Is extensive livestock production compatible with biodiversity and soil conservation?

El efecto de la ganadería comercial sobre la conservación de la biodiversidad y de los suelos es difícil de evaluar debido a la falta de relictos sin ganado, a la heterogeneidad del paisaje y a la complejidad de las respuestas. Para describir en qué condiciones la ganadería comercial resulta compatible con la conservación de la biodiversidad y de los suelos, analizamos a distintas escalas los modelos y la información existentes. Concluimos que en sistemas que evolucionaron con altas presiones de herbívoros, ya sean domésticos o silvestres, la ganadería a cargas comerciales puede ser compatible con la conservación, y aun necesaria. Sin embargo, mientras que la biodiversidad se maximiza con una presión de herbivoría heterogénea dentro de cada uno de los diferentes ambientes que componen el paisaje, la producción ganadera tiende a optimizarse con una presión homogénea. Por ello, aún en sistemas que evolucionaron con alta presión de herbivoría, la compatibilidad con la conservación exige una cierta heterogeneidad de la presión, lo que puede disminuir la producción con respecto a la máxima posible. En sistemas que evolucionaron con baja presión de herbívoría es menos probable que la ganadería comercial resulte compatible con la conservación de la biodiversidad y de los suelos.The effect of commercial livestock production on biodiversity and soil conservation is difficult to evaluate due to the lack of relicts without livestock, landscape heterogeneity and the complexity of responses. We analyzed the available information and models, integrating different scales, to describe in what conditions commercial livestock production results compatible with biodiversity and soil conservation. We conclude that in systems that evolved with heavy pressure of either wild or domestic herbivores, commercial livestock production is compatible with conservation, and may even be necessary. However, biodiversity is maximized with a heterogeneous herbivore pressure within each of the habitats that constitute the landscape, while livestock production tends to be optimized with a homogeneous pressure. Thus, even in systems that evolved with heavy herbivore pressure, compatibility with conservation requires certain heterogeneity of herbivore pressure, which may decrease production relative to the potential maximum. In systems which evolved with light herbivore pressure, commercial livestock production is less likely to be compatible with biodiversity and soil conservation

Actualistic taphonomic study of the rodents digested by the Achala culpeo fox (Lycalopex culpaeus smithersi) in the highlands of central Argentina

We present the first actualistic study of the rodents consumed by the South American foxLycalopex culpaeus smithersi (Achala culpeo fox), a subspecies of the culpeo fox that is endemicto the highlands of central Argentina. We provide a taphonomic characterization of this canidbased on digested micromammal bones, and compare it to other carnivores. We studied over 1000bones derived from 83 scats collected in Quebrada del Condorito National Park, Córdobaprovince, Argentina, corresponding to caviomorph and myomorph rodents. Galea leucoblepharawas the main prey (59.8% MNI, 93.1% biomass). Average relative abundance for the totalassemblage was 26.7. Cranial and, to a lesser extent, proximal limb bones were the most abundantelements. A high degree of breakage was observed in cranial elements and, to a lesser extent, inlimb bones. A high proportion of heavy and extreme digestion was inferred, while some elementsbear light or no digestion traces at all. Overall, the Achala culpeo fox fits best with othermammalian carnivores in the category of extreme modification, and shows types and proportionsof taphonomic attributes similar to other South American mammalian predators. These resultscontribute to the understanding of regional taphonomic processes and of digestivemodifications by Lycalopex foxes generally, and are thus relevant to interpreting the presence of micromammal remains in the archaeological and palaeontological recordsand the impact of these foxes in their formation.Fil: Coll, Daiana Geraldine. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Montalvo, Claudia Inés. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Fernández, Fernando Julián. Universidad de Buenos Aires. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pia, Monica Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; ArgentinaFil: Mondini, Nora Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Antropología de Córdoba. Universidad Nacional de Córdoba. Facultad de Filosofía y Humanidades. Instituto de Antropología de Córdoba; Argentin

Not a melting pot: Plant species aggregate in their non-native range

Aim: Plant species continue to be moved outside of their native range by human activities. Here, we aim to determine whether, once introduced, plants assimilate into native communities or whether they aggregate, thus forming mosaics of native- and alien-rich communities. Alien species might aggregate in their non-native range owing to shared habitat preferences, such as their tendency to establish in high-biomass, species-poor areas. Location: Twenty-two herbaceous grasslands in 14 countries, mainly in the temperate zone. Time period: 2012–2016. Major taxa studied: Plants. Methods: We used a globally coordinated survey. Within this survey, we found 46 plant species, predominantly from Eurasia, for which we had co-occurrence data in their native and non-native ranges. We tested for differences in co-occurrence patterns of 46 species between their native (home) and non-native (away) range. We also tested whether species had similar habitat preferences, by testing for differences in total biomass and species richness of the patches that species occupy in their native and non-native ranges. Results: We found the same species to show different patterns of association depending on whether they were in their native or non-native range. Alien species were negatively associated with native species; instead, they aggregated with other alien species in species-poor, high-biomass communities in their non-native range compared with their native range. Main conclusions: The strong differences between the native (home) and non-native (away) range in species co-occurrence patterns are evidence that the way in which species associate with resident communities in their non-native range is not species dependent, but is instead a property of being away from their native range. These results thus highlight that species might undergo important ecological changes when introduced away from their native range. Overall, we show origin-dependent associations that result in novel communities, in which alien-rich patches exist within a mosaic of native-dominated communities

Germination response of common annual and perennial forbs to heat shock and smoke treatments in the Chaco Serrano, central Argentina

Fire is a key ecological factor affecting plant dynamics. In the last few decades, fire occurrence in the Chaco region has increased noticeably, challenging the adaptive capacity of plants to regenerate after a fire. Broad-leaved forb species have been much less studied than woody and graminoids, although they are an important component of fire dynamics. Here we analysed the germination response to heat shock of 70 and 110°C, smoke and their combination in 10 broad-leaved herbaceous species frequently occurring in the Chaco Serrano of Córdoba province, central Argentina, including five annual (Bidens subalternans, Conyza bonariensis, Schkuhria pinnata, Tagetes minuta and Zinnia peruviana) and five perennial species (Borreria eryngioides, Sida rhombifolia, Solidago chilensis, Taraxacum officinale and Verbena litoralis). We also compared the response of annual versus perennial species. Six species had highest germination when treated with heat and smoke combined, whereas two had lowest germination under this treatment, indicating synergistic and antagonistic interaction of these factors respectively. Most of the species tolerated heat shock (i.e. germination was similar to that in control treatment), whereas others had higher germination in response to heat shock, especially under the moderate 70°C treatment. Germination was higher than control (i.e. no heat and no smoke) after smoke treatment in four species. Perennial species showed higher average germination than annuals in both heat treatments and in the control. Annual species had higher average germination for all treatments involving smoke. The high variability observed at the species level, and the limited number of species studied calls for precaution in interpreting and extrapolating results. Nevertheless, our study shows a general positive response of both perennial and annual species to fire cues, suggesting an advantage of these species for colonizing post-fire environments, and being favoured under scenarios of increasingly frequent low-to-medium intensity fires.Fil: Arcamone, Julieta Rocío. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Diversidad Biológica y Ecológica. Cátedra de Ecología; 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; ArgentinaFil: Jaureguiberry, Pedro. 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; Argentin

Data from: Secondary compounds from exotic tree plantations change female mating preferences in the palmate newt (Lissotriton helveticus)

Selection can favor phenotypic plasticity in mate choice in response to environmental factors that alter the costs and benefits of being choosy, or of choosing specific mates. Human-induced environmental change could alter sexual selection by affecting the costs of mate choice, or by impairing the ability of individuals to identify preferred mates. For example, variation in mate choice could be driven by environmentally induced differences in body condition (e.g. health) that change the cost of choosiness, or by environmental effects on the ability to detect or discriminate sexual signals. We teased apart these possibilities experimentally, by comparing female mate choice in the palmate newt Lissotriton helveticus between environments that mimic water from either native oak forests or exotic eucalypt plantations. In laboratory two-choice mate trials in clean water, females with prolonged exposure (21 days) to waterborne chemicals leached from eucalypt leaves did not preferentially associate with the male with a stronger immune response, but females exposed to water with chemicals from oak leaves did. In contrast, female choice was unaffected by the immediate presence or absence of eucalypt leachates during mate choice (using only females previously held in oak-treated water). The habitat-related change in female choice we observed is likely to be driven by effects of eucalypt leachates on female physiology, rather than immediate inhibition of pheromone transmission or blocking of pheromone reception

Predicting cover types in a mountain range with long evolutionary history of grazing: a GIS approach

Aim To determine how the distribution and cover of different vegetation types are affected by physical factors and livestock in a mountain range with a long evolutionary history of grazing. Location Upper vegetation belt of the Córdoba mountains (1700–2800 m a.s.l., 31º34' S, 64º50' W) in central Argentina. Methods Using GIS, we analysed the relationships of plant cover types to physical features (physiography and topography) and indicators of accumulated livestock pressure (distance to human settlements and roads) through multinomial logistic regression. We predicted a present vegetation map which was validated with a real map. We then constructed two maps simulating minimum and maximum values of accumulated livestock pressure for the whole area. Map comparisons allowed evaluation of the possible influence of livestock,both in extension and intensity. Results Both physical features and livestock pressure influenced the occurrence of vegetation units. The overall accuracy of the predicted map at the pixel level was low (26%) indicating low habitat specificity of the vegetation units. We suggest that some part of the unaccounted for variance was due to livestock pressure patterns that were not fully captured by our indicators. Our models proved adequate for predicting the total percentages of vegetation units at coarser scales. The extrapolations showed that under a history of low livestock pressure, such as in sites far away from human settlements and roads, the area would be dominated by woodlands, tussock grasslands and natural rock outcrops. Under a history of heavy livestock pressure, in turn, rock exposed by erosion, tussock grasslands and natural rock outcrops would dominate. Main conclusions Vegetation units showed low habitat specificity, and were associated with accumulated livestock pressure, indicating that livestock and its associated activities are important factors structuring the landscape and have important consequences for the integrity of the ecosystem. Results suggest that although this system evolved with large herbivores, it has experienced irreversible degradation processes, and intensification of current domestic livestock pressure is likely to lead to even more land degradation.Fil: Cingolani, Ana María. 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; ArgentinaFil: Renison, Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Tecco, Paula Andrea. 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; ArgentinaFil: Gurvich, Diego Ezequiel. 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; ArgentinaFil: 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; Argentin