Summer on a Shoestring

Crew Times

Sorry Shoestring subscribers for not getting a blog out sooner. The crew is busy, and will continue to be busy until the time most of us leave (Aug. 5th).

Anyway, what’s up?! I’m supposed to talk about the Hubbard Brook Meeting, but it was so long ago. The Shoestring crew presented their work very well. There’s so much work being done here. I’m surprised we haven’t run out of questions to ask. It was nice seeing old faces from the Cary Institute. I can’t really say much about the Meeting other than it being informative. Overall, I give it 4 out of 5 stars. Missing a star because of the AC situation. Those who were forced to sit near the AC wall vents know what I’m talking about.

Now, let me shift to what we’ve been up to lately. Here’s a photo of me, Craig, and Neal, trying to take on the “Death by Burger” served at Woodstock Inn. $15 for 18 oz. of burger. It’s as big as my head! The manliest of the three of us is Neil, who finished his burger all in one sitting.

Tim Fahey came over on Tuesday to give a talk for our Science Night. He talked about his Arnot Forest study where he and his team traced 13C through belowground communities. Interesting stuff! I personally took interest in the earthworm part of his study. Earthworms increase soil CO2 emissions, but they also sequester carbon, which he observed through tracing the amount of 13C in their burrows. However, this sequestered carbon doesn’t stay in the ground for too long due to microbial activity. I was thinking of doing a similar study but using the urban LTER plots in Baltimore. We’ll probably observe the same thing as Fahey’s study. Maybe it’ll be a side project for me.

Shinjini and I just finished collecting soil cores from C7, 8, and 9. We had to separate the cores into Oe, Oa, and mineral soil. Separating Oe is easy! Just remove the leafy stuff. Oa is a bit tricky because sometimes it could be just a tiny sliver. But we got it done! 144 cores.

Craig and Neal just finished hiking the Presidential Traverse. Something like 25 miles or so, all in one day! Congrats guys!

For the next couple of weeks, we will be doing tree inventory for all 13 stands, installing resin strips, and fertilizing ingrowth cores.

This will probably be my only blog entry for this summer. I’ll probably be here again next summer. If you’re going to ESA, I’m giving a talk on Thursday at 8am or so about soil respiration in the urban forests of Baltimore.




Gavin MacKellar, thoughts, dreams, and soil cores
July 21, 2010, 12:53 pm
Filed under: Soil Power Coring, Soil Respiration, Trenching

Taking soil cores with a power corer and a power house!  by Gavin MacKellar

At the start of last week, 7/12, April arrived from Cornell with the
power corer to start taking soil samples from sites HB Mid, HB Old, JB
Mid, JB Old, C3, C5 and C7.  Within each of these sites April, with
extensive help from the field crew, will take five soil cores from
each plot.  One core will be in the very center of the plot and the
remaining four will be placed in the buffer (for minimal disturbance)
at each plot corner.  Each soil core is 50cm into the mineral layer
and including the Organic layers above it. The organic layers are
sampled as Oi & Oe and the second sample as the Oa.

After this the mineral layer is exposed and the increments measured for samples are 0-10cm, 10-20cm, 20-30cm, 30-50cm soil and roots.  These depth measurements are marked on the corer in marker.

At each depth increment the sample is removed and placed in its appropriate and labeled bag, with the core half way done.

After each sample is taken the corer is reinserted into the core hole and drilled to the appropriate depth then removed, repeating the process.  After each core the hole is measured to double check the depth and April scoops out any loose soil from the bottom of the core, which by the end can be really deep to reach.  For the 30-50cm core the sample is divided into two, the extra being for root sampling.  Once the samples have been taken there is a total of eight bags of samples from each power core.  Taking eight (big) samples from each core and taking five cores per plot, the amount of soil samples adds up very quickly and is quite a heavy load to carry out of the plot.

Once all the soil samples are removed a smooth core into the soil is left behind.  The power corer has the ability to cut through small rocks and sometimes, with persistence, big rocks.  Additionally with a bit of misfortune a rock may get stuck in the core, but can be removed. The soil samples that are being taken by the power corer are going to be measured for bulk density and nitrogen/carbon ratio.  Since the corer cuts through rocks, which releases minerals, minerals such as calcium and phosphorus cannot be measured.  For the deep samples, 30-50cm there is a root sample that is being taken which will go to Tim Fahey for fine and coarse root measurements.

Other Shoestring thoughts:
The soil respiration in the trenches has been measured three times
since the trenching, leaving one more measurement this Friday then
monthly until next July.