Landscape sensitivity is a concept referring to the likelihood that changes in land use may affect in an irreversible way physical and chemical soil properties of the concerned landscape. The objective of this study is to quantitatively assess the sensitivity of the southern Alpine soil landscape regarding land use change-induced perturbations. Alpine soil landscapes can be considered as particularly sensitive to land use changes because their effects tend to be enhanced by frequent extreme climatic and topographic conditions as well as intense geomorphologic activity. In detail, the following soil key properties for soil vulnerability were analysed: (i) soil texture, (ii) bulk density, (iii) soil organic carbon (SOC), (iv) saturated hydraulic conductivity (K_sat), (v) aggregate stability and (vi) soil water repellency (SWR). The study area is characterized by a steep, east-west oriented valley, strongly anthropized in the last centuries followed by a progressive abandonment. This area is particularly suitable due to constant lithological conditions, extreme topographic and climatic conditions as well as historic land use changes. The analysis of land use change effects on soil properties were performed through a linear mixed model approach due to the nested structure of the data. Our results show a generally high stability of the assessed soils in terms of aggregate stability and noteworthy thick soils. The former is remarkable, since aggregate stability, which is commonly used for detecting land use-induced changes in soil erosion susceptibility, was always comparably high irrespective of land use. The stability of the soils is mainly related to a high amount of soil organic matter favouring the formation of stable soil aggregates, decreasing soil erodibility and hence, reducing soil loss by erosion. However, the most sensitive soil property to land use change was SWR that is partly influenced by the amount of soil organic carbon and probably by the quality and composition of SOM.

In times of global change, it is of fundamental importance to understand the sensitivity, stability and resistivity of a landscape or ecosystem to human disturbance. Landscapes and ecosystems have internal thresholds, giving them the ability to resist such disturbance. When these thresholds are quantified, the development of countermeasures can help prevent irreversible changes and support adaptations to the negative effects of global change. The main objective of this analysis is to address the lack of recent studies defining terms like sensitivity, resistivity and stability in reference to landscapes and ecosystems through a Bibliometric analysis based on Scopus and Web of Science peer-reviewed articles. The present research also aims to quantify landscape statuses in terms of their sensitivity, stability and resistivity. The term “landscape stability” is mainly related to quantitatively measurable properties indicating a certain degree of stability. In contrast, the term “landscape sensitivity” is often related to resilience; however, this definition has not substantially changed over time. Even though a large number of quantification methods related to soil and landscape stability and sensitivity were found, these methods are rather ad hoc. This study stresses the importance of interdisciplinary studies and work groups.

The sensitivity of a landscape to changes is expressed by the likelihood that a given change in the controls of a system will produce a sensible, recognizable and persistent response in the properties of the system (Brunsden & Thornes, 1979).The aim of this study is to investigate the sensitivity of an alpine soil landscape for human-induced perturbation in terms of land use changes that might affect soil properties and consequently affect also the stability of the soil landscape. The latter is of particular relevance since in alpine landscapes, land use effects tend to be intensified by extreme climatic and topographic conditions (Gordon, 2001). The study area is located in the southern Alps in the Canton Ticino (Switzerland) which is characterized by a centennial history of land use changes. The landscape can be subdivided into the following main land use-topography units: (i) forest areas in “natural” conditions on south and north facing slopes (reference state), (ii) pasture, (iii) meadow, (iv) cultivated agricultural terraces, and (v) abandoned terraces with forest regrowth in the last 40 years. Land use effects were verified by comparing the different land use-topography units with the reference state of “natural” forested slope. The following physicochemical key soil properties and soil water dynamics were measured that are known to be vulnerable to land use changes: saturated hydraulic conductivity, soil organic carbon (TOC), soil bulk density, hydrophobicity and aggregate stability as well as surface runoff generation and related soil erosion. Especially the latter can be considered the main contributor to soil degradation in alpine landscapes, reflecting the sensitivity of the soil landscape to land use changes. Statistical methods were used to detect changes, differences and correlations of key soil properties and soil water dynamics in the different land use-topography units in comparison to the natural conditions.The results of the analysis show that land use and land use changes have a significant impact on soil properties and soil water dynamics. Most of the investigated soil properties show statistically significant differences compared to the reference condition. Land use-induced vegetation changes have a considerable effect on soil’s TOC which is directly related to hydrophobicity and inversely related to bulk density. Soil water dynamics are also land use-specific showing higher values of surface runoff in forests and abandoned terraces where soil hydrophobicity plays a significant role. Even though, land use and related vegetation change had significant effects on investigated soil properties, no effect on soil erosion. Hence, due to the particular characteristics in the lithology and soils of the study area, the soil landscape in the Onsernone valley seems to be resistant at least under the present-day climate variability.ReferenceBrunsden, D., Thornes, J. B. (1979) – Landscape sensitivity and change. Transactions Institute of British Geographers, 4(4), 403–484.Gordon, J. E., Brazier, V., Thompson, D. B. A., & Horsfield, D. (2001) – Geo-ecology and the conservation management of sensitive upland landscapes in Scotland. Catena, 42(2–4), 323–332

The management of Mediterranean agroecosystems is crucial to prevent, reduct, and mitigate sediment-related threats like soil erosion, water quality issues, or reservoir sedimentation. Hence, the assessment of sediment connectivity and sediment dynamics at catchment scale is essential for identifying hotspot areas susceptible to sediment loss. Therefore, the identification of type, extent, and location of sediment sources and the analysis of the connectivity between these sources and the channel network are a prerequisite for assessing sediment yield and transport. This study is aimed at elaborating an integrated georeferenced inventory map of sediment landforms and evaluating sediment (dis)connectivity within a Mediterranean agricultural catchment located in Val d’Arda (Northern Apennines, Italy). We performed extensive geomorphic field surveys together with the application of remote and proximal sensing methods in order to identify and characterize the dominant processes involved in the sediment production and transportation throughout the catchment. Based on a detailed terrain analysis using a high-resolution DTM we quantified the physical (structural) linkages between catchment compartments, sediment sources and the drainage pattern following a morphometric connectivity approach. Our study revealed that the Val d’Arda catchment is widely characterized by several large active landslides, in particular complex earthflows and mudflows, but also wide dormant coalescent landslides with small evidence of intermittent reactivation, which are directly linked to the channel network. The terrain analysis highlights clear evidence about the role of such geomorphic processes in shaping the topographic features of the catchment, e.g. their influence on the steepness of the slopes and the lateral morphological evolution of the fluvial system. The processes active in the study area are highly influenced by the structural sediment connectivity and present high spatio-temporally variability. Moreover, we identified several rill-interril, piping and gully systems, whose genesis and evolution appeared to be mainly controlled by lithology and land-use. In some cases these systems have evolved into badlands, with a high potential in terms of soil loss and sediment production. On the other hand, several badlands’ systems are stabilizing, showing revegetation processes, becoming active only due to shallow mudflows. In this study we show that the comparison between the sediment landforms and topography-based connectivity maps allows to highlight the main processes involved in the sediment production and their role in downslope transfer of sediments.