Analysis and definition of potential new areas for viticulture in the Azores

8 Vineyards in the Azores have been traditionally settled on lava field “terroirs” but the practical 9 limitations of mechanization and high demand on man labor imposed by the typical micro parcel 10 structure of these vineyards contradict the sustainability of these areas for wine production, except 11 under government policies of heavy financial support. Besides the traditional vineyards there are 12 significant areas in some of the islands whose soils, climate and physiographic characteristics 13 suggest a potential for wine production that deserves to be object of an assessment, with a view to 14 the development of new vineyard areas offering conditions for a better management and 15 sustainability. 16 The landscape zoning approach for the present study was based in a Geographic Information 17 System (GIS) analysis incorporating factors related to climate, topography and soils. Three thermal 18 intervals referred to climate maturity groups were defined and combined with a single slope interval 19 of 0–15% to exclude the landscape units above this limit. Over this resulting composite grid, the soils 20 were than selectively cartographed through the exclusion of the soil units not fulfilling the suitability 21 criteria. 22 The results show that the thermal interval of warmer conditions, well represented in the traditional 23 “terroir” of Pico island, has practically no expression in the other islands. However, for the 24 intermediate and the cooler classes, we could map areas of 5611 and 18115 ha respectively, fulfilling 25 the defined soils and slope criteria, indicating thus the existence of some landscapes in the studied 26 islands revealing adequate potential for future development of viticulture, although certainly 27 demanding a good judgment on the better grape varieties to be adapted to those climatic conditions. 28

The results show that the thermal interval of warmer conditions, well represented in the traditional 23 "terroir" of Pico island, has practically no expression in the other islands. However, for the

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Under the holistic concept of "terroir", which deals with the influence of environmental factors on vine 30 behavior and grape ripening, climate is recognized as the factor that exerts one of the most 31 significant effect on the ability of a region to produce quality grapes (Jones, 2006).

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It is also well accepted that geology and the particular soil conditions are of great importance in 33 defining the characteristics and qualities of the wine as the final product (Mackenzie, 2005), in spite 34 of the recognized difficulty of establishing and interpreting this relationship clearly.

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Moreover, although it is known that the vine is adaptable to a wide diversity of soil types, it appears 36 also that many of the world's most famous vineyards are installed in poor, shallow or rocky terrain 37 (Leeuween and Seguin, 2006) where no other crop would be grown in favorable conditions. Such is 38 the case, almost extreme, of the vines implanted in the lands of "biscoito" and "lagido", the traditional

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Besides Pico island, where the costal landscape is dominated by lava fields of abandoned vineyards 55 with the exception of the classified area, a few small spots also exist in some of the other islands of 56 the archipelago, where in most cases the production has been partially abandoned as well.

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Apart from this traditional Azorean model of "terroir" of recognized cultural value and where a few 58 interesting wines have been produced, there are significant areas in some of the islands whose soils, 59 climate and physiographic characteristics suggest a potential for wine production that deserves to be 60 object of an assessment, with a view to the development of new vineyard areas offering conditions 61 for a better management and sustainability. We refer specifically to landscape units of the lower area 62 of some islands, in many cases presently devoted to pasture where productivity tends to be marginal

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In this preliminary study climatic, pedological and topographical characteristics of the landscape are 67 considered based on GIS tools, in order to define the distribution of the most representative 68 landscape units with the greatest apparent potential for wine production in some islands of the 69 Azores. It is not our objective to produce a detailed cartographic definition of vineyard suitability 70 classes but rather to establish some basic criteria for prediction and identification of new areas from 71 which representative sites can be depicted for experimental studies in a subsequent phase.

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In this work, the spatial climatic differentiation for viticulture is based on climate/maturity classes 79 defined from the sum of the daily average temperatures that exceeds a base temperature of 10º C 80 along the growing season, as expressed in growing degree-days (GrDDs) concept and representing 81 the potential for the region to ripen given varieties based upon heat accumulation.

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A first cartographic approach has been attempted ( Fig. 1)

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The three thermal intervals referred to climate maturity groupings were combined with a single slope 105 interval of 0-15% to exclude the landscape units above this limit. The resulting composite grid for each island was finally combined with the respective digitazed soil map to select and incorporate the 107 cartographic units of Hapludands, Udivitrands and Eutrudepts, whose average parameters of drainage, 108 water holding capacity, depth to bedrock and pH fall within the adequacy limits for grapevine growth 109 and production, as depicted from the soil survey database and reports.  for the lower altitudes (<100m) of the Azorean islands is presented in Fig. 2.

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A strong climatic differentiation can be observed in altitude, as well as significant climatic 120 asymmetries inland of each island. The spatial expression of the climatic elements is related in each 121 island with its dimension and orography, the topographical orientation, the superficial geologic 122 structure, the top soils and the vegetation. In some cases the climate of one island is affected by the 123 "shadow" effect from its neighboring islands (Azevedo, 1996).        year. In the summer months, on the contrary, the wind velocity decrease to values under 10 km/h. It 157 is also in this period that, due to the diminishing influence of the higher predominance systems, we

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The model consists of two main sub-models. One, relative to the advective component simulation,

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In this work the topography was analyzed based on the tridimensional models of the islands in GIS.

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Instead of various slope classes we considered only one global interval in the 0-15% range as the

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The typical parent material of Andisols is tephra, a general term for all airborne volcanic ejecta,

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In volcanic landscapes the profile characteristics concerning horizon sequence and thickness can be 267 quite variable even within short distances. Depth to bed rock of the Hapludands in the selected areas 268 averages 60 cm with no less than 40 cm and the Udivitrands are in general more than 1m deep.

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The soil reaction found in the considered altitudes for both soil categories is in general slightly acid to 270 neutral, being the pH range of 5.6 to 6.5. From a soil standpoint, highquality wines are made from 271 grapes grown in many different types of soils with no single type considered ideal (Wilson, 1998).

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Grapevines will tolerate a wide range of soils, but yield and variation in vine vigour commonly match

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Here, we attempt to define and map landscape areas with apparent potential for grapevine growing 289 in the Azores islands of S. Miguel, Terceira, Faial and Graciosa, as an alternative to the traditional 290 "terroir". The lava field "terroir" was not included in the potential areas here defined because the     The calculated surfaces (ha) of the cartographic areas with potential for grapevine production, as 318 defined for each island and thermal class are presented in Table 1

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The expansion of the viticulture onto new soil types will also affect resulting grape and wine characteristics