Hi Nancy,

You made a good observation about the two trees -that the trunks were not damaged or cracked.   Physical cracks, wounds etc in trees can be bad for their health and increase the likelihood of diseases and other problems.  Most healthy trees in spring will have green leaves - new leaves often begin as light green, and get darker as they age (I'm in Ohio, and actually many trees don't have leaves yet or are just starting!)  You noticed the leaves don't have holes - good observation.   Insect pest feeding is not desirable and can cause holes.  Even environmental injury like frost can cause leaves to look tattered if the leaves are injured when they are developing.   So the fact that you aren't seeing this is good.  I was curious about the first tree you described with bright colorful leaves - what color?  It's not typical to see bold colors unless it's fall.   Of course there are some varieties of trees that do have colorful leaves, like red-leafed maple.   There's even a tricolor beech tree with pink/green/white leaf coloration.  Finally, I thought I would share an excerpt from a very interesting news article from Ohio State: 

In the fight against climate change, expanding and better managing the nation’s forests are the cheapest and easiest steps to cutting carbon dioxide emissions, according to new research at The Ohio State University. 

Across the United States, trees take up about 12% of the carbon dioxide that cars, planes, factories, and other sources generate every year, said Brent Sohngen, a professor of natural resources and environmental economics at Ohio State’s College of Food, Agricultural, and Environmental Sciences (CFAES). 

But trees could do even more, Sohngen said—possibly taking up as much as 16% of the nation’s annual carbon dioxide emissions—nearly a one-third increase. That would happen by planting more trees across the country; allowing some existing stands to grow longer before they’re cut; and managing some stands more intensively with weed and pest control, fertilizer, thinning, and other measures, he said. 

Within a decade of adding up to 7 million more acres of forests and more intensively managing 50–70 million acres of forestland, an additional 160 million tons of carbon dioxide would be taken out of the atmosphere every year, Sohngen said. 

Over time, the carbon uptake potential of the trees would increase—rising to 200 million tons per year after two decades.

“It’s not just going out and sticking a bunch of trees in the ground. It’s about managing them better,” Sohngen said. “If you spend more effort keeping down the weeds and other pests, they’ll grow better, and you’ll get a better return.”

The price tag for such measures is estimated to be $8 billion per year for the next decade or two, he said.

“These costs are substantially lower than the costs some companies may face if they try to go carbon neutral all on their own,” Sohngen said, referring to the goal of some companies to offset their emissions by funding projects beneficial to the environment. 

There are a lot of questions in the project above.   What products do trees give us?  The number one product is wood - many types of wood - used in construction of buildings and items like furniture.  Trees also produce fruit and provide shade, food, and habitat for wildlife.  

How can trees mitigate climate change and improve health?  As already mentioned above, trees remove carbon dioxide from the air.  They use it as a building block for sugars, and they use the energy from sunlight to drive this process which is called photosynthesis.   So yes, trees absolutely remove CO2 from the air through photosynthesis, and in doing so, can mitigate climate change.    The impact of one tree might not be much (you are not likely to be able to prove that one tree slows down climate change because climate is on a much bigger scale than a single tree) but the impact of something like the Amazon rain forest could be huge.   Sometimes you hear the term "sequestered" which describes the removal of the greenhouse gas CO2 from air and fixation into many other types of carbon-containing molecules in the structure of the plant.  Carbon that is sequestered in plants can be released at a later time.  For example, when wood burns, the carbon is returned to the air as CO2.   

Other benefits of trees - trees in cities provide shade and can lessen the amount of heat absorbed by concrete, asphalt etc.   Trees also absorb other pollutants.   Their root systems hold the soil and slow the movement of water across the landscape - all of this is good.   Water sweeping across a city landscape can wash pollutants into our lakes and rivers and also lead to the loss of soil - all of this is bad.  

So we come back to one tree.   Can you prove that it slows climate change?   No, but you can prove that a single tree removes carbon dioxide from the air.   Special equipment is needed to do this that actually measures how much CO2 is removed from the air at the level of the leaf.  I have used small equipment that encloses a single leaf, and you can see the CO2 reading inside the chamber drop!  It is cool!  

What do you think you might want to keep constant if you are measuring how much CO2 a leaf or small plant is using?   Hint:  Think about what I told you drives photosynthesis.   You also might want to make sure that the tree is well watered before you start, because that affects the ability of the plant to photosynthesize.  Do you know why drought causes photosynthesis (and CO2) use to go down? 

Hello,

This is Mary Ann with a request for the teacher to provide an update and some guidance.  So far, I see nothing to respond to except Nancy's message from March 16.   Can you please let me know what to expect so that I can be sure I'm not missing out on opportunity to provide mentoring feedback??   Please respond to these questions:   1)  Is this  chat the only way that mentors interact?  or.......2) will there be project documents for us to review -  I see nothing in the files at this time.   3) can we expect more questions over the next few weeks in this chat?  4) When is the end date for this project?    Please respond, and thank you -