Dirt roads could be providing important corridors for seed distribution.

Alberto Suárez-Esteban and his colleagues at the Doñana Biological Station in Seville, Spain, collected animal faeces from 66 kilometres of man-made breaks in vegetation, such as firebreaks and dirt roads, as well as adjacent scrubland, in Doñana National Park in southwest Spain. The researchers identified and counted the seeds contained in 615 faecal samples from rabbits, carnivores and ungulates such as deer.

Carnivores and rabbits preferred to defecate on tracks, dispersing up to 124 times as many viable seeds along the tracks as in the scrub. Although ungulates avoided defecating along the tracks, their faeces also contained considerably fewer viable seeds.

The authors suggest that such human disruptions could have an overlooked role in plant conservation by helping animals to spread seeds between isolated plant populations, but they could also provide routes for invading species.

J. Appl. Ecol. http://dx.doi.org/10.1111/1365-2664.12080 (2013)