Oceanic islands face very serious environmental issues such as climate change, environmental degradation, loss of biodiversity
and proliferation of invasive alien species. The delimitation of the IES shall consider the many inter-relationships between all
biophysical and cultural variables, contributing therefore to a better understanding of the socio-ecological system. The Island
Ecological Structure (IES) includes the key natural resources, biophysical functions and ecological processes within this territorial
unit, in order to ensure the existence of a continuum naturale across the island. This paper presents a methodological proposal of
mapping IES. A case-study based on consistent biophysical and land policy criteria was conducted for S. Miguel Island
(Archipelago of the Azores, Portugal). The results have showed that the Island Ecological Structure covers about 75% of its total
area. The land use conflictive areas within the Island Ecological Structure (21%) have also been identified and should be
addressed by Land Management Plans in order to minimize the conflict effects.