Scale is a key concept in landscape ecology. Although several studies have analyzed the effect of scale on landscape structure metrics, there is still a need to focus on the ability of these metrics to discriminate between landscape types at different scales, particularly in Mediterranean forest landscapes. In this paper we assess the scaling behavior and correlation patterns of eight commonly-used landscape metrics in two Spanish forest districts (Pinares in Burgos and Soria, and Alto Tajo in Guadalajara) in order to detect at which grain sizes the landscape type differences are emphasized. This occurred in both districts at fine spatial resolutions (25 m) for the metrics related to shape complexity and the amount of boundaries, while a coarser spatial resolution (500 m) was required for the landscape diversity and mixture metrics, suggesting that the differences in the spatial and compositional diversity of these landscape types are not so large locally (alpha diversity) but amplified at broader scales (gamma diversity). The maximum variability for the fragmentation-related metrics did not appear at the same scale in both districts, because forest fragmentation in the Pinares district is mainly driven by harvesting treatments that operate at considerably different scales from those related to the less intensively managed district of Alto Tajo. Our methodology and results allow identifying and separately assessing those complex land cover mosaics that result from a similar set of biological and social forces and constraints. This should be valuable for an improved forest landscape planning and monitoring with a quantitative ecological basis in the Mediterranean and other temperate areas.Key words: grain size, spatial resolution, minimum mapped unit, variability analysis, metric correlation, forest planning.
ResumenEvaluación del efecto de la escala en la capacidad de los índices de estructura del paisaje para discriminar tipos de paisaje en comarcas forestales mediterráneas La escala es un concepto básico en ecología del paisaje. A pesar de que varios estudios han analizado el efecto de la escala en los índices de estructura del paisaje, todavía es necesario profundizar en la capacidad de estos índices para discriminar entre los tipos de paisajes a diferentes escalas, particularmente en los paisajes forestales mediterráne-os. En este artículo analizamos, en dos comarcas forestales españolas (Tierra de Pinares en Burgos y Soria, Alto Tajo en Guadalajara), el comportamiento frente a la escala y los patrones de correlación de ocho de los índices del paisaje más ampliamente utilizados, con el fin de detectar a qué tamaños de grano se enfatizan en mayor medida las diferencias entre los tipos de paisaje. Esto ocurrió en ambas comarcas a las resoluciones espaciales más finas (25 m) para los índices relacionados con la complejidad de formas y cantidad de bordes, mientras que para los índices de diversidad del paisaje y entremezclado espacial se requirió una resolución espacial menor (500 m), lo que sugiere que ...