Ch. 1 Reconsidering Climatic Roles of Marshes: Are they Sinks or Sources of Greenhouse Gases? / Serena Moseman-Valtierra -- ch. 2 The Introduction, Impacts, and Management of a Large, Invasive, Aquatic Rodent in the United States / Stephen R. Kendrot -- ch. 3 The Mesocosm Marsh Ecology of Two Southwestern Spanish Estuaries: Applications / A. Toscano -- ch. 4 Factors Conditioning the Vegetation in the Salt Marshes of the Atlantic Coast of the Iberian Peninsula / Jose M. Sanchez -- ch. 5 Nutrient Cycling in Salt Marshes: An Ecosystem Service to Reduce Eutrophication / I. Cacador