Diurnal 2

So yesterday was our second, and last, diurnal. We spent 14 hours in the field, including the drive back. It was kind of rough, and a lot more difficult compared to the last one. I think a large part of that had to do with this round we did not have the cloud cover like last time. Right now I'm waiting to get batteries so I can download the data and analyze it.

I hate the waiting part of this REU. In general I think we do way too much waiting. While its nice since our field days are pretty intense/long, at the same time I could be productive right now. The worse part of this lazy time is once I get the data I have A LOT of work to do to get it in the correct format for the poster.

7th Inning Stretch

Coming down to the final stretch of this REU experience. We are doing a night measurement at Lucky Hills on Tuesday and we have one more diurnal on Thursday. Besides that we are spending a lot of time processing some more grasses to see if there is any difference in leaf area now compared to the measurements we got pre-monsoon. In addition, slowly but surly I'm starting to get pieces of my poster put together. The final week I am here will be focused on the poster, though admittedly I'm a little nervous about being able to process all the diurnal data before I leave (which would be data I want to include in my poster). Only time will tell.

Science Nerd Hazing

Today was our first of two diurnals, which affectionately became nicknamed as "science nerd hazing." We started out at 1a.m. to arrive at the Santa Rita experimental range at 2:30a.m. Once we arrived at the site we found that one of our two green wagons had been stolen. The day before we had left the wagon hidden near the road in hopes that we would be able to take a cooler with food to the site early in the morning. The two most promising theories are that 1) someone stole the wagon for drug runs or 2) Border Patrol thought the wagon was being used for drug runs and confiscated it.

Once we got to the site Erin and I did the pre-dawn water potential measurements on Lehman's lovegrass, Arizona cottontop, and Bush Muhly. The pre-dawns were done relatively quickly and we started our tenting exercises. We had two teams for tenting (4 people total) and 1 person doing soil moisture and leaf-level gas exchange. All in all it took about an hour and a half for each set of measurements. Each team did 12 measurements: 2 bush muhly in the open, 2 bush muhly under mesquite trees, 2 lovegrass, 2 cottontop, 2 open bare soil plots, 2 bare soil plots under a mesquite. On each of the grass plots we took photosynthesis measurements and respiration measurements (using a space blanket draped over the tent). Measurements were taking at 3 a.m., 6 a.m., 9a.m., and noon. After noon another group came in to take measurements at 3p.m., 6p.m. and 9p.m.

All in all the diurnal was pretty intense. My body definitely misses sleep and its been difficult to try to stay awake once we got back. However, it was relatively cloudy today so it was a lot cooler than it could have been.

Pre-dawns are brutal!

This week of work was really weird. Having been away for the 4th of July weekend and working in Biosphere 2 it seemed like we hadn't been in the lab in the longest time. We finished processing (i.e. getting the leaf-area index) of the grasses from our first pre-dawn. There were 12 samples total of 3 different species, thus 4 samples of each species. The lovegrass proved to be the easiest, followed by the cottontop, while the bushy muhly was a massive little plant and we were only able to get two done in a day before we went cross-eyed.

Our pre-dawn on Friday went well (at Walnut Gulch). Our numbers were very consistant unlike our first run in Walnut Gulch. We had about two hours to kill between pre-dawn water potential measurements and the leaf-level gas exchange measurements so we went into Bisby to look around. Bisby is an eccentric little artsy town full of old people and charm, though admittedly most things were closed at 6am. Bisby use to be a mining town, and its painfully apparent as there is the "Lavendar mine" right on the side of the road. This was Erin and my first experience using the leaf-level gas exchange instrument without anyone around to help us as Michelle had never used it before. (http://www.licor.com/env/Products/li6400/6400.jsp) We will see on Monday if we successfully completed our task (though we think we did).

In other Tucson news, the monsoon season has started and its amazing how much life comes into the system once its wet. The people I work with complain that it's much better if things are drier, but I'm kind of partial to the monsoon season...maybe its the new humidity?

Biosphere 2 Work

Today (7/7) Erin and I got to help a post-doc with her experiment in Biosphere 2. Travis Huxman tried really hard to get us out there and working on a project during our summer here, so it's neat to have the opportunity.

Our work was with a woman from the UK named Alex who is examining the effects of climate change on soil microbial systems. She is also studying how the microbial system may evolve in response to two different climate change scenarios: 1) periods of drought with short spurts of intense rainfall and 2) periods of drought with more frequent moderate rainfall. We did a lot of the prep work, which furthers the theme of the summer that most of the time for experiments is in the form of prep work.

Essential the experiment works like this:
- set out soil colonies from the Santa Rita experimental range in the desert biome
- after a certain amount of time select the 5 "best" (i.e. most productive) soil microbial systems
- allow those 5 systems to reproduce and set new colonies in desert biome
- repeat

Erin and I were working on the second generation mixing the soil from the reproductive systems into sterile soil. There seems to be a lot of assumptions in this experiment. One of the big assumptions that I have trouble with is the assumption that the 5 best colonies will reproduce in nature. According to Alex there is reason to believe it happens that way, but no one has studied it since soil microbial systems didn't really come in vogue until recently.

Another thing I found out that I do not enjoy: soil sampling. It's too meticulous and small scale for my taste. I also question how "sterile" the soil samples can actually be since even with the best of care there are still possibilities for contamination. I think I prefer to look at the ecosystem as a whole. But they say "don't miss the forest for the trees."