The role of dispersal potential on phylogeographic structure, evidenced by the degree of genetic structure and the presence of coincident genetic and biogeographic breaks, was evaluated in a macrogeographic comparative approach along the north-central coast of Chile, across the biogeographic transition zone at 30°S. Using 2,217 partial sequences of the mitochondrial Cytochrome Oxidase I gene of eight benthic invertebrate species along ca. 2,600 km of coast, we contrasted dispersal potential with genetic structure and determined the concordance between genetic divergence between biogeographic regions and the biogeographic transition zone at 30°S. Genetic diversity and differentiation highly differed between species with high and low dispersal potential. Dispersal potential, sometimes together with biogeographic region, was the factor that best explained the genetic structure of the eight species. The three low dispersal species, and one species assigned to the high dispersal category, had a phylogeographic discontinuity coincident with the biogeographic transition zone at 30°S. Furthermore, coalescent analyses based on the isolation-with-migration model validate that the split between biogeographic regions north and south of 30°S has a historic origin. The signatures of the historic break in high dispersers is parsimoniously explained by the homogenizing effects of gene flow that have erased the genetic signatures, if ever existed, in high dispersers. Of the four species with structure across the break, only two had significant albeit very low levels of asymmetric migration across the transition zone. Historic processes have led to the current biogeographic and phylogeographic structure of marine species with limited dispersal along the north-central coast of Chile, with a strong lasting impact in their genetic structure.

Background: The use of wild plants depends on a number of sociocultural and ecological factors, such as the ease of access to natural environments. This limitation for urban inhabitants leads to differences in the knowledge and use of wild plants compared to rural inhabitants. Hypothesis:  Rural and urban populations tend to share a similar knowledge of plants and use similar plants species when easy access to natural landscapes is available. Study site and years of study: Rural and urban area of Curarrehue, Araucanía region (southern Chile), 2017. Methods: The use patterns of wild edible plants (WEPs) and wild medicinal plants (WMPs) were compared between the rural and urban population of Curarrehue. We evaluated the number of WEPs and WMPs collected, their richness and diversity, the most important gathering environments and the way in which knowledge was acquired. Results: No differences were observed in the use of wild plants between the populations, except for the richness of WMPs. The WEPs were gathered mainly from the forest by both populations, and in the case of the WMPs, from forest and disturbed areas. The knowledge was acquired mainly through relatives, collecting plants from forest areas. Conclusions: Access to natural environments is key to preserving traditional practices and contributes to reducing gaps in the knowledge and use of wild plants between local rural and urban populations.

Seed dispersal is a critical process for plant reproduction and regeneration. Successful recruitment depends on pre- and post-dispersal processes that complete a seed’s journey until becoming a new plant. However, anthropogenic stressors may disrupt the seed dispersal process at some stages, collapsing plant regeneration and hampering its long-term persistence. The Chilean palm tree Jubaea chilensis is the southernmost and the only non-tropical palm species, which currently relies on the scatter-hoarding rodent Octodon degus for seed dispersal. We assessed seed fate by measuring predation and dispersal rates through experimental fieldwork in the Palmar de Ocoa site (located within La Campana National Park) and the Palmar El Salto. We also used previous reports on seed harvest and seedling herbivory to depict the whole J. chilensis seed dispersal process and assess the relative importance of different anthropogenic pressures. We asked the following questions: (1) What is the effect of human harvesting on J. chilensis recruitment? (2) Do native and exotic rodents predate J. chilensis seeds in the same way? and (3) Does post-dispersal herbivory matter? We found that J. chilensis fruits are harvested for human consumption, reducing pre-dispersal available seeds by removing about 23 tons per season. Then, post-dispersal seeds at the Ocoa palm grove are heavily predated by exotic (Rattus rattus) and native (Octodon spp.) rodents; only 8.7% of the seeds are effectively dispersed by Octodon degus. At Palmar El Salto, 100% of the seeds were predated by Rattus rattus, precluding further analysis. Finally, 70% of the seedlings were consumed by exotic herbivores (mainly rabbits), resulting in a success rate of 1.81%. Only 7.9% of the surviving seedlings become infantile plants (4 year-old). Our assessment suggests that J. chilensis has aging populations with very few young individuals in disturbed sites to replace the old ones. For those reasons, we suggest increasing its conservation category to critically endangered as land-use change is rapidly fragmenting and shrinking the extant J. chilensis populations. We urge to take urgent actions to protect this relict palm, which otherwise may go extinct in the next decades.

Background: Wild edible plants are species that are not cultivated but can be consumed as food. These plants may exhibit the highest taxonomic and phylogenetic diversity within urban floras, since they have a longer history of use associated with humans than non-edible plants. Also, because biodiversity is strongly associated with biomass, edible plants plant might show higher productivity (biomass per site) than non-edible plants. Questions: Is taxonomic and phylogenetic diversity of wild edible plants higher than non-edibles within urban areas? Is the alpha-biodiversity of wild edible plants positively related to biomass productivity in urban areas? Study sites and years of study: Cities of the coastal Mediterranean-type ecosystem, central Chile, 2015 and 2016. Methods: We characterized the taxonomic and phylogenetic diversity of urban flora differentiating wild edible and non-edible plants. Then, we assessed whether alpha-diversity of assemblages is related to their biomass productivity. Results: Both taxonomic and phylogenetic diversity were higher for edibles than non-edible plants. For edible plants, biomass was positively related to species richness and negatively with the mean phylogenetic diversity (MPD, a measure of evolutionary relationship among plants within an assemblage). Conclusions: Species richness is a suitable proxy to estimate wild edible plant diversity and their biomass in cities surpassing other proxies, such as phylogenetic diversity. Negative effect of MPD on biomass suggests that only a subgroup of related plants, possibly highly adapted to urban conditions, contribute to edible plant production. The distinction between wild edible and non-edible plants offers a better understanding of the assembly rules and biodiversity-biomass relationship within urban floras.

Exotic species are one of the main threats to biodiversity, leading to alterations in the structure and functioning of natural ecosystems. However, they can sometimes also provide ecological services, such as seed dispersal. Therefore, we assessed the ecological impacts of exotic species on native dispersal systems and the mechanisms underlying the disruption of mutualistic plant–disperser interactions. Exotic species negatively affect dispersal mutualisms by (i) altering dispersal behavior and visitation rates of native dispersers, (ii) predating native dispersers, (iii) transmitting forest pathogens, and (iv) predating seeds. Conversely, positive impacts include the dispersal of native plants, forest regeneration, and native habitat restoration via (i) increasing the visitation rates of frugivorous birds, (ii) facilitating the colonization and establishment of native forest trees, (iii) enhancing forest species seedling survival, and (iv) facilitating seed rain and seedling recruitment of early and late successional native plants. The reviewed studies provide similar results in some cases and opposite results in others, even within the same taxa. In almost all cases, exotic species cause negative impacts, although sometimes they are necessary to ensure native species’ persistence. Therefore, exotic species management requires a comprehensive understanding of their ecological roles, since the resulting effects rely on the complexity of native–exotic species interactions.