Alexandra Rodriguez Pereiras
Forest Ecologist
Ph.D., 2009, Pablo de Olavide University

Dr. Rodriguez is interested in effects of plants and environmental perturbations on soil nutrient cycling and spatial distribution of soil resources in temperate forest ecosystems. Plants can determine the availability and spatial distribution of the soil resources affecting on soil physical, chemical and biological properties. In turn, the spatial patterns of soil resources influence the individual functioning of plants, and ultimately the structure and function of plant communities and ecosystems. Thus, the spatial relationship between plants and soil is clearly bi-directional. On the other hand, soil-plant system perturbations, such wildfires, can modify not only the availability but also the spatial pattern of soil nutrients. Her current research as a Fulbright postdoctoral scientist focuses on assessing the role of nitrogen (N) deposition and tree species composition on the carbon (C) storage in the soil of Northern Hardwood Forests.

Current Research

Understanding the controls on C storage in forests is a crucial need for predicting the future CO2 concentrations of the atmosphere. The role that N deposition plays in determining sink strengths of forest soils for C depends on where N inputs to forests ultimately reside. If the primary recipient is the “heavy fraction” mineral-associated organic matter, which is expected to be resistant to further decomposition, then it should serve as a long-term physically protected sink for C and N. However, if N inputs are sequestered mainly in the “light fraction” predominantly mineral-free organic matter, then the resultant C storage is minor. By taking advantage of an ongoing long-term replicated, single-species, paired-plot N fertilization experiment in the Catskill Mountains of southeastern NY, we will use density fractionation (physical fractionation) and long-term laboratory incubation of soil (biological fractionation) to measure the amount of C and N in both soil fractions.