Onaylis Triay-Limonta

Frugivorous mammals play a key role in forest regeneration by dispersing seeds yet their effectiveness can vary with landscape disturbance and the native or exotic status of the plant species. In the temperate forests of southern Chile, we evaluated the seed dispersal efficiency (SDE) of foxes (Lycalopex spp.) for native and exotic fleshy-fruited plants across 10 sites spanning a gradient from less to more disturbed landscapes. SDE was assessed though two components: quantity (frequency of feces containing seeds and number of seeds per plant species) and quality (proportion of viable seeds and their germination success under natural conditions). Between November 2022 and July 2023, we collected 199 fox fecal samples, of which 131 contained seeds. In total, we recovered of 23,012 seeds from three native species (Aristotelia chilensis, Gaultheria mucronata, Ugni molinae) and three exotic species (Prunus spp., Malus sylvestris, Rubus ulmifolius). Native seeds were more frequently found in feces from less disturbed landscapes, whereas exotic species exhibited more variable patterns. Seed viability was generally high and unaffected by landscape type, although germination rates were higher in less disturbed areas. Notably, G. mucronata failed to germinate in more disturbed landscapes despite high viability. Conversely, U. molinae showed significantly greater SDE in more disturbed areas due to higher seed quantity and germination. These findings demonstrate that foxes are effective seed dispersers of both native and exotic species, with their effectiveness shaped by landscape type and plant species. Our results highlight the dual ecological role of generalist frugivores in supporting native plant regeneration while potentially facilitating the spread of exotic species. We recommend that future conservation and restoration efforts consider these dynamics when managing fragmented temperate forests.

Seed dispersal by frugivorous mammals is crucial for plant reproduction, but anthropogenic disturbances can disrupt this process. However, there is a lack of research on mammalian seed dispersal in anthropogenic habitats, with few systematic literature reviews available. In order to address this gap, a review of scientific literature published since 1990 was conducted. A total of 275 articles from 52 countries, predominantly from South America, were found for the review. These articles contained information on 764 mammal species from 54 families, with Canidae being the most studied. The studies focused on various aspects of seed dispersal, including animal visitation rates (60%), seed quantity in faeces (78.9%), seed viability (49.1%), germination (49.5%), and seedling recruitment. However, only a small percentage of the studies examined the impacts of human disturbance on seed dispersal (5.8%), particularly the quantity of seeds dispersed. There is a need for further studies that integrate the analysis of seed dispersal effectiveness by mammals while considering the effects of human disturbances, particularly in areas with high plant and mammal diversity threatened by human activities.