Estimation of vegetation cover resilience from satellite time series

Resilience is a fundamental concept for understanding vegetation as a dynamic component of the climate system. It expresses the ability of ecosystems to tolerate disturbances and to recover their initial state. Recovery times are basic parameters of the vegetation's response to forcing and, therefore, are essential for describing realistic vegetation within dynamical models. Healthy vegetation tends to rapidly recover from shock and to persist in growth and expansion. On the contrary, climatic and anthropic stress can reduce resilience thus favouring persistent decrease in vegetation activity. <br><br> In order to characterize resilience, we analyzed the time series 1982–2003 of 8 km GIMMS AVHRR-NDVI maps of the Italian territory. Persistence probability of negative and positive trends was estimated according to the vegetation cover class, altitude, and climate. Generally, mean recovery times from negative trends were shorter than those estimated for positive trends, as expected for vegetation of healthy status. Some signatures of inefficient resilience were found in high-level mountainous areas and in the Mediterranean sub-tropical ones. This analysis was refined by aggregating pixels according to phenology. This multitemporal clustering synthesized information on vegetation cover, climate, and orography rather well. The consequent persistence estimations confirmed and detailed hints obtained from the previous analyses. Under the same climatic regime, different vegetation resilience levels were found. In particular, within the Mediterranean sub-tropical climate, clustering was able to identify features with different persistence levels in areas that are liable to different levels of anthropic pressure. Moreover, it was capable of enhancing reduced vegetation resilience also in the southern areas under Warm Temperate sub-continental climate. The general consistency of the obtained results showed that, with the help of suited analysis methodologies, 8 km AVHRR-NDVI data could be useful for capturing details on vegetation cover activity at local scale even in complex territories such as that of the Italian peninsula

Going Conservative or Conventional? Investigating Farm Management Strategies in between Economic and Environmental Sustainability in Southern Italy

The European “Green Deal” strategy is aimed at making Europe the first climate-neutral continent by 2050 through integrated actions relying on healthier agricultural systems grounded in (environmental and economic) sustainable practices, including soil carbon management and biodiversity enhancement. In this vein, the present study contrasts the economic-environmental performances of conventional (deep tillage) and conservative (no-tillage and soil ripping) practices for two varieties of durum wheat (Triticum turgidum spp. durum), namely a modern (Anco Marzio) and an ancient landrace (Saragolla Lucana) variety in the Basilicata region (Southern Italy). Field and laboratory analysis (granulometry, mineralogy, and geochemistry) as well as satellite data (RapidEye) were used to characterize the soil and vegetation patterns. The empirical results indicate a higher biomass production and vegetative potential together with higher grain yields in soils managed with conventional deep tillage compared with soil managed with conservative practices. Similarly, the modern wheat variety exhibited better performance with respect to the old landrace. The soils managed with conventional practices had a distribution of exchangeable macro-nutrients characterized by a reduction in Ca+ and an increase in Mg2+ and K+ between pre-sowing and post-harvesting. Such a distribution was also genotype-dependent, with a higher variability for Saragolla Lucana than Anco Marzio, showing a diverging adsorption of macro-elements between the modern and ancient landrace varieties

Delineating the Intrinsic, Long-Term Path of Land Degradation: A Spatially Explicit Transition Matrix for Italy, 1960–2010

Vulnerability to land degradation in southern Europe has increased substantially in the last decades because of climate and land-use change, soil deterioration, and rising human pressure. The present work focuses on a quantitative evaluation of changes over time in the level of vulnerability to land degradation of a Mediterranean country (Italy) using a composite indicator, the environmentally sensitive area index (ESAI), which is the final outcome of a complex model conceived to assess land vulnerability on the basis of climate, soil, vegetation, and human pressure. Considering four different levels of vulnerability to land degradation (not affected, potentially affected, fragile, and critical), the main trajectories of this index were highlighted in a long-time perspective (1960–2010), discriminating dynamics over two sub-periods (1960–1990 and 1990–2010). The empirical results at a very detailed spatial scale (1 km2 grid) reflect spatial consolidation of degradation hot-spots over time. However, aggregated trajectories of change indicate an overall improvement in the environmental conditions between 1990 and 2010 compared with what is observed during the first period (1960–1990). Worse environmental conditions concerned southern Italian regions with a dry climate and poor soil conditions in the first time interval, large parts of northern Italy, traditionally recognized as a wet and affluent agricultural region, experienced increasing levels of land vulnerability in the second time interval. Being classified as an unaffected region according with the Italian national action plan (NAP), the expansion of (originally sparse) degradation hot-spots in northern Italy, reflective of an overall increase in critical areas, suggests a substantial re-thinking of the Italian NAP. This may lead to a redesign of individual regional action plans (RAPs) implementing place-specific approaches and comprehensive measures to be adopted to mitigate land degradation

Modeling Spatio-Temporal Divergence in Land Vulnerability to Desertification with Local Regressions

Taken as a classical issue in applied economics, the notion of ‘convergence’ is based on the concept of path dependence, i.e., from the previous trajectory undertaken by the system during its recent history. Going beyond social science, a ‘convergence’ perspective has been more recently adopted in environmental studies. Spatial convergence in non-linear processes, such as desertification risk, is a meaningful notion since desertification represents a (possibly unsustainable) development trajectory of socio-ecological systems towards land degradation on a regional or local scale. In this study, we test—in line with the classical convergence approach—long-term equilibrium conditions in the evolution of desertification processes in Italy, a European country with significant socioeconomic and environmental disparities. Assuming a path-dependent development of desertification risk in Italy, we provided a diachronic analysis of the Environmental Sensitive Area Index (ESAI), estimated at a disaggregated spatial resolution at three times (1960s, 1990s, and 2010s) in the recent history of Italy, using a spatially explicit approach based on geographically weighted regressions (GWRs). The results of local regressions show a significant path dependence in the first time interval (1960–1990). A less significant evidence for path-dependence was observed for the second period (1990–2010); in both cases, the models’ goodness-of-fit (global adjusted R2) was satisfactory. A strong polarization along the latitudinal gradient characterized the first observation period: Southern Italian land experienced worse conditions (e.g., climate aridity, urbanization) and the level of land vulnerability in Northern Italy remained quite stable, alimenting the traditional divergence in desertification risk characteristic of the country. The empirical analysis delineated a more complex picture for the second period. Convergence (leading to stability, or even improvement, of desertification risk) in some areas of Southern Italy, and a more evident divergence (leading to worse environmental conditions because of urban sprawl and crop intensification) in some of the land of Northern Italy, were observed, leading to an undesired spatial homogenization toward higher vulnerability levels. Finally, this work suggests the importance of spatially explicit approaches providing relevant information to design more effective policy strategies. In the case of land vulnerability to degradation in Italy, local regression models oriented toward a ‘convergence’ perspective, may be adopted to uncover the genesis of desertification hotspots at both the regional and local scale

Effects of four food dyes on development of three model species, Cucumis sativus, Artemia salina and Danio rerio: Assessment of potential risk for the environment

Food dyes, or color additives, are chemicals added to industrial food products and in domestic cooking to improve the perceived flavor and attractiveness. Of natural and synthetic origin, their safety has been long discussed, and concern for human safety is now clearly manifested by warnings added on products labels. Limited attention, however, has been dedicated to the effects of these compounds on aquatic flora and fauna. For this reason, the toxicity of four different commercially available food dyes (cochineal red E120, Ponceau red E124, tartrazine yellow E102 and blue Patent E131) was assessed on three different model organisms, namely Cucumis sativus, Artemia salina and Danio rerio that occupy diverse positions in the trophic pyramid. The evidence collected indicates that food dyes may target several organs and functions, depending on the species. C. sativus rate of germination was increased by E102, while root/shoot ratio was ∼20% reduced by E102, E120 and E124, seed total chlorophylls and carotenoids were 15–20% increased by E120 and 131, and total antioxidant activity was ∼25% reduced by all dyes. Mortality and low mobility of A. salina nauplii were increased by up to 50% in presence of E124, E102 and E131, while the nauplii phototactic response was significantly altered by E102, E120 and E124. Two to four-fold increases in the hatching percentages at 48 h were induced by E124, E102 and E131 on D. rerio, associated with the occurrence of 20% of embryos showing developmental defects. These results demonstrated that the food dyes examined are far from being safe for the aquatic organisms as well as land organisms exposed during watering with contaminated water. The overall information obtained gives a realistic snapshot of the potential pollution risk exerted by food dyes and of the different organism' ability to overcome the stress induced by contamination

Synthetic torpor protects rats from exposure to accelerated heavy ions

Hibernation or torpor is considered a possible tool to protect astronauts from the deleterious effects of space radiation that contains high-energy heavy ions. We induced synthetic torpor in rats by injecting adenosine 5′-monophosphate monohydrate (5′-AMP) i.p. and maintaining in low ambient temperature room (+ 16 °C) for 6 h immediately after total body irradiation (TBI) with accelerated carbon ions (C-ions). The 5′-AMP treatment in combination with low ambient temperature reduced skin temperature and increased survival following 8 Gy C-ion irradiation compared to saline-injected animals. Analysis of the histology of the brain, liver and lungs showed that 5′-AMP treatment following 2 Gy TBI reduced activated microglia, Iba1 positive cells in the brain, apoptotic cells in the liver, and damage to the lungs, suggesting that synthetic torpor spares tissues from energetic ion radiation. The application of 5′-AMP in combination with either hypoxia or low temperature environment for six hours following irradiation of rat retinal pigment epithelial cells delays DNA repair and suppresses the radiation-induced mitotic catastrophe compared to control cells. We conclude that synthetic torpor protects animals from cosmic ray-simulated radiation and the mechanism involves both hypothermia and hypoxia

Properties of 42 Solar-type Kepler Targets from the Asteroseismic Modeling Portal

Recently the number of main-sequence and subgiant stars exhibiting solar-like oscillations that are resolved into individual mode frequencies has increased dramatically. While only a few such data sets were available for detailed modeling just a decade ago, the Kepler mission has produced suitable observations for hundreds of new targets. This rapid expansion in observational capacity has been accompanied by a shift in analysis and modeling strategies to yield uniform sets of derived stellar properties more quickly and easily. We use previously published asteroseismic and spectroscopic data sets to provide a uniform analysis of 42 solar-type Kepler targets from the Asteroseismic Modeling Portal (AMP). We find that fitting the individual frequencies typically doubles the precision of the asteroseismic radius, mass and age compared to grid-based modeling of the global oscillation properties, and improves the precision of the radius and mass by about a factor of three over empirical scaling relations. We demonstrate the utility of the derived properties with several applications.Comment: 12 emulateapj pages, 9 figures, 1 online-only extended figure, 1 table, ApJS accepted (typo corrected in Eq.8