Just beyond the rolling hills of the piedmont in South Carolina, a few bends past where the community of Union calls home, is a place full of mysteries. A quiet, sleepy forest that if you’d probably never look at twice unless you heard some of the local stories. This mysterious place I speak about is Calhoun Critical Zone Observatory.

Check out these "tiger stripes" of oxidized and reduced iron at the Calhoun CZO!

Calhoun CZO's amazing soil pit with young forest growth. Dan Richter for scale!

Dan Richter and Justin Richardson

Check out those colors of the Tyger River at the Calhoun CZO!

Dan Richter and company examining the soil-water interface for iron oxide precipitation.

A data collector gathering solar power to store that data! Calhoun CZO.

The Calhoun CZO started off as part of the Calhoun Experimental Forest. However, as questions became much deeper than timber harvesting and loblolly rotation, Dan Richter and fellow scientist were able to propose much more in-depth geoscience/soil questions, which led to the creation of the Calhoun CZO, to pursue these more perplexing mysteries of the Earth’s surface in face of human dominance.

Most mysteries are about who did it. In this case, we know who did the damage. It was the harsh system of oppression on the slaves and soils in this long abandoned cotton farm. At the command of belligerents, slaves tore at the earth and laid waste the top soil. The real curiosity of the Calhoun CZO is how did things end up as they are and how will they be in the future.

Trying to understand the gorgeous “tiger stripes” of alternating bands of oxidized and reduced iron is a big boggling. We are told that under certain conditions, iron is reduced or oxidized. But how can they be both in just a few inches of each other and alternate as such for many feet! This is a feature we may think we know but there are many questions still unanswered.

The next big mystery is how will this modernized loblolly tree farm act in the future? Will it be a truly sustainable system, since foresters happily call loblolly pine a ‘weed’, will it continue to be a flourishing tree. How will the soils respond in the future? These are only a few of the questions visited in Dan Richter book Understanding Soil Change he co-authored with his former student Dan Markewitz. Both are fantastic scientists and great people to be around.

From the fantastic colors of the ‘tiger striped’ Ultisols to the red-blue colors of the Tyger River. Calhoun is an amazing place to do research and there are plenty of mysteries left unsolved!