Submitted by Anonymous on Sun, 04/08/2012 - 16:04

Hi John,

This is Julia - I'm taking the professional development course, and we are supposed to post a question for you as an assignment. I usually have no trouble coming up with LOTS of questions, but I'll spare you and only give you two! I work with high school science homeschooled students through a distance learning program. I'm going to come up with a lesson plan around your project there, offer it very soon (like tomorrow) as an option, and hopefully we'll get one or 2 of them tuning into your webinar next week. Here are my questions:

1 - My experience, living in northern NY, where we often have snowpack until late April (not this year!), is that when there is a heavy winter snowpack, even with normal spring temperatures, it takes longer for it to all melt and growth to start. I know you spend a lot of time shoveling to make the experimental plots more equal to the control plots, and that makes sense. But if in fact a climate change causes more snow, as I thought I read somewhere was one prediction, you may have more warmth under the ground in winter combined with a later start to spring growth. What do you think of this hypothesis? Do you have any test plots where you are leaving that extra snow behind the snow fence to melt on its own? I think it would be an interesting comparison. I realize it opens up another whole project, but if it is part of warming, then it seems to be worth studying!

2 - For the control plots, why do you need an FC at all? Can't you just sample the outside air? Am I missing something obvious?

3 (sorry- thought of another!) - I would love to hear more about your "decomposition chamber" project, and how it works. Having students all over the country/world, this would be a fascinating collaborative project.

Thanks a lot! Julia

John Wood

Good to hear from you. I have been reading your posts for the class and it sounds like you have a fun and challenging job. I can't imagine dealing with the variety of people you must have to teach! It must really keep you busy!Thank you for using my expedition with your students. If there is anything I can do specifically for you to help, please let me know. Let's get to the questions;
1. I think your hypothesis is a valid one. You make a good case for experiments that would focus more on that type of scenario. Of course, how much more snow, how much longer would the increase in snow last under warmer conditions, or would it result in a late spring, are questions we all wonder about, but will have to wait for now. And what would all of that extra melt do to the area? It is intriguing. For now we do not have any test plots that address this question. We do consider the first part of that model and ask, if there is an increase in snow cover in the winter will that change the carbon balance in the summer due to the warmer ground temps.
2. If we had an eddy tower sampling the site we would not capture discrete data. We need the flux chambers on both sides for control and for volume sampled. The specific sites being sampled vary considerably and have been quantified in terms of numbers and types of species, biomass, and NDVI. We not only measure the CO2 flux, we record changes in the communities on both sides. Does that help?
3. Yes, the decomposition bags are a great activity for a comparative study. I have yet to write a protocol for that activity, but would love to get a "bank" of student measurements from all over the world for classroom use. The project's bags mesh with stripes of cellulose. I have been making the bags from nylon screening material and wood fiber resume paper. We haven't done enough of them yet to see if they are consistent, but the initial test look good. I can finish that write up and send it to you for your comments, if you wouldn't mind helping? That would be great.
I hope this helps. Thank you for your questions and your insights. I look forward to talking more.
Cheers,
John

Anonymous

Hi John,
Thanks a lot - that does help. I figured you would say something like that for #1, and I can see that the flux chambers are necessary for consistent sampling of all the things you are testing. For #3, I would love to see what you have. To be honest, I didn't write down the details, and I have no idea where in your journals you wrote about it, but I don't think you gave a lot of details. I had written a note to myself, "decomposition bags - cool project - ask John about it." It seems like something that homeschoolers could do easily, but I'm not even sure what you are doing! So whenever you get around to it, I'd love to see it and give feedback.
Thanks, and I'll be in touch about the lesson I come up with.
Julia
PS - I'm also watching the weather, as we are bicycling from AK down the AK highway starting in mid-May. Maybe we'll get some of those warm temps you had last year!

John Wood

Sounds good. I will let you know about the decomp bags. The bike trip sounds great! I will see if we can bank some of this sunshine for you! And if you are in the Healy area, you should stop by the study site. Elizabeth would love to show you around.Best of luck,
John