Title: The Phosphorus Paradox(es): How do sediment and soil processes control the most geologically scarce and biologically crucial element of the periodic table?
Abstract: Phosphorus (P) presents several compelling paradoxes. Phosphorus is arguably the most crucial element for life as we know it, while at the same time is the most geologically unavailable relative to its biotic need. The biogeochemical cycling of P is mediated by a unique combination of complex interacting biological and geochemical processes that make it both challenging and interesting to study. In human dominated watersheds, like many of the tributaries that flow into the Great Lakes, concern with P cycling mainly relates to excess P loads from mostly non-point sources causing eutrophic conditions and harmful algal blooms in vulnerable downstream aquatic ecosystems. At the poles, where soils are warming at unprecedented rates, P availability may limit the capacity of plant growth to offset some of the net loss of long-stored soil C to the atmosphere as permafrost thaws and soil respiration is enhanced. In this talk, I will share research on how soil and sediment biogeochemical processes influence P availability to plants and algae in temperate human-dominated systems and polar systems experiencing rapid change.