In regards to whole tree harvesting, which is very common in this area and makes up half of my jobs. does any one know of and any studies which show it having an negitive impact on soil health/productivy I've heard so many conflicting opinions about this and Iam intrested in seeing some data(if any exists). One group (foresters) wants to see very last twig loaded and headed to the mill (biomass plant) and the other thinks most of the top should be left were it falls. Anybody have anything?
Most of the Foresters I've spoken with, leave the fines in the woods. The big argument generally comes from the Pine Straw harvest, not the chipping operation. Even if you chipped everything, you would probably leave enough fines (twigs and leaves) to add nutrients back to the soil.
Research in Germany has shown that if all the biomass is removed, like in harvesting all the limbs and twigs constantly for firewood, that after many years, year in and year out, nutrients loss results in a loss of soil productivity and tree growth. However, this is intense removal.
Whole tree chipping once every 40 years or so may have a small impact. You would have to do it over and over again for many decades and centuries to make a large impact, and that is not likely to happen.
There are not many nutrients tied up in the wood of a tree. The nutrients are tied up in the leaves/needles, and these fall to the forest floor and are recycled. That is the issue with repeated harvests of pine straw.
Whole tree chipping using a flail to remove limbs and leaves/needles would not a significant concern. Again, it is the constant removal of the leaves, needles, and twigs that mounts up to cause a problem.
Here's a study:
http://smallwoodnews.com/Docs/PDF/Utilization/LoggingResidueReport.pdf
If you put "whole tree chipping nutrient loss" into a search engine, you'll get a lot more.
It seems that the ones I scanned say that there is nutrient loss if you take the fines and the foliage. But, each site is different. Intensity and time of year also have an impact.
Thank you for the input. The smallwoodnews.com paper was a good place to start. It appears that this issue is typical of so many things in forestry- nothing is black and white. Each site and objective is different- in the end some sort of happy medium is most likey the right thing to do.
NC State was doing a long-term research project that was wrapping up when I was there (in 2006). It was being conducted on some IP land in NC. The study started 30-40 years ago and was looking at a few different things. One of those was whole tree harvest vs. taditional harvests. They measured the current forest conditions including tree hts, BA, diameters, etc. Then they harvested different sites using each method of harvest and recorded the volumes from each.
After the cuts were made they replanted each site with loblolly. Each site had a different harvest method, site prep, and some sites were herbicided and some were not. They were looking at a couple of different aspects of forest practices and their effects on the next generation.
I did an undergraduate study poster on the effects of the litter fall that was collected one year before the final harvest in 2006 - 07. I noticed no significant differences in the litter accumultion from similar sites where the only difference was the harvest method. That is important to note since trees often put a lot of nutrients into their leaves and that is where food is made.
I think the professor in charge of that was Dr. Lee Allen with the NCSU School of Forestry and Nat. Resources. He was also my Silviculture professor and the Director for the Forest Nutrition Coopertive. Dr. Allen would know more about the over all results of the study. I only focused on litter fall.
You can find is email on the College's website http://cnr.ncsu.edu/fer/ Just look under Faculty and Staff. His email should be on there. Or if you would like I could contact him with your question. Just let me know.
The US Forest Service and the Canadian Forestry Service has done a number of Soil Poductivity studies in regards to logging methods on different land and soil types around the country. I was in charge of implementing such a study with Research on the Huron National Forest when I worked on the Huron-Manistee National Forests in northern lower Michigan.
As Ron W said, there are different impacts on different ecological land types and soil types. Total tree harvesting was not normally not allowed on the dry sterile, mesic soils of the Huron Forest. The number of repetitions of such a logging practice on a site was also a factor as stated above.
I remember having this question on my silviculture exam. Like 240b said, this isn't a black or white issue. It depends on the the species; it depends on the time of year; it depends on the nutrient you're talking about; it depends on the soils; it depends on the time frame; it depends on who you're working for or who's funding the study :-\.
that is the conclusion I've come up with.
One thing I have found with whole tree removal is that the damage to soil and leave trees is much less as the branches seem to hold the trunk from compaction and associated gouging of the skid trail. Also, even without chipping the entire tree and one does all of the log trimming at one landing, you could chip the slash or burn depending and all of the slash is in one location. Makes alot more sense to me than trying to pile and burn out in the leave stand.
Weyerhaeuser down here whole tree harvests and aerial applies prilled fertilizer with SEAT's. Now that is taking care of business. They normally use our helibase area at the airport and so the Forest Service gets blamed for herbiciding the forest. As was mentioned earlier, a lot depends on the circumstances - some of the whole tree chipping we've done leaves so much needle fall on the site I doubt any change will occur on productivity for several entries. Even whole tree chipping leaves material non usable for chips, we normally have the skidders relocate that material back out on the skid trails. We follow up with a burn 6 mos to a year afterward to release nitrogen back into the soil.
Quote from: pappy19 on December 17, 2009, 10:44:04 AM
One thing I have found with whole tree removal is that the damage to soil and leave trees is much less
I've noticed the opposite. UP here generally the machines drive over the tops and slash so that they hardly even touch the soil they just drive on the "mat" of debris. When they do whole tree harvesting operations the slash is removed, therefor the machines are forced to drive directly on the soil. Noticed the last timber sale I inspected (whole tree harvest) that there was much more impact on the soil compared to driving over the tops and slash.
240b,update your profile so I know where "in this area" is. I have no idea,but some outfits do a little both around here.I went on school trip and they was doing both.I think most of the guys that I see around here do logs and pulp,no chips.But 2-3 hours north is differant.Can't be much money in chips because not many are doing it here.I'm only 15 minutes from a bio mass plant and don't see hardly any chipping operations.I see alot of trucks coming form the North.
Quote from: chevytaHOE5674 on December 20, 2009, 07:51:20 PM
Quote from: pappy19 on December 17, 2009, 10:44:04 AM
One thing I have found with whole tree removal is that the damage to soil and leave trees is much less
I've noticed the opposite. UP here generally the machines drive over the tops and slash so that they hardly even touch the soil they just drive on the "mat" of debris. When they do whole tree harvesting operations the slash is removed, therefor the machines are forced to drive directly on the soil. Noticed the last timber sale I inspected (whole tree harvest) that there was much more impact on the soil compared to driving over the tops and slash.
If that's the case, then what do they do with the slash after it is run over so many times?? Do they pile it after harvest and then burn or what? Again, if skid trails are "loggers" choice, the skidders generally take a different trail from each tree, or the shortest distance to the landing. This method usually makes for a limited effect on soil compaction. Soil scarification isn't bad, but compaction is very detrimental to recovery and adds to water/erosion velocity.
They leave the slash in the woods after its been run over on normal log/pulp harvesting. It rots away and adds to the soil over time.
pappy,I had my lot cut and he did a nice job.Did not take the shortest route or make a mess with the slash.There was some places they did not run over the slash.A few more cut with a chainsaw will lay the brush down on to the ground.He stayed to the main trails.Some are going to forwarder like what he used.The lot next to me was cut off with a skidder.I would of kicked him out if they would of done what they did on his land.Run over small marketable trees and bark up others and just leave them.This guy use to run a skidder all the time.He does have one for the hard places,he used it on my land.I watched him cut for 20 years and every lot that I saw him cut looked good.I don't what you to think skidders make a mess,operators make the mess.A good,clean,pretty job can be done.I told the guy that cut my lot I would kick his ass of my land if he made a mess and he knew I meant it.I checked on him daily,not that I needed too.When I went to ask him about cutting on my land,he was on paper company land.He was moving brush,by hand,to make a road for the forwarder to ride on so it would not sink into the soft ground so much when I saw him.He had no idea I was there.We need more like him.
Any trees that are cut for logs,the slash is left in the woods.Around here I have not ever heard of any burning of the brush in the woods.
Burning of the slash/ brush is used in the west. The slash will not rot quickly and turns into a fire hazard. So, to mitigate the slash needs to be disposed of, chipped ($$), piled and burned ($) or lopped and scattered with a possible burn the next year or two.
With the different forest types and conditions no one way works for all of us.
Not just the West, we burn about 30,000 acres/year here and maybe 25% of that is post harvest burns. Everything from seed trees to first and mature thinnings. Sure makes the place clean up good.
Quote from: chevytaHOE5674 on December 20, 2009, 07:51:20 PM
Quote from: pappy19 on December 17, 2009, 10:44:04 AM
I've noticed the opposite. UP here generally the machines drive over the tops and slash so that they hardly even touch the soil they just drive on the "mat" of debris. When they do whole tree harvesting operations the slash is removed, therefor the machines are forced to drive directly on the soil. Noticed the last timber sale I inspected (whole tree harvest) that there was much more impact on the soil compared to driving over the tops and slash.
In my dealings with loggers (mostly in the south) everyday I inspect I have to ask to please take the slash in the woods and spread it on the trails. But they give me a sad story that it costs them in fuel and time to do so. I usually get a halfA$$ed job of it. Most of them would rather leave it on the deck. Down here in FL the problem with not taking the slash and spreading it on the trails is that if it rains, the is shut down for a day or more b/c of rutts. If the logger had taken the time when it was dry to spread the slash on the trails it helps prevent that. And doesn't help to fill in the rutts with slash after you have a 2-3 ft hole/ditch in the ground.
That's one of the reasons why I don't allow tree length logging on most of my jobs. ;)
If it's a clear cut, I like trails stuck to, so regen isn't destroyed. Nothing burns me more to see a fully stocked understory destroyed by machinery going every which way imaginable. I've seen spruce take a hold in (regenerate) those old skidder trails better than when trees are forwarded. All I seen all summer was either bare forwarding trails that had to be planted, or forwarding trails with nothing but pin cherry and raspberry bushes. Slash is never much trouble here, it's all gone in 10 years. Even from brush saw work, 10 years and clean as the floor. The best maple and yellow birch regeneration I've seen around here on hardwood clearcuts was after the wood was twitched by skidders. And extremely thick, often times two layers of regen. The advanced ones already there, and from the newest seed that fell. ::) One guy tried to convince me his processor would protect the regen. When he was done fishing around to find the buts of every tree with that felling head he had 80 % of the softwood regen chewed up. It wasn't little 1 foot regen, it was advanced.
Due to our reliance on mechanized logging here we almost always have "pull through" delimbers on the landings; I only know of one saw crew still left in the woods. Either Belsaw or Hydro Axe harvesters, the biggest skidders you can get through the woods, pull through delimbers and four bunk trucks. Production has to be high to make any $, lots of steel on the ground and diesel guzzling utensils working. Back in Colorado we had a side that used a "danglehead" delimber and one using a "stroke". Seen more "strokes" in Oregon. I haven't really seen any more damage from whole tree than CTL's. We can argue over skidder passes on the ground (compaction) vs damage to residual trees, but using "bumper trees" along the skid trail and then cutting them last seems to work well.
Swamp, our clearcuts don't got no regeneration, wait a couple years and we do. Very little clearcutting, mainly seed trees and either first or mature thinnings. Limits on regen area sizes prompts more attention to thinning the stands. We log hardwoods here too, only district on this Forest to do so. It's either mark and sell it or herbicide it and let it die and fall...... Makes sense to me to sell it. I had some "push back" right after I got here due to a reluctance to sell the hardwood - some didn't think there was a market for it. I always eat lunch out back on the picnic table during the summer and I kept seeing all these "brush piles" going down the road/highway. Somebody thought hardwood made a good chip - now, so do we........ Just different merchantability specs for the hardwoods - as one would expect.
It sounds like many foresters here are having a hard time getting high quailty work done in the woods. It is pretty standard to haul slash off the landing and not drive thur the regen here. (vt) Most of the bad apples have left the woods here in vt. Also, I've seen pretty crude work accomplished with horses, farm tractors, dozers, forwarders,skidders (big and small). IT boils down the operater in the end. The damage you cause is your legacy. I work with in 10 miles of my home ( average 3 miles ) so people know what I do. I don't understand people willing to trash their land for a few extra $. Takes all kinds I guess.
im not big on te idea of ctl loggin w a cable skidder . w a fowarder or prehauler maybe but def not w a skidder
Timberjack,
When you say CTL are you talking about CTL in the woods or on the deck? TL or CTL: doesn't matter if you are skidding the whole tree to the deck anyways. If you mean CTL in the woods the best way, in my opinion is with a forwarder. But of course, I'm young and have only seen one operation using a forwarder.
Most loggers around here (FL) will merchandise for both. When I cruise I look for what would give me the best profit based on the prices I get at the mill. Thats the way it was when I was in NC as well.
Most woodlot logging here is by cable skidder and mostly clear cuts or usually what's left should be cut to. A handful of processors, but usually grapple skidder with them. Tree length usually. Some CTL, but very small volumes here and there. The wood isn't worth enough with high stumpage being paid.
My jobs are 99% cut to length at the stump. Forwarders remove the cut products.
Just driving by a couple logging operations here today and they were all skidder. Mostly aspen and fir being harvested. The markets are tree length for pulpwood. I saw 3 other skidders sitting in yards, one guy has 2 John Deeres. One operation up the road is using a farm tractor, skidding tree length into the field, but very slow going and small volumes. Loads are send out by straight truck, maybe once every week or two, owner of the farm is cutting it. He owns a lot of land and doesn't even make a dent in the amount of wood he cuts.
It comes down to the company operations and the on the ground work. We whole tree chip in the bush and haul the hog fuel to town for the power boiler if it is within the sweet spot (75 km haul distance). We also have a down woody debris requirement under provincial legislation as well leave 15 % retention left standing across the landscape on average. On top of this, there is understory protection measures put in place for young spruce in our mixed aspen/spruce stands, as well, if there is a lot of spruce in a block, and our retention left resembles what was previously there, them spruce will be left standing and a few extra aspen/poplar trees to help keep them windfirm.
Check these pictures out and see what you think of our operations as it relates to soil quality.
http://www.dmi.ca/about_dmi/dmi_in_alberta/prpd/media_gallery/criterion_1/ (http://www.dmi.ca/about_dmi/dmi_in_alberta/prpd/media_gallery/criterion_1/)
My opinion: lop/scatter tops to retain fixed soil nutrients. Burn to control fuels. Underplant to encourage uneven-aged/sized stand structure. Thin with an eye to both frequency and patchiness. Avoid clearcuts at all costs. Avoid scarification as site prep at all costs. Take the long view of land management rather than worrying about stockholders. Listen to the permie weirdos when they make sense.
We don't have trouble with regen, so under planting isn't an option. Mostly, the understory is fully stocked with shade tolerant species. Fir, cedar, maple, beech, red spruce. Certainly can't plant pine or oak in under, won't live, and will be browsed to death by hare. Even spruce regen get hit hard. They will find and nip about any spruce unless a thicket of fir is growing up around it or the spruce is thick like dog hair itself. If thick, a few browsed ones don't matter.
http://www.treesearch.fs.fed.us/pubs/4259 (http://www.treesearch.fs.fed.us/pubs/4259)
Dr. Tat Smith...he's at the University of Toronto. He specializes in studying the effects of timber harvesting on forest soils, and asking "what is sustainable forestry?"
One of our biggest successes here is clearcutting that was done 15 - 20 years ago, planted to improved loblolly (shortleaf sites) and we are now thinning and getting 8 - 10 Ccf/acre removed and still leaving 60 - 70 sq ft. Our Forest Plan has since changed so we can only plant shortleaf back in regen sites (mainly seed trees, 5 - 10 sq/acre leave). Still very effective in pine & pine/hardwood lands. Only clearcutting we can do is in plantations of at least 35 years old and loblolly pine. Nasty lob, only thing it's good for is growing timber - fast!
Just so I am clear, what are you calling a plantation, a cut block that was planted or a filed converted to trees? Sometimes this gets Grey, especially when you start talking FSC and certification.
Our plantations are regenerated clearcuts (as in previously timbered). Plantation = trees in a row, all of the same age class. Can also happen in seed trees but not as spatially attractive (to me, anyway).
ncsuclell
i dont know what you mean by takin them to the deck. we cut the tree down top it out lop the tops drag 3-5 at a time to either the pile or a slasher . theyre sawed apart and contract haulers keep them hauled to the mill that were contracted to. we dont cut them int eh woods unless we cant get em out or there to big to pull. that was i was saying tho ctl in the woods should only be done with a fowarder not a skidder like some ppl try to do.
if you figure on cuttin 15 triaxle load a week around here and you have to saw em apart inteh woods and skid em w a skidder you kiddin yourself.
all the loggers around here pull the whole tree only way you can make any money around here. the guy i used to work for wnated me to measue out y tree and cut the crotch out of em in the woods makin 3 peices instead of 1 which ties up more chains so you get less done all to leave a 3 ft block of wood in the woods. that didnt fly w me