Interactions Between Vegetation And Nutrient Dynamics In Coastal Marine Ecosystems: An Introduction

The intent of this chapter is to provide a brief background for the ideas and hypotheses that led to the making of this book. Primary producers are quantitatively important in most shallow coastal ecosystems, and although these areas represent less than 2% of the oceanic surface they produce about 20% of the global marine primary production (Charpy-Robaud and Sournia 1990). Autotrophic communities in coastal ecosystems are complex in nature, i.e. they are typically made up of various forms of microalgae (benthic, epiphytic and pelagic), macroalgae (ephemeral and persistent, sensu Littler and Littler 1980) and rooted macrophytes, representing a wide range of life strategies, morphological features and, physiological, functional as well as ecological properties (Littler and Littler 1980; Sand-Jensen and Borum 1991; Duarte 1995; Schramm 1996). These inherent differences may influence the way that different plant types respond to environmental changes (for example eutrophication), but we also expect that they affect the fate of organic matter produced during photosynthesis and, thus, modify major pathways of energy, carbon and plant nutrients (especially N and P). The composition of plant communities that inhabit coastal marine areas may thus play an important role for the functioning of these ecosystems (Duarte 1995).