Soil Comparisons in a Disturbed Chaparral Area: Evidence of Primary Succession

Abstract

In 1996, the construction excavation of a mature chaparral area at Flintridge Sacred Heart Academy created a barren area named the Cut, stripped of previously present plants, nutrients, organic matter, and soil. Thirty years later, this area is slowly redeveloping and appears to be a stable community with sparse vegetation surrounded by chaparral and coastal sage scrub. The severe nature of the disturbance means that primary succession is most likely the successional pathway to recovery. This study focuses on the slow recovery of a disturbed chaparral ecosystem through soil and ecological analyses, including tests of nutrient levels, pH, organic matter content, clay composition, and root depth, while comparing the cut to the surrounding mature chaparral. Our results show that despite the disturbance, the Cut is undergoing slow primary succession. The key findings include depleted nutrients, regular pH, elevated clay and organic matter content, higher water retention, longer water infiltration, and shorter plant root depth, all in the cut, indicating characteristics of an area going through primary succession. This study confirms that chaparral ecosystems can recover from severe disturbances through primary succession, albeit at a slow rate. These findings underscore the importance of long-term monitoring to understand the trajectory of ecosystem recovery.