The Closing Notes of Summer

Fall Conference starts next week at Cal Poly, signaling the end of summer 2015. Based on this blog my summer appeared to be full of vacation, however that would be an illusion. The Scotland vacation was lovely, but I have worked the remainder of the summer.

To keep my job in the long term (i.e. get tenured) I need external validation of my scholarly standing. The form of external validation I need is peer-reviewed publication. Peer-reviewed publications require data. And so I spent the summer running 20 experiments to generate data, preparing courses (my contract is 100% teaching, after all), and analyzing data I have for a teaching methods manuscript I am writing.

My first round of experiments were in a seed germination study. I was examining char inclusion in substrate. The data look promising. I will be repeating aspects of this experiment this fall.

A seed germination experiment in progress.

The second study I launched involved char inclusion in cuttings substrates. I’m still in the process of harvesting data, but some of the data are intriguing. I will aim to repeat these experiments in the late winter or spring.

Root response to different substrates (I was happy they were not all the same).

The third study I set up involved char inclusion in cutting substrates and different forms of auxin application. I’ve collected some of the data from these experiments, and so far I am seeing some interesting trends.

Cuttings with different rooting responses (I’ll take the one on the left, but as a researcher I love the one on the right too, because it shows that the treatment on the left makes a difference).

The root studies involve root scanning. I wash the substrate from the plant, use a razor to slice off all the roots, and scan them. Later I will analyze the scans to count the number of first order lateral roots (i.e. primary roots initiated by the cutting), primary root length, and root area and/or volume. Analysis of the scans will be done this fall when I find time. For now obtaining the scans is a full time job. I still have many hours of scanning remaining, so I’ll fit those into the gaps next week and probably the weekends early in the fall quarter.

A root scan.

If all goes well I’ll have two manuscripts submitted by early 2016, with another one or two in production. If all does not go well the number will be lower. I prefer to think things will go well.

Designing Rhizotrons

I’ve been designing rhizotrons. Sketches of plans are in my notebooks and on loose sheets of paper on my floor, desk, coffee table, nightstand, and kitchen counter. I’ve tried conceptualizing all sorts of materials and dimensions. Some of my ideas are very cool, and I’d love to build them. A constraint exists, however. My rhizotron needs to be cheap because I need to build a fleet of them.

With some sadness and reluctance I discarded a PVC-framed design due to cost. It would have been an elegantly simple yet devastatingly stylish rhizotron. Instead I turned to a cheap wood frame. This means the frame will be boxier (a loss of style points) and prone to decomposition (but should easily survive long enough for my purposes). And less cool.

Here are some sketches:

Figure1. A simple rhizotron design.

Figure 2. The side.

 

The rhizotron is composed of two 12″x24″ sheets of plexiglass with a 1.5″ thick wooden frame between them (I am considering making it 2″). Bolts run through the frame and plexiglass, with wing nuts holding the glass in place. The rhizotron will be filled with soil and two firs will be planted in it. Pieces of foil-covered foam insulation will be placed over the glass to block the light and buffer the temperature. To encourage the roots to grow to the glass the rhizotron will be held at a 30° angle. After root developemnt occurs I’ll be incorporating flooding treatments of varying lengths.

Right now my estimated cost for the design above is less than $20 per rhizotron. My current task is to figure out just how many I need.

Figure 3. All is well in the rhizotron.

I’m confident I won’t be able to see clear pictures of fir root systems like I sketched above. I’ll see bits and pieces. Many of the roots will be shy.

Developing an idea based upon theory, speculation, and anecdotal evidence is a bit scary. Especially when it is linked to my ability to graduate. The behavior of fir roots in flooded soils is not well-studied or documented. It seems that differences in morphology and physiology should be apparent following flooding. One question that is fascinating is why do vast differences in flooding tolerance exist between different species of firs? Another is how quickly does permanent damage caused by flooding occur in Fraser fir? I hope to explore these questions this summer.

Designing rhizotrons is the easy part. Experimental design and procedure will be trickier. My journey in the wilderness of research continues. . .

Two Busy Days

The past two days I dedicated to preparing firs for my upcoming experiments. I washed all the peat and perlite from the root systems and potted them in DeePots. I’m working with Abies fraseri (Fraser fir), Abies balsamea var. phanerolepsis (Canaan fir), and two seed sources of Abies nordmanniana (Nordmann fir).

After two long days this is what I had:

A formation of firs.

If they knew I was plotting to kill them they might not be so calm. Flooding and fungal-like organisms are in their future.

 

Next up is culturing two isolates of Phytophthora on rice. I pick up my inoculum cultures next week. Since I’m giving my firs phytophthora infested rice I thought I might include some General Tso’s chicken, it’s the least I can do.