Foxes provide a direct dispersal service to phoenician junipers in mediterranean coastal environments: ecological and evolutionary implications

Background and aims: Exploring the role of mammalian carnivores as seed dispersers in Mediterranean environments is crucial for understanding biotic interactions and preserving mutualistic networks in areas with high biodiversity. We examine the potential role of the Sardinian fox (Vulpes vulpes subsp. ichnusae) as a seed-disperser of two juniper species (Juniperus phoenicea subsp. turbinata and J. oxycedrus subsp. macrocarpa) in Mediterranean coastal environments. Methods: Observational and manipulative experiments were conducted in five coastal sites in northwestern Sardinia (Italy) between 2010 and 2013. Key results: We found that Sardinian fox actively disperses seeds of J. phoenicea subsp. turbinata, whereas no evidence was obtained for the fox dispersing seeds of J. oxycedrus subsp. macrocarpa. Fox scat contained, on average, 73-86 J. phoenicea subsp. turbinata seeds, accounting 16.3-17.8 % of the average dung weight. The role of Sardinian fox as a primary disperser of J. phoenicea subsp. turbinata is by directly dispersing juniper seeds (via defecation) to a specific microhabitat (i.e. 80-90 % of dung was released on dwarf plants, mainly Helichrysum italicum subsp. microphyllum), which positively affected the survival of emerged seedlings). We quantified that fox dispersed 30 to 100 seeds per day per hectare (3 500-10 500 seeds per hectare in one winter season). Conclusions : We reported that Sardinian fox is a direct disperser of J. phoenicea subsp. turbinata, thus playing a major role in secondary successional dynamics in Mediterranean coastal environments. Evolutionary implications are discussed, in that the positive interaction between Sardinian fox and J. phoenicea subsp. turbinata could be recent, following the introduction of fox to the Tyrrhenian islands during the 7th-6th millennium BC.