Carbon budget of the vineyard \u2013 A new feature of sustainability

Vineyards received scarce attention in relation to the continuous monitoring of carbon fluxes and the assessment of their overall budget, as a common believe is that agricultural crops cannot be net carbon sinks. Indeed, many technical inputs, massive periodical harvests, and the repeated disturbances of upper soil layers, all contribute to a substantial loss both of the old and newly-synthesized organic matter. Woody perennials, however, can behave differently: they grow a permanent structure, stand undisturbed in the same field for decades, originate abundant pruning debris, and are often grass-covered. We have been monitoring the Net Ecosystem Exchange (NEE) by eddy covariance and the carbon partitioning in a temperate vineyard in North Eastern Italy. Five complete yearly budgets confirm a steady and substantial sink capacity of the system, with a yearly NEE around 800\u2013900 gC m 122, grape harvest representing about 20\u201325% of it. Biometrical assessment of growth and partitioning show a good agreement with micrometeorological measurements and demonstrate a large input of organic matter into the soil. Even if it can be objected that this sink may be only temporary and the built-up can be substantially disrupted at the end of the vineyard life cycle, these results show that there is a concrete possibility of storing carbon in temperate-climate vineyards, possibly contributing to the global carbon budget. This sink capacity might be accounted in the official calculation of wine carbon footprint and represents a new, relevant feature of their sustainability

Year-round variability of field-saturated hydraulic conductivity and runoff in tilled and grassed vineyards

The soil management adopted in vineyard inter-rows has a great influence on soil hydraulic properties, and, consequently, on runoff at the field scale. Conventional management with tillage is adopted by vine-growers to improve the soil water recharge during winter. Nevertheless, this practice is known to increase runoff and soil erosion in steep areas, especially in mechanized vineyards, thus grass cover is adopted to reduce these negative impacts. The year-round values of field-saturated hydraulic conductivity and of the field-scale runoff were measured in vineyard plots from November, 2012 to March, 2016 in the Alto Monferrato vine-growing area (Piedmont, NW Italy). Field-saturated hydraulic conductivity values were obtained by 110 infiltration measurements. The tests were carried out by adopting the Simplified Falling Head methodology in two adjacent vineyards plots, where inter-rows were managed with conventional tillage (CT) and grass cover (GC), respectively. The runoff, the soil temperature and the soil water content in the two plots have also been recorded. As it was expected, the tillage increased the field-saturated hydraulic conductivity with respect to the plot with permanent grass cover. However, this effect was only temporary, since a decrease in field-saturated hydraulic conductivity was observed as a consequence of cumulative precipitation and tractor passages after the tillage operations. The field-saturated hydraulic conductivity ranged between 9 and 9119 mm h-1 in the tilled plot and between 4 and 1775 mm h-1 in the plot with grass cover. The response of the plots to precipitation events, in terms of runoff also varied considerably. Generally, during most of the events, the runoff in the tilled plot resulted higher (up to nearly 20 times) than in the grassed one. The grass cover was less effective in occasion of large precipitation events during the wet seasons than in other months

APPLICATION OF DEFICIT IRRIGATION STRATEGY FOR BARLEY (HORDEUM VULGARE L.) AND WHEAT (TRITICUM DURUM DESF.) IN THE REGION OF BISKRA

Cette étude a été réalisée pendant la saison agricole 2013-2014 afin de déterminer l'effet de l'irrigation déficitaire sur le rendement en grains et de paille de l'orge et du blé, ainsi que l'efficience de l’utilisation de l’eau d'irrigation sur le rendement en grains (IWUEg) et le rendement de biomasse aérienne (IWUEbio), en utilisant l'irrigation par submersion sous le climat aride de la région de Biskra. Trois stratégies d'irrigation déficitaire ont été adoptées: T1 (50% du total de la  quantité d’eau, à partir de la levée jusqu’à la fin du stade de l’épiaison), T2 (déficit de 50% pendant le remplissage du grain), T3 (alterné, pendant tout le cycle de croissance). Ces différents traitements ont été comparés avec T0 (irrigation complète).Les résultats obtenus ont montré que le rendement moyen en grains et le rendement en paille pour les traitements T1, T2 et T3 des deux cultures sont significativement affectés par l'irrigation déficitaire (p<0,005). Le déficit de l’eau appliqué pendant le remplissage des grains (50%  du total de la quantité d’eau donnée) pour les deux cultures a eu un impact réduit sur le rendement en grain (11% et 15% respectivement pour l'orge et le blé), permettant une économie d’eau de 27,58%  et améliorant l’IWUEg  et l’IWUEbio comparativement au traitement T0 (irrigation complète).  Les résultats de cette étude soutiennent l'idée que la stratégie la plus efficace de l'irrigation déficitaire est d'améliorer l’IWUE, en réduisant la quantité d'eau appliquée pendant les phases de croissance qui ont le moindre impact sur le rendement et la croissance.This study was carried out during the growing season 2013-2014 in order to determine the effect of deficit irrigation on grain and straw yield of barley and wheat, along with irrigation water use efficiency at grain yield (IWUEg) and total biomass (IWUEbio), using flood irrigation  for clay loam to slit clay soil texture  under the arid climate of Biskra. Three deficit irrigation strategies were applied: T1 (50% of full water supply, from initiation to heading), T2 (50% deficit during grain filling), T3 (alternate deficit during whole season). Different treatments were compared with T0 (full irrigation). The obtained results show that mean grain and straw yield forT1, T2and T3treatments of both crops, were significantly affected by deficit irrigation (P<0.005).The water deficit during grain filling (50% water supply) for both crops had a less impact on grain yield (11% and 15% for barley and wheat, respectively), saving 20.32% of water and improving both IWUEg and IWUEbio, compared to full irrigation supply (T0).The findings of this study support the idea that the most effective strategy of deficit irrigation is to improve IWUE, by reducing the amount of applied water during those growing phases which have less impact on the yield and growth

Benthic studies in LTER sites: the use of taxonomy surrogates in the detection of long-term changes in lagoonal benthic assemblages

In benthic studies, the identification of organisms at the species level is known to be the best source for ecological and biological information even if time-consuming and expensive. However, taxonomic sufficiency (TS) has been proposed as a short-cut method for quantifying changes in biological assemblages in environmental monitoring. In this paper, we set out to determine whether and how the taxonomic complexity of a benthic assemblage influences the results of TS at two different long-term ecological research (LTER) sites in the Po delta region (north-eastern Italy). Specifically, we investigated whether TS can be used to detect natural and human-driven patterns of variation in benthic assemblages from lagoonal soft bottoms. The first benthic dataset was collected from 1996 to 2015 in a “choked” lagoon, the Valli di Comacchio, a lagoon characterised by long water residence times and heavy eutrophication, while the second was collected from 2004 to 2010 in a “leaky” lagoon, the Sacca di Goro, a coastal area with human pressure limited to aquaculture. Univariate and multivariate statistical analyses were used to assess differences in the taxonomic structure of benthic assemblages and to test TS on the two different datasets. TS seemed to work from species to family level at both sites, despite a higher natural variability of environmental conditions combined with multiple anthropogenic stressors. Therefore, TS at the family level may represent effective taxonomic surrogates across a range of environmental contexts in lagoon environments. Since the structure of the community and the magnitude of changes could influence the efficiency of taxonomic surrogates and data transformations in long-term monitoring, we also suggest periodic analyses at finer taxonomic levels in order to check the efficiency of the application of taxonomic substitutes in routine monitoring programmes in lagoon systems

The METCRAX II Field Experiment: A Study of Downslope Windstorm-Type Flows in Arizona\u2019s Meteor Crater

The second Meteor Crater Experiment (METCRAX II) was conducted in October 2013 at Arizona\u2019s Meteor Crater. The experiment was designed to investigate nighttime downslope windstorm 12type flows that form regularly above the inner southwest sidewall of the 1.2-km diameter crater as a southwesterly mesoscale katabatic flow cascades over the crater rim. The objective of METCRAX II is to determine the causes of these strong, intermittent, and turbulent inflows that bring warm-air intrusions into the southwest part of the crater. This article provides an overview of the scientific goals of the experiment; summarizes the measurements, the crater topography, and the synoptic meteorology of the study period; and presents initial analysis results

Assessing across-scale optical diversity and productivity relationships in grasslands of the Italian alps

The linearity and scale-dependency of ecosystem biodiversity and productivity relationships (BPRs) have been under intense debate. In a changing climate, monitoring BPRs within and across different ecosystem types is crucial, and novel remote sensing tools such as the Sentinel-2 (S2) may be adopted to retrieve ecosystem diversity information and to investigate optical diversity and productivity patterns. But are the S2 spectral and spatial resolutions suitable to detect relationships between optical diversity and productivity? In this study, we implemented an integrated analysis of spatial patterns of grassland productivity and optical diversity using optical remote sensing and Eddy Covariance data. Across-scale optical diversity and ecosystem productivity patterns were analyzed for different grassland associations with a wide range of productivity. Using airborne optical data to simulate S2, we provided empirical evidence that the best optical proxies of ecosystem productivity were linearly correlated with optical diversity. Correlation analysis at increasing pixel sizes proved an evident scale-dependency of the relationships between optical diversity and productivity. The results indicate the strong potential of S2 for future large-scale assessment of across-ecosystem dynamics at upper levels of observation