Archive for the ‘trees’ tag

Tiny Woolly Terrors: The Attack of the Adelgid

By December 20th, 2013 at 10:35 am | Comment 1

If you’re looking for more projects for the holiday season, we’ve got 12 Days of Citizen Science for you!

Don’t forget to check out the public radio segment about Tiny Terrors on WHYY’s The Pulse!

woolly adelgid

Evidence of hemlock woolly adelgid on hemlock

The Grinch is back and this time in the form of a tiny insect invader. Meanwhile, scientists are looking for the one tree… that will save Christmas. Ok, dramatics aside, this is only half wrong. Eastern Hemlock, balsam, and Fraser fir are three evergreen trees that dominate large swaths of terrain across Eastern America dying from the attack of two invasive pests. One, the balsam woolly adelgid or Adelges piceae, has had a devastating impact on Fraser fir and balsam fir, trees you may recognize in your living room if you celebrate Christmas. Eastern hemlock trees dying from the hemlock woolly adelgid, otherwise known as Adelges tsugae, are also leaving behind bald patches on a damaged forest landscape.

The key to preserving our forests? Scientists at North Carolina State University and in the Alliance for Saving Threatened Forests believe that a particular tree or rather some particular groups of trees might be the solution. The idea is that there may be trees within each species that have a natural resistance to the adelgid that most trees in America don’t have.

This is part of the reason why hemlocks and firs are dying in such large numbers. The Balsam woolly adelgid is originally from central Europe and the hemlock woolly adelgid is from East Asia, where native trees have evolved resistance or tolerance to adelgid infestation. But the trees in the U.S.? Dr. Fred Hain, an entomologist at North Carolina State University, says they have had “no co-evolution [with the adelgid] and the trees do not show any resistance and are very susceptible. And also, there are no natural enemies in this system to keep pests under control.”  But there may be trees in our native range are lucky enough to have some form of resistance to the adelgid; we just haven’t found them yet. As it turns out, they’re extremely hard to find. “It’s like looking for a needle in a haystack,” Dr. Hain says.

This is where the Tiny Terrors Project (official site) enters. Led by Dr. Hain and grad student Erin Mester, the Tiny Terrors project is a piece of the Alliance for Saving Threatened Forests that enlists the help of citizen scientists to find those resistant trees. With so much land to cover and so many trees to see, citizen scientists can provide a significant boost to the search for resistant trees. Hain and Mester ask volunteers to try and identify resistance by finding trees that have very few or no adelgid in infested areas. The team will then try to get either a cone, if possible, or clippings from the tree to run experiments on.

The first thing they need to do is determine whether or not the tree has been treated with chemical pesticides, since that would make a tree appear to be resistant even if it actually has no natural resistance. Then, if the tree hasn’t been washed or injected with pesticides, then the scientists will grow seedlings from a cone or try to clone the tree from cuttings and expose it to adelgid to see if it really is resistant. If the adelgid doesn’t take, or if the trees survive the infestation, then it becomes a task of understanding what the cause of resistance is. “So far, we’ve identified a thicker cuticle of the needle as being critical,” Dr. Hain says, meaning the few trees the Tiny Terrors project has pulled up as promising appear have a thicker skin. This makes it more difficult for adelgids to penetrate the tissue. This hypothesis also seems to be supported by the fact that trees native to central Europe and Asia have this adaptation as well.

Hopefully, scientists like Hain and Mester will be able to transfer the resistance genes over to other hemlocks or firs if they’re able to find those special trees. Unfortunately, even this is easier said than done. A similar story played out on the continent in the early 20th century, when a fungal infection called the chestnut blight nearly wiped out the American chestnut. Chinese chestnut varieties had a natural form of resistance to the blight, and scientists tried then to create a viable hybrid between Chinese and American trees to combat the blight. By breeding that hybrid with other surviving American chestnut trees for many generations, scientists were finally able to create a blight-resistant tree that had 98% American genes and 2% Chinese genes. But that wasn’t until nearly seventy years after the blight had decimated the population of chestnuts in America. At this point, much of the original genetic diversity of the American chestnut is gone forever, and it’s unclear whether or not chestnuts will ever return to the full extent of their former distribution.

This could happen for Fraser and Balsam firs as well, should nearly all of the population of trees be killed. Fortunately for hemlocks, however, an organization called Camcore has been stockpiling a bank of hemlock seeds for the purpose of preserving their genetic diversity. But Fraser firs may not be so lucky since not as many people are looking out for them, despite Christmas trees occupying a nearly 1 billion dollar industry.

While none of these trees are important as timber, hemlocks are what is known as a keystone species and have a disproportionate impact on the ecosystem. “The ecological impact,” Dr. Hain says, “could be quite traumatic.” For instance, hemlocks are often found by streams and provide a good deal of shade. This shade might be critical to keeping the water temperature down, which is already reaching the thermal limit for trout in the south. The loss of that shade could also ruin the habitat for trout.

The Tiny Terrors project is just getting on its feet. But, if it’s successful, it could help prevent the deaths of many conifer forests and the life depending on them. That success hinges on a number of things, including whether or not naturally resistant trees exist and if a successful hybrid can be made, but most importantly on how many people volunteer as citizen scientists. Dr. Hain believes that the project will move forward, as more people spread the word.  In any case, Christmas is probably still on this year with a Fraser fir and, who knows, maybe a trout. But in the future, people may have to find alternatives.

To get involved with the Tiny Terrors project, either visit the site through SciStarter’s portal or join on the Alliance for Saving Threatened Forests page.

Image: Wikipedia


Angus R. Chen is a research assistant at Princeton University, where he does geochronology research using uranium and lead isotopes from zircon crystals. Previously, he was a research intern at the Harvard Forest, studying the impacts of climate change on soil. He recently graduated from Oberlin College with a double major in environmental science and creative writing. When he’s not in the lab admiring rocks and then pulverizing them, he writes poetry, fiction, science articles, and makes cool videos.

Fraxinus to Fight Fungus

By September 27th, 2013 at 11:08 am | Comment

Human beings are remarkably capable animals when it comes to pattern recognition. The human ability to quickly and accurately recognize recurrent patterns is a skill that numerous citizen science projects have put to work on large, difficult data sets. Galaxy Zoo uses these skills to assist with the morphological classification of galaxies. Pattern recognition and also spatial reasoning contribute to the success of the protein folding project Foldit. Another project aims to take advantage of these human skills and, like Foldit, does so with a game.

Fraxinus is a game created by The Sainsbury Laboratory (TSL) to help researchers address ash dieback in the common ash tree (Fraxinus excelsior). Players attempt to match a nucleotide sequence to a reference genome to look for sites of variation. The game was designed for the social media platform Facebook and allows users to play the game as they would any other on the site. However, this game provides more than entertainment. Fraxinus also provides scientists with small pieces of data that can be aggregated to provide a better understanding of the mechanisms that protect some common ash trees while others perish.

With more than 10,000 puzzles to solve in the game there is a significant amount of work for citizen scientists, but already each of these puzzles has been examined, according to a recent report on the game. Now that each puzzle has been looked at, players will begin to “steal” patterns from one another, in an attempt to increase their game score, and at the same time they will help refine sequence patterns, which in-turn provides better quality data for researchers.

You can learn more about the background for the project, including the basic science, and Fraxinus with Dan MacLean, Bioinformatics at Sainsbury Laboratory, here.

Image: news.jic.ac.uk.


Ashley Rose Kelly is a Ph.D. candidate in the Communication, Rhetoric, & Digital Media program at North Carolina State University. Ashley studies how emerging technologies may be changing science communication. She also teaches scientific and technical writing courses as well as an introductory course on science, technology, and society. You can find Ashley on Twitter as @ashleyrkelly

Why do some tree leaves turn red?

By September 17th, 2013 at 11:43 am | Comment

SciStarter has a whole round-up of tree-related projects for you this season. Branch out into citizen science!

maple-tree-leaves-in-autumn-110661300185760w40

Walking around my neighborhood the other day, I was casually observing the local flora when I was struck by the redness of one particular set of leaves. While the tree pictured is not the exact one I spied upon, look at how vibrant these colors are! I began to wonder why this tree turned red while the others around it stayed orange and yellow. To begin, we must learn about why autumn leaves deviate from their greener shades in the first place.

As you probably already know, the color that most plants have is derived from chlorophyll, the yellow-green pigment found in chloroplasts responsible for allowing photosynthesis to take place. If you’ve forgotten how this process works, Crash Course Biology has a great video for this. While there are multiple forms of chlorophyll, it is generally true that most reflect green light, causing for plants to appear the way they do. (This raises the even better question of why aren’t plants black, but that deserves its own post.)

So, what happens to the chlorophyll as we approach the cooler months? When the temperature drops, deciduous plants slow the production of chlorophyll in preparation for the dormant period they will undergo during the winter. The plants will then be able to conserve energy by halting all photosynthetic processes during the lack of available sunlight. As this happens, orange and yellow carotenoids present in the leaves are exposed. These are pigments that are normally produced in leaves that help to absorb additional energy from the sun that is passed along to the chlorophyll and also to prevent auto-oxidation (basically the wear down of cells due to free radicals) from occurring. In addition to all of this, the plant begins to produce a cell wall between the stem and the leaf called an abscission layer. This will eventually cause for the leaf to be completely separated from the plant, allowing for it to fall to the ground.

Screen shot 2013-09-17 at 11.24.16 AM

Absorption spectrum of chlorophyll A & B

Okay. We’ve covered green, orange, and yellow, but what produced the scarlet beauty found above and why doesn’t it occur in all trees? The answer is anthocyanins. If you’ve ever eaten a blueberry, raspberry, pomegranate, or any other fruit that can stain your hands and clothes, you’re probably already familiar with these little molecules. These pigments are similar to the carotenoids mentioned above but serve a different purpose. In cases during the late summer when plants are beginning to slow their photosynthetic processes but there is still plenty of sunlight abound, the leaves can actually be harmed by receiving too much high-intensity light in the region of Photosystem II (photoinhibition). In order to prevent this damage, the plant begins to synthesize anthocyanins to permeate through the leaves’ surfaces. Because of its red color, the pigment absorbs a large amount of the high energy visible and ultraviolet photons striking the plant, basically acting as a “plant sunscreen.” (Check out how you can even build your own anthocyanin-based solar cell!) Additionally, anthocyanins are good indicators of plant stressors including freezing temperatures and low nutrient levels.

Next time you see a particularly red tree, make sure to think about its environment! Does it receive an abundance of light? Has it been particularly cold? Feel free to comment with links to your own pictures of vibrant trees and plants!

Just like leaves, citizen science also happens to grow on trees! Don’t believe us? Check out our tree projects round-up!

References:

Why do leaves change color and turn red?

Carotenoid-to-chlorophyll energy transfer

Understanding Vegetation and Its Reflectance Properties

Winter Adaptations of Trees

Photo: Public Domain Pictures, Wikipedia


This was a guest post by Joe Diaz, a science educator and enthusiast. Follow @RealJoeDiaz. View the original post.

Citizen Science Opportunities with The American Chestnut Foundation

By September 1st, 2011 at 10:32 pm | Comment

Jay Hoar describes various chestnut artifacts to visitors of PA Outdoor Heritage Days in Somerset, PA.  (Photo: Karen Danes)

Jay Hoar describes various chestnut artifacts to visitors of PA Outdoor Heritage Days in Somerset, PA. (Photo: Karen Danes)

Sara Fitzsimmons is the Regional Science Coordinator at The American Chestnut Foundation

The American Chestnut Foundation (TACF) is a 501(c)(3) organization dedicated to restoring the American chestnut (Castanea dentate) to its original range. Once estimated to be 25% of the Appalachian forests, the species was all but eliminated from the landscape by an imported fungal disease caused by Cryphonectria parasitica, the chestnut blight fungus.

Since 1983, TACF has been working with volunteers and citizen scientists to breed disease-resistant trees and return them to the landscape. The program involves a minimum of six breeding generations, each of which requires labor-intensive controlled pollination to make the seed, and about 5-10 years to grow the trees and properly select them. To work through the entire breeding pipeline, then, takes a large amount of resources, and about 35 – 60 years!

A program such as this would not be possible without the many hands, minds, and legs of citizen scientists. TACF volunteers come from a wide variety of backgrounds – from salesmen to engineers, farmers to doctors and teachers – all of whom can bring a unique perspective to the program and enhance TACF’s work in a multitude of ways.

Over the past 25+ years, 1000s of volunteers have bred various generations of trees and grown tens of thousands of trees on their land. While breeding is the backbone of TACFs work, and there is continued need for more growers, citizen scientists have not only participated in, but also initiated, some unique programs.

Read the rest of this entry »

In the Philadelphia area? Contribute to PhillyTreeMap!

By June 23rd, 2011 at 11:17 am | Comment

One of several  Honeylocust trees living harmoniously among 18th Century homes in Philadelphia

One of several Honeylocust trees living harmoniously among 18th Century homes in Philadelphia

Participating in PhillyTreeMap, one of the newest projects in the Science for Citizens Project Finder, is almost as simple as fetching the morning paper from the front “stoop,” as we say here in Philly.

This morning, I opened my front door, walked 10 feet to the nearest tree (pictured here), wrapped a measuring tape around its trunk, snapped this picture, and simply uploaded the picture and trunk width online. THAT’s how simple it was to help the City of Philadelphia take an inventory of trees.

In the process, not only did I learn we have Honeylocust trees lining our street but that these trees provide these yearly ecological benefits to my region:

Total Benefits: $318,804 saved. How? Greenhouse Gas Benefits: 554,597lbs CO2 reduced ($2,797 saved); Water Benefits: 3,928,345 gallons conserved ($38,890 saved); Energy Benefits: 184,521kWh conserved ($265,389 saved); Air Quality Benefits: 4,677lbs pollutants reduced ($11,726 saved).

Here’s how this works and why it’s important according to the software developers at Azavea:

PhillyTreeMap is an open-source, web-based map database of trees in the greater 13-county, three-state Philadelphia region. The wiki-style database enables non-profits, government, volunteer organizations, and the general public to collaboratively create an accurate and informative inventory of the trees in their communities. The project was funded by a USDA Small Business Innovation Research Grant, and is in support of the City of Philadelphia Department of Parks and Recreation’s 30% tree canopy goal, and the Pennsylvania Horticultural Society’s “Plant One Million” campaign. As more trees are added to the database, we are able to use software from the US Department of Agriculture to calculate the environmental impact of the region’s urban forest. So get outside and add some trees!

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