and special factors of land-use changes related to terraces are typical of the Mediterranean world in general, including the Slovenian sub-Mediterranean area (Ažman Momirski and Gabrovec 2014). A volume on terraced landscapes at the regional scale of sub-Mediterranean Slovenia (Ažman Momirski 2014) contains a survey of historical sources of terraces, geological data, physiognomy of the terrain and terraced landscapes, and use/functions of terraces in various areas at the level of region, municipality, cadastral municipality, settlement, and plot. In some cases, preventing landslides on slopes is not necessary because terraces and their slopes have preserved the same form for almost two hundred years. However, planning and constructing new terraces demand a contemporary methodological approach (Ažman Momirski 2015b). In the Mediterranean landscape, terraces are a traditional element, whereas in the Pannonian landscapes, terraces are modern phenomena, created mostly in the 1960s and 1970s to facilitate intensive mechanized farming (Ažman Momirski and Kladnik 2015a). After reviewing documents at the national level (laws and strategies) and local level (spatial documents) to determine whether and how they refer to terraced landscapes, it is possible to propose a procedure to allow institutions at the national and local levels to map and evaluate terraced landscapes (Ažman Momirski and Berčič 2016). Nowadays, Lidar data offer an unprecedented accurate new interpretation tool for detecting terraced landscapes. The most significant feature of this new method is its reliability for detecting the exact boundaries of terraced areas (Berčič 2016). This new methodology will probably challenge the findings of previous studies presenting the diversity of Slovenian terraced landscapes (Kladnik et al. 2016a, b). The same authors contributed to a publication for the general public presenting terraced landscapes of the world and Slovenia (Kladnik et al. 2016a, b). Recently, Likar (2017) called attention to the fact that terracing was not only carried out on slopes to prevent erosion and mitigate the effects of droughts and flooding on farmland, but was also used in excavations for house foundations in settlements, for example, in northern Istria.

4.3State of Terraced Landscapes in Slovenia

Reviewing all Slovenian territory, only 19 municipalities (out of 211) have no terraced landscapes, which altogether represent 3.3% of the country’s entire territory. In other words, terraced areas that form part of the cultural landscapes in Slovenia can be found in more than 90% of the country’s municipalities, corresponding to a little less than 97% of Slovenian territory. The presence of terraced landscapes in the municipalities is not uniform: In some municipalities, where most of the territory is flat, there may be only a few terraces on slopes that are not very steep at the edge of the municipality’s territory (borderline cases were included in the category of municipalities with terraced landscapes). In other municipalities, terraced landscapes may be the dominant landscape feature. Both active (i.e., cultivated) and abandoned terraces were considered in the review (Ažman Momirski and Berčič 2016).

Various types of terraces exist within Slovenia’s terraced landscapes, but they are all made up of two basic formal elements: a terraced platform (or tread) and a terraced slope (or riser; Ažman Momirski 2008a, b, c, d). The criteria for determining the types of terraced landscapes are defined according to:

–The use or function of the terrace slope and terrace platform;

–The form of the terrace slope and terrace platform; and

–The construction of the terrace slope.

Land use relates to the exploitation of land through human activity in the landscape, and it is one of the best indicators of landscape structure and processes. Within Slovenia’s cultural landscapes, three main types of terraces can be distinguished based on land use (Ažman Momirski and Kladnik 2008, 2009):

–Agricultural terraces;

–Viticultural terraces; and

–Fruit-growing terraces.

Mixed types of terraces can be also found. Vegetables are grown below olive groves on terraces, fruit trees are planted on the slopes of agricultural terraces, and so on.

Agricultural terraces can be found all over Slovenia, in all of its major regions. Agricultural terraces are mostly meadows and pastures, and sometimes they are cultivated more intensively with crops or vegetables. Agricultural terraces in Slovenia differ extensively in their forms: Terraces in the high mountains just below the ridges mainly have wide terrace platforms with a steep gradient, an irregular plan, and extremely low terrace slopes; however, because of the high terrain inclination, these terraces are extremely high. In contrast, terraces at the foot of the hills, which are often low, have medium-wide terrace platforms and an almost equal proportion between terrace slopes and terrace platforms. There are also uniform, regular, higher terraces with only a few centimeters of the gradient of the terrace slope, and therefore again an identical proportion between the terrace slope and terrace platform (Ažman Momirski and Berčič 2016).

In many Slovenian landscapes, the development of cultural landscapes is inseparably linked to the development of viticulture. In the Middle Ages, farmers started to cultivate unworked land, and in the Gorizia region, for example, they planted vines on flat fields. After 1574, this type of grape cultivation was sometimes banned because it began to threaten cereal production. Prohibitions on planting grapes in fields and pastures, and a general prohibition on planting vineyards, appeared until the eighteenth century. Since the middle of the nineteenth century, the development of viticulture has been significantly affected by pests and diseases, such as gray mold of grape, peronospora, and grape phylloxera. Because phylloxera destroyed many vineyards, they had to be reconstructed, which prompted the renewed progress of viticulture. The farmers dug deep into vineyards, planting vines in rows and at proper distances. The new arrangement also improved the production options. During the First and Second World Wars, many vineyards were

destroyed and farmers started to abandon old vineyards and vineyards in less favorable areas because of labor shortages (Ažman Momirski 2008b).

Due to the specific features of production and favorable conditions for cultivating grapes, most vineyards in Slovenia are located on steep terrain, and one-fifth are terrace plantations (21%), among which 71% are arranged on slopes with a gradient over 9.1° (16%). Approximately, half of the vineyards on terraces can be found in the gradient class of 9.1°–17.0° (16–30%), and just under one-third are on slopes from 17.2° to 26.6° (31–50%). In 2015, 959 vineyards (229 ha) were planted on terraces with inclinations of 24.4°–31° (45–60%) and 101 vineyards (9 ha) on terraces with inclinations over 31° (60%) (Vineyard Census 2015). Viticulture on vineyard sites at elevations over 500 m, on slopes greater than 17.0° (30%), on terraces or embankments, and on small islands under difficult growing conditions is classified as “heroic viticulture.” This is a marginal form of viticulture, which is widespread in less than a tenth of wine-growing areas in Europe, and for which the criteria have been defined by CERVIM (2017). Since 1987, the International Organisation of Vine and Wine (OIV) has paid special attention to it.

It is also important to emphasize that an average winegrower in Slovenia cultivates only a small area, about half a hectare of vineyard. In 2015, over 90% of winegrowers were cultivating less than one hectare of vineyard, and the average vineyard size was 0.3 ha. For comparison, an average winegrower was cultivating a much smaller area (0.1 ha less) than in 2009 (Vineyard Census 2015). The study further showed that 104 municipalities in Slovenia have terraced vineyards (Fig. 4.1).

The wine-growing area of Slovenia is divided into three wine-growing regions (the Drava Region, which includes the Drava Valley in the northeast; the Lower Sava Region, which includes the Lower Sava Valley, White Carniola, and Lower Carniola in the southeast; and the Littoral Region, covering the traditional region of the Littoral in the southwest) and nine wine districts (Prekmurje, Styria, Bizeljsko-Sremič, Lower Carniola, White Carniola, the Gorizia Hills, the Vipava Valley, the Karst Plateau, and Slovenian Istria) as a consequence of the great variety of the landscape, different climate and soil conditions, and different natural conditions (Pravilnik 2003).

According to data from orthophotograph maps, there is almost 19,300 ha of vineyards in Slovenia, although the Register of Grape and Wine Producers (RPGV) lists only about 16,000 ha (Vinogradništvo in vinarstvo 2016). Data show that vineyards are increasingly shrinking at the beginning of the twenty-first century. Based on data from orthophotograph maps, vineyards have decreased by 3651 ha in the last 10 years; based on data from the RPGV, vineyards have decreased by 1192 ha in the last 10 years (Table 4.1).

In 2007 in Slovenia, 37% of vineyards were located on terraces (in 2011 only 34.9% and in 2016 only 31%): in the Drava Valley 24% (1757 ha), in the Sava Valley 27% (824 ha), and in the Littoral 55% (3759 ha; Štabuc and Hauptman 2008; RPGV 2016) (Tables 4.2 and 4.3).

In some areas in Slovenia, such as the Brkini Hills, the majority of orchards were planted on terraces or terrace slopes by the beginning of the nineteenth century.

Fig. 4.3 Grassed terrace slopes in vineyards in Medana in the Gorizia Hills (Photo Lučka Ažman Momirski), in an olive grove in Krkavče in the Koper Hills (Photo Lučka Ažman Momirski), and in meadows and pastures in Artviže in the Brkini Hills (Photo Kras in Brkini) and the Materija Lowland (Photo Matevž Lenarčič)

Grassed terrace slopes are much more common in the cultural Slovenian landscape than dry stone wall construction and can be found in all Slovenian regions (Fig. 4.3).

Terraces can be also categorized by cultivation extent or state of decay:

–Cultivated terraces;

–Partly abandoned terraces; and

–Abandoned terraces.

The terraced landscape contributes to the identity and profile of local cultures. It is an important part of the quality of people’s lives, providing variety and making the region attractive, and in this way making possible the preservation of the settlements and vitality of rural areas (Ažman Momirski 2008a, b, c, d). In this connection, terraces are often recognized as significant landscape features. Terraces with minor or medium significance are a very common feature in Slovenia.