By Lisa Micheli, PhD, President & CEO, written on September 15, 2015
It is a pitch black harvest morning at 5 AM and I find myself in the Sonoma Safeway at the Starbucks counter trying to calculate how much coffee I can safely transport to the Bechtel House via Prius without spillage. I am headed up to Pepperwood to meet some of our incredible TBC3 scientists - who all arrived the night before to share a nice sunset dinner on our deck overlooking the incredible view. We are prepping for a full day of Sentinel Site work, complete with a field excursion to dig a soil pit. The field trip requires an early departure due to the threat of hundred degree temperatures by midday. I get the most sugary doughnuts I can find and carry them out to my car with several pints of hot coffee.
This is a great day at Pepperwood. This particular group of folks, which includes my TBC3 co-chair David Ackerly of UC Berkeley, Alicia Torregrosa and Alan and Lorrie Flint of the US Geological Survey, and Stu Weiss of Creekside Earth Observation - the mastermind behind the Bay Area’s Conservation Lands Network. Who wouldn't get up early to secure stimulants for this brilliant crew!? I want to arrive in time for the breakfast window which often is the most creative, with people freshly out of their tents watching the sunrise, some still in jammies, cracking open their laptops and brainstorming hypotheses about how our natural world works. This is how great interdisciplinary science happens - unless, of course, you are out of coffee.
|The TBC3 team visiting a weather station on the preserve.
In peering into the hole from close-up we all discover something different through that window into the skin of the earth. We notice the influence of roots on potential water flow pathways, evidence of burrowing animals stirrings the strata up, and the wildly variable conditions just a few feet away in this hummocky forest landscape. This complexity and diversity is thought-provoking but working against our desire to rapidly generate statistically-significant field measurements of the soil hydraulic properties across David’s tennis court-sized field plot. The more the variability, the more pits Celeste will have to dig to get a valid average. That's how statistics works.
So what is the story the soil pit tells? First of all, it’s darn dry. There isn't one iota of moisture evident below the earth’s surface in the midst of California’s worst drought in centuries. The soils are only about 7 inches thick, but below is a layer of deeply weathered porous rhyolite capable of storing great amounts of moisture. This actually what is keeping this patch of forest alive - a secret water cache deep below where our spade can reach-something we would not know without digging this hole in the ground. Lorrie rips out a clod and pours some water on the light gray rhyolite material that absorbs the liquid right up - not exactly the behavior you’d expect of a rock.
The soil protocol we planned to use assumes much deeper soils than we are finding, so we debate how to adjust our sampling strategy to handle that. (We love standardized protocols but in nature rarely do they work everywhere!) We also brainstorm how we can we use our map data to estimate how variable the soil thickness may be across all of David’s sites to minimize how many of these pits Celeste will have to dig. Solutions to these sampling questions are never perfect due to the complexity we find everywhere we look in nature - but they do have to be internally consistent!
Too late, perhaps my most important amateur botanical observation of the day is that we are holding this discussion in a deceptively leafless patch of poison oak. Upon return we are joined by the new executive director of the Laguna the Santa Rosa Foundation, where several TBC3 scientists have also worked. In my hostess’ haste I forget to do my usual Technu rubdown post hike-normally a ritual since as a non-native I am wildly allergic to poison oak. I think I am out of the woods, so to speak, but now I write this with a few bubbles on eyelid, arm and knee to prove that plants can be smarter than people. The toxic oils apparently traveled right through my field pants. (“Oh those tricky plants” as Pepperwood’s Preserve Ecologist Michelle Halbur likes to say.)
But today I wear my poison oak as a badge of honor, proof that this mostly desk-bound scientist still can make it into the field with dear colleagues who share a keen desire to understand the relationships between water, earth, sun and life. I am reassured that in this age of technology humans observing nature directly remains the ultimate source of our knowledge and inspiration. And, at the end of the day, as the first sprinkles of fall rain try to slake the earth’s deep thirst, I am reminded that really meaningful collaborations are always sustained by the joys of camaraderie.