Michael Conway of the Arizona Geological Survey was on hand at the recent BioBlitz in Arizona’s Saguaro National Park to teach students, scientists, and bloggers about something many of us don’t readily associate with a 24-hour inventory of all the species we could find in the preserve: the rocks and soil.
To get a better idea of the impact of dirt, Conway takes you back to the planet’s distant past, to the geological forces that produced the soils that facilitated life across the epochs. There is talk of volcanoes and a shallow sea that once covered the area. Some 12,000 years ago, the desert we were standing in at the BioBlitz was home to 12-foot-tall mammoths, enormous animals traveling in herds like African elephants.
The soils sustaining the megafauna back then were not necessarily the same kind of soils of the region today, Conway explained. As the climate changed at the end of the Ice Age all those centuries ago, the soils would have been exposed to rainfall, ice and snow and probably would have been largely washed away, exposing rock and forming new kinds of soils. “Soils play a major role here, in terms of what kinds of vegetation you see here,” Conway said.
The geology reminded me that life is really a thin veneer on top of our rocky planet. There is much to think about, even as we dip our finger into the soil.
David Braun is director of outreach with the digital and social media team illuminating the National Geographic Society’s explorer, science, and education programs.
He edits National Geographic Voices, hosting a global discussion on issues resonating with the Society’s mission and major initiatives. Contributors include grantees and Society partners, as well as universities, foundations, interest groups, and individuals dedicated to a sustainable world. More than 50,000 readers have participated in 10,000 conversations.
Braun also directs the Society side of the Fulbright-National Geographic Digital Storytelling Fellowship.