Gabriele Cola

Climate change in Europe and effects on thermal resources for crops

Atmospheric variables play a fundamental role in driving man-managed ecosystems and more specifically in agro-ecosystems, determining the quantity and quality of crop production. On the other hand, climate variability can be seen as the superimposition of gradual and abrupt changes. This paper is focused on European surface air temperature in the period 1951–2010. Analysis of this dataset identified breakpoints that define two homogeneous sub-periods: 1951–1987 and 1988–2010. Thermal resources for crops were analyzed adopting a “normal heat hours” approach. Computation highlighted a general increase in thermal resources in the European continent for crop groups II and III (C3 and C4 plants adapted to high or moderate temperatures), while a decline of thermal resources for crop group I (cold adapted C3) was highlighted in the Mediterranean area. The climate variability justifies a change in the potential latitudinal limits of different groups of crops, representing a fundamental step for crop adaptation to climate change.

Climatological analysis of the mitigating effect of vegetation on the urban heat island of Milan, Italy

Abstract The urban heat island (UHI) of Milan (Italy) was analyzed by means of an Energy Balance Model calibrated for four different sites representative of an urban park, the UHI plateau and the UHI peak of the selected town. The model was driven by weather stations data and parameterized as a function of land use, urban morphology, human activities and soil hydrology. A run of the model on the 1981–2014 period was carried out on four hourly datasets. Results provided useful statistics of energy balance terms and the climate risk of extreme thermal events (sensible heat fraction of the total turbulent flux H% exceeding specific thresholds). Results for summer (June–August trimester) show that the mitigation of climate risk of high values of H% given by the urban park is more effective for June than for July and August. We also discuss the relevance of enhanced soil water reservoirs in urban green areas to improve the mitigating effect of urban vegetation on UHI by both the substitution of sensible heat fluxes with latent heat ones and the increase of the shading effect of tree canopies.

Meteorological and pedological influence on the PCBs distribution in mountain soils

Polychlorinated biphenyls (PCBs) are a threat to environmental and human health due to their persistence and toxicological effects. In this paper, we analyse some meteorological and organic-matter-related effects on their distribution in the soils of an Alpine environment that is not subject to direct contamination. We collected samples and measured the contamination of 12 selected congeners from three soil layers (O, A1 and A2) and from North-, plain- and South-facing slopes on six different dates spanning the entire snowless portion of the year. We recorded the hourly air and soil temperatures, humidity and rainfall in the study period. We found evidence that PCBs contamination in soils varies significantly, depending on sampling date, layer and aspect. The observed seasonal trend shows an early summer peak and a rapid decrease during June. The layer effect demonstrates higher dry-weight-based concentrations in the O layer, whereas the differences are much smaller for SOM-based concentrations. Different factors caused significantly higher concentrations in northern soils, with a N/S enrichment factor ranging from 1.8 to 1.5 during the season. The southern site has significantly more rapid early-summer re-volatilisation kinetics (half-time of 16d for South, 25d for North).

Early Neolithic wine of Georgia in the South Caucasus

Significance The earliest biomolecular archaeological and archaeobotanical evidence for grape wine and viniculture from the Near East, ca. 6,000–5,800 BC during the early Neolithic Period, was obtained by applying state-of-the-art archaeological, archaeobotanical, climatic, and chemical methods to newly excavated materials from two sites in Georgia in the South Caucasus. Wine is central to civilization as we know it in the West. As a medicine, social lubricant, mind-altering substance, and highly valued commodity, wine became the focus of religious cults, pharmacopoeias, cuisines, economies, and society in the ancient Near East. This wine culture subsequently spread around the globe. Viniculture illustrates human ingenuity in developing horticultural and winemaking techniques, such as domestication, propagation, selection of desirable traits, wine presses, suitable containers and closures, and so on. Chemical analyses of ancient organic compounds absorbed into the pottery fabrics from sites in Georgia in the South Caucasus region, dating to the early Neolithic period (ca. 6,000–5,000 BC), provide the earliest biomolecular archaeological evidence for grape wine and viniculture from the Near East, at ca. 6,000–5,800 BC. The chemical findings are corroborated by climatic and environmental reconstruction, together with archaeobotanical evidence, including grape pollen, starch, and epidermal remains associated with a jar of similar type and date. The very large-capacity jars, some of the earliest pottery made in the Near East, probably served as combination fermentation, aging, and serving vessels. They are the most numerous pottery type at many sites comprising the so-called “Shulaveri-Shomutepe Culture” of the Neolithic period, which extends into western Azerbaijan and northern Armenia. The discovery of early sixth millennium BC grape wine in this region is crucial to the later history of wine in Europe and the rest of the world.

Grapevine phenology and climate change in Georgia

While the climate of Western Europe has been deeply affected by the abrupt climate change that took place in the late ‘1980s of the twentieth century, a similar signal is detected only few years later, in 1994, in Georgia. Grapevine phenology is deeply influenced by climate and this paper aimed to analyze how phenological timing changed before and after the climatic change of 1994. Availability of thermal resources in the two climatic phases for the five altitudinal belts in the 0–1250-m range was analyzed. A phenological dataset gathered in two experimental sites during the period 2012–2014, and a suitable thermal dataset was used to calibrate a phenological model based on the normal approach and able to describe BBCH phenological stages 61 (beginning of flowering), 71 (fruit set), and 81 (veraison). Calibration was performed for four relevant Georgian varieties (Mtsvane Kakhuri, Rkatsiteli, Ojaleshi, and Saperavi). The model validation was performed on an independent 3-year dataset gathered in Gorizia (Italy). Furthermore, in the case of variety Rkatsiteli, the model was applied to the 1974–2013 thermal time series in order to obtain phenological maps of the Georgian territory. Results show that after the climate change of 1994, Rkatsiteli showed an advance, more relevant at higher altitudes where the whole increase of thermal resource was effectively translated in phenological advance. For instance the average advance of veraison was 5.9 days for 250–500 m asl belt and 18.1 days for 750–1000 m asl). On the other hand, at lower altitudes, phenological advance was depleted by superoptimal temperatures. As a final result, some suggestions for the adaptation of viticultural practices to the current climatic phase are provided.

IPHEN—a real-time network for phenological monitoring and modelling in Italy

This paper aims to describe the Italian PHEnology Network (IPHEN), a cooperative project started in 2006 with the aim of producing nationwide maps of analysis and forecast of plants phenological stages mainly used to satisfy the needs of agriculture, health and environmental care. Iphen is a data processing system composed of the following main segments (a) collection of atmospheric and phenological data, (b) processing of data with suitable phenological and geo-statistical models and (c) phenological maps of analysis and forecast. In more detail, IPHEN maps of analysis (featuring phenological stages reached at the date of processing) are produced with models based on a Normal Heat Hours approach which weighs hourly air temperature effectiveness for plant phenological progression applied to national grids of hourly temperature derived from the operational agro-meteorological network of CRA-CMA. A correction scheme based on phenological surveys provided by volunteer observers is applied to the first guess maps of analysis to obtain final maps. Forecast maps (prediction of the days of occurrence of relevant phenological stages) are produced on the basis of GFS model medium range forecasts and climatic data. Freeware IPHEN maps for grapevine, common and Arizona cypress, black elder, olive and locust trees are broadcasted weekly on the CRA-CMA website. The positive operational results of IPHEN are testified by 150 maps broadcasted during the 2011 season for the above-mentioned species. The system performances and reliability have been analysed focusing on the analysis of phenological simulation errors and on the sensitivity of phenological maps to anomalous atmospheric circulation patterns. The error analysis shows that phenological models are characterized by advances/delays that justify the adoption of an observation based correction scheme. The sensitivity analysis highlights that the system is responsive to the effects of circulation blocking systems leading to phenological advances and delays.

Space and time variability of heating requirements for greenhouse tomato production in the Euro-Mediterranean area

The Euro-Mediterranean area is the seat of a relevant greenhouse activity, meeting the needs of important markets. A quantitative assessment of greenhouse energy consumption and of its variability in space and time is an important decision support tool for both greenhouse-sector policies and farmers. A mathematical model of greenhouse energy balance was developed and parameterized for a state-of-the-art greenhouse to evaluate the heating requirements for vegetables growing. Tomato was adopted as reference crop, due to its high energy requirement for fruit setting and ripening and its economic relevance. In order to gain a proper description of the Euro-Mediterranean area, 56 greenhouse areas located within the ranges 28°N-72°N and 11°W-55°E were analyzed over the period 1973-2014. Moreover, the two 1973-1987 and 1988-2014 sub-periods were separately studied to describe climate change effects on energy consumption. Results account for the spatial variability of energy needs for tomato growing, highlighting the strong influence of latitude on the magnitude of heat requirements. The comparison between the two selected sub-periods shows a decrease of energy demand in the current warm phase, more relevant for high latitudes. Finally, suggestions to reduce energy consumptions are provided.

Influence of climate cycles on grapevine domestication and ancient migrations in Eurasia

The objective of this work is to investigate the Holocenic climate cycles that may have influenced the domestication of grapevine in the Subcaucasian area and its subsequent spread in Eurasia. The analysis covered the longitudinal belt ranging from the Iberian Peninsula to Japan, seen as the preferential pathway for the Holocenic spread of grapevine and many other crops in Eurasia. Spectral analysis was considered as the criterion of investigation and the Holocenic cycles were analyzed considering different geochemical and biological proxies, of which seven are directly referred to vine. In this context the relation of the abovementioned proxies with spectral peaks of possible causal factors like Solar activity (SA), North Atlantic oceanic factors (Atlantic Multidecadal Oscillation - AMO and North Atlantic Oscillation - NAO), and subtropical oceanic factors (El Nino Southern Oscillation - ENSO) was also analyzed. In order to acquire a sufficiently wide number of proxies sensitive to the causal factors, we referred to a latitudinal belt wider than the one colonized by vine, also acquiring proxy from the Scandinavian area, notoriously susceptible to North Atlantic forcings. The analysis of the proxy spectral peaks, considering 20 classes with a 50-years step in the 0-1000 years range, showed that the 50% of the classes have a higher frequency of peaks at East than West, the 20% a higher frequency at West than East and the 10% an equal frequency, showing the efficiency of the propagation of Western signals towards the center of Eurasia. The search of the causal factors spectral peaks in the proxy series showed that AMO, NAO and SA acted with a certain regularity on the entire belt investigated both latitudinally and longitudinally, while spectral peaks linked to ENSO underwent a considerable attenuation moving northward. Finally, the specific analysis on viticultural proxies showed common peaks with causal factors.

Utilization of a freeze-thaw treatment to enhance phenolic ripening and tannin oxidation of grape seeds in red (Vitis vinifera L.) cultivars

Phenolic ripening represents a major interest for quality wine producers. Nevertheless, climatic or genotypical limitations can often prevent optimal maturation process. During winemaking seeds can be easily separated and technologically processed to improve their quality. Relying on the key role of oxidation for phenolic ripening, a freeze-thaw treatment was proposed to improve the fruit quality for potential use in challenging growing conditions. The experiment was carried on in two distinctive viticultural areas, Michigan and Italy. Five cultivars (Cabernet Franc, Cabernet Sauvignon, Merlot, Pinot noir and Chambourcin) and six cultivars (Cabernet Sauvignon, Sangiovese, Syrah, Croatina, Barbera and Nebbiolo) were used in Michigan and Italy, respectively. Samples were collected at different phenological stages, to describe the natural ripening process and grape seeds were characterized before and after a freeze-thaw treatment. Colorimetric and spectrophotometric data highlighted similarities among natural and artificial seed ripening promising future applications for the wine industries.

Agrometeorology and water needs of crops

This paper aims to present some agrometeorological methods useful for water management in agriculture discussing the existing technology and giving some insights about research and development activities in this field. After a general discussion about the importance of water for plants and more generally for the ecosystem the agrometerological aspects of water balance are discussed and opportunities of use of forecasts are also presented. Some effects of climatic change on water needs of crops are also discussed.