The route to root processing


Roots collected from the top of the screen from soil pits in 2018

  1. Get a sample out of the freezer. Weigh it and record the weight on the data sheet.
  2. Place the sample on a big sheet of paper and sort the roots into diameter classes (< 1, 1-2 mm, 2-5 mm, 5-20 mm, and 20-100 mm). Use calipers to confirm diameters. Cut small roots where they attach to larger roots if they belong in a different pile. Roots identified as dead at this point can go into a different pile.


a.unsorted pile sorted roots                   b. sorted roots                 c. group of fine roots

3. Wash the roots. Separate live from dead roots, and distinguish live roots from dead. Dead roots may feel squishy, be decayed, or be distinguishable by morphological criteria.

Morphological criteria Live Dead Source
Stele color white or slightly brown brownish/dark Persson &  Stadenberg, 2009; Schuurman,1971)
Elasticity elastic broke easily Vogt and Persson 1991; Schuurman,1971
Root branching well branched broken off/ separated Vogt and Persson 1991
Texture smooth wrinkled (Gwenzi et al., 2011).


Subsampling can be used to speed up processing when there is too much material <1 mm in diameter. This may happen for the samples collected above the screen in the Oie, Oa and 0-10 cm depth increments. Combine all <1 mm roots into one pile and subdivide them into six or more groups. Weigh each of the piles, to be used for scaling the results to the whole sample. Randomly select two groups to process.


                                                 Subsampling of <1 mm size

4. Bag the rest of the root diameter classes (1-2 mm, 2-5 mm, 5-20 mm, and 20-100 mm) and label bags indicating the site, plot, depth class, diameter class, and date of collection. Use coin envelopes if the samples are small.

5. Put samples in the oven at 60 degrees C for at least two days. When samples have dried to a constant weight (they don’t lose more weight on further drying), weigh the samples and record the masses on the datasheet.

By Amelyn Ambal and Ruth Yanai


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2008-2010 Roots

When analyzing data collected from past lab participants, we discovered many errors. There were discrepancies in relation to root samples from 2008-2010. The Qorpak jars that held the roots had the incorrect size classes labeled on them, and the matching spreadsheet also had the incorrect size class recorded. Fortunately, we were able to find all the root samples and correct the size classes of the roots.


After revising the incorrect size classes, we decided to transfer the roots out of the Qorpak jars and into coin envelopes. Each Qorpak jar costs 2 dollars, and by transferring the roots, the jars could be reused. In addition, the coin envelopes take up less room in the attic. We carefully transferred the roots into the envelopes, wearing gloves to maintain the root’s chemical integrity in case they are used for chemical analysis. We copied the label from the Qorpak jars onto the envelope, with the correct size class.  


The “pre-treatment roots inventory” spreadsheet now has the correct size classes and the Qorpak jars are ready to be reused. The 2008-2010 root samples are done!

By Abby Kambhampaty

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Mistaken Identities in HBO (Hubbard Brook Old): Time to Resort the Birches!

As some of you know, Ruth Yanai, our most senior (Professor) lab member, is not the greatest at distinguishing leaves of white birch, Betula papyrifera, from yellow birch, Betula alleghaniensis.  It slows things down when she has to ask a high school student to verify every leaf.

Pictured on the left are the leaves of a yellow birch tree, and on the right are the leaves of a white birch tree.  Could you tell them apart?  A white birch leaf is typically wider, and the petiole longer. A yellow birch leaf has a stubby petiole, and is thinner and longer. And white birch leaves have 5-9 veins, while yellow birch has 9-11 veins.

On Saturday, March 24, when Ruth was sorting with Mia, Anna, and Dan, all the birch leaves in sample HBO-4-A1 were turning out to be yellow birch.  So she asked Becky, who was Lab Host that day, “Are there any white birch in this basket?  This would go a lot faster if I knew there was only one kind of birch!”

Archived on the MELNHE web site, Becky found the data for HBO-4-A1 in 2010, in which there was only 1 g of white birch leaves, but 34 g of yellow birch.  However, in 2015, there were 13 g of white birch leaves reported, in addition to 40 g of yellow birch leaves.  It’s not surprising that the masses are not exactly the same from year to year (if they were, we wouldn’t be sorting litter every year).  But this amount of difference seemed suspicious.  The litter baskets are in the exact same place every year, and birch trees can’t move around or change their species.

Fortunately, the 2015 samples were still across the hall in B-6, awaiting transport to the attic of Bray Hall for Long-Term Storage.  Becky found the bags from basket HBO-4-A1, and dumped out the bag labeled white birch on the table for us to sort.


The first thing Ruth noticed (remember, she’s not good at distinguishing the birches), was two beech leaves!  Everyone can tell a beech from a birch, that’s easy.  The rest of the team were able to verify that most of the bag was yellow birch, not white birch.

It’s alarming to find errors from past lab crews, but reassuring that we can find the samples, resort them, and reweigh them.  Alex Young, a graduate student, is now making stacked bar graphs of the species in each basket over time to help us determine which samples should be rechecked.  The other thing we discovered is that there is no record of who sorted (or rather failed to correctly sort) that basket from 2015.  So we won’t publicly humiliate them.  We do, now, record in our notes which baskets are processed each day, as well as who was present.

Thanks to Terrance and Ed for finishing with error detection and recovery of basket HBO-4-A1 from 2015 on Sunday, March 25.  There were just a few leaves that were correctly classified as white birch by the crew that sorted that 2015 sample, probably some time in 2016.  It turned out that they also had some birch leaves in the sugar maple bag.  Ruth was proud to report that by the end of sorting the 2017 HBO-4-A1 sample, she, too, could tell a white birch from a yellow birch.

by Becky Rew and Ruth Yanai

Use this for a post about the basket labeling system:

Click here to see the Forest Plot Layout!


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Who are these yellow creatures?


What are these creatures we found on Yellow Birches from Jeffers Brook Forest?

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Who is eating our sugar maple leaves?



We found these pretty sugar maple leavs from Jeffers Brook.  Does anyone know what insect does this?  –Nidaa Aljabbarin–

This is from a Maple Leaf Cutter Moth. Doug Allen, an ESF professor, wrote a short article on this insect and its life cycle. The caterpillar of the moth constructs a portable shelter using two bits of the leaf blade and seals it with silk. The caterpillar then feeds along the edge of the shelter, creating rings on the leaf that will eventually fall out. For more info, the attached pdf discusses the moth more!

– Gabriel D-R

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The 2016 Litter Year is Over! Enter in 2017!

The very last leaf litter sample, C2-4-A3, from 2016 has finally been sorted on November 5, 2017. Just in time for the 2017 leaf samples to come in later today!


Nidaa Aljabbarin, Fidaa Aljabbarin, and Shahad Abdulameer were the lucky researchers who finished up the last few samples!

– Gabriel Deutschman-Ruiz

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Tips for Taking Off Your Gloves

Did you know that our hands have a lot of sodium on them, and the leaf samples we are studying have very little? The 2016 Fall Litter Samples are being chemically analyzed, therefore we are wearing gloves when dealing with these samples so as not to contaminate them. It’s important to wear gloves and when putting on, wearing, and taking off the gloves to not touch the outside of them. Using the method described in the video you can take off your gloves if necessary and be able to put the same gloves back on without contaminating the outside of the gloves or needing to get a new pair.    –Maria Scheibel

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