Insights into seascape ecology: landscape patterns as drivers in coastal marine ecosystems = Perspectives en l'ecologia del paisatge marí: els patrons del paisatge com a factors de control en els ecosistemes marins costaners

摘要

[eng] Habitats commonly occur as more or less interconnected patches constituting spatial heterogeneous mosaics. Connectivity and interactions among habitats can determine their functioning. Therefore, ecological patterns and processes within these habitats, and among them, are modulated by the spatial structure of the entire mosaic. Landscape ecology is aimed at understanding how the composition (patch types and sizes) and configuration (how those patches are arranged spatially) of habitats in a mosaic influence the functioning of the overall system and its individual components (the patches and the species moving across), at a panoply of spatial scales. Interactions at landscape level are usually associated either to the movement of organisms (active mobile entities) or to the transfer of materials (passive mobile entities) from one habitat to another. Applying landscape ecology, the interactions among and within ecosystems can be identified and evaluated to optimize conservation efforts across broad spatial scales. This approach, although has been successfully used in terrestrial ecosystems, remains poorly explored in the marine realm. This thesis is an attempt to assess the influence of landscape patterns in the ecological function of marine habitats. The thesis focus on the study of coastal landscapes (or seascapes) due to its resemblance to terrestrial ones, and because they are among the most vulnerable to human action and climate change. With this objective we focus on the study of three main processes of special importance in the coastal systems. First, we focus on the study of landscape patterns influence on fluxes of material among habitats of the coastal seascape and resource-driven processes, such as trophic webs and recycling of nutrients. Secondly, we study how landscape patterns can influence on sediment carbon storage in coastal habitats, particularly in seagrass ecosystems. And in third place we study the influence of landscape patterns in shaping communities. In particular we study the role of landscape patterns in shaping littoral fish assemblages, as due to its mobility they can be strongly affected by the landscape structure and their biology could also play an important role.). Doing this, we attempt not only to improve general knowledge on seascape ecology, but also to provide new insights useful for management. Therefore, this thesis provide new evidence emphasizing the importance of landscape-level interactions and processes in driving coastal ecosystems, and underlining how the relative abundance of habitats and their spatial arrangement influence ecological functions across the coastal ecosystem mosaic.