Earthy science

12/22/2015

Libby Porzig paces 19 meters—19 of her long strides—from the center point of a study site seemingly located in heaven. From this grassy ridge, high above the Russian River mouth, the winter sunlit view is phenomenal, and Libby sings out “gor-geous” as she reaches her destination. She sets down a gallon water jug and slides her backpack onto the ground.  

Meanwhile, Ryan DiGaudio tucks away the GPS unit he used to locate this center point on an enormous landscape. It worked well; we even found the miniscule plastic marker that anchors a 50-meter radius sampling area. Several dozen points like this are scattered across the 5,600 acres of Jenner Headlands Preserve. Ryan is familiar with them all, having gathered bird data point by point across the preserve in recent years. 

He follows Libby downhill holding an odd-looking implement in each hand. There’s a long, slender, tubular probe made of stainless steel and a meter-square frame made of PVC pipe holding a criss-crossed grid of nylon twine. Suzie Winquist brings a garden spade and a binder labeled “Rangeland Monitoring Network—Field Data.” 

I stumble along behind, slowed by the mesmerizing environs, a fresh-dug badger burrow and the steep, uneven ground. At last I deliver the two small plastic pails I’ve carried from Ryan’s vehicle on the gravel road above us.

The three biologists, all on the staff of Point Blue Conservation Science, have an appointment this morning with dirt. They are keen on getting down on the ground to gather grains of knowledge about the substance that’s a source for much terrestrial life on this planet. Soil, that is. 

The Rangeland Monitoring Network is now in its second year of data collection on dozens of properties across California. The goal: new detailed knowledge of the soil’s health—its looseness (compaction), carbon content (built up by plants, especially native perennials) and ability to receive and hold water (infiltration plus compaction). 

With other members of an extended team, Libby and Ryan will repeat today’s routine at 200 points this winter. Additional rounds of monitoring at the same locations will focus on vegetation in early spring and on birds during their nesting season. 

All three biologists here are colleagues of mine. Libby and Ryan both reside in Bolinas, where each was once a bird-monitoring intern at the Palomarin Field Station. So was Suzy, who arrived more recently and now is part of a growing collaborative program that includes soil monitoring. She is learning the methodology today.

This is how it goes. First, toss the gridded square on the ground and examine vegetative cover. Then press down a plastic ring, pour in some water and time the infiltration rate. Pound a small steel ring into the ground and pull out a precise amount of earth, the weight of which, both fresh and dried, will indicate soil compaction. Extract a core of soil 40 cm. deep, for lab analysis of carbon content. Record these and some other metrics, repeat the whole rigmarole in four other random spots paced out from the center point, and call it a good morning’s work.

Partway through all this, Libby crumbles a handful of the chocolate brown soil, admiring its texture. “This is so different from a sample I got last week in Yolo County: that was uniform, yellowish and dense as a solid block,” she says.  

From the same handful she extracts a tiny living assemblage and dangles it from her fingertips. “Look,” she says. “Life is here.” A single seed is married to a strand of fungal hypha that ends in a clump of living brown dirt. Myriad interactions of this sort, generally unseen below our boots, are the focus of this fascination.

“What interests me most about soil ecology is the dynamic feedback loops driving the system,” Ryan says. “Soils influence the life above ground, and in turn the life above ground influences the soil. Part of our job as ecologists is to understand how all the pieces fit together, and since soil is the ‘engine of life,’ soil ecology is a fundamental piece of the puzzle.” 

With the knowledge gained from rangeland monitoring, Point Blue can provide recommendations to land managers who aim to improve the ecological functions of soil through grazing and other practices.  

For Libby and Ryan and Suzie, there is clearly more to this work than penciling numbers into the data notebook. While wedded to the ground, they embrace the surrounding life, from the red crossbills calling high above to the ferruginous hawk perching majestically. These are curious people, fully alive in the field.

 

Claire Peaslee is a naturalist, writer and improviser exploring ways that people learn from the living world. This is the first in an irregular series about the curious people of West Marin: what are they investigating?