Geophysical characterization Quehue Basin, La Pampa province

La cuenca de Quehué se reconoce como una faja continua de valores negativos de anomalías gravimétricas de Bouguer, muy estrecha y elongada, que se ubica en el este de la provincia de la Pampa. Se desarrolla a lo largo de unos 300 km con una orientación N35ºO, desde Luan Toro al norte, pasando por Quehué y Abramo, hasta la Laguna Colorada Grande al sur. En base a los resultados geofísicos, se considera que está limitada por importantes fallas y que se trata de una cuenca tipo rift similar a la de General Levalle. Se considera que esta cuenca forma parte del sistema de rifts pampeanos de la Argentina, en conjunto con la cuenca de Macachín con la que se relaciona genéticamente. En el área comprendida en esta investigación se observan máximos y mínimos gravimétricos relativos de diferente magnitud que se asocian con cambios en la profundidad del basamento. En la cuenca se reconocen seis depocentros que varían en extensión y espesor sedimentario. Aunque sólo se ha confirmado la presencia de sedimentitas cretácicas, es posible que el relleno inicial de la cuenca haya comenzado en el jurásico y esté apoyado, en parte, sobre sedimentos paleozoicos. Las variaciones en los datos gravimétricos y magnéticos a ambos lados de la cuenca señalan diferencias en la composición del basamentoQuehué basin is a continuous belt of negative values of Bouguer anomalies that are located in the east of the province of La Pampa. It is very narrow and spreads along 300 km, with an orientation N35°W, from: Luan Toro in the north, through Quehué and Abramo, Laguna Colorada Grande in the south. Based on geophysical results, it is believed to be limited by major faults and that is a rift basin similar to General Levalle’s. It is part of the pampeano rift system of Argentina; parallel and genetically associated to the Macachin basin. The area studied in this research includes maximum and minimum gravity of different magnitudes associated with changes in basement depth. In Quehue basin six depocenters are recognized, they vary in extension and sediment thickness. Although only the presence of Cretaceous sediments was confirmed, it is possible that initial filling of basin has begun in the Jurassic and is overlying, in part, on Paleozoic sediments. Variations in gravity and magnetic data in both sides of the basin show differences in basement composition.Fil: de Elorriaga, Elena E.. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Kostadinoff, Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Geológico del Sur; Argentina. Universidad Nacional del Sur. Departamento de Física; ArgentinaFil: Raniolo, Luis Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Argentino de Oceanografía (i); Argentina. Universidad Nacional del Sur; Argentin

Activity budget and movement patterns of Brown Swiss and Alpine Grey lactating cows during summer grazing in alpine pastures

We used GPS tracking to monitor the grazing patterns of Brown Swiss and Alpine grey lactating cows on an alpine summer pasture (2038 m a.s.l.; SD = 146) in the Dolomites. The pasture (171 ha) was managed with a continuous grazing system (0.52 LU/ha) with morning and evening milking in the barn, guided grazing during the ‘day’, and free grazing at ‘night’. GPS positions were collected from 8 Brown Swiss multiparous and 9 Alpine Grey (4 primiparous and 5 multiparous) cows every two minutes. We inferred behaviours (grazing, resting, walking) from movement metrics, activity sensors and direct behavioural observations. After excluding milking periods, the cows grazed for 8 h/d, rested 10–11 h/d, and walked for 1.5/d. Grazing extended into late evening after milking, and resting prevailed throughout the ‘night’ until the morning milking. When grazing and resting, cows mainly used grasslands as the preferred habitat, but forest and sparse shrub were also used remarkably without consistent negative or positive selection. The pasture use was highly heterogeneous, with higher animal loads close to the barn, especially at night, and in areas with gentler slopes. Alpine Grey primiparous cows were less limited by slope and distance from the barn in their movement but were more selective in habitat use than multiparous cows. Differences between multiparous cows of the two breeds were less marked. Further studies should help understand the internal and external drivers of cattle grazing patterns to devise management practices combining animals’ productivity and welfare with the conservation of the grassland ecosystem services

Activity budget and movement patterns of Brown Swiss and Alpine Grey lactating cows during summer grazing in alpine pastures

We used GPS tracking to monitor the grazing patterns of Brown Swiss and Alpine grey lactating cows on an alpine summer pasture (2038 m a.s.l.; SD = 146) in the Dolomites. The pasture (171 ha) was managed with a continuous grazing system (0.52 LU/ha) with morning and evening milking in the barn, guided grazing during the ‘day’, and free grazing at ‘night’. GPS positions were collected from 8 Brown Swiss multiparous and 9 Alpine Grey (4 primiparous and 5 multiparous) cows every two minutes. We inferred behaviours (grazing, resting, walking) from movement metrics, activity sensors and direct behavioural observations. After excluding milking periods, the cows grazed for 8 h/d, rested 10–11 h/d, and walked for 1.5/d. Grazing extended into late evening after milking, and resting prevailed throughout the ‘night’ until the morning milking. When grazing and resting, cows mainly used grasslands as the preferred habitat, but forest and sparse shrub were also used remarkably without consistent negative or positive selection. The pasture use was highly heterogeneous, with higher animal loads close to the barn, especially at night, and in areas with gentler slopes. Alpine Grey primiparous cows were less limited by slope and distance from the barn in their movement but were more selective in habitat use than multiparous cows. Differences between multiparous cows of the two breeds were less marked. Further studies should help understand the internal and external drivers of cattle grazing patterns to devise management practices combining animals’ productivity and welfare with the conservation of the grassland ecosystem services

GPS tracking indicates high variability in grazing patterns of lactating cows in Alpine summer farms

Understanding grazing patterns is necessary to manage semi-natural grasslands for both productivity and conservation of biodiversity with the associated Ecosystem Services. This study used GPS tracking to characterize the daily movement patterns and use of Alpine pastures by lactating Brown Swiss cows in three summer farms located at an average elevation of 1,900 m a.s.l. (SD: 90) in the eastern Italian Alps. Herd management was similar for all summer farms. Each day, after the morning milking in the barn, cows were driven to graze in different areas of the pastures, where they were then left free until the return to the barn for the evening milking, after which they were again released free to spend the night outdoor. From July 5th to September 5th in 2019 and 2020, 12 and 10 lactating cows per each farm, respectively, were equipped with GPS \u2018collars\u2019 scheduled to collect a position every 2 minutes. After editing data to exclude individual milking periods in the barns and outlier positions, the total daily distances walked by cows were on average close to 7 km but ranged from less than 2 km to around 15 km, varying greatly between dates, but also farms and years, mostly in relation the farmers daily decisions for grazing areas. Slopes steeper than 30\ub0 were very seldom used, most likely reflecting the cows choices of single movement steps. The total surface used by the cows of each summer farm (average: 211 ha; SD: 29 ha) varied by 4 to 30% between years, because of pasture patches being used only in one year. Internal use of such surface was highly heterogeneous: the quartile of surface with the lowest locations density contained <1% of total locations, while that with the highest density contained around 80% of the locations and was concentrated in the proximity of the barns. Use of high-frequency GPS tracking outlined the great variability of movement patterns and pasture use of the cows in the extensive conditions of Alpine summer farms, and helped to outline the role of farmers and animals choices. This knowledge is necessary to assess movement costs for the animals, and the fine scale spatial distribution of animals load and potential impacts on the grazed area

Human choices, slope and vegetation productivity determine patterns of traditional alpine summer grazing

Grazing behaviour influences animal productivity and the conservation of grassland ecosystem services. We used GPS tracking and remote sensing (NDVI index) to monitor the grazing patterns of lactating cows on the 'Malga Ombretta' summer farm (1,957 m asl) in the Dolomites, eastern Italian Alps, from 5th July to 5th August 2018. The pasture area (35 ha) was grazed by a mixed herd of Simmental and Alpine grey cows (stocking density = 0.6 LU/ha) under traditional management: each morning the farmer led the cows to graze in a selected sub-area of pasture, and during the afternoon he left them free to graze unrestricted until they returned to the barn for the night. GPS positions were collected every minute from 9 Simmental and 4 Alpine Grey cows with low milk production during the time they were outdoors. The farmer's choice of where to drive the herd to graze in the morning determined the distances the cows walked/day, which varied from 2.0 to 8.9 km, and favoured the use of higher and steeper areas that the cows tended otherwise to avoid. When free in the afternoon, the cows selected areas with higher NDVI values than those selected by the farmer in the morning, and Alpine Grey cows used slightly higher slopes and altitudes than Simmental cows, suggesting better adaptation to mountain pastures. The study revealed highly heterogenous grazing patterns dependent on multiple factors that can be assessed at fine temporal and spatial scales using GPS and remote sensing technologies to improve grazing management

Relationships between cattle grazing, soil microbiology and nutrients cycle in highland pastures

Highland pastures are particular agro-ecosystems with a high level of plant and animal biodiversity, and for this reason semi-natural grassland are classified as High Nature Value Farmland. This study aims at characterizing the agroecological relationships among grazing animals-plants-microorganisms in alpine summer pastures. The study area included two summer farms in the Dolomites, Eastern Italian Alps. Both summer farms were located at an elevation around 2,000 m asl, and were grazed by dairy cows from mid-June to mid-September. In order to assess the impact of dairy cattle grazing on the functional microbial biodiversity, surveys were carried out using topsoil cores before (\u2018point zero\u2019) and during the grazing period. The distribution of cattle stocking rate at temporal and spatial scale was analysed by using GPS tracking of grazing animals and farmer\u2019s interviews. The samples of soils were collected in patches representative of different vegetation types and stocking rates, with three repetitions for each sampling points. A molecular ecological approach was applied, analysing microbial communities in terms of abundances relative to copies of target genes through the application of real-time PCR. The studied genes were nosZ for denitrification, amoA archea and bacteria for nitrification. The analysis highlighted different outcomes between the considered areas, showing a likely impact of grazing on microbial communities but in different terms depending on the local pedoclimatic and vegetational conditions and on the cattle stocking rates. This kind of approach will be integrated with indicators on carbon sink, in order to have an in-depth view of the ecosystem support services, such as nutrient cycle and soil formation regulation, carbon storage and supply in soil, and forage production. These preliminary results could be used to develop specific and minimally-invasive biophysical indicators of supporting (and regulating) ecosystem services. These tools will assist the definition of strategies aiming at enhancing the sustainability of grazing livestock systems in compliance to agroecology principles

Relazione tra il pascolamento bovino, microbiologia del suolo e cicli dei nutrienti nei pascoli di alta quota

The following work illustrates an exploratory approach as regards the characterization of high altitude pastures from the point of view of the functional soil microbiology, linked to the nitrogen cycle. The study took place over two years, from 2018 to 2019, involving 4 different pastures between Trentino and Veneto. Topsoil samples were taken, from which DNA was subsequently extracted and purified. The extracted DNA was amplified through the application of real-time PCR with primer for target genes related to nitrification and denitrification processes. The genes studied were the nosZfor denitrification and the amoA, archea and bacterial variant, for nitrification. The statistical analysis was based on the evaluation of the presence and absence of genes in the study areas in the various periods considered. Differences were observed between nitrifying and denitrifying genes during the two years of the test. AmoAgenes are found linked to local morphological factors, such as altitude, while nosZdo not. These also show less variability, appearing with greater constancy, taking over that high altitude pastures have good denitrification potential

Balance between dairy cows\u2019 production and supporting ecosystem services in highlands pastures

Mountain pastures are agro-ecosystems depending on livestock farming and providing a large spectrum of services. Nowadays, these systems are facing social, economic and climatic challenges that threaten their equilibrium and externalities. This study aimed at characterising the relationships between grazing livestock, land morphology, and the microbial community of mountain pastures. Four different mountain pastures of Italian eastern Alps, grazed by dairy cows producing milk for PDO cheese, were considered during multiple summer transhumance (from mid-June to mid-September). Herd size (average \ub1 SD) was 74\ub156 dairy cows, pasture surface 165\ub177 ha, and elevation 1,990\ub181 m asl. The study was developed at different spatial scales, with a particular focus on the supporting ecosystem services linked to the nitrogen cycle. At a macro scale, cattle movement was GPS-tracked to estimate individual grazing patterns and map the local intensity of grazing. Daily distance travelled by cows was 8.0\ub13.8 km. At a micro scale, pasture soils were characterised with a molecular approach to obtain the nitrification (copies of bacterial and archaeal amoA genes) and denitrification potentials (copies of nosZ genes) genes. Slope was the most important morphological variable at both spatial scales, determining animal movement patterns, also between breeds, and the nitrification potential of soils, which increased at lower slopes. In contrast, the denitrification potential (nosZ gene copies) of grazed areas was unaffected by land morphology. In addition, amoA Archaea showed a much higher residual variability than nosZ. The knowledge of how grazing patterns and environmental conditions determine individual productivity and soil supporting ecosystem services can be used to develop good practices for the sustainable management of mountain livestock-grassland systems. Identifying multi-purpose pasture management practices may increase the resilience of grazing agro-ecosystems while maintaining the productivity of local livestock systems