Search

The coexistence of several species involves a complex mix of positive and negative interactions that can be represented as networks. As much as other ecological features, patterns of multispecies co-occurrence are susceptible to anthropogenic disturbance. In ant communities, wildfires may enhance competitive interactions by benefiting active, aggressive species, and by increasing encounter probabilities through decreased space availability. We explored ant co-occurrence patterns by analysing the macro and microscopic structure of their interaction networks in burned and unburned habitats. We built co-occurrence networks using significant aggregations and segregations between species pairs as positive and negative interactions, respectively. We described aggregate network properties and microscopic structural changes by comparing species and interactions turnover between burned and unburned sites. We found no differences in the macroscopic structure of co-occurrence networks between different fire regimes. However, we detected changes in the composition of both species and negative interactions. Interaction turnover between networks of different habitats was mostly explained by rewiring of interactions between shared species rather than by species replacement. Our results reflected changes in ant communities in response to fire although there were no changes in global structural patterns. These changes in species and negative interactions suggest modifications in species roles translated into changes in the spatial distribution of ant species. The analysis of species co-occurrence networks is a useful tool to detect and visualize patterns in ant communities and to understand the mechanisms underlying the effects of disturbance on biodiversity. Fil: Tavella, Julia Rita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Cagnolo, Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

A great challenge in ecology is to link patterns in nature with the factors that determine species coexistence and community structure. In general, these patterns have been associated with different environmental conditions and species traits. The coexistence of ant species could be affected by the availability of food and nesting resources, which depend on vegetation diversity and structural complexity. In this study, we attempt to reproduce, through null models, the properties of ant community structure in areas with different physiognomy of vegetation associated to different wildfire regimes. The null model construction considered ant traits such as occurrence frequency, body size, and nest type; and site characteristics such as vegetation height and extra-floral nectar availability, and their combinations. The null models were compared to observed species segregation and nestedness patterns. Ant species were more aggregated in space than expected by chance. Vegetation height and extra-floral nectar availability were included in the most successful models in predicting ant segregation and aggregation pattern. Furthermore, ants' body size was enough to reproduce the nestedness of species distribution in sites. Our results suggest that under post-fire conditions, habitat complexity, resource availability and species traits such as body size may be the determinants of ant community structure. Fil: Tavella, Julia Rita. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Alvarez Pringles, Ana Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Córdoba; Argentina Fil: Cagnolo, Luciano. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Current biodiversity loss is mostly caused by anthropogenic habitat loss and fragmentation, climate change, and resource exploitation. Measuring the balance of species loss and gain in remaining fragmented landscapes throughout time entails a central research challenge. We resurveyed in 2013 plant species richness in the same plots of a previous sampling conducted in 2003 across 18 forest fragments of different sizes of the Chaco Serrano forest in Argentina. While the area of these forest remnants was kept constant, their surrounding forest cover changed over this time period. We compared plant species richness of both sampling years and calculated the proportion of species loss and gain at forest edges and interiors. As in 2003, we found a positive relationship between fragment area and plant richness in 2013 and both years showed a similar slope. However, we detected a net decrease of 24% of species’ richness across all forest fragments, implying an unprecedentedly high rate and magnitude of species loss driven mainly by non-woody, short-lived species. There was a higher proportion of lost and gained species at forest edges than in forest interiors. Importantly, fragment area interacted with percent change in surrounding forest cover to explain the proportion of species lost. Small forest fragments showed a relatively constant proportion of species loss regardless of any changes in surrounding forest cover, whereas in larger fragments the proportion of species lost increased when surrounding forest cover decreased. We show that despite preserving fragment area, habitat quality and availability in the surroundings is of fundamental importance in shaping extinction and immigration dynamics of plant species at any given forest remnant. Because the Chaco Serrano forest has already lost 94% of its original cover, we argue that plant extinctions will continue through the coming decades unless active management actions are taken to increase native forest areas. Fil: Aguilar, Ramiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Calviño, Ana Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Ashworth, Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Aguirre Acosta, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Carbone, Lucas Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Albrieu Llinás, Guillermo. Universidad Nacional de Córdoba. Facultad de Medicina. Instituto de Virología "Dr. J. M. Vanella"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina Fil: Nolasco, Miguel Martín. Universidad Nacional de Córdoba. Facultad de Cs.agropecuarias. Departamento de Ingeniería y Mecanización Rural. Cátedra de Matemática; Argentina Fil: Ghilardi, Adrián. Universidad Nacional Autónoma de México; México Fil: Cagnolo, Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Understanding global drivers of changes in species interacons is vital, both in terms of improving our knowledge of fundamental large-scale ecology, and in order to predict and protect against human-driven changes to ecosystems. Here we present the LifeWebs project, which aims to collate existing data on interacon networks in order to understand their large-scale paerns. Inially we will collate data relating to plant?herbivore interacons, and this arcle is a call for contributions. We outline the kinds of data in which we are interested, the procedure for making contribuons, and what contributors can expect in terms of co-authorship on subsequent papers and access to the database for conducting their own analyses. Fil: Fayle, Tom Maurice. Biology Centre of the Academy of Sciences of the Czech Republic; República Checa Fil: Sam, Katerina. Biology Centre of the Academy of Sciences of the Czech Republic; República Checa Fil: Humlova, Anna. University Of South Bohemia; República Checa Fil: Cagnolo, Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Not all species are likely to be equally affected by habitat fragmentation; thus, we evaluated theeffects of size of forest remnants on trophically linked communities of plants, leaf-mining insects, and theirparasitoids. We explored the possibility of differential vulnerability to habitat area reduction in relation tospecies-specific and food-web traits by comparing species-area regression slopes. Moreover, we searched for asynergistic effect of these traits and of trophic level. We collected mined leaves and recorded plant, leaf miner,and parasitoid species interactions in five 100-m2 transects in 19 Chaco Serrano woodland remnants in central Argentina. Species were classified into extreme categories according to body size, natural abundance,trophic breadth, and trophic level. Species?area slopes differed between groups with extreme values of natural abundance or trophic specialization. Nevertheless, synergistic effects of life-history and food-web traits were only found for trophic level and trophic breadth: area-related species loss was highest for specialist parasitoids.It has been suggested that species position within interaction webs could determine their vulnerability to extinction. Our results provide evidence that food-web parameters, such as trophic level and trophic breadth,affect species sensitivity to habitat fragmentation. Fil: Cagnolo, Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Valladares, Graciela Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Salvo, Silvia Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Cabido, Marcelo Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Zak, Marcelo Román. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Cordoba. Facultad de Filosofia y Humanidades; Argentina

The structure of mutualistic networks is likely to result from the simultaneous influence of neutrality and the constraints imposed by complementarity in species phenotypes, phenologies, spatial distributions, phylogenetic relationships, and sampling artifacts. We develop a conceptual and methodological framework to evaluate the relative contributions of these potential determinants. Applying this approach to the analysis of a plant-pollinator network, we show that information on relative abundance and phenology suffices to predict several aggregate network properties (connectance, nestedness, interaction evenness, and interaction asymmetry). However, such information falls short of predicting the detailed network structure (the frequency of pairwise interactions), leaving a large amount of variation unexplained. Taken together, our results suggest that both relative species abundance and complementarity in spatiotemporal distribution contribute substantially to generate observed network patters, but that this information is by no means sufficient to predict the occurrence and frequency of pairwise interactions. Future studies could use our methodological framework to evaluate the generality of our findings in a representative sample of study systems with contrasting ecological conditions. Fil: Vazquez, Diego P.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; Argentina Fil: Chacoff, Natacha Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentina Fil: Cagnolo, Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Córdoba . Facultad de Ciencias Exactas Físicas y Naturales . Centro de Investigaciones Entomológicas de Córdoba; Argentina

El reemplazo de áreas naturales por zonas urbanizadas afecta la composición de las comunidades arbóreas, generalmente favoreciendo la ocurrencia de especies vegetales exóticas. Esto tendría implicancias directas en la estructuración de las comunidades de hongos patógenos que hospedan estas especies arbóreas. En este trabajo se propuso examinar: a) la estructura de la red de interacciones entre especies del arbolado urbano y los hongos patógenos degradadores de la madera, b) la composición de hongos patógenos en especies nativas y exóticas. Se observó que la red de interacciones mostró un patrón de anidamiento en donde varias especies de hongos patógenos establecen múltiples interacciones con diversas especies arbóreas, tanto nativas como exóticas, mientras que otras establecieron interacciones más específicas. Se observó mayor riqueza de hongos en árboles exóticos en comparación a sus pares nativos. Trece de las especies fúngicas se registraron exclusivamente en árboles exóticos, una exclusivamente en sustrato nativo y las nueve restantes compartieron tanto árboles exóticos como nativos. The replacement of natural areas by urban areas promotes changes in the composition of tree communities, frequently favoring the occurrence of exotic species. This may have direct implications in the structure of pathogenic fungal communities which grow in these hosts. Here we examine: a) the structure of the interaction networks between urban tree species and their pathogenic wood-decay fungi, b) the composition of pathogenic fungi in native and exotic hosts. The interactions network shows a nested pattern where several species of pathogenic fungi establish multiple interactions with various tree species, both native and exotic; while others establish more specific interactions. Richness of pathogenic fungi was higher in exotic trees than in natives. Thirteen fungal species occurred exclusively in exotic hosts, one in natives and the remaining nine species shared both exotic and native hosts. Fil: Cagnolo, Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina Fil: Heredia, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina Fil: Morera, Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina Fil: Robledo, Gerardo Lucio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina Fil: Urcelay, Roberto Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina

In this study we ask whether parasitic complexes of leafminers display differences associated to host order, by comparing species number, taxonomic composition, parasitism rates and host ranges in parasitoid assemblages associated with lepidopteran and dipteran leafminers, in Chaco Serrano woodlands, central Argentina. Parasitoid assemblage size did not significantly differ between host orders, but dipteran hosts suffered higher parasitism rates. Lepidopteran hosts recruited a higher proportion of species and individuals of Braconidae, whereas dipteran leafminers were attacked by a higher proportion of Pteromalidae. We found clear effects of host taxonomic affiliation on the associated parasitoid fauna. Fil: Salvo, Silvia Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina Fil: Valladares, Graciela Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina Fil: Cagnolo, Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina

The Chaco Serrano Woodland from central Argentina has been dramatically reduced during the past 30 years, and is currently confined to several isolates of different size. In this study, we evaluated the effects of forest size, isolation and edge formation on plant species richness. Furthermore, we tested whether plants species with particular ecological traits were differentially affected by habitat fragmentation. Habitat area showed the highest explanatory value for plant species richness in stepwise multiple regressions. The effect of area was most pronounced for rare species, suggesting that large forests are necessary to preserve species with low local or regional abundance. Differences between edge and interior of Chaco Serrano were more pronounced for native and shrub species richness. The analysis of individual species cover revealed that native and biotically pollinated plants were less abundant in woodland edges. Our results showed that forest transformation into smaller remnants has lead to an impoverishment of plant communities, with particular subsets of species defined by ecological traits (rarity, origin and pollination mode) being more susceptible. Fil: Cagnolo, Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Cabido, Marcelo Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Valladares, Graciela Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinar de Biología Vegetal (p). Grupo Vinculado Centro de Relevamiento y Evaluacion de Recursos Agricolas y Naturales; Argentina