Assessing transhumance corridors on high mountain environments by least cost path analysis: the case of yak herds in Gilgit-Baltistan, Pakistan.

Mountain environments in the world host highly specialized flora and fauna which are vulnerable because of land use and climate change. Transhumance and other land use traditional practices are present in most of the mountains of the world, and management tools able to cope with new socioeconomic settings and environmental changes are urgently needed. During past centuries, yak (Bos grunniens) herding in Northern Pakistan involved the migration of herds to high mountain international rangelands, but the recent establishment of international borders breaks the traditional transhumance paths, promoting several ecological problems. In this paper, we propose the use of least cost path (LCP) algorithm to identify the most efficient corridors of transhumance for yak herds on northern high altitudes of Pakistan. Specifically, LCP was implemented to identify the critical grazing areas and the connecting zones to be accounted in a new management plan for the yaks in the region. The LCP analysis showed that some grazing areas are connected with several paths, whereas other areas are connected to a lesser extent. The analyses identified a set of best minimum cost paths able to guarantee local connectivity. We also delineated several medium and low efficient paths that could play a crucial role for maintaining regional connectivity which is essential for reducing the isolation of herds and the consequent inbreeding problems. The analytical framework implemented in this study allowed to (1) provide valuable information concerning the movement of yak herds in Gilgit-Baltistan, (2) identify potential corridors that are able to promote herd movement between villages and high mountain rangelands, and (3) identify critical areas for the connectivity of yaks by ranking of the potential corridors according to their length and permeability. The analysis would be extended to other transhumant herds and high mountain areas that are facing sociopolitical transformations and environmental changes.

A systematic conservation planning approach to fire risk management in Natura 2000 sites.

A primary challenge in conservation biology is to preserve the most representative biodiversity while simultaneously optimizing the efforts associated with conservation. In Europe, the implementation of the Natura 2000 network requires protocols to recognize and map threats to biodiversity and to identify specific mitigation actions. We propose a systematic conservation planning approach to optimize management actions against specific threats based on two fundamental parameters: biodiversity values and threat pressure. We used the conservation planning software Marxan to optimize a fire management plan in a Natura 2000 coastal network in southern Italy. We address three primary questions: i) Which areas are at high fire risk? ii) Which areas are the most valuable for threatened biodiversity? iii) Which areas should receive priority risk-mitigation actions for the optimal effect?, iv) which fire-prevention actions are feasible in the management areas?. The biodiversity values for the Natura 2000 spatial units were derived from the distribution maps of 18 habitats and 89 vertebrate species of concern in Europe (Habitat Directive 92/43/EEC). The threat pressure map, defined as fire probability, was obtained from digital layers of fire risk and of fire frequency. Marxan settings were defined as follows: a) planning units of 40 × 40 m, b) conservation features defined as all habitats and vertebrate species of European concern occurring in the study area, c) conservation targets defined according with fire sensitivity and extinction risk of conservation features, and d) costs determined as the complement of fire probabilities. We identified 23 management areas in which to concentrate efforts for the optimal reduction of fire-induced effects. Because traditional fire prevention is not feasible for most of policy habitats included in the management areas, alternative prevention practices were identified that allows the conservation of the vegetation structure. The proposed approach has potential applications for multiple landscapes, threats and spatial scales and could be extended to other valuable natural areas, including protected areas.

Ecosystem classification for EU habitat distribution assessment in sandy coastal environments: an application in central Italy.

Many recent developments in coastal science have gone against the demands of European Union legislation. Coastal dune systems which cover small areas of the earth can host a high level of biodiversity. However, human pressure on coastal zones around the world has increased dramatically in the last 50 years. In addition to direct habitat loss, the rapid extinction of many species that are unique to these systems can be attributed to landscape deterioration through the lack of appropriate management. In this paper, we propose to use of an ecosystem classification technique that integrates potential natural vegetation distribution as a reference framework for coastal dune EU Habitats (92/43) distribution analysis and assessment. As an example, the present study analyses the EU Habitats distribution within a hierarchical ecosystem classification of the coastal dune systems of central Italy. In total, 24 land elements belonging to 8 land units, 5 land facets, 2 land systems and 2 land regions were identified for the coastal dunes of central Italy, based on diagnostic land attributes. In central Italy, coastal dune environments including all the beach area, mobile dunes and all the fixed-dune land elements contain or could potentially hold at least one EU habitat of interest. Almost all dune slack transitions present the potentiality for the spontaneous development of EU woodlands of interest. The precise information concerning these ecosystems distribution and ecological relationships that this method produces, makes it very effective in Natura 2000 European network assessment. This hierarchical ecosystem classification method facilitates the identification of areas to be surveyed and eventually bound, under the implementation of EU Habitat directive (92/43) including areas with highly disturbed coastal dune ecosystems.