Maryland's effort to restore hemlock forests

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#11)  Re: Maryland's effort to restore hemlock forests

Postby Joe » Sun May 15, 2016 12:55 pm

Gaines said, "Want to get depressed?  In NH, Ag. extension says, forget it, don't bother with any control method.  --and, this  !!  The hemlocks don't have enough value to make control worth the expense and effort!  Yikes!"

unfortunately, amongst most forestry people, the only value that counts is timber value- and it's true, hemlock is always near the bottom in THAT value- but, there are other values of course

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#12)  Re: Maryland's effort to restore hemlock forests

Postby jclarke » Sun May 15, 2016 5:54 pm

Are they not finding a few resistant individuals?  I read somewhere that some trees are resistant and they are rooting cuttings from those ones to establish a clonal seed orchard for local seed.
I can't find the reference right now.
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#13)  Re: Maryland's effort to restore hemlock forests

Postby jclarke » Sun May 15, 2016 6:00 pm

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#14)  Re: Maryland's effort to restore hemlock forests

Postby Will Blozan » Sun May 15, 2016 7:56 pm

Gaines,

Sorry for your internet headache regarding HWA. I can summarize it all for you, and have tried. A few more thoughts:

NO ONE has ever been able to separate winter kill from Sasi impact. EVERY release has failed south of CT. The CT "success" is not credible. They are no longer considered a viable control agent, at least south of a single CT site.

I have NEVER seen a restriction on a federal label for MD.

I can treat over 300 diameter inches with one injector full of solution (~3 quarts). A little goes a long way. The chemical cost of this single injector-full? <$20.00. We can do over 10K diameter inches per day easy- on easy access, dense forest.

Here is a Sasi release site.
               
                       
Kelsey Tract beetle failure small.jpg
                       
Green trees are imidacloprid treated
               
               

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#15)  Re: Maryland's effort to restore hemlock forests

Postby gnmcmartin » Sun May 15, 2016 9:11 pm

Will:

  When I was a freshman at Michigan State University, maybe the first class of any kind I attended was a class in my introductory logic course in the philosophy department.  I remember when the instructor first walked into the class room, he said, and to this day, I remember the words, I think correctly, "post hoc, ergo propter hoc." He then explained that this was a common fallacy, and that it has done much damage.  I see this all the time today, and it confuses all kinds of issues, and leads to all kinds of errors. The fallacy is reasoning that says that because X happened after Y, it was caused by Y.

  So, now you tell me that the supposed success of Sasajiscymnus tsugae is apparently an example of this classic fallacy.  So these beetles were released, and after that, there was a significant reduction in HWA.  Did the Sasa beetles cause the reduction? No, cold snaps did.  Wow!

  Well, so far, lots of people are convinced that the Sasa beetles are effective, including researchers in PA, in NY (Cornell) and Connecticut (U Conn). This IS very disturbing!

  Here is a something I found from Cornell U that is interesting, especially about the Leucopis flies, AKA silver flies:
-----------------------------

Releasing flies in Skaneateles, NY
Credit:  Mark Whitmore

New biocontrol agents targeting the invasive insect Hemlock Woolly Adelgid (HWA) were released last week for the first time in New York State. The two species of silver fly, Leucopis piniperda and L. argenticollis, are being imported from the Northwestern US, where they are the second most abundant predator on HWA in its native range.   Mark Whitmore, a researcher from Cornell University and a principal investigator on the project, hopes that these new flies will establish and, in association with other introduced predators (Laricobius nigrinus and Sasajiscymnus spp.), effectively control HWA populations.

This research project has been a collaborative effort between scientists from University of Vermont, Oregon State University, Penn State University, Cornell University and the Forest Service based in New Haven, CT. Collaborators in Oregon collect and ship materials to a quarantine facility in New Haven, where Leucopis predators are raised and then sent to release locations. Currently, flies have been released at sites near Skaneateles Lake New York and Tennessee.

So far the flies are showing promise for successful establishment at the Tennessee release sites. Researchers plan to continue monitoring survival and reproduction in bag experiments and survey for fly presence at wild release sites throughout the season.

Looking to the future, researchers are applying for the release of predacious beetle Laricobius osakensis (approved federally and currently in testing in Tennessee), and approval of several predatory lady beetles (Scymnus coniferarum, Scymunus camptidromus) may be in the works. HWA poses a serious threat to the health of forests across the Eastern US, where hemlocks cover approximately 2.3 million acres. HWA can colonize trees of any age, and their feeding causes dieback as leaves and branches to dry out and drop from the tree.   Severe infestations can kill a mature tree in as little as four years.
-----------------------------
 The silverflies are interesting because other articles I have read suggest they might work in colder climates--at least one person is touting them for the Adirondacks. I have also looked up the Scymnus camptidromus, and it is possibly something for colder areas also.

  As for Laricobius nigrinis--as far as I have been able to find, opinion seems to be that they are good for areas as cold as USDA zones 6A and 6B.  My timberland is, I think, in 5A, but I wonder if my very specific location could be colder than that.  Can you tell me that it would be worth releasing at my timberland? Or might Laricobius osakensis be better, if available?

  --Gaines
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#16)  duplicate??

Postby gnmcmartin » Thu May 19, 2016 2:03 pm

I see my last post was, somehow duplicated,  I can't, it seems remove the extra one so this "edit" is the best I seem to be able to do.

  --Gaines
Last edited by gnmcmartin on Thu May 19, 2016 2:14 pm, edited 1 time in total.
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#17)  Re: Maryland's effort to restore hemlock forests

Postby gnmcmartin » Thu May 19, 2016 2:06 pm

Will and hemlock lovers:

  My search for information on the status of biological control of hemlock Wooly adelgid may be, essentially, at a close. I have found much, at least, of what is available on-line, and talked to enough people to have a pretty good idea of the current situation. First, what Will has said is essentially the heart of the matter.  The best and substantially the only predator currently in wide release is the Laricobius nigrinis.  Other predators are on the verge of release, or perhaps (?) have been very, very recently released, but little is known about how they might perform.  While a few people in CT, NY, and PA still talk about the Sasajicymnus tsugae, the consensus is that evidence that it is an effective predator is lacking. Some, who have seen the lack of evidence, are reluctant to entirely rule it out as a potential contributor.

  My prior post included a bit of info about other possibly effective predators under study and planned for release, but it could be a good while before much is known about their contributions.

  Contrary to what I had read, and reported earlier about the limited cold hardiness of the Laricobius nigrinis, has been contradicted to some degree by personal communications I have had with the heads of the biological control efforts in both MD and WV.  Both individuals assure me that there have been recoveries of released beetles in the higher elevations of the Allegheny Plateau, but no observable reduction in HWA can yet be attributed to the activity of these beetles.  Both individuals have some hope for the future, and are continuing their work. Both MD and WVA are , cooperatively, working with their own strains of the Laricobius beetle, and there is no lab raising them for sale to the public. Will, do you know of a lab that might be selling a cold-hardy strain of Laricobius nigrinis to the public?

  One basic fact stands out about how devastating HWA can be in different locations--it is strongly site dependent.  Hemlocks on slopes with a generally southern exposure, and on soils more subject to drought, are most vulnerable.  The area just to the east of my timberland, where the hemlocks were very, very near death, may have a SSW exposure, but I have not measured with a compass.  Hemlocks in a stream valley only a mile or two away--as the crow flies--were much less severely impacted.

 I discussed with both men some "outliers" of apparently unaffected, or only slightly affected hemlocks I have seen far to the east of the Allegheny Plateau, and both men said that there is a lot they don't yet know about such places--a variety of factors could be in play.  There should be resources available to examine such sites, but no.

 The "biology" involved in the whole HWA predator work is extremely complex, and much of that complexity is not yet well understood.

  One problem is that it is very difficult to get approval for the release of any exotic insect in the US, and with the HWA program, extremely difficult, if not impossible, to get approval for any "generalist" predator that can feed on HWA and other prey, and thus sustain itself at good levels when HWA is much reduced by unusual weather events, especially extreme cold.  There are, or so I have been told, some "generalist" predators native to our HWA infested area and they do eat "some" adelgids, but they have no significant effect on HWA control. Perhaps in the future some predator already native to the area will adapt and make better use of this new food source.

  If we understand the large numbers of predators of HWA in Japan and the Pacific NW of the US, and understand that the hemlocks in those areas have some natural resistance to HWA, and realize that, in stark contrast, here in the eastern part of the US where HWA is rampant, we are relying, as of now, on one or a very few "specialist" predators, and have a completely vulnerable strain of hemlock, it would seem that the "picture" for our hemlocks remains bleak. But no one I talked to is "despondent" about future prospects. But then a part of their "implied" job description, is that they avoid despondency over the issue.

  --Gaines
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#18)  Re: Maryland's effort to restore hemlock forests

Postby dbhguru » Fri May 20, 2016 8:26 am

Gaines,

    Thank you for your in depth investigation of HWA. We feel your pain with respect to the potential loss of your gorgeous hemlocks. Attitudes toward the demise of the species here in New England have been super frustrating to me and not just from the predictable sources. I accept that the timber interests will always be indifferent to species that are not economically valuable to them, but the environmental organizations haven't been exactly on board with treatment strategies either. I'm very disappointed in the main stream environmental organizations on their unwillingness to even consider treatment.

   On a recent trip to the Adirondacks, I saw many, many healthy hemlocks of all ages. No sign of adelgid - but for how long?

   Here is an image from the old growth. Be sure to double click on the image to expand it.

               
                       
AmpersandRegionHemlocks copy.jpg
                                       
               


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#19)  Re: Maryland's effort to restore hemlock forests

Postby Joe » Fri May 20, 2016 9:42 am

Bob (once known as Burl-belly) said, "I accept that the timber interests will always be indifferent to species that are not economically valuable to them, but the environmental organizations haven't been exactly on board with treatment strategies either."

True in that foresters and loggers must as part of their work- strongly consider economic value of species, but that's not necessarily bad. If forests in the past have been high graded, leaving mostly poor specimens and low value species- it's our obligation to "improve" the composition of the forest by encouraging the revival of the higher value species and better specimens- that were, often, the dominant species on that site in pre-pale-face days.

Reading one of the articles mentioned in another thread- it said hemlock was extremely common in the Northeast in those pre-pale-face days since it's very shade tolerant and will make up part of a late succession forest. Though the current forestry party line is to cut heavy because it's great for wildlife (especially browsers)- I have no doubt those ancient forests with many big/old hemlocks were a very rich habitat both for their seed production and for the dense cover they provide in snow storms or in heat waves. For some reason, our current forestry/wildlife "leaders" fail to mention that. Oh, and we mustn't forget the work of the wildlife biologist Lynn Rogers who explained that momma bears like big, rough, branches to the ground hemlocks because their cubs can climb them. I never see THAT fact in establishment forestry "literature" and "science".

I'm currently marking a stand in north central Mass. It was high graded about 40 years ago. All the weeviled white pine and all hemlock and all poor quality red maple were left- all the good white pine and oak were cut. Under the weeviled white pine, grew a dense understory of hemlock and amazingly, some nice oak with maybe one every 75' or so. So, that high grading logger made out like a bandit (with permission of the state and forestry organizations)  and now I have to earn my bread trying to manage this low value stand with little likelihood of producing economic value if left alone. So, my strategy is to cut fairly heavily - not for the phony justification of browsing wildlife, but to bring the stand back to what it might once have been- with large, healthy, straight pines and oaks and some hemlock. I'm leaving what mid size unweeviled pines there are, all the oaks and a few hemlocks per acre to add diversity. Those pines and oaks should reclaim the stand and I think the regeneration will be a mix of pine and oak and not so much hemlock.

We all like old growth forests and huge specimen trees- but the vast majorty of the forests don't qualify that way. It's the job of honest foresters to turn around the damage done by the wood industry over centuries- and to do this "good work" we must have to live with low income. It would be nice if more people could appreciate such work. It's not easy because the benefit won't be noticed for decades- often several decades. Neither the wood industry nor the enviros seem to appreciate what good silviculture can do- and as a result, we still have bad laws on the books in most states.  The enviros fight to protect wetlands and rare species and to get more reserves- the industry fights to retain its right to high grade! I only wish I could see some of my work several decades from now, but that's not very likely- so I have to resort to a rich imagination.
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#20)  Re: Maryland's effort to restore hemlock forests

Postby gnmcmartin » Fri May 20, 2016 2:50 pm

Bob and Joe:

  During my search for information, I found a lot about the "inner complexities" of deciding on which predators to study for possible use here, and that included a lot of things unrelated to possible environmental disruptions they could cause. For example, there must be some interactions with the environment, including other insects and other "life," that has caused the Sasajiscimnus beetle to fail, at least in most regions.  It eats adelgids, reproduces very effectively, etc., etc., but over time, released beetles just seem to disappear, or at least can't be recovered.  Why?  We just don't know. or, if someone knows, that information is not on-line, and no one I talked to knows.

  My guess is that we just don't know, and that brings up a big problem--funding for people to study the issue.  OK, this bug failed, let's move on, but on the other hand, if we were really willing to make a commitment to this biological control effort, we should find out, and that information could be very useful.

  The program directors for both the MD and WVA programs told me that their funding has been reduced recently.  Of course, some of the sophisticated science may be a bit difficult for some people to understand, and decide to fund, but even on the level of beetle collection and release, there seems to be little interest in making the kind of effort needed.  In MD, they have their own program of collecting and, I think, growing beetles, but they can only get enough for  small releases at the most high priority sites, and only those in State ownership.  I explained the beauty, and especially the ecological value of my hemlock forests, with the wetlands, beaver ponds and meadows, and the streams.  Clearly my timberland has special ecological value, and the people I talked to agreed, but, they said, sadly, no funding.  I explained I would spend a lot of my own money, but then, no beetles, and no staff to help me monitor.

  Beetles these days are not always raised in labs in artificial conditions, but in "insectaries," which in the case of HWA, are plantings of hemlocks which are then infested deliberately with the HWA, and then beetles are released on them to feed and reproduce.  One of the men--I can't remember from which state--said that a lack of funds has caused them to abandon the use of any insectaries for beetle raising. Many of the beetles used are simply collected "in the wild, and that also requires staff/money.

  Maybe the highest priority would be the discovery and study of new possible predators, but this work can be very expensive, involving highly trained entomologists, and travel to Japan and China, in addition to our own Pacific NW.

  In some of the articles I have read, Hemlock is described as a "foundation" species.  I did not look up the exact definition of this term, but the context seemed to make it clear that hemlocks are the essential element in some forests that gives them their special ecological "character" and value.  In other words, remove the hemlocks, and the forest becomes something entirely different ecologically.  I know that ash trees are very important, and removing them from our hardwood forests results in a real loss, but, that removal, unlike the removal of hemlocks from some forests, will not drastically change, or destroy the ecology of the forest, including that of the streams and wetlands, to anywhere near the same degree,  Our hemlock forests have a very, very important and unique ecological value.

  I am, to my core, stunned that a much larger effort is not being made.

  --Gaines
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