# Forest Dynamic in the Italian Apennines
## 1 Introduction  
According to [PERSON] et al. (1986) [1], the landscape can be defined as \"_a heterogeneous land area composed of a cluster of interacting ecosystems that is repeated in similar form throughout\"_. By its nature, the landscape is a complex system which has to be considered as holistic (the whole is greater than the sum of its parts), relativistic and dynamic: changing an element always means, in some way, changing the whole. This is the reason why some complex systems have been found to reorganize themselves so drastically that they really become something new [2]. Anthropogenic activities are responsible for many changes in the heterogeneous scale and patterns of landscape [3] and a modification is also expected when the anthropogenic pressure decreases [4]. A pan-European scale study over the last 25 years revealed that the most important landscape transitions are urbanization and natural afforestation processes [5]. Currently, more than half of the Earth's terrestrial surface is shaped by agro-pastoral activities, including a high fraction of protected areas [6]. Over time these practices originated landscapes which can be defined as traditional, and which played an important role in creating new high-quality habitats, which evolved into unique and characteristic biodiversity [7; 8; 9]. Traditional landscapes are defined as those that have a distinct and recognizable structure resulting from the integration of abiotic, biotic and cultural elements over the centuries and through slow development processes characterized by few periods of change and long periods of consolidation [10]. In Italy, a relevant example of traditional landscape can be found in the Apennines, that are a mountain range of about 1350 km from northwest to southeast Italy. Until 1900, traditional agricultural and forestry practices in these areas have altered the natural landscapes, resulting in a complex mosaic of sparse open areas and woodland patches [4]. Many Italian regions, including the Apennines, were affected by the decline of the traditional agro-pastoral activities that occurred as a result of the deep socio-economic changes after WW2 and then by the economic boom that followed [11; 12; 13]. The diffusion of intensive farming in favorable areas and the urbanization in the lowlands also triggered the abandonment of mountain areas and, consequently, of seasonal mountain pastures. This phenomenon was also common in many southern European mountain regions, where the processes of urbanization and the contemporary decline of agricultural activities have led to changes in rural land use practices, that since the 1950s have often caused the complete abandonment of agricultural land and of traditional activities [14]. As a consequence of this social phenomenon a progressive renaturalization of rural areas and of open grazing areas occurred in the Apennines and in other Mediterranean mountain regions such as Spain [15], France [16], Greece [17; 18]. As the dynamics and magnitude of the changes increased, the traditional landscape structure was, therefore, greatly disturbed [19] also as a consequence of a change at the plant community level [12; 16; 20; 21]. Natural succession processes, with shrub and woodland encroachment [4; 11; 20; 22], led to a return to a seminatural state showing an increase in size and number of woodland patches [19]. Forest expansion occurred both in terms of the gap filling process at a lower elevation and as an upward shift of the treeline [23]. As reported in [PERSON] et al. [11], the increase of Italian forests is sizable; forests measured as a square kilometer, shifted from 60,000 in 1936 (Italian Kingdom Forest Map) to 85,000 km\({}^{2}\) in 1985 (First Italian Forest Inventory, IFN185), and to 105,000 in 2005 (Second Italian Forest Inventory, INFC05) and it was estimated at about 110,000 km\({}^{2}\) in 2015, with an increase of 20% in the last 30 years [24]. Land use land cover (LULC) change is reported by many authors as the single most important driver of biodiversity and geodiversity loss.