Analisi multitemporale del consumo degli oliveti periurbani nel nordovest della Sardegna: il caso di studio della città di Sassari

In Sardinia the presence of olive stands plays an important role in economic business and landscape planning. In particularly, since the 16th century, the Miocene calcareous plateau of North- West is covered by an olive stand system mainly for olive oil production. These olive groves actually are composed by a local variety (Bosana) of which the oil is rich in antioxidant and flavour compounds and for this reason appreciated by the consumer. In the same region is located the city of Sassari, the second biggest city of Sardinia, which territory contains 50% of the whole olive stands of North Sardinia, most of them are concentrated in a “ring” around the city. The survey was conducted with historical and spatial explicit data of land-use and land-use change from the half of 19th century to the present (2007), to test the hypothesis that during the 20th century the area of olive stands decreased against urban expansion. In fact, changes in land-use (in particular those regarding agriculture lands) are a widespread phenomenon in Mediterranean regions and particularly intensive along urban borders. Historical land use data were derived from a variety of sources including cadastral data, maps and aerial photographs. A GIS was necessary to store, manipulate and analyse the digital information and to carry out land use change analysis. The historical analysis started by analysing the cadastral data of 1860, 1920 and 2007. The first one shows a higher density of olive groves in the ring around the city than the present. They were associated with vineyards, pasture and ploughed land. From 1860 to 1920 the olive stands increased due to destruction of the vineyards affected by Grape phylloxera. The information regarding the period between 1920 and 1977 and from 1977 to 2007 is given by aerial photographs that allow determine high resolution details in a spatial complex landscape. From 1960’s the city of Sassari had had the major expansion characterized also by an uncontrolled diffusive urbanization (sprawl) for the leak of a specific legislation. Between 1920 and 1977 the urban development caused the decline of the olive stands due cover density reduction or land use change, with the final result of disappearance of almost 100,000 olive trees in fifty years. The decline operates along the internal limit of the ring caused by urban expansion, and in several locations within the ring due the realization of small villages and the transformation of the olive grove in a garden. The former pattern is the principal factor of the olive landscape fragmentation. Despite the decline, in the external limit of the ring was verified the increase of olive groves but with lower magnitude than the decrease. Similar trends were evaluated for the period 1977-2007 using cadastral data, and digital land use maps. The main causes of olive stand decrease can be summarized in the request of lands for the realization of new industrial and 12 residential areas; in the people movement from the city to the rural area motivated by the better life condition; in the absence of a specific legislation for landscape protection and regulation. Finally the research gives some guideline for management and recovery of the olive groves in Sardinia which rule in Mediterranean ecosystems is recognized in a wide range of studies

Light distribution on <i>citrus canopy</i> affects physiological parameters and fruiting pattern

Light interception by the orange tree canopy during flower bud differentiation and subsequent flowering and fruit setting has been monitored by continuous data recording from 48 silicon cells distributed in different canopy zones. Two experimental conditions have been tested: trees artificially shaded by a black nylon net cage, and non-shaded trees. Observations were made on the total radiation accumulated in the different canopy zones, and they were related to photosynthetic activity, stomatal conductance) flowering and fruiting pattern, and fruit quality. The different light distribution affected both photosyntesis and stomatal conductance: in fact, they were both drastically reduced in shaded trees, and a significant decrease was also found in both shaded and unshaded trees in relation to different canopy zones. A significant decrease of flowering and fruit setting was found from the top of the canopy to the bottom and from outside to inside, in relation to the different amount of radiant energy availability. Finally significant differences were found on fruit quality

Performance di recenti imboschimenti con quercia da sughero in ex-coltivi

Growth performance of cork oak plantations recently established on farmlands in Sardinia, Italy. Recently, significant forestry activities have taken place in Sardinia thanks to EU Regulation 2080/92 funds. Some 80% of the afforestated surface has been planted with holm oak and cork oak. The latter also characterizes 89% of the reforestation area. Given the funding source, plantations have been established on farmlands. Growth performances of these recent cork oak stands have been quantitatively evaluated and compared with the performances of two experimental plots. In Gallura (north-east of Sardinia), that is the traditional cork production area and still is economically the most important cork district of the island, these new cork oak plantations have an average size of 28 ha. They have been established on lands that, before plantation, were either pastures (30%) or arable lands (70%). Plantation failures are limited to 8.8% of the total (in term of mass) and seem independent of environmental factors or plantations species composition (conifers have been frequently used as secondary species). Average growth of the stem, measured above cork at collar height, is in the range 4 to 8mm/year with a mean value of 5.5mm/year. No correlation appears with either environmental conditions or species composition of the plantations. In the first experimental plot, soil management practices (natural vegetation removal vs its cutting and mulching) does not differentiate young plants growth trends. In the control subplots (no removal) stem collar diameter is 20% smaller. Localized manual hoeing around trunk base increased the diameters by 13% but reduced cork thickness by 21%. The second experimental plot allows comparisons among 27 Mediterranean proveniences of cork oak. The trial exhibits reduced genetic influence: diameters and heights growth are significantly different only among extreme groups. In conclusion, reduced growth performances of the plantations established in farmlands is due, to some extent, to the limitations inherent with private land management (constrained to costs minimization) and, on the other hand, to the generally very limited thickness of Gallura soils. Demand for good quality commercial cork is steadily raising. To sustain the request, in the short term, it would be necessary to extend financial support for plantations care, from 5 to 10 years, or even up to the first stripping (virgin cork)

LAND UTILISATION IN THE AGER OF THE SASSARI CITY. THE COMPETITION WINE VS OLIVE BETWEEN THE 19TH AND THE 20TH CENTURY

Le superfici a vigneto e olivo del comune di Sassari sono state indagate con analisi diacronica: Cessato (1860) e Nuovo Catasto Terreni (1920), Censimenti dell’Agricoltura Istat 1960- 2000 e carta di Uso del Suolo della regione Sardegna (2006). A metà del XIX secolo l’olivo, nell’Hortus, e la vite, nell’Ager, si estendevano su 3.884 e 2.986 ettari nell’ordine. I vigneti, colpiti dalla fillossera sul finire del XIX secolo, occupavano, nel 1920, solo 780 ettari contro i 5.074 dell’olivo. La diffusione dei portinnesti “americani” non era sufficiente per un completo recupero e i vigneti si estendevano, al 2000, su soli 191 ettari distribuiti in 353 aziende (Istat), mentre l’UDS individua al 2006 145 ettari ubicati in larga misura in quelle che erano le open lands di Saltus e Sylva.Vineyards and olive orchards were investigated in Sassari municipality (North Sardinia) by diachronic analysis of different source of data: cadastral (from 1860 to 1920), decal Agricultural Census (from 1970 to 2000) and Land Use Map (LUM) (2006/07). In 1860 Olives covered 3,884 hectares in the /Hortus/ system and Vines 2,986 hectares in the /Ager/ one. At the beginning of 20th century the vineyards decreased to 780 hectares because of the Grape phylloxera infection, while the olive stands increased to 5,074 hectares. Even the use of American resistant rootstocks did not allow the extension of the vineyards area that in 2000 was 191 hectares split into 350 farms. On the other hand, the LUM 2006 identified 145 hectares of it, most of them located in the old open lands of /Saltus/ and /Sylva/

The Use of cork in antiquity: some archaeological data in Sardinia

In this paper, we report some archaeological data from Sardinian contexts useful to summarize the use of the cork and the cork oak in antiquity. This use has its roots in the prehistory of Sardinia Island. Many archaeological researches document that it was already used during the Nuragic period (Bronze Age). The cork was extracted and processed in order to obtain plates, foils, planks, shavings and it was shaped to create various artefacts, such as footwear, containers, boxes, cases, stoppers, etc. Cork wedges were also used in nuragic dry stonewalls as thermal insulating

Stima evapotraspirativa dei fabbisogni irrigui nelle principali aree agricole della Sardegna

ETP calculation for three important irriguous areas of Southern (39°17' N. I), Central (39°53' N. I) and Northern (40°41' N. I) Sardinia through F.A.O. method shows too much high values with originai Blaney-Criddle equation, reduced differences with Penman (original and F.A.O.) equation, Radiation method and B.-C. F.A.O. equation respectively. The last method, believed the most suitable according to the first lisimetric measurements, estimates annual mean ETP equal to 1194 mm, 1077 mm and 1022 mm for Southern, Central and Northern Sardinia. Effective rainfall successive analysis shows they are 50% of total rainfall (in case of grasses) and they hold ETP for about 22%. Therefore seasonal irrigation requirements, calculated through F.A.O. crop coefficients, are among 841 mm, 791 mm and 706 mm concerning grasses, and 353 mm, 322 mm and 311 mm concerning olive tree, for Southern, Central and Northern Sardinia

Local landscape dynamics in a traditional cork-oak agro-forest system (Sardinia)

The Alta Gallura region contributed to the development of Italian cork industry that since the nineteenth century has driven the improvement of a multi-functional model based on the breeding of beef cattle into the cork oak forests. The study case is a cork-oak agro-forest farm extended to 212 hectares, with a quantity of livestock close to 0.1 LU ha-1. It were collected data from the farm registry (business records of the last 70 years) and by photo-interpretation of images related to 1955 (GAI), 1977 (CGR), 2006 (Terra Italy) and 2013 (AGEA)

Monitoring raw cork TCA content in Sardinian woodlands

The studies on stopper contamination by TCA have focused on manufacturing phase and on relations between the wine and the cork. Less numerous are the forest and environmental monitoring research useful to evaluate whether different management models of the cork stands may have an influence on the process

Provenance behaviour in the cork-oak internationl network trials FAIR 202

The international network of provenance trials in cork-oak was established as a result of the EU Concerted Action FAIR 202, 1995-2000. 34 provenances were selected in the natural range of cork oak and trials were established in 1996/97 in France, Italy, Portugal, Tunisia and Spain. This study compares the behavior of provenances in the trials of Grighini (Sardinia), Monte Fava and Quinta da Nogueira (Portugal), Monfrague (Spain), Les Maures (France) and Tebabe (Tunisia)

Management problems in Mediterranean cork oak forests: post-fire recovery

The objective of this paper is to present the results of a long-term research project carried out in north-east Sardinia, which aims to evaluate the effects of three different kinds of forest management (traditional trunk coppicing, branch pruning, and no sylvicultural practice) on the post-fire recovery of a cork oak (Quercus suber L.) stand. The most and the least effective forestry operations appeared to be traditional trunk coppicing and the branch pruning, respectively. Where traditional trunk coppicing is considered strictly necessary, the opportunity of thinning some of the new suckers should be carefully considered, as modern harvesting techniques should be combined with appropriate strategies to protect the soil from erosion