Soil mineralogy (e.g., percent clay and clay mineralogy, especially the concentration of poorly or non-crystalline minerals) exerts a primary control on soil C cycling. Other drivers of soil C storage include temperature, moisture and land-use, but how poorly or non-crystalline minerals influence soil C balance following release from intensive human land management and under projected climate change conditions is largely unknown.
To better constrain our understanding of soil C cycling under global change, we are exploring three research questions at a volcanic ash-dominated, tropical site: 1) What role does mineralogy play in soil C process rates and storage? 2) To what extent and over what time frame do degraded soils accumulate C following afforestation? Finally, 3) is a degraded soil’s capacity to stabilize and accumulate C altered by the interactive effects of changing climate and afforestation?
Accurately capturing these potentially offsetting effects is critical to projecting ecosystem-level C balance under changing management and climate. The field site is located at the Lyon Arboretum in Manoa, and installation is ongoing.
Graduate student, Casey McGrath, is leading the effort – watch her progress on her project blog!