1 1 2 3 Spatial structure of deciduous forest stands with contrasting 4 human influence in northwest Spain 5 6 7

Five contrasting deciduous forest stands were studied to characterise the spatial structural 23 variability in human-influenced forests. These stands are representative of cultural forest types 24 widely represented in western Europe: one plantation, two coppices, one wood-pasture, and one 25 high forest stand. All stems with DBH > 5 cm were measured and mapped, and stem DBH 26 distributions, spatial structure of DBH, spatial point patterns and spatial associations were 27 analysed. Spatial autocorrelation for DBH was calculated with Moran’s I correlograms and 28 semivariograms. Complete spatial randomness hypothesis for spatial point patterns, and both 29 independence and random labelling hypotheses for spatial associations, were analysed using 30 Ripley’s K function. The results showed that tree sizes were conditioned by particular former 31 management systems, which determined unimodal symmetric, positively skewed, or compound 32 DBH distributions. Spatial structure was more complex when human influence became reduced. 33 Coppice stands showed clumped spatial patterns and independence among size classes, as a 34 consequence of sexual and vegetative establishment of new stems in open areas. The largest 35 clumping intensity was observed in the wood-pasture with an intermediate disturbance frequency 36 and low inter-tree competition. The high forest stand displayed spatial traits consistent with the 37 gap-dynamics paradigm, such as clumping of smaller trees, random arrangement of larger trees, 38 negative association between juveniles and adults, and high structural heterogeneity. It can be 39 expected that after cessation of human interference, coppices and wood-pastures would evolve to a 40 more heterogeneous structure, perhaps with a higher habitat and species diversity. 41 42