Larch and iWraps

[Scooter]

[Edit, December 15th, 2016: This thread was just created as a split of a conversation from the 2017 Public Bid Results thread].



Time for a short rant:

Why are foresters including Larch iWraps on so many projects this year? The only two times that I brought up questions about storage temperatures, the foresters DID NOT UNDERSTAND what I was talking about.

iWraps are frozen stock. The bundles are wrapped differently than conventional bundles, because a convention bundle, if frozen, has a problem in that all the seedling plugs stick together due to the moisture in the roots. iWrap stock is delivered to the field frozen, and when the bundles are unwrapped, it is a longer plastic wrapper that contains every single seedling in an individually wrapped portion. The planters bag up with the trees while they're still frozen, and plant the stock while it's still frozen. The rationale for this practice is that it becomes impossible to j-root a tree when the plug is frozen. The drawbacks are that there's a bit more plastic waste (minor), a bit more time required for bagging up (minor), additional stock-handling logistics (significant), and much heavier loads for the planters (significant).

Let me be clear here: Foresters are mixing prescriptions on blocks to include both iWrap (frozen) stock AND conventional (thawed) stock on the same blocks. I have seen this on probably half a dozen contracts, not just two.

This type of stock-handling requires TWO separate reefers on site, one set to sub-zero temperatures, and one set to the regular temperature range of 2-4 degrees above freezing. Does this not strike people as asinine?

[jdtesluk]

The only thing asinine is if the people taking on the jobs (both contractors and workers) are not properly compensated for this additional and cumbersome increased step in the productive process.

Imagine if I had ongoing contracts for building houses. Then I start demanding from my framers that they use two different types of nails. Specially magnetized and individually wrapped nails for use around key electrical systems, and regular nails. They have to be stored in different boxes on site. The framers will see no real difference in the individual nail, other than the inconvenience of their handling.
Hot chance in hell of me slipping that into the framing job without seeing some type of fee increase.

[Scooter]

I just got an interesting email, in response to my larch comments. Reprinted with permission:

Regarding Iwrap Larch, they are very much in use in southern B.C. and have been for a number of years. Nobody requires separate reefers for them. Generally they end up getting planted partly thawed. This is however better than planting them fully thawed as Larch is susceptible to early bud break or "flushing". The new buds being succulent are easily damaged or knocked off by planters. It's a win win situation for the most part. It's easy to hold them frozen when submitting a thaw request. A component of frozen boxes in a shipment keeps the whole shipment cooler and it makes it harder to j-root the trees, although this is an unanticipated plus. The whole idea really came from trying to keep the trees from flushing early.

PRT's thawing and handling guidelines says - "Larch species must be planted immediately upon thaw, as they will flush in the boxes very quickly."

A study by Kooistra & Bakker concluded;

This study demonstrated that seedlings of western larch, lodgepole pine , and interior spruce are tolerant of being outplanted with frozen root plugs. Packaging seedlings individually before frozen storage and removing the thawing stage from the seedling production process would provide significant operational advantages with respect to cold storage management, coordination of transportation to planting sites, and the logistics of planting operations.

This assumes that all species would be planted frozen. Here’s the study.

http://library.eri.nau.edu/gsdl/collect ... ir/doc.pdf

[jdtesluk]

It all makes total sense. Anyone that has planted larch, knows how flimsy the seedlings can be. We all want good trees.

However, to say it is a win-win without considering the people actually planting the tree is misleading. There is no way that the advantage of an albeit easier-to-plan half-frozen tree outweighs the inconvenience of unwrapping each individual seedling and dealing with the garbage. There is no productivity balance point here. The seedling system is good, but it makes it harder for the worker. Unless the licensee ordering this stock is somehow paying out additional money that somehow makes it through to the hands of the people doing the work, this is a burden on the worker and contractors. Thank goodness it is generally only a small percentage of trees. One may also rightly ask if workers will simply unwrap all their larch before bag up, or adapt their handling of them in a manner that works against the goals of stock-protection.

Warning: Amusing larch story to follow

I was a rookie-ish worker (at some point, yet it's true) working in Silverton. I hadn't seen larch before and we were doing 5 or 6 different species with mixed bags and 10% larch. Some of the stock (all species) was pretty ratty and there were some mold issues. My foreperson at some point said to cull the really really bad ones. No use planting a dead tree.
Close to the end of the day, I say "These larch are just terrible. I've had to cull almost a quarter of them!"
She's like "You did WTF?" Then she explains to me how larch work, and the lack of greenery on the seedling is normal. Ooops. Honest mistake.

Best thing about larch, is seeing them 15 -20 years later after you planted them. Recently during the autumn season, I toured some areas I planted in the Spillimacheen (Columbia trench) . The teenage larch were all lit up like gold amidst the evergreens. Spectacular sight. Like watching your kids up on stage for a the school play.

[Scooter]

Two photos of larch taken last month, just as the right time to catch them starting to yellow, a few weeks before the needles dropped off.

[jdtesluk]

I did a bunch of surveying this fall and the growth of larch was exceptional, four year old trees were over two meters tall. I wouldn't be surprised if we start seeing more of it in the future.

I have heard from foresters, that this growth really tapers off after the first few decades, and larch don't necessarily yield superior trees (i.e. caliper) in the long run. If this is true, one may wonder why they are increasingly selected.

[salbrecher]

Scooter, feel free to move this lw sidetrack to a new thread if it is clogging up the OP.

I happened across an article on Lw, Pli, and Fdi mixures this morning in regards to fire origin stands however similar principals would apply to planted stands. See excerpt below.

" DEVELOPMENT OF PL, LW AND FD MIXTURES
The US Forest Service website describes Pl and Lw as early seral species that often compete after fires. Pl will perform better on the drier or more exposed sites, but Lw will out-compete the Pl on other sites. They describe Lw–Pl stands with as little as 10% larch that eventually become dominated by Lw. This is similar to what is being observed on TFL 59 following the 2003 fires (Thrower 2013) where Lw are the tallest trees in high density mixtures of Pl, Lw, and Fd. On the one site where Lw is leading, 10 years after the fire the tallest Lw are about 50% taller than other species.
Lw is a fast growing pioneer species that often outgrows other species in terms of juvenile height growth. Parent et al. (2010) state “One of larch’s greatest attributes is its rapid juvenile (i.e., first 20 years) height growth. This rapid growth quickly gets the seedling above competing brush and other associated tree species so it can get control of the site. While sufficient upper-soil moisture is necessary to enable this growth, its fast growth enables its roots to penetrate lower water levels, sustaining it during periods of drought once it is established.” Owens (2008) states “Very rapid height growth, equal to or better than its associated species, occurs in western larch until about 12 years of age. It then maintains a comparable or better growth rate than many associated species.”

The species commonly associated with Lw in BC are Pl and Fd. The developmental patterns of such mixtures are strongly influenced by the pattern and magnitude of the height-growth trends of the component species (Larson 1992, Oliver and Larson 1996). Usually Lw has a height-growth advantage over both Pl and Fd. Lw reaches breast height 1-2 years sooner than Pl (Nigh and Everett 2007) and the site index of Lw is usually 1m-2m higher than Pl on the same site (Nigh 1995). There are additional differences between Lw and Pl in the pattern of height growth. They exhibit similar growth up to about age 50, but after that the growth-rate of Pl declines relative to that of Lw (Schmidt and Shearer 1990). The advantage of Lw over Pl will persist beyond 100 years (Schmidt and Shearer 1995). In summation, we should expect Lw to grow faster in height than Pl, and if Lw does get ahead it will say ahead for at least the first 100 years. If present in sufficient numbers, Lw will dominate mixtures with Pl."

In addition to its rapid establishment that reaches free growing heights quickly, planting of lw has also increased as it is identified as a species that will have an expanded range with climate change and for some years now the ministry has approved the planting of Lw in these areas. Planting mixed stands can potentially reduce risk if one particular species is impacted by a pest or disease. A fdi Lw mix will still leave one species on the site if the fdi are killed by budworm or fir bark beetle etc.

In my experience the growth tapers off after a decade or two but it still stays on a higher growth curve than most other conifers.

[jdtesluk]

Great insight from an actual forester. Thanks SA. I attended a presentation on species migration with Sally Aiken at UBC. Her work, and that of others, suggests that larch will play a major role in the future of the province's forests. Imagine vast swaths of forest turning gold in the autumn. That and the carpet of golden needles. Could be quite the sight.Personally, I'm looking hard at some larch flooring right now. Nice looking stuff.

It's particularly encouraging to see the reasoning behind the advantages of mixed stands. Who knows what pests and blights the future may bring. Again, great post.

Back to the plastic wrap...You know what would be great? Some type of biodegradable wrapper! I wonder if it is possible to use some type of film or coating to protect the plug, that will rapidly breakdown, particularly as temperatures increase, so that the plugs maintain their integrity. This would reduce plastic waste and reduce productivity impacts on workers. Perhaps such an idea could have wider applications. Just a random thought.

[salbrecher]

Glycerol applied to plugs to eliminate wrapping has been tried at a few different solution levels and was effective in allowing seedlings to come apart at or around -2 to 0 degrees Celsius (Glycerol lowers the freezing point). The glycerol unfortunately seems to have a negative impact on seedling survival at certain concentration levels however this varied by species. Likely not an operational "solution" due to negative effects and not all species would be able to be treated the same (some species wrapped some not).

Perhaps biodegradable plastic would be the easier solution.

On the iwrap/productivity side, I would be interested to know what planters who worked on longer contracts where 100% frozen stock for all species was used thought of it. I had heard that planters became accustomed to it and actually preferred it once they switched back to contracts with non-frozen stock.

[jdtesluk]

I had originally proceeded on the assumption that the wrapping/unwrapping process would take more time than the advantages of the better plug, and considering the reefer demands (which may be overstated). This was certainly an assumption, and a reaction to another poster's assessment of the issue. It was not based in any reports from the field......and I may indeed be wrong in my assessment of its impact on production.

It would be a difficult thing to measure. You would have to control for intervening variables, and it would be difficult to make contract-to-contract comparisons when you consider all possible impacts on productivity. However, you could time distinct steps in the process. Time bagging up with wrapped larch vs without. Then time planting of (x) # of wrapped larch vs planting (x)# of flimsier unwrapped larch. Then weigh the differences against each other.

In the end we may be talking about nickels and dimes, and the cost of a coffee. Perhaps not worth the rigamarole of such a study when the actual percent of prescribed larch is taken into account. One may suggest that if the burden of single-wrapped larch is really a major problem to contractors, they may start asking licensees to divulge the number of such trees during bidding (similar to the way fertilizer teabags are identified). Then they would adjust their bids accordingly IF they actually think it makes a difference. In this respect, let the market sort it out.

Frozen plugs are interesting. Frozen plugs without individual wrapping are tricky. If they come apart easily, they are great to plant. If they stick together, you have a problem. Workers may mangle plugs that stick together, or try to thaw them in novel ways. There is also the consideration of weight, but I would expect a properly frozen plug does not present the same problem as an over-watered thawed plug.

(Now facetiously)...if the plugs are frozen, how will that affect workers? Will it freeze their hands, and require the development of heated gloves? Or will it have a beneficial effect by providing ice-therapy-on-the-go as a pre-emptive treatment for tendonitis?

Again, it is very refreshing to have input from a forester here to shed light on some of these issues!

[ryguy]

I've worked the last couple of seasons on contracts that had frozen pine as a major component. The biggest issue for myself hasn't been the unwrapping, but the extra weight, caused by all the water retention. On top of that, you can't compress the seedlings, so you have to take smaller bag-ups, which can create logistical problems, forcing you to do a lot more walking.

[salbrecher]

The weight would have more to do with how much rain there was before they were lifted. A wet plug weighs the same as a wet frozen plug. The frozen plugs are not watered differently than non frozen plugs.

Ironically, not being able to compress plugs and water retention in the plugs are reasons why frozen plugs are desirable from a stock handling point of view.

[legoman]

They weigh the same at the start according to science. But the frozen plugs always seem to weigh more. Why?? Do the nurseries water them before freezing to protect the root hairs like a frozen mastadon which is better to be encased in ice than frozen and exposed to air?? Does some water evaporate from thawed stock in the week before it gets planted, which cannot evaporate from frozen plugs?? Has anyone done a study to compare how much boxes weigh??