Abrupt fragmentation thresholds of eight zonal forest types in mainland Spain

Abstract

Highlights1. We measured fragmentation of eight zonally distributed forest habitat types in mainland Spain by fitting power laws of cumulative patch frequency over patch size.2. The Korcak exponent, if determined by segmented regression of log-log transformations of the raw data, enables scale breakpoints in a spatial structure to be found. These area thresholds become new meaningful indicators of the underlying causes of fragmentation.3. Unexpectedly, all eight forest types had abrupt breakpoints in their respective fitted functions, showing that relatively large patches become very rare beyond a certain, always small (27-101 ha) area threshold.4. General interpretations coincide on landscape structures as the spatial memory of current and past events of human pressure on forest resources. The method and its resulting indicators can potentially produce forest-specific hypotheses based on patch size.

Land use intensification affects the relative importance of climate variation and active land degradation: Convergence of six regions around the world

“…Some examples are the Mesta (historic merino livestock guild), the Spanish confiscation (seizure and sale for profit of land owned by the Catholic Church), 19th century mining, etc. (del Barrio, Sainz, et al, 2021). However, the most recent (entry in the EU in 1986) has led to relaxation of human pressure on agroecosystems (Martínez‐Valderrama et al, 2021).…”

Multiscale fragmentation of forest types in Spain

“…A major factor hindering their implementation is the lack of a spatial or statistical context of real-world landscapes (Cardille et al, 2005) which constitutes a major contribution of this work. Del Barrio et al (2021) reported a complete fragmentation analysis for eight FTs in Spain and provided fragmentation thresholds from the cumulative frequency of the number of forest patches and their sizes. Although they used the same data source in their study (SFMap50), they applied a patch-scale model instead of a landscape-scale model (i.e., in their frequency analysis each observation corresponds to a patch, whereas in our framework each observation corresponds to a landscape).…”