Spatial pattern in Anthyllis cytisoides shrubland on abandoned land in southeastern Spain

Univariate and bivariate distribution patterns of small shrubs on abandoned land in semi‐arid southeastern Spain were investigated by second‐order spatial analysis (Ripley's K ‐function). All shrubs ( Anthyllis cytisoides and subdominant Artemisia barrelieri ) were either randomly distributed or clumped at scales of 0.25 ‐ 1.0 m. The pattern shown by A. cytisoides shrubs alone changed from clumped to random with decreasing density. Pattern analysis and demographic data suggest a successive replacement of A. barrelieri , which had high proportions (44 ‐ 86 %) of dead shrubs, by the dominant A. cytisoides . In two of three plots there was a positive association between A. cytisoides and A. barrelieri at a scale of 0.25 ‐ 0.5 m. In the third plot, believed to represent a more advanced stage of colonization, there was a negative association (repulsion) between the two species, presumably as a result of interspecific competition from A. cytisoides . Dead shrubs present in spring 1994 were randomly distributed in all plots. Living and dead A. cytisoides shrubs were positively associated at a scale of 0.5 m, suggesting that the shrubs died as a result of intraspecific competition in small clumps. The shrubland previously dominated by A. barrelieri is changing to A. cytisoides shrubland with increasing biomass and ground cover.