Impact of land use changes on mountain vegetation

In this study the impact of land use changes on vegetation in the sub-alpine-alpine belt is analysed. The study sites (4.7 km(2)) are located in the Passeier Valley (South Tyrol, Italy), at an elevation of 1500-2300 in a.s.l. The whole study area was used for hay-making ca. 60 yr ago. Today, part of the meadows are more intensively used, while other parts have been converted to pasture or have been abandoned. We analysed the reasons for these land use changes and the effects on vegetation with a Geographical Information System and geostatistical analysis. The result of these analyses are: (1) Current land use is mainly controlled by the degree of accessibility for vehicles. Accessible areas are being used more and more intensively, while poorly accessible areas are being abandoned or used as pasture. (2) Current vegetation is highly determined by current land use. Particular vegetation units can be assigned to each form of land use. (3) Succession starts immediately after abandonment. Depending on altitude, succession proceeds at different speeds and with different numbers of stages. Hence the type of vegetation indicates the time passed since abandonment. (4) Land use changes lead to characteristic changes in vegetation; they are considered to be the most important driving force for vegetation change. (5) Measures of intensification and abandonment of extensively used areas both lead to a decrease in the number of species.