Quantifying spatio-temporal patterns of forest fragmentation in Hymettus Mountain, Greece

• The internationally protected Hymettus Mountain near Athens is under severe human pressures the latest decades.
• Changes in composition and spatial pattern of the area was studied using 9 Landsat images and random forest classification.
• Cross-classification for three periods during 1985–2013 and eight class based landscape metrics were used.
• The results indicate that human pressures increased forest fragmentation especially at the class boundaries.
• A cost effective approach is presented to facilitate science based policy for realistic management plans of the area.

The rapid land use/cover change (LUCC) and landscape fragmentation occurring around the world is largely attributed to human induced factors. Landscape fragmentation has become a central issue in landscape ecology and conservation policies due to its direct influence on biodiversity which consequently endangers the sustainability of ecological goods and ecosystem services. Thus, fragmentation monitoring and assessment is a critical issue in land use planning and sustainable environmental management in order to avoid any irreversible negative consequences. This research explores the application of methodologies that employ multi-temporal satellite imagery, combined with geographical information systems and landscape metrics, to assess forest fragmentation. The objective is to determine spatio-temporally the LUCCs focusing on the woody vegetation in Hymettus Mountain of Greece over the last decades. The study area, which has been designated as a Natura 2000 site, is situated near the city of Athens. It faces various perturbations triggered by socio-economic factors and the absence of an ongoing contextual appraisal for conservation. To quantify the LUCCs, nine Landsat images spanning 28 years are classified. Post classification comparison is applied to generate transition maps. Additionally, eight landscape metrics are calculated. The change detection results identify hot-spots of forest fragmentation where mitigation measures should be taken, so that further irreversible alteration of the ecosystem is prevented. The landscape metrics advocate that, during the last three decades, the woody vegetation have steadily been more fragmented. The primary direct causes are economic driven intense anthropogenic activities along with frequent wildland fires whereas the indirect cause is the absence of a sustainable environmental management and conservation strategy.