New studies gauge impact and cause of beech leaf disease | Hacker News Reader

New studies gauge impact and cause of beech leaf disease

science.org

42 pointsmhb19 comments

In most forests in the New England and New York State areas that I am familiar with, it's actually nearly impossible to find healthy beech trees, and has been for decades. Beech bark disease kills mature trees over a period of years, and what's left is either smaller trees with significant scarring or thickets of sprouts (which we used to call "beech hell" since they are super annoying to traverse when doing field work). There are some beech bark disease resistant individuals and populations, as well as some isolated patches of forest where there are healthy beeches (and they are... magnificent). I haven't really kept up with the literature on beech leaf disease, but it leaves me wondering if this will potentially fully remove the unhealthy beeches. It would be interesting, in the long-term (is there a long term anymore?), if there are doubly-resistant individuals and if someday they may once again make beech a major forest component.

It's hard to watch beloved tree species disappear. It's very hard. I love these forests so much. But something I have seen time and time again -- is that life is resilient, and it's not like a barren wasteland takes over (at least here). I try to think what amazing solutions life will cook up next.

My background: I studied beech bark disease in Eastern NA forests back in the early 2000s, mostly working on modeling populations and the evolution of resistance.

Do you know if either of these diseases affect European Beech?

Yeah, beech bark disease was actually introduced from Europe, to Halifax in the late 1800's. (well, i should say, the insect part was. The mechanism is that the scale insect creates an opening for the native-to-North America fungi in the Nectria genus to infect the bark). So the disease has been around in Europe (with local Nectria infecting) for much longer and my understanding was that European beech has better defenses and was more resistant, thought not entirely unaffected.

Not super up on the leaf disease, but it does appear that European beech can be as well.

In Europe we have problems with the bark beetle (https://en.wikipedia.org/wiki/Bark_beetle) which can devastate spruce-monoculture forests.

Given your background I just wanted to mention I am very impressed by what this area of study was able to accomplish for similar issues in our forests. There was a heartbreaking few years when winter moths were destroying maples all over New England and as I understand it a mitigation developed at the UMass agricultural extension lead to them mostly vanishing.

I can confirm the spread of this disease in southern Rhode Island. My 1.5 acre lot has a magnificent stand of several very large beech trees and a number of smaller ones -- perhaps 50 trees in all. Beginning in 2022, all of them have been affected by this disease. The canopy in that area is effectively gone.

We lost seven beeches - most of the big trees in our front yard - to beech leaf disease. Talked to one guy who pointed out that there is a treatment, but it's experimental and it's not even clear it works. $2000 per tree per two years for a "maybe" was just too much. Plus, the longer we kept the trees, the more likely it would become that the culprit nematode would spread to other trees in our back yard or our neighbors'. Very sad, but the silver lining is that we're now a better candidate for solar.

How long did it take between when you first noticed something and the decision to try to treat and then remove?

IIRC it was a couple of months from "these trees don't look so great" to conclusively identifying BLD as the culprit, then one more to get a quote for the possible cure. After that it was just a matter of scheduling the crew to cut them down. That varies according to demand etc., but I'm lucky that I know the owner of the largest tree-service company in the area so for us it went quickly.

For reference, this article is from November 2021.

No mention if it affects fagus sylvatica (European Beech)?

This Wikipedia article says that it does:

https://en.wikipedia.org/wiki/Beech_leaf_disease

It does not provide a source but this Massachusetts government website that is linked in the Wikipedia article also says that European beech is affected too:

https://www.mass.gov/guides/beech-leaf-disease-in-massachuse...

It started on Japanese Beech (but only causing mild symptoms). It affects a lot of beech

Lost the chestnuts, in the process of losing ash and now beech. It’s pretty sad but it sounds like soon we may have no native North American species left.

And elms. Lots of US cities had streets completely lined with elm trees that were never replaced.

> [starting in 1928] The disease spread from New England westward and southward, almost completely destroying the famous elms in the "Elm City" of New Haven, Connecticut, reaching the Detroit area in 1950, the Chicago area by 1960, and Minneapolis by 1970. Of the estimated 77 million elms in North America in 1930, over 75% had been lost by 1989.

https://en.wikipedia.org/wiki/Dutch_elm_disease

Oak wilt is pretty bad around here too, though fortunately not so bad as dutch elm disease yet.

Don't forget the eastern hemlock, which is being decimated by the hemlock woolly adelgid:

> The adelgid has spread very rapidly in southern parts of the range once becoming established, while its expansion northward is much slower. Virtually all the hemlocks in the southern Appalachian Mountains have seen infestations of the insect within the last five to seven years, with thousands of hectares of stands dying within the last two to three years.

https://en.wikipedia.org/wiki/Tsuga_canadensis#Hemlock_wooll...

There is at least Laricobius nigrinus for HWA, which has been identified as a method of biocontrol.

https://www.washingtonpost.com/climate-environment/2022/08/2...

As many as one in six U.S. tree species is threatened with extinction

Some 100 native tree species could die out amid an onslaught of invasive insects, a surge in deadly diseases and the all-encompassing peril of climate change

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