Fruits produced under mountain environment are known to develop peculiar high quality traits that can vary depending on fruit species and cultivar. Moreover, fruit development and ripening is normally also postponed, therefore allowing extra season commercialization and higher prices. All these aspects are strictly linked with the environmental-climatic conditions acting under mountain environment on plant growth and fruit development. There are two categories of environmental changes with altitude: those physically tied to the altitude (such as: the decrease in total atmospheric pressure and partial pressure of all atmospheric gases; the reduction of atmospheric temperature; the increase in radiation under a cloudless sky and, specifically, the higher fraction of UV-B radiation) and those that are not generally altitudespecific (such as: moisture, wind, cloudiness, etc.). This review aims to shed light on the potential causes and effects of environmental conditions linked with altitude on specific quality traits that are characteristic of “mountain fruits”, such as: elongated shape, reddish fruit skin color, higher pulp crispness, higher antioxidant potential and nutritional value, more intense aroma and taste. Mountain environment also involves the need to adapt fruit production techniques to specific constrains and cultural conditions. These aspects were considered by looking at one of the main Italian apple-producing district as case-study: South Tyrol. Nearly one million tons of apples are produced every year in South Tyrol, half of the whole Italian production. The most appropriate cultivar and/or clone selection for each specific area of cultivation is linked to the orchard altitude, exposition and other environmental parameters. This is a key point to fully exploit the site potential for a top quality crop. Cultivar selection is also of extreme importance for other fruit productions of relevance in South Tyrol, such as apricot and cherry, where the availability of local variety, fully adapted to the mountain environment, can be also seen as a valuable tool for fruit commercialization and marketing. Sustainability of the production methods is also a key issue, especially when the cultivation area is of high naturalistic value and, therefore, hosts other important economic activities, such as tourism. This is the case for instance of strawberry production within the National Stelvio Park (Martello Valley), where the cultivation is in open field, no plastic tunnels are allowed for landscape conservation, and water and nutrient inputs are carefully managed in order to minimize the ecological impact.
Keywords: climatic and environmental parameters, altitude effect, nutritional value, cultivar selection, South Tyrol.