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Spatio-ecological heterogeneity is strongly linked to many ecological processes and functions such as plant species diversity patterns and change, metapopulation dynamics, and gene flow. Remote sensing is particularly useful for measuring spatial heterogeneity of ecosystems over wide regions with repeated measurements in space and time. Besides, developing free and open source algorithms for ecological modelling from space is vital to allow to prove workflows of analysis reproducible. From this point of view, NASA developed programs like the Surface Biology and Geology (SBG) to support the development of algorithms for exploiting spaceborne remotely sensed data to provide a relatively fast but accurate estimate of ecological properties in vast areas over time. Most of the indices to measure heterogeneity from space are point descriptors : they catch only part of the whole heterogeneity spectrum. Under the SBG umbrella, in this paper we provide a new R function part of therasterdivR package which allows to calculate spatio-ecological heterogeneity and its variation over time by considering all its possible facets. The new function was tested on two different case studies, on multi- and hyperspectral images, proving to be an effective tool to measure heterogeneity and detect its changes over time.

The present work provides an overview of recent studies in coastal dune systems performed by the Plant Ecology Laboratory, Roma 3 University (Italy), highlighting major findings. In this review major habitat types along the sea-inland environmental gradient are described, emphasizing their ecological value in terms of biodiversity and landscape heterogeneity. A synthesis of major threats is also presented. Occupying transition zones between terrestrial and marine ecosystems, coastal dune systems are characterized by strong environmental gradients which determine the coexistence of different plant communities in a relatively small area. Despite the presence of numerous habitats which are considered priorities for international conservation goals, coastal dune ecosystems have undergone consistent transformations and are currently considered to be highly endangered. The understanding of major threats is a crucial step toward developing effective management strategies to safeguard coastal dune biodiversity, in the hope of preserving the functionality and uniqueness of these fragile ecosystems.