Soluble Reactive Phosphorus Transport and Retention in Tropical, Rainforest Streams Draining a Volcanic and Geothermally Active Landscape in Costa Rica.: Long-Term Concentration Patterns, Pore Water Environment and Response to ENSO EventsFrank J. Triska, Catherine M. Pringle, John H. Duff, Ronald J. Avanzino, Alonso Ramirez, Marcelo Ardon and Alan P. Jackman · Biogeochemistry · 2006