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Re: spider mites

In hemlocks, Imidacloprid definitely can lead to spider mite outbreaks, especially on hedges and trees near reflective hardscapes. This has been substantiated in scientific research papers (and not just hemlocks on hemlocks). However, some of the worst infestations of spider mites I have seen in the wild (as in old-growth, in-forest conditions) was in Cook Forest State Park, PA. These trees had never seen HWA or been treated with imidacloprid.

It seems like the larger hemlocks and those in more natural conditions and not suffering from drought stress or poor soils do much better at resisting mites even with imidacloprid. If spider mites are a concern and HWA is the target, use dinotefuran soil or foliar oil spray. Actually, a foliar spray of dinotefuran (1/2 to 1 lb per 100 gallons) with oil (1-2%) is awesome for hedges and smaller trees.

by Will Blozan
Wed Jun 27, 2012 9:43 pm
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Re: Tree health questions


The blue-green plants growing on the bottom of the tree are foliose lichens, I am not sure what species. They have nothing to do with the health or lack of health of the tree. The bulge really looks as if the tree had been constricted at that point, perhaps it had been wrapped by a wire? Could it have been along an old fence row? That is my best guess as to what is going on here.

Edward Frank
by edfrank
Thu Dec 20, 2012 6:30 pm
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Carolina hemlock genetics study


I received an e-mail from Robert Jetton of NCSU today, saying that a population genetics study of Carolina hemlock is planned for later this year, and that samples of the local Ohio populations will be taken. I'm hoping this will explain their existence in NE Ohio.

by Steve Galehouse
Wed Mar 13, 2013 10:34 pm
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Re: eastern hemlock needle tea

I think regardless of chemical traces the tea would be nasty. Carolina might be pretty good with the tangerine essence. With chemical traces any lice, fleas, ticks would have a rough time... but wouldn't harm you unless allergic. I'd steer clear if you suspect they have been treated.
by Will Blozan
Thu Mar 14, 2013 6:21 pm
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Drone Explores & Measures Trees In A Very Remote Forest

I recently explored the remote redwood forest of by UAV. No tree over 350' were found there but the area was completely unexplored so it was a new frontier and it needed to be surveyed. It would take 3 full days to just reach the upper part of this basin on foot. Now I can explore it in 30 minutes.

The attached represents the Mission Planner Software I use to program the drone to access a remote, unexplored redwood forest. The flight path in 3D overlay on Google Earth and Terrain maps + front mounted GoPro pictures. The mission must be carefully planned otherwise the drone will crash.

This mission had the UAV flying 400 feet over the surface features. After locating all the tallest tops on HD video I later returned with a point cloud mapping drone/UAV for targeted height measurement. This UAV/drone uses a downward pointed digital camera in photo burst mode. The triggering is accomplished through the AutoPilot software at each waypoint arrival.

Michael Taylor

California Big Trees Coordinator droneinside.jpg bridge creek mission4.jpg bridge creek mission3.jpg bridge creek mission2.jpg bridge creek mission1.jpg bc4.jpg
by M.W.Taylor
Fri Jul 19, 2013 1:21 pm
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Secrets of the Forest Floor

Secrets of the Forest Floor
Air Date: Week of April 12, 2013

When we think about carbon sinks, we usually picture dense forests packed with big trees. But new research from Sweden suggests that tiny fungi in the soil may deserve a little more credit for slowing global warming. Host Steve Curwood talks mushrooms with ecologist Karina Clemmensen.


CURWOOD: It's Living On Earth, I'm Steve Curwood. If you hear the words "carbon sequestration", you might well think of dense forests filled with mighty trees. But new research reported in Science magazine suggests that tiny fungi in the soil may deserve a little more credit for fighting global warming. Ecologist Karina Clemmensen of the Swedish University of Agricultural Sciences in Uppsala joins us now via Skype to discuss her fungi research. Welcome to Living on Earth.

CLEMMENSEN: Thank you.

CURWOOD: So before your research, what was the thinking on the mechanism for carbon sequestration in forests?
CLEMMENSEN: Yes, so the way people think about it is that carbon enters the soil through litters on the soil surface. So like needles and leaves and branches fall to the soil surface. And then after some decomposition the remains that stay behind accumulates as humus as we call it in forest soil.

CURWOOD: Your research suggests that the fungi in the soil play a much larger role. Can you explain that for us?

CLEMMENSEN: Little bit simplified, there's two major groups of fungi for forest soil. So there's the fungi working with the leaves that are falling on the soil surface. That's free living saprophytic fungi? So they basically release carbon out of organic material. And then there's the other group of fungi which live in symbiosis with the tree roots.

CURWOOD: What are these fungi called?
The white structures in the soil are visible mycorrhizal fungal structures on the roots tips (mantles) and fungal mycelium extending from the root tips into the surrounding organic soil. (photo: KE Clemmensen)

CLEMMENSEN: Mycorrhiza fungi. They sit on the tree roots and receive carbon directly from the tree, which makes carbon into photosynthesis. And they use that carbon to grow in the soil and produce biomass. And in return, as part of the symbiosis, they return nutrients and water to the tree. So they basically have the capacity to add carbon to the soil at depth.

CURWOOD: So the tree harvests the sunlight for the fungi, and the fungi does the processing to sequester the carbon.


CURWOOD: So what do these fungi look like?

CLEMMENSEN: Yes, as many of the mushrooms that you know from the forest - like chanterelles and different other edible mushrooms that you see. But that's some that you see there, like the apple on the apple tree. The rest of the fungus is living like small threads in the soil. But if you look closely on the root tips of the tree, you can see that the tips are normally rounded, and they can have different colors - and that's the fungus that form those structures. It can be completely black or some are yellow and you can see hair structures extending from the root tip.

CURWOOD: How much carbon are they adding, do you think?

CLEMMENSEN: So this is kind of the major finding here. So this mechanism of the mycorrhiza fungi to grow in the soil has been known for a long time, but here we're able to quantify how much carbon they actually add - more than 50 percent, 50 to 70 percent of the carbon that is currently stored in the soil is derived from the root rather than from above ground litter.

CURWOOD: Tell me, in general, how important are boreal forests to carbon sequestration around the world?
The study was conducted on 30 islands of different sizes in the two large lakes, lake Uddjaure and lake Hornavan, near Arjeplog in N Sweden (photo: A Bahr)

CLEMMENSEN: If you consider the boreal forest, the biome, together with the Arctic biome, they actually contain a third of the carbon stored in soils globally. If you consider the boreal forest only, it's 16 percent of the carbon stored in soil globally.
CURWOOD: Now, are the fungi working in the Arctic area as well?
CLEMMENSEN: Yes, definitely. We have the same major groups of fungi, but there we have a transition of more dominance of Ericacoid plants like heather plants. They associate with the so called mycorrhiza fungi. And definitely we think that those fungi have an equally big role in carbon sequestration in those areas.

CURWOOD: So what needs to be done to keep fungi happy? In other words, how does your research shift how we should think about the way we should be managing forests?

CLEMMENSEN: The study we present here is only done in natural forests. It's a long age gradient with forests ranging from 100 years to over 5,000 years. So we have not addressed the question of how to manage forests really. But from this grading we can say that if we leave a forest undisturbed for more than 1,000 years, several thousand years, then it continues to suck in carbon into the soil.
CURWOOD: Ah ha, because people have been saying, look, a tree, once it gets to be full mature size, it's not taking up any more carbon - be almost better to cut it down and plant a new tree. But you're saying no.

CLEMMENSEN: Yes, maybe the story for the soil is a bit different, right? So we have to consider these processes in the soil more. And definitely when you cut down the tree, then the mycorrhiza fungi will die. And that would leave this other group of fungi, the free living saprotrophs that I talked about living in remote...normally living in the litters, fresh litters in the soil surface. So they could potentially move down and start decomposing more of the stored carbon. A general thing to say here would be, OK, clear cutting in forest management would probably not be good for carbon sequestration.
CLEMMENSEN: Karina, what do you hope comes out of your research?

Karina Clemmensen photographing fungi (photo: A Bahr)
CURWOOD: I hope modelers creating predictive models of future carbon balances and so on would consider this different pathway, and try to create response functions of the two different pathways - the litter and the root derived carbon - because those two pathways might react differently through forest management and climate changes. So it's important to describe them as two different ways of carbon to enter the soil.
CURWOOD: Karina Clemmensen is a researcher at the Swedish University of Agricultural Sciences in Uppsala, Sweden. Thank you so much for taking the time.
CLEMMENSEN: Yes, thank you.

Clemmensen’s paper in Science:

Science 29 March 2013:
Vol. 339 no. 6127 pp. 1615-1618
DOI: 10.1126/science.1231923
Roots and Associated Fungi Drive Long-Term Carbon Sequestration in Boreal Forest
K. E. Clemmensen1,*, A. Bahr2, O. Ovaskainen3, A. Dahlberg1,4, A. Ekblad5, H. Wallander2, J. Stenlid1, R. D. Finlay1, D. A. Wardle6, B. D. Lindahl1
+Author Affiliations

1Department of Forest Mycology and Plant Pathology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Box 7026, SE-75007 Uppsala, Sweden.
2Department of Biology, Microbial Ecology Group, Lund University, Box 117, SE-221 00 Lund, Sweden.
3Department of Biosciences, University of Helsinki, Box 65, FI-00014 University of Helsinki, Finland.
4Swedish Species Information Centre, Swedish University of Agricultural Sciences, Box 7007, SE-750 07 Uppsala, Sweden
5School of Science and Technology, Örebro University, SE-701 82 Örebro, Sweden.
6Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden.
↵*Corresponding author. E-mail:

ABSTRACT EDITOR'S SUMMARY Boreal forest soils function as a terrestrial net sink in the global carbon cycle. The prevailing dogma has focused on aboveground plant litter as a principal source of soil organic matter. Using 14C bomb-carbon modeling, we show that 50 to 70% of stored carbon in a chronosequence of boreal forested islands derives from roots and root-associated microorganisms. Fungal biomarkers indicate impaired degradation and preservation of fungal residues in late successional forests. Furthermore, 454 pyrosequencing of molecular barcodes, in conjunction with stable isotope analyses, highlights root-associated fungi as important regulators of ecosystem carbon dynamics. Our results suggest an alternative mechanism for the accumulation of organic matter in boreal forests during succession in the long-term absence of disturbance.

by edfrank
Sun Apr 14, 2013 5:28 pm
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