BUSCADOR RECOLECTA

data_PerezMendez_Neochamaelea_populations_JEcol Genetic distances among populations of N. pulverulenta in Gran Canaria, Tenerife and La Gomera (Euclidean genetic distances, GD; conditional genetic distance, cGD), and isolation by resistances values for: topographic complexity, potential and current vegetation, climate, non-resistance, and range shape of N. pulverulenta, 1. Defaunation of large-bodied frugivores could be causing severe losses of crucial ecosystem functions such as seed dispersal. The immediate ecological consequences may include alteration or even collapse of seed-mediated gene flow affecting plant population connectivity, with impacts on the regional scale distribution of genetic variation. Yet these far-reaching consequences of defaunation remain understudied. 2. Here we tested whether human-induced defaunation of the Canarian frugivorous lizards (Gallotia, Lacertidae) altered within-island population connectivity and the amount and large-scale distribution of genetic variation of Neochamaelea pulverulenta (Rutaceae), which relies exclusively on these lizards for seed dispersal. Our study system defines a lizard downsizing gradient with three contrasted ecological scenarios (islands) with relatively optimal (Gran Canaria; large-sized lizards), sub-optimal (Tenerife; medium) and collapsed seed dispersal processes (La Gomera; small). We extensively sampled individual plant genotypes from 80 populations spanning the full geographic range of the plant to examine their genetic diversity, population-genetic network topologies, and the patterns of isolation both by distance (IBD) and resistance (IBR) across these three ecological scenarios. 3. Plant genetic diversity appeared unaffected by defaunation-mediated downsizing of frugivorous lizards. However, we found a reduced overall plant population connectivity together with an increased isolation by distance within the most defaunated islands (La Gomera and, to a lesser extent, Tenerife) when compared with the scenario preserving the functionality of lizard-mediated seed dispersal (Gran Canaria). The results, with a significant effect of lizard downsizing, were robust when controlling for biotic/abiotic differences among the three islands by means of isolation by resistance models (IBR). 4. Synthesis. Our results provide valuable insights into the far-reaching consequences of the deterioration of mutualisms on plant population dynamics over very large spatial scales. Conservation of large-bodied frugivores is thus essential because their irreplaceable mutualistic dispersal services maintain an extensive movement of seeds across the landscape, crucial for maintaining the genetic cohesiveness of metapopulations and the adaptive potential of plant species across their entire geographic range., Peer reviewed

Plant traits and plant-frugivore interactions data Data collected in the field to assess plant-frugivore interactions and plant traits. The methodologies used were: Camera traps to quantify the number of visits and the number of fruits removed by each frugivore species at each Prosopis flexuosa tree and, vegetation transects using the modified point quadrat method at the microhabitat and habitat scales. Plant traits include individual tree characteristics, neighborhood description, microhabitat and habitat variables. Miguel_etal_datafile.csv, Anthropogenic activities, such as grazing by domestic animals, are considered drivers of environmental changes that may influence the structure of interaction networks. The study of individual-based networks allows testing how species-level interaction patterns emerge from the pooled interaction modes of individuals within populations. Exponential random graph models (ERGMs) examine the global structure of networks by allowing the inclusion of specific node (i.e. interacting partners) properties as explanatory covariates. Here we assessed the structure of individual plant-frugivore interaction networks and the ecological variables that influence the mode of interactions under different land-use (grazed vs ungrazed protected areas). We quantified the number of visits, the number of fruits removed per visit and the interaction strength of mammal frugivore species at each individual tree. Additionally we quantified ecological variables at the individual, microhabitat, neighborhood and habitat scales that generated interaction network structure under the different land uses. Individual plant-frugivore networks were significantly modular in both land uses but the number of modules was higher in the grazed areas. We found interaction networks for grazed and ungrazed lands were structured by phenotypic traits of individual trees, by the microhabitat beneath the tree canopy and were affected by habitat modifications of anthropogenic origin. The neighborhood surrounding each individual plant influenced plant-frugivore interactions only at the grazed-land trees. We conclude that anthropogenic land uses influence the topological patterns of plant-frugivore networks and the frugivore visitation to trees through modification of both habitat complexity and the ecological traits underlying interactions between individual plants and frugivore species., Peer reviewed

seed_rain_pistacia Data on the magnitude of seed rain in seed traps placed in different microhabitat types and in each of the study periods (early, mid and late) of the 2014–2015 fruiting season of Pistacia lentiscus (FIGURE 2a). viability_seeds_fruits Data on the viability test (‘flotation/sink’ method) conducted on depulped seeds from Pistacia lentiscus ripe (black) fruits (Figure S3 in Supplementary Material). seed_predation_pistacia Data on the seed predation experiment (FIGURE 3b). Each row corresponds to an individual Pistacia lentiscus seed within a seed depot. sowing_experiment_pistacia Data on the sowing experiment of Pistacia lentiscus seeds to assess seed germination (FIGURE 3c) and seedling survival (FIGURE 3d). Each row corresponds to an individual Pistacia lentiscus seed within a sowing station. timing_sde_pistacia Mean values of multiple demographic processes used to calculate the quantity (QT) and (QL) components of seed dispersal effectiveness (SDE) for different bird species groups contributing to seed dispersal in different periods and microhabitat types (FIGURE 4). seeds_pistacia_barcoding_viability Data on the Pistacia lentiscus seeds sampled for DNA barcoding analyses, which includes the bird species responsible for dispersal (FIGURE 2b) and the outcome of the viability test (FIGURE 3a)., The seed dispersal effectiveness framework allows assessing mutualistic services from frugivorous animals in terms of quantity and quality. Quantity accounts for the number of seeds dispersed and quality for the probability of recruitment of dispersed seeds. Research on this topic has largely focused on the spatial patterns of seed deposition because seed fates often vary between microhabitats due to differences in biotic and abiotic factors. However, the temporal dimension has remained completely overlooked despite these factors – and even local disperser assemblages – can change dramatically during long fruiting periods. Here, we test timing effects on seed dispersal effectiveness, using as study case a keystone shrub species dispersed by frugivorous birds and with a fruiting period of nine months. We evaluated quantity and quality in different microhabitats of a Mediterranean forest and different periods of the fruiting phenophase. We identified the bird species responsible for seed deposition through DNA barcoding and evaluated the probability of seedling recruitment through a series of field experiments on sequential demographic processes. We found that timing matters: the disperser assemblage was temporally structured, seed viability decreased markedly during the plant’s fruiting phenophase, and germination was lower for viable seeds dispersed in the fruiting peak. We show how small contributions to seed deposition by transient migratory species can result in a relevant effectiveness if they disperse seeds in a high-quality period for seedling recruitment. This study expands our understanding of seed dispersal effectiveness, highlighting the importance of timing and infrequent interactions for population and community dynamics., Peer reviewed