A GIS for the SIEG

Françoise Gourmelon (1) , Frédéric Bioret (1), Judd Howell (2)

(1) LETG UMR 6554 CNRS - Institut Universitaire Européen de la Mer (UBO), Technopôle Brest-Iroise, Plouzané (FR)
(2) Patuxent Wildlife Research Center (USGS), Laurel MD (US)

In 1999, the Small Island Ecosystem Group (SIEG) was created by the USGS and the French CNRS, to identify a network of small islands managed as nature reserves as potential sites for long term ecological monitoring methodologies and for understanding ecological processes. The goal was to develop a common protocol for interdisciplinary monitoring of marine and terrestrial environments of islets as nature sanctuaries and integral reserves for applications to research, management and education. The islets in concern are located in protected areas of Mediterranean, northern Atlantic and Pacific oceans. Their long term monitoring with common issues and methodology would provide a contribution to research on the effects of Global climate change. European and US scientists and managers are gathered into this group. During a first workshop held in 1999, several recommendations were produced for ecological processes research, for long term ecological monitoring and for testing methodologies for adaptive management : 1) use a global approach about ecological interactions and functions of marine islets, 2) use indicator features that are representative of changes or trends which can be monitored for the long term, 3) establish guidelines for management that will maintain the integrity of the ecological process of the islets.

In this pluridisciplinary context, the use of GIS is also recommended for their capability to provide a efficient methodology for storing, retrieving, analysis, modelling and visualising the vast amount of spatial data collected on such a complex network by different providers. GIS may contribute to long term ecological monitoring methodologies and for understanding ecological processes on small protected islands for data inventory, environmental analysis and decision making.

One of the French contributions to this international project concerns the terrestrial component of protected islets. In 1992, the Marine Islets Working Group of Reserves Naturelles de France has identified a common process on the islets of the network: the degeneration of the vegetation cover probably due to fauna pressure such as rabbits and gulls. According to scientific and management purpose, the terrestrial vegetation mapping of several atlantic and mediterranean islets has been performed in 1996 according to a common methodology. Based upon a phytosociological approach, which takes into account the dynamic by replacing each vegetation unit within a vegetation serie, the data are collected with local aerial photographs. Data are updated every 6 years according to the management plan of each reserve. The diachronic analysis of the vegetation dynamic characterises trends and changes between two inventories. An equivalent methodology based on common typology and time-scale schedule, standardized protocols for data collection, and data analysis with a GIS provides the establishment of comparative synthesis. It appears that this kind of approach may provide the first step for an adaptive management which would contribute efficiently to the understanding of management issues.