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Remote sensing for the assessment of spatio-temporal variability of grassland cover and phenology
No full textGlobal change is impacting grasslands through multiple processes and is driving severe consequences to their structure and functioning, and to the ecosystem services they provide. The recent advancements in remote sensing imagery availability offer new opportunities to tackle the challenge of grasslands monitoring, providing unprecedented revisiting frequency on wide areas at fine spatial resolution. Unfortunately, there are still few standardized indicators available to track grassland processes, and many processes still lack a thorough understanding. During my Ph.D., I focused on four main goals: i) assessing the grassland fractional vegetation cover prediction capability of newly available remote sensing products; ii) developing a easy to use, free, and cloud-based tool for grassland management intensity monitoring; iii) developing a workflow for grassland flowering phenology extraction using time-lapse cameras; iv) better understanding how plant phenology is shifting in climatically heterogenous mountain landscapes, and how this is affecting ecosystem productivity. Our findings demonstrated that the raw spectral signature of grasslands does not exhibit a linear variation across the fractional vegetation cover gradient, and that Sentinel-2 and PlanetScope have a higher fractional vegetation cover prediction capability compared to previously available imagery, especially in areas under patchy degradation and restoration processes. We introduced a model for estimating grassland mowing frequency, which can effectively be used under different management and environmental conditions. It was validated on small and fragmented parcels compared to previous studies, and it can be run using a provided ready to use code working on a cloud platform. We presented a new workflow for grassland flowering phenology extraction of single (or group of) species from time-lapse cameras. The workflow opened new possibilities for phenological studies, overcoming laborious and time-consuming ground-based vegetation observations. In the fourth study, we revealed substantial differences in the phenological response among vegetation types and across elevations in the European mountains over the last two decades. In grasslands, spring phenology was advanced at high altitudes and delayed at low altitudes, thus becoming more uniform along the elevational gradient, while in deciduous forests we observed the opposite trend. Remote sensing data indicated that growing season length has not been the primary factor limiting productivity over the last two decades. Therefore, it is crucial to incorporate the decoupling between phenology and productivity when simulating the potential carbon uptake of terrestrial ecosystems in future climate change scenarios. Overall, these four studies showed that remote sensing images and processing workflows can greatly contribute to a better understanding of human- and climate-induced processes impacting grassland and forest ecosystems
Characterization of kefir-like cereal-based beverages volatilome during fermentation by using PTR-ToF-MS
No full textMonoterpenoids isomerization and cyclization processes in Gewürztraminer wines: a kinetic investigation at different pH and temperatures
Get PDFThe evolution of volatile compounds in wine comprises several acid-catalyzed reactions, such as glycosides precursors’ hydrolysis and rearrangements, and significantly contributes to its sensory qualities, even after prolonged aging. The aim of this work was to use a well-defined experimental design and to examine how terpenoids in Gewürztraminer wine change over time when subjected to different temperatures and pH levels over two weeks. A theoretically-based approach was used, involving the definition of a complete system of ordinary differential equations (ODE) with well-established boundary conditions (initial concentration of reactants/products), using Kinetiscope, a kinetic simulation software. The calculated optimal rate constants, based on the experimental curves, produced a comprehensive data set describing the evolution of the terpenoid profile, highlighting the reversible and irreversible interconversion processes. Finding revealed that higher pH and lower temperature conditions are crucial for preserving the important terpenoid compounds that characterize the typicality and exemplarity of Gewürztraminer aroma profil
Expansion of cyanobacteria outbreaks in the Alpine region: first report of an intense Microcystis bloom in Lake Serraia
Get PDFLake Serraia is a small eutrophic dimictic lake located in the town of Baselga di Pinè, in the Province of Trento. The lake has an average depth of 7 m and a maximum depth of 18 m and is mainly used for recreational activities. During the last decade, summer blooms of non-toxigenic populations of Dolichospermum spp. were documented over the entire lake. Conversely, at the end of August 2023, an intense toxigenic bloom of Microcystis aeruginosa developed over several weeks, resulting in a bathing ban by the local authorities. Besides the usual monitoring for the control of bathing waters, a few opportunistic samples were collected for microscopical examinations, toxins analyses using LC-MS techniques, and strain isolation and cultivation. In the areas where the surface scums developed, the MC-LR and MC-RR congeners of microcystins showed concentrations of 200 μg L-1 and 42 μg L-1, respectively. The bloom episodes documented in Lake Serraia are part of a more general increasing trend of cyanobacterial outbreaks actively documented in the southern Alpine region. Besides persisting high trophic status, as in Lake Serraia, the causes were also connected to the general increasing temperature trends at the global and local levels
La fragolicoltura in ambiente montano conquista nuovi spazi
No full textSperimentazione, nuove tecnologie produttive, varietà adatte all’arco alpino sono alla base del successo e della qualità delle fragole di montagn
QTL analysis on a lemon population provides novel insights on the genetic regulation of the tolerance to the two-spotted spider mite attack
Get PDFBackground: Among the Citrus species, lemon (Citrus limon Burm f.) is one of the most affected by the two-spotted spider mite (Tetranychus urticae Koch). Moreover, chemical control is hampered by the mite's ability to develop genetic resistance against acaricides. In this context, the identification of the genetic basis of the host resistance could represent a sustainable strategy for spider mite control. In the present study, a marker-trait association analysis was performed on a lemon population employing an association mapping approach. An inter-specific full-sib population composed of 109 accessions was phenotyped through a detached-leaf assays performed in modified Huffaker cells. Those individuals, complemented with two inter-specific segregating populations, were genotyped using a target-sequencing approach called SPET (Single Primer Enrichment Technology), the resulting SNPs were employed for the generation of an integrated genetic map. Results: The percentage of damaged area in the full-sib population showed a quantitative distribution with values ranging from 0.36 to 9.67%. A total of 47,298 SNPs were selected for an association mapping study and a significant marker linked with resistance to spider mite was detected on linkage group 5. In silico gene annotation of the QTL interval enabled the detection of 13 genes involved in immune response to biotic and abiotic stress. Gene expression analysis showed an over expression of the gene encoding for the ethylene-responsive transcription factor ERF098-like, already characterized in Arabidopsis and in rice for its involvement in defense response. Conclusion: The identification of a molecular marker linked to the resistance to spider mite attack can pave the way for the development of marker-assisted breeding plan for the development of novel selection coupling favorable agronomical traits (e.g. fruit quality, yield) with a higher resistance toward the mit
Identifying the environmental drivers of corridors and predicting connectivity between seasonal ranges in multiple populations of Alpine ibex (Capra ibex) as tools for conserving migration
Get PDFAim Seasonal migrations, such as those of ungulates, are particularly threatened by habitat transformations and fragmentation, climate and other environmental changes caused by anthropogenic activities. Mountain ungulate migrations are neglected because they are relatively short, although traversing heterogeneous altitudinal gradients particularly exposed to anthropogenic threats. Detecting migration routes of these species and understanding their drivers are therefore of primary importance to predict connectivity and preserve ecosystem functions and services. The populations of Alpine ibex Capra ibex have all been reintroduced from the last remnant source population. Despite a general increase in abundance and overall distribution range, ibex populations are mostly disconnected but display intra-population migrations. Therefore, its conservation is strictly linked to the interplay between external threats and related behavioural responses, including space use and migration. Location Austria, France, Italy and Switzerland. Methods By using 337 migratory tracks from 425 GPS-collared individuals from 15 Alpine ibex populations distributed across their entire range, we (i) identified the environmental drivers of movement corridors in both spring and autumn and (ii) compared the ability of a connectivity modelling algorithm to predict migratory movements between seasonal ranges of the 15 populations, using either population-specific or multipopulation datasets, and three validation procedures. Results Steep, south-facing, snow-free slopes were selected while high elevation changes were avoided. This revealed the importance of favourable resources and an attempt to limit energy expenditures and perceived predation risk. The abilities of the modelling methods we compared to predict migratory connectivity from the results of those movement analyses were similar. Main Conclusions The trade-off between energy expenditure, food and cover was the major driver of migration routes and was overall consistent among populations. Based on these findings, we provided useful connectivity models to inform conservation of Alpine ibex and its habitats, and a framework for future research investigating connectivity in migratory specie
Comparative analysis of antioxidant activity and capacity in apple varieties: Insights from stopped flow DPPH• kinetics, mass spectrometry and electrochemistry
Get PDFThe aim of this research was to investigate the antioxidant kinetics of different apple varieties, a red-flesh variety (‘R201’), a non-browning (‘Majda’), and a ‘Golden Delicious’. Kinetic approaches for antioxidant activity provide more detailed information than conventional assays by examining both the quantity and velocity of active molecules in their reaction with radicals. In this study, DPPH• stopped flow method was applied to study the antioxidant activity and capacity of the three apples varieties, allowing the determination of the reaction rates. The results show that the antioxidant activity of ‘R201’ was not significantly different from ‘Golden Delicious’. Instead, the activity of the non-browning variety was 20 times higher than the others according to the DPPH• kinetic approach, despite having the lowest phenolic content. To further understand their reactivity, the antioxidant molecules were identified using HPLC-HRMS/MS coupled with a coulometric array detector, which validated the DPPH• kinetics. This analysis also found differences in the phenolic profile of the three varieties, attributed to the enhanced antioxidant activity of ’Majda’ to its high content of ascorbic acid. Overall, the research highlights that the antioxidant behavior of apples primarily depends on the velocity of the antioxidants rather than the amount of phenolic compound
Under the mantra: ‘Make use of colorblind friendly graphs’
Get PDFColorblindness is a genetic condition that affects a person's ability to accurately perceive colors. Several papers still exist making use of rainbow colors palette to show output. In such cases, for colorblind people such graphs are meaningless. In this paper, we propose good practices and coding solutions developed in the R Free and Open Source Software to (i) simulate colorblindness, (ii) develop colorblind friendly color palettes and (iii) provide the tools for converting a noncolorblind friendly graph into a new image with improved colors