Desertification risk fuels spatial polarization in ‘affected’ and ‘unaffected’ landscapes in Italy

Abstract

Southern Europe is a hotspot for desertification risk because of the intimate impact of soil deterioration, landscape transformations, rising human pressure, and climate change. In this context, large-scale empirical analyses linking landscape fragmentation with desertification risk assume that increasing levels of land vulnerability to degradation are associated with significant changes in landscape structure. Using a traditional approach of landscape ecology, this study evaluates the spatial structure of a simulated landscape based on different levels of vulnerability to land degradation using 15 metrics calculated at three time points (early-1960s, early-1990s, early-2010s) in Italy. While the (average) level of land vulnerability increased over time almost in all Italian regions, vulnerable landscapes demonstrated to be increasingly fragmented, as far as the number of homogeneous patches and mean patch size are concerned. The spatial balance in affected and unaffected areas—typically observed in the 1960s—was progressively replaced with an intrinsically disordered landscape, and this process was more intense in regions exposed to higher (and increasing) levels of land degradation. The spread of larger land patches exposed to intrinsic degradation brings to important consequences since (1) the rising number of hotspots may increase the probability of local-scale degradation processes, and (2) the buffering effect of neighbouring (unaffected) land can be less effective on bigger hotspots, promoting a downward spiral toward desertification.

Multi-Decadal Assessment of Soil Loss in a Mediterranean Region Characterized by Contrasting Local Climates

“…Basilicata shows a pronounced vulnerability to land degradation [64] similar to that of most Italian landscapes and Mediterranean countries [65][66][67][68]. This proneness originates from an intrinsic weakness of key environmental parameters: Soils are often thin and with a scarce presence of organic matter [69], while vegetation appears sparse and intermixed with barren areas in many zones [70,71].…”

Locally available compost application in organic farms: 2-year effect on biological soil properties

“…Nevertheless, the improvement of soil biological properties and related functions, such as suppressive activity toward soil-borne pathogens, an increase of nutrient bioavailability and promotion of plant growth, are the most frequently observed benefits of the compost use as an amendment (Hoitink et al, 1997;Bonanomi et al, 2010;Jakubus, 2016;Eden et al, 2017). However, the increase of soil biological features following compost incorporation into the soil largely varies according to soil characteristics and management, environmental conditions as well as the origin and composition of waste material (Noble and Coventry, 2005;Franke-Whittle et al, 2019;Jat et al, 2022). Most studies concerning the increase of microbial-mediated soil functions (soil suppressiveness, plant growth promotion) after compost incorporation into the soil linked this improvement to the general increase of soil biological activity expressed in terms of microbial biomass, basal respiration or enzymatic activities (Lee et al, 2004;Pérez-Piqueres et al, 2006;De Corato, 2020).…”

“…This intensively cultivated area, which had formerly hosted fruit tree (particularly peach), has been evolving to field crops over the last 5–10 years and is currently the primary seed-producing district in Italy. The soil organic matter content here is lower than 2% (Zdruli et al ., 2004) and it is one of the Italian regions where the desertification rate is reported to have increased most in the early-2010s (Nickayin et al ., 2022). The main objectives of this field experiment were: (i) to evaluate the impact of a locally available compost suitable for organic farming; (ii) to verify the early boosting effect of compost application on biological soil features, as already reported in other environmental conditions (Kandeler et al ., 1999; Ros et al ., 2003); and (iii) to estimate whether compost incorporation to the surface layer of soil in fall, the commonly adopted practice in the area under study, can improve biological soil features for the subsequent crop cycle.…”

Quantitative analysis of desertification driving mechanisms in the Shiyang River Basin: Examining interactive effects of key factors through the Geographic Detector Model

“…In addition, more than 12 million hectares of farmland are lost yearly due to only desertification and drought, with an approximate yearly loss of 20 million tons of crops supposedly produced by degraded lands [11]. South and East Asia, Southern Africa, the Citrum of Sahara, the Middle East, Latin America, the Caribbean, and western and southwestern parts of the United States of America are the most damaged areas by desertification [11][12][13][14].…”