Sometimes networking with new scientists at conferences and workshops can pay dividends in terms of new ideas. Steve Garrity and I recently attended and taught practicum sessions at the PEPg (Plant Environmental Physiology group) Ecophysiology Workshop. The mission of this workshop was twofold: to invite the world experts on plant physiology measurements to come and lecture, and to invite the manufacturers to teach about instrumentation and provide hands-on training.
Workshop participants check the water potential of soil with a UMS T5 mini-tensiometer.
With three sessions per day using METER instrumentation and only two of us, neither Steve nor I could teach about leaf water potential using the WP4C chilled mirror dew point instrument. So, we asked another scientist who is an expert in plant water relations to teach it for us. Not only did he do a great job of teaching about measuring leaf water potential using a hygrometer, but he also inspired us to take another look at how to make this measurement as we learned about its importance to his research (to learn more about how to do this, watch our virtual seminar).
He’s developed a procedure where you can freeze the leaf and break all of the cells so you are left with the cell water (the symplastic water).
Later in the conference, this same scientist gave a talk about the importance of osmotic potential. He’s developed a procedure where you can freeze the leaf and break all of the cells so you are left with the cell water (the symplastic water). He was able to squeeze that sap out and test it in a thermocouple psychrometer, where he established a relationship between how tolerant plants are for drought and what their osmotic sap water potential (turgor loss point) was. We have made many of those sap measurements but had not used them in this manner. That’s really interesting to us at METER because we were unaware of this relationship, and we have now found another use for osmotic potential measurements in leaves.
We would never have realized this new idea without the help of our colleague. Meeting with other scientists at conferences and talking over ideas can be really important. Have you ever struck gold in terms of coming up with new ideas for research, funding, or inventing new research tools at a conference you’ve attended?
METER’s founder, Dr. Gaylon S. Campbell was born in Blackfoot, Idaho, and grew up on a dry farm in Juniper, Idaho. He went to school in Logan, Utah, finally attending Utah State University where he received a B. S. in Physics in 1965 and an M. S. in Soil Physics in 1966. He was granted a Ph. D. in Soil Physics from Washington State University in 1968. He became an officer in the U. S. Army in 1969, doing meteorological research at White Sands Missile Range, New Mexico. In 1971 he returned to Washington State University as Assistant Professor of Biophysics and Assistant Soil Scientist. There he taught and did research in Environmental Biophysics and Soil Physics until 1998. Since 1998 he has worked as vice president, engineer, and scientist at Decagon Devices, Inc (now METER). He has written three books, over 100 refereed journal articles and book chapters, and has several patents. Today we are interviewing him about his book, An Introduction to Environmental Biophysics.
Dr. Campbell is the author of An Introduction to Environmental Biophysics
Where did you get the knowledge to write the book?
I was hired to teach Environmental Biophysics at Washington State University in 1971, and when I looked around for a textbook to go with the class, there weren’t any that fit very well. I knew what I wanted to teach in the class, and some of the principles were in books that were available, but a lot weren’t. So I started writing up notes to hand out to the students and then improved them over time.
One of the important sources of knowledge for my book was John Montieth’s book, Principles of Environmental Physics. Its first edition came out in 1973. It’s a wonderful book. I didn’t know about it until one of my students brought it into class and let me borrow it overnight.
I went home and started reading it. I read it all night, and by morning I’d finished it. I have read some novels that could keep me awake all night, but that’s the only science book I ever read that could do it.
I was really excited about his approach because it was perfect for what I wanted to do in the class. However, it was at a different level than I needed, so I went ahead and developed my own notes, but his book certainly was an important source.
I started writing up notes to hand out to the students and then improved them over time.
How difficult was it to understand the theory behind what you were writing about?
When I’d take a class in school, I felt like I never understood what was in that class until I attended the next class. Then when I got a bachelor’s degree, I thought, I hope nobody expects me to know something just because I have this degree, because I don’t feel like I know anything. I hoped when I earned a masters degree that it would be better, but I got there and thought, oh boy, I still don’t know anything. It was probably when I took my prelim exam that I finally felt confident enough that I could be a soil physicist if I had to.
But I was wrong about that. I really didn’t understand physics very well, even then. It was when I had to teach it that the real understanding came. When I understood it well enough to lecture about it was when I felt like I had really mastered the theories and understood them at the level that I wanted to.
I suppose that came one piece at a time. In the beginning, I certainly didn’t understand things as well as I did later on. And that still happens today. I learn things that I hadn’t understood before. So I guess when you ask how hard it was: it was an ongoing process. Even when somebody’s already laid it out for you, it doesn’t mean you’re going to understand it. But when you lecture about it and write about it, those are the processes that help to deepen your knowledge and understanding.
When you lecture about a subject and write about it, those are the processes that help to deepen your knowledge and understanding.
The subject is extremely complicated, but people are always saying how easy it is to understand environmental biophysics from your book. How did you bring it down to the level of the students?
When I was in the Army, the philosophy they had was, “If the student hasn’t learned, the teacher hasn’t taught.” That was not the philosophy that you normally encountered at the university. Many professors complained often about how lousy their students were. I never found it to be that way. I always thought my students were getting better and better.
I think it comes down, to some extent, to the philosophy the teacher has. We often see teachers come in and fill the board with equations and wonder why their students don’t understand them. But it’s likely the teacher hasn’t looked at it from the standpoint of the students. The student is going to gain understanding by the same path the teacher did. Professors work and work to put together a wonderful picture of things, and once they have that wonderful picture, they tend to want to dump the whole thing on the student. But students can’t assimilate the whole picture all at once. They have to go step by step too.
If people wanted to learn from your book, what is the best way to get the principles down?
It’s no accident that there are lots of both worked examples and problems for students to solve. I don’t think you can learn physics without solving problems, and so the best way to do it is to look through the ones that we’ve solved in the book and then look through the problems we give at the end of the chapters and solve them. That, I think, is the best way to get there.
Though collaboration can fuel innovation and increase the relevance and complexity of the scientific questions we study, I’ve noticed it does have its ups and downs. The highs and lows we’ve run into on our research projects may help others avoid some of the pitfalls we experienced as many diverse groups tried to learn how to work together.
Researchers discussing science at the Lytle Ranch Preserve, a remarkable desert laboratory located at the convergence of the Great Basin, Colorado Plateau, and Mojave Desert biogeographical regions.
There can be bumps in the road when collaborating with companies who want to test their product. Being at the forefront of innovation means that untested sensors may require patience as you work out all the bugs together. But from my perspective, this is part of the fun. If we are late adopters of technology, we wouldn’t get to have a say in creating the sensors that will best fit our projects as scientists.
Collaborating scientists can also sometimes run into problems in terms of the stress of setting up an experiment in the time frame that is best for everyone. During our experiment on the Wasatch Plateau, we had six weeks to get together soil moisture and water potential sensors, but our new GS3water content, temperature, and EC sensors had never been outside of the lab. In addition, we planned to use an NDVI sensor concept that came out of a workshop idea my father Gaylon had. We’d made ONE, and it seemed to work, but that is a long way from the 20 we needed for a long-term experiment in a remote location at 3000 meters elevation. In the end, it all worked out, but not without several late nights and a bit of luck. I remember students holding jackets over me to protect me from the rain as I raced to get the last sensor working. Then we shut the laptop and ran down the hill, trying to beat a huge thunderstorm that started to pelt the area.
Desert-FMP Researchers at the Lytle Ranch Preserve
Other challenges of scientific collaboration present organizational hardships. One of the interesting things about the interdisciplinary science in the Desert FMP project is the complexity of the logistics, and maybe that’s a reason why some people don’t do interdisciplinary projects. We are finding in order to get good data on the effects of small mammals and plants you need to coordinate when you are sampling small mammals and when you’re sampling plants. Communicating between four different labs is complicated. Each of the rainout shelters we use cover an area of approximately 1.5 m2 . That’s not a lot of space when we have two people interested in soil processes and two people interested in plants who all need to know what’s going on underneath the shelter. Deciding who gets to take a destructive sample and who can only make measurements that don’t change the system is really hard. The interesting part of the project where we’re making connections between processes has required a lot of coordination, collaboration, and forward-thinking.
In spite of the headaches, my colleague and I continue to think of ways we can help each other in our research. Maybe we’re gluttons for punishment, but I think the benefits far outweigh the trouble we’ve had. For instance, in the above-mentioned Desert FMP project we’ve been able to discover that small mammals are influential in rangeland fire recovery (read about it here). We only discovered that piece of the puzzle because scientists from differing disciplines are working together. In our Wasatch Plateau project, my scientist colleague said it was extremely helpful for him to be working with an instrumentation expert who could help him with setup and technical issues. Also, we’ve been able to secure some significant grants in our Cook Farm Project (you can read about it in an upcoming post) and answer some important questions that wouldn’t have occurred to either one of us, if we hadn’t been working together. In addition, solving problems that have cropped up in our projects has spurred us on to a new idea for analyzing enormous streams of data in near-real time. (read about it here).
When we talk with scientists at conferences they often want to know the difference between TDR versus capacitance or FDR. We’ve written a paper about this in our app guide that has been pretty popular, but it can be difficult to find on our website. Here is an introduction and a link if you are interested in learning more.
TDR Sensor Installation (Giulio Curioni, School of Civil Engineering, Univ. of Birmingham)
Capacitance and TDR techniques are often grouped together because they both measure the dielectric permittivity of the surrounding medium. In fact, it is not uncommon for individuals to confuse the two, suggesting that a given probe measures water content based on TDR when it actually uses capacitance.
10HS capacitance sensor
With that in mind, we will try to clarify the difference between the two techniques. The capacitance technique determines the dielectric permittivity of a medium by measuring the charge time of a capacitor, which uses that medium as a dielectric. We first define a relationship between the time, t, it takes to charge a capacitor from a starting voltage, Vi , to a voltage V, with an applied voltage, Vf. Read more….
Watch the webinar
In this webinar, Dr. Colin Campbell discusses the details regarding different ways to measure soil moisture and the theory behind the measurements. In addition, he provides examples of field research and what technology might apply in each situation. The measurement methods covered are gravimetric sampling, dielectric methods including TDR and FDR/capacitance, neutron probe, and dual needle heat pulse.
Take our Soil Moisture Master Class
Six short videos teach you everything you need to know about soil water content and soil water potential—and why you should measure them together. Plus, master the basics of soil hydraulic conductivity.
