Summary Afforestation with pines (Pinus pinaster and, to a lesser extent, P. pinea and P. halepensis) seems to be the most probable land‐use change over large areas of dry cereal croplands in central Spain in the next 10–20 years. This will be encouraged by changes in the subsidy policies of the Common Agricultural Policy that aim to decrease food production and restore the environmental diversity previously lost through agricultural intensification. This study addresses the factors influencing the richness and composition of breeding bird communities in these pine plantations and evaluates the potential environmental benefits of the afforestation programmes. The complement of bird species breeding in 88 plantations ranging in size from 0.1 to 6775 ha was determined. Plantations were characterized according to size, distance to the nearest large plantation, vegetation structure and geographical location (northern moist vs. southern xeric Iberian plateaux). Plantation size alone accounted for 67–75% of the variation in species richness, and was also the maintrait explaining the patterns of presence/absence of most individual bird species. Plantations smaller than 25 ha only maintained 50% of the regional pool of forest birds during breeding, whereas this proportion increased to 69–86% for plantations of 25–100 ha. Geographic location, degree of isolation and vegetation structure were also important. Bird species richness decreased with distance to a large plantation, and increased with prevalence of undergrowth shrubs and with plant species richness. Both species richness and the incidence of individual species in plantations were affected by geographical location. They were greater in plantations of the northern plateau, reflecting a trend of increasing densities of most forest bird species in Spain in more northerly locations. The results of this study suggest that re‐afforestation of former arable land in the Spanish plateaux is unlikely to increase species richness in forest bird communities. Given the regional scarcity of many forest birds and the small scale of new plantations, re‐afforestation schemes are unlikely to promote rich forest bird communities. Since plantations are unsuitable habitats for the bird species breeding in Spanish dry cereal croplands, and such birds have a high conservation value because of their small and declining populations the overall environmental benefits of large‐scale afforestation programmes will not include increased diversity of birds.

1999. Dispersal of Spanish juniper yiCfy/iL' w.s' timrifera by birds and mammals in a fragmented landscape. -Ecography 22: 193 204.Dispersal of Spanish juniper Junipems timriferu was examined in a farming landscape of central Spain to study the effects of fragmentation on the dispersal effectiveness of the different dispersers. and the eonsequenees for the plant. The study was conducted in two large forests (LF: 280 and 150 ha) representative of unfragmented eonditions, and 18 small isolated fragments (0.1-3 ha) which were classified in two groups: 1) FI, forest remnants with both high juniper cover and cone production (N =5): and 2) F2, remnants in which fragmentation has caused a heavy reduction in junipers (N = 13). Cone production, disperser abundances and quantity of dispersal by birds (Turdus thrushes) and mammals (earnivores, rabbits and sheep) were estimated throughout two study years. Dispersal by thrushes was measured in three types of trees representing a decreasing attraction focus to birds: Spanish junipers with cones (SJI). Spanish junipers without cones (SJ2) and holm oaks (HO). Cone production greatly decreased from LF to Fl and F2 in both study years, affeeting F2 dramatically. Thrush abundances were similar in LF and Fl, but thrushes lacked or were very scarce in F2, Carnivores showed an even distribution throughout the whole area, but herbivores were relatively scarce in F2 fragments, especially rabbits, which were lacking in the fragments under 0.6 ha. Patterns of seed deposition around trees showed decreaj>ing dispersal activity of thrushes from SJI (83.1% of the examined trees had seed-packets-thrush pellets) to SJ2 (53.6';

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