Land use change in the high mountain belts of the central Apennines led to marked changes of the grassland mosaic

Abstract

Aims:High mountain pastures are hotspots of biodiversity, but grazing cessation and climate change are causing tall-grass encroachment and expansion of scrublands and forests. As part of biodiversity conservation efforts, grassland variation needs to be investigated at different spatial scales. We aimed to assess the landscape mosaic variation that occurred between 1988 and 2015 in the higher Mediterranean mountains. We investigated the recovery or land-degradation processes related to land use change, the effects of site condition, the impacts on grassland mosaic heterogeneity, and the threats to biodiversity. Location: Sibillini Mountains (central Italy), over 1,650 m a.s.l. Methods: We used two-step object-based supervised classification on Landsat 5 and 8 satellite images to analyze changes in landscape patterns and vegetation cover on formerly low-intensity pastures, by assessing the Normalized Difference Vegetation Index variation between 1988 and 2015. Twenty percent of the polygons obtained from segmentation were visually interpreted and assigned to five land cover classes.We generated a land use transition matrix and used Fourier Transforms to detect trends in variation of landscape mosaics and fragmentation. Results:We observed prominent dynamics of the grassland mosaic leading to the homogenization of its structure through decreasing patch heterogeneity, especially on south-facing slopes. Grasslands shifted from open communities to dense pastures, with a reduction of scree and spread of tall grasses. The former trend could be understood as a recovery process reverting screes to conditions in equilibrium with local landform and climatic features, while the invasion of tall grasses is a landdegradation process that might lead to local species extinction and loss of habitat connectivity. Conclusions:Pronounced changes in the large-scale landscape characteristics, mainly due to land use changes, of which scientists and managers of protected areas are not fully aware, are underway in the top mountain sectors of the study area. | Applied Vegetation ScienceMALATESTA ET AL.

Using UAV Imagery to Detect and Map Woody Species Encroachment in a Subalpine Grassland: Advantages and Limits

“…Finally, according to the results of photo-interpretation, the encroachment rate in the study area from 2012 to 2018 was~1% per year, in terms of tree and shrub cover expansion. This result is consistent with other studies which found that the increase of woody species cover due to the encroachment process ranged from 0.9% to 2.3% per year [10,84,87].…”

“…Therefore, in light of the above results, we suggest using a semi-automatic classification of RGB images when the main aim of the study is to describe the vegetation cover of several areas or long-term land cover changes. For instance, Malatesta et al [87] successfully detected 27 years (1988-2015) of land cover change of a pastoral landscape in the central Apennines in Italy through a supervised object-based classification of satellite imagery. On the other hand, we suggest preferring more accurate methods, such as visual photo-interpretation, when the objective is to describe short-term land cover changes on a small scale.…”

Climatic changes and the fate of mountain herbivores

“…The use of grassland by red deer is an important factor accelerating the depletion of resources for chamois (Central Alps: Anderwald et al 2015;Corlatti et al 2019;Central Apennines: Lovari et al 2014;Ferretti et al 2015). The spread of unpalatable pioneer tall grass (for the Central Apennines: Malatesta et al 2019) and the concurrent reduction of foraging areas (for our study area: Lovari et al 2014;Corazza et al 2016) may also play a role, helping the recolonisation of Alpine grasslands by woodland (Gehrig-Fasel et al 2007;Espunyes et al 2019). A warming temperature may also influence the life cycle of parasites, leading to a faster development rate, a longer period when a transmission is possible and increasing transmission rate (e.g.…”

An updated checklist of the vascular flora of Montagna di Torricchio State Nature Reserve (Marche, Italy)

“…Floristic studies are foundational for the ongoing research in the Reserve and neighbouring areas, and provide a reference for the ecological processes underway in the Apennine area (Bracchetti et al 2012;Catorci et al 2012b;Troiani et al 2016;Malatesta et al 2019). Such continuously updated studies fulfil the Reserve's objective of increasing knowledge about natural processes, and contribute to long-term studies of the LTER-Italy network (Rogora et al 2018).…”