Software
Houzz Logo Print
rockman50

Dead Oaks

19 years ago

Now that the forests are in full-leaf, it is easy to spot the many victims of repeated defoliation by those nasty foreign invaders (winter moth, gypsy moth). Large numbers of oaks are now dead in the interior parts of SE Mass. I feared the worst last August/September when huge numbers of oaks made a valient effort to leaf-out again but then gave up, and the leaves turned brown on the trees. I hoped that perhaps the trees were not truly dead. But alas, they are indeed very dead. The areas around Lakeville and Freetown appear to be particularly hard hit. For those of you who know the area, if you drive along route 140 in those communities, the oak mortality in the forest is 75 to nearly 100% in some stretches. Also, I have seem some unlucky homeowners with large numbers of dead oaks surrounding their homes. Gee, I wonder how much it will cost to remove all of those dead trees (many many $1000's???). Now I know what it must have been like earlier in the century when the chestnuts rapidly died off. I sure hope the state gets this problem under control. For what it is worth, I haven't seen too much defoliation damage this year---yet. Also, I am really bad at identifying the different types of oak trees (black, white, red, etc.), but it seems that most of the dead oaks are the same variety. So, perhaps, there is a different level of tolerance among the oak species to repeated defoliation. We can only hope.

Comments (4)

  • 19 years ago

    That's really sad, Rockman. I haven't seen it here on the Cape, but then again I haven't been in the woods since the first tick was spotted a couple of months ago.

    On the bright side, the state released a batch of parasitic flies over in East Falmouth earlier this month. It is estimated that it will take 5 years for them to get the winter moths under control; meanwhile I'll stick with BT to save my smaller trees and shrubs, and leave the Norway maples for them to consume.

    I don't think oaks are a particular favorite if the WMs but that may be because I don't have any mature oaks on my property so I wouldn't notice. There are certainly other nasty critters who attack those trees, I'll probably get to know them when my small willow oaks get big enough to become targets.

    I do wonder how many of the forests in SE MA are truly "native" old growth, and whether any undisturbed old forests are faring better than those that were planted after the area was logged. Do you happen to know?

  • 19 years ago

    I don't think there is any true old growth forest in this area. The only exception would be the large tracts of swampland, including the Hockomock Swamp and the Great Cedar Swamp. But those areas do not experience too much defiation because it does not seem that that catepillars like the swamp red maple which is a common tree. So the swamp white oaks tend to do OK in that environment. It is on the drier uplands where the defoliation seems to be most extreme. Those areas were not planted so the trees are all of the usual native oaks, pine, some hickory, etc. But none of it is real old growth. But your comment about the winter moth not preferring oaks is interesting. I am wondering if the repeated defoliation that killed these trees was actually the dirty work of the gypsy moths, which reached huge populations last year in these areas before the population crashed last summer due to a fungal disease (the normal pattern for gypsy moth infestestions). Also, I have noticed in past years that when the oaks were completely defoliated, the less abundant hickories stood out like a green mass of foliage among the wreckage. These catapillars do not appear to like hickory. If the oaks die off, perhaps the hickories will rise up and take their place. BUT, all of this leads in only one direction: less diversity in our forests as a direct consequence of invasive species. It is very sad.

  • 19 years ago

    I'm quite sure you're correct rockman, I can't imagine that any of this is really old growth. I suspect old growth in eastern Massachusetts was usually dominated by hemlock back in the day.

    In any case, I remember last summer driving through stretches of SE Mass. and thinking that I was seeing oaks that were soon going to be dead if they kept getting stripped. A huge amount of that is winter moth.

    The good news about winter moth is that there's a fly that eats only it, but it takes some time to get it introduced. This year the state finally has enough of them reared that they've started releasing them. I have no idea how long it will take for the fly to catch up with the moth, but it will catch up. This moth was a serious pest somewhere in the Canadian maritimes until the Canadians realized they could successfully introduce this fly. They did that years ago, but once it drastically reduces the number of moths its numbers crash as well. That's why it takes time to introduce the fly into a new infestation. Once the fly's numbers crash it takes effort to find it and then rear it up in the lab into a big enough population for it to released into the new infestation.

    The state's just now releasing the fly on the Cape.

  • 19 years ago

    The files, Cyzenis albicans, were released last week in East Falmouth by the USDA; in recent years they've been "seeded" in Hingham and Wenham, and have been used sucessfully in Nova Scotia and in the Pacific northwest.

    The Falmouth Enterprise reported that it may take about 5 years for them to gain the upper hand. Meanwhile, I'm happy that this was a bad year for them, at least locally, but I'll have my BT at the ready for specific young trees.

    Here is a link that might be useful: parasitic fly release, F.E.