Found in Complexity, Lost in Fragmentation: Placing Land Degradation in a Landscape Ecology Perspective

This article was originally published here

Int J Environ Res Public Health. 2022 Feb 25;19(5):2710. doi: 10.3390/ijerph19052710.

ABSTRACT

The United Nations Convention to Combat Desertification (UNCCD) assumes that spatial disparities in land resources are a key driver of land degradation and early desertification processes all over the world. Although regional fractures in soil quality have been frequently observed in Mediterranean-type ecosystems, the impact of landscape configuration on the spatial distribution of sensitive soils has been little studied in southern Europe, a region affected sensu UNCCD. Our study provides a spatially explicit analysis of 16 ecological metrics (namely, patch size and shape, fragmentation, interspersion and juxtaposition) applied to three classes of a landscape with different levels of exposure to degradation. land (‘unaffected’, ‘fragile’ and ‘critical’). The land classification was based on the Ecologically Sensitive Areas Index (ESAI) calculated for Italy at 3 points over a 50-year period (1960, 1990, 2010). Ecological parameters were calculated at both landscape and class scales and summarized for each Italian province – a policy scale relevant for the Italian National Action Plan (NAP) to combat desertification. With the average level of soil sensitivity increasing over time almost everywhere in Italy, “unaffected” land has become more fragmented, the number of “fragile” and “critical” plots has increased significantly and the average size of plots of the two classes followed the same trend. Such dynamics have resulted in inherently disordered landscapes, with (i) larger (and widely connected) “critical” land patches, (ii) spatially dispersed and convoluted “fragile” land patches, and ( iii) a more dispersed and heterogeneous matrix of “untouched land”. Based on these results, we discussed the effects of increasing the number and size of “critical” plots in terms of land degradation. A sudden expansion of “critical” lands can have negative environmental consequences since (i) the increasing number of such plots can trigger a risk of desertification and (ii) the buffering effect of neighboring unaffected lands is assumed to be less effective, and it less effectively contains a downward spiral towards land degradation. The political strategies proposed in the NAPs of the affected countries must take into account more explicitly the intrinsic spatio-temporal evolution of the “critical” land parcels in the affected regions.

PMID:35270402 | DOI:10.3390/ijerph19052710

Sharon D. Cole