Western forest fires has been the proximity of the trees to each other and not necessarily the forest floor growth. Modern "management" of forests has stressed fire suppression not only allowing more tinder to accumulate but also more trees. It is these trees which are the fire ladders. Photos from the 1800's show trees out west being much further apart. So , the natural cycle was for flash fires to burn of the floor duff and kill off smaller seedlings also . The heat from this floor fire was not hot enough long enough to ignite the taller trees and if one did it was not close enough to other trees to spread. I am not suggesting we use fire but maybe clear off some trees . Then clear the floor of smaller growth ala Jean Pain and put it to good use. The report I read stated that trees were more like 50-60 feet apart , not 10 feet apart as is now common.

Modern forest 'mismanagement' favors this close spacing.
It forces the trees to grow taller and straighter, in their quest for the sun.
This results in higher profits/acre for the owners.

Valuable timber trees, such as walnut, are planted at 4 times (or greater) the rate that would be used if they were being grown as a nut crop. The extremely tall growth that this forces, creates a straight grained wood which has tremendous market value.

Human greed trumps nature in most commercial forestry.

I would say leave the forest alone. Your Zone 4 area should be designed as a fire break.
Use the concepts posted by the US gov as a starting place "http://efotg.sc.egov.usda.gov/references/public/NE/NE394DP.pdf".

Not to hijack friend, but was kinda wondering about taking rotten wood from decaying logs, the whole HK thing. Am I robbing the forest to benefit myself alone?

I kinda figured to take a small percentage from a lot of rotten logs, if possible. Spread out any damage, take some, leave some.

Your question along these same lines, prompted me to ask. From you even thinking to ask about the duff, I figure you have your priorities straight.

Best, TM

Healthy ecosystems can withstand huge losses. You couldn't have a more sustainable green manure crop than a living forest. In England, many farms are replacing hedgerows that were foolishly removed to make bigger fields. The narrow hedgerows loose many leaves to the crop fields, but the new ones continue to expand and improve in volume and diversity. These narrow little forests indicate that leaf loss will not do much harm.

well out here in northern cal fire is a major concern, it happens quite regularly in the dry season, and i think its good for you to do some clearing. i agree also that the forest is a powerful and resilient entity, what you take out will be replaced by something else, but it is good to be careful and thoughtful about what you remove and use. with the leaf litter/duff you also get your local IMO s....which is really valuable to your garden.

this is kind of a small point, and perhaps some wont agree, but i think its a good thing for habitation to create some holes/enclosed areas. there are so many animals who love a good hole to hide away in, something like one of those trees thats dead and rotting and fallen already...if you clear out the inside part and the parts around it that are already rotting.... it makes a good mulch and also creates an animal hole/habitat.

i suppose most people arent neccessarily going for creating habitat for animals...but i have intentionally created some of these, then i get the mulch.
not sure what this could be called, i dont just mean digging a hole in the soil, but theres areas where the way the land is....you can clear out some kind of enclosed space, and animals really dig this (no pun intended=))

ahhh---->>>> i remember where i first got this idea, which prompted me to try it out.

this book was an excellent read, you might enjoy it:

The Earth Manual: How to Work on Wild Land Without Taming It

A forest fire can instantly set you back decades in soil building and forest growth. Any measure that can help prevent loss of the whole forest to fire is a good thing.

On creating habitat --- I have plunged the nose of my chainsaw into standing dead maples and filled the holes with peanut butter. Various critters dug it out and went after bugs that congregated to eat it. They left nice round holes that were occupied by nesting birds the following year. This is the fastest way to build a birdhouse that doesn't go through huge temperature swings like lightly built houses on a post do. The rotting tree provides lots of bugs.