Understanding herbivore-plant-soil feedbacks to improve grazing management on Mediterranean mountain grasslands

The surface of many European mountain grasslands is decreasing due to global change and extensive grazing stands out as a key tool for their conservation. Sound knowledge of grassland ecosystem functioning and its feedback processes is required to implement sustainable grazing management. This study aimed to understand the effect of different grazing intensities on herbivore-plant-soil feedbacks in Mediterranean mountain grasslands. We estimated spatial distribution of sheep grazing intensity using GPS technology in order to assess the effect of grazing pressure on vegetation and soil properties measured throughout the study area. Our results showed that grazing intensity ranged from 0.06 to 2.85 livestock units / ha, corresponding to a gradient of pasture utilisation rates varying from 2.38% to 45.60% of annual productivity from pasture. Increasing grazing pressure was associated with smaller relative cover and species richness of non-leguminous forbs, while the opposite trends were observed for graminoids. Forage had a greater concentration of N and smaller C:N ratio in more heavily grazed areas. Increasing grazing intensity was also associated with higher values of total soil N, NO3-, NH4+, soil organic carbon, microbial biomass C and activity of ß-glucosidase. Higher litter quality was the main factor explaining greater content of soil organic matter, which favoured both soil microbes and plant productivity. Grazing induced changes in the plant community triggered positive hervibore-plant-soil feedbacks, as they ultimately improved forage quality and productivity, which significantly influenced the pasture preference of free-ranging domestic grazers. Our work showed that grazing management aiming pasture utilisation rates of around 45% is critical in sustaining positive herbivore-plant-soil feedbacks and preserving or enhancing the whole ecosystem functioning in the Mediterranean mountain grasslands studied. © 2021 The Author

Do vegetation patch spatial patterns disrupt the spatial organization of plant species?

Thelong-range spatial autocorrelationwasevaluated based on the dispersal abilities of the species.Among the 106 species evaluated, 39%of thewoody species, 17% of the forbs, and 12% of the grasses exhibited disrupted long-range spatial autocorrelation where patches were small. The species that are more vulnerable to the effects of fragmentation tended to be those that have restricted dispersal, such as those that have short-range ispersal (atelechoric), e.g., Phlomis purpurea, Cistus albidus, Teucrium pseudochamaepytis, Brachypodium retusum, and the ballistic species, Genista spartioides. Helianthemumalmeriense is another vulnerable species that has actively restricted dispersal (antitelechory), which is common in arid regions. Wind dispersers such as Launaea lanifera were less vulnerable to the effects of fragmentation. Long-distance dispersers whose persistence depends on facilitative interactions with other individuals, e.g., allogamous species such as Thymus hyemalis, Ballota hirsuta, and Anthyllis cytisoides, exhibit disrupted long-range spatial autocorrelation when patch size is reduce

A deep search for planets in the inner 15 au around Vega

We present the results of a deep high-contrast imaging search for planets around Vega. Vega is an ideal target for high-contrast imaging because it is bright, nearby, and young with a face-on two-belt debris disk which may be shaped by unseen planets. We obtained $J-$ and $H-$band data on Vega with the coronagraphic integral-field spectrograph Project 1640 (P1640) at Palomar Observatory. Two nights of data were obtained in 2016, in poor seeing conditions, and two additional nights in more favorable conditions in 2017. In total, we obtained 5.5 hours of integration time on Vega in moderate to good seeing conditions (<1.5"). We did not detect any low mass companions in this system. Our data present the most sensitive contrast limits around Vega at very small separations (2-15 au) thus far, allowing us to place new constraints on the companions which may be sculpting the Vega system. In addition to new constraints, as the deepest data obtained with P1640, these observations form the final legacy of the now decommissioned instrument.Comment: Accepted for publication in A

En los autos de apelacion, introducidos por D. Joseph de Dios vezino del Lugar de Azara de una multa impuesta contra el dicho por el Dr. D. Jospeh de Pueyo y Garcés como procurador de su hermano Fr. D. Juan Estevan de Pueyo comendador de la encomienda de Barbastro y de dicho lugar de Azara, pendiente en revista en el Real acueerdo, por don Joseph de Pueyo y Garcés y por Don Pedro Escudero y consortes.

Enc. perg.Precede al tít.: una cruz de malta, "Jesus, Maria, y Jos. J. y A." en orla tip.Texto firmado por "Joseph Azara"En p. 22 consta el año 1730.Sign.: A-E2, F1.Letra capital tip.Sello del Instituto y provª. de Huesca. Biblioteca

Plant-plant interactions scale up to produce vegetation spatial patterns: The influence of long- and short-term process

Vegetation spatial patterns emerge in response to feedback interactions between organisms and their environment, because of the redistribution of water and nutrients around the plant canopy or as a consequence of facilitation/competition interactions at the plant level, even in the absence of pre-existing substratum heterogeneities. It has been suggested that changes in vegetation spatial patterns are a signal of transition shift in ecosystems. Understanding the factors that lead to aggregated spatial patterns and control the transition to random distributions requires that environmental and species information is taken into account. In this study, we investigated the relative contributions of aridity (a long-term process), to which vegetation is adapted, and the area covered by bare soil (short-term process) to plant-plant associations and their contribution to aggregated spatial patterns. The study was conducted in a gradient of aridity ranging from that in subalpine grassland habitats in the Pyrenees and Sierra Nevada mountains to that in the semiarid steppes of Cabo de Gata and the middle Ebro Valley in Spain. We compared sites that differed in aridity and a geophysical feature (north- vs. south-facing slope). We observed that the relative contribution of aridity and bare soil to plant-plant facilitation and vegetation aggregation differed in subalpine and semiarid areas. Facilitation in subalpine habitats had a marked effect on aggregated spatial patterns, while aridity contributed to disruption of these patterns. Conversely, in semiarid habitats, the disruption of aggregated patterns was mainly promoted by an increase in bare soil area rather than in aridity. In semiarid habitats, the higher level of stress on south-facing slopes increased facilitation interactions relative to north-facing slopes, although this did not enhance the persistence of aggregated spatial patterns. We conclude that the use of aggregated spatial patterns as an indicator of ecosystem shift must distinguish and separately take account of long-term processes to which vegetation adapt, and short-term process

Fundamentación para una ética animalista al margen de los afectos.

Resumen: En este trabajo he tratado de proponer la teoría ética de Kant en Fundamentación para una metafísica de las costumbres como una forma mediante la cual puede fundamentarse una ética animalista que no dependa de los sentimientos ni voluntad de cada uno. Para ello, he analizado, por un lado, la teoría animalista, de corte utilitarista, de Peter Singer. Esta teoría basa el derecho a la consideración moral en la capacidad de sufrir del individuo afectado. Tras ello, he planteado a su vez los posibles puntos en los que puede resultar insuficiente para fundamentar una ética animalista para determinadas personas. Por otro lado, he analizado la teoría de la compasión de Schopenhauer desde Ursula Wolf, encontrando también los puntos en los que puede llegar a resultar insuficiente, como sería en relación a aquellos individuos que no sientan compasión por los demás. En último lugar, he presentado los argumentos por los que Kant excluye a los animales de la comunidad moral, y, tras ponerlos en cuestión, exponer su teoría moral en Fundamentación para una metafísica de las costumbres como una alternativa a las teorías de Singer y Wolf en aquellos puntos en los que resultan insuficientes<br /