Terroir-Driven Viticultural Micro-Zoning In Bozcaada-Turkey

Bozcaada is renowned for its vineyards and wines. The island is located in the northeast of the Aegean Sea, in the southwest section of the Marmara region in Turkey. It is the third largest island in the Aegean Sea after Gökçeada and Marmara Islands. The dominant crops are grapevines, legumes, cereals, and fruits. The total vineyard area in Bozcaada is 11.850 ha, which covers 1/3 of the island and 80% of the agricultural lands. The two main factors that support viticulture and winemaking on the island are the unique soil types and the climate conditions, especially the north winds that determine the optimal diurnal temperature variation for viticulture. The island is unique for its viticulture and is characterised by its “terroir”. Terroir is a French word that describes how the interaction of the soil, terrain, and climate effect the vine, and how the combination of this effect with the human factor and viticulture management practices influence the quality of the grapes. In this study, qualitative and quantitative land evaluation tools were implemented to assess the lands and to suggest the most suitable rootstocks and varieties to winemakers. The land evaluation model uses climate, soil, and terrain indicators to evaluate the suitability of the soil-mapping units to the rootstocks and vine varieties. A detailed soil map was produced and has been implemented into the process together with other soil characteristics and climatic/topographic indicators. GIS and remote sensing tools have been used to create the soil map and input layers. Aspect, slope, and elevation layers were produced using the ArcGIS 3D Analyst tool from SRTM (Shuttle Radar Topographic Mission) data distributed by the Joint Research Centre together with the International Centre for Tropical Agriculture in Colombia. The SRTM digital elevation data, originally produced by NASA, is a major breakthrough in digital mapping and provides high quality elevation data for mapping and survey studies. Soil plays an important role in land evaluation and site selection, especially in site assessment for vineyards as the soil use to grow vines effects the fruit quality and flavours of wines. A detailed soil map of the island was produced to provide high quality soil data to be used in the land evaluation model. In this study, the components of the terroir concept and their complex relationships have been analysed to evaluate the land resources of the study area and several indices have been calculated for use in the land evaluation model, these are: Branas Heliothermic Index, Huglin Heliothermic Index, Cold Night Index, Winkler Index (IW), Jackson and Cherry Index, Riou's Drought Index, and Jones Index.