Postdispersal seed predation in a Mediterranean patchy landscape

Seed predation rates of Pistacia lentiscus (Anacardiaceae) were determined at within and between site spatial scale in an Eastern Spanish Mediterranean landscape, a mosaic of scrubland and field patches. At within site scale, no differences in seed predation rates were found regarding the spatial location of the seed within scrubland patches (under parent plant, on the bare soil and under other woody perch different than P. lentiscus) nor within field patches (under woody perches and on the bare soil). Other significant factors related to seed predation in both fields and scrubland patches emerged at between site scale. In field patches, seed predation was higher in abandoned than cultivated fields. In scrubland patches, seed predation increased as the perimeter/surface ratio of the patch increased, as habitat fragmentation theory predicts due to the immigration of the ecotonic predators inside the patch. Also, seed predation rates were high at both low and high woody plant cover of the scrubland patches. Detectability of the seed would explain high seed predation rates at low woody plant covers, whereas the total seed density of the seeds and/or the presence of refuges for seed predators would explain high seed predation rates at high woody plant covers. A decreasing pattern of seed predation rates was found from scrubland patches through distant fields, suggesting a scrubland patch-specific behaviour of seed predators.