Can motor vehicles substitute the movement of livestock for effective seed dispersal in the modern rural landscape?
2011 (English)Conference paper (Refereed)
Before agricultural industrialisation, the dispersal of plant species through the rurallandscape was largely mediated by the movement of livestock. Today, species-rich,semi-natural grasslands exist as only small, isolated fragments, and livestock aregenerally kept within the same pasture throughout the grazing season. On the otherhand, the introduction of motor vehicles has provided a potential vector for seeddispersal through the landscape, and farming machinery, which is not confined toroads, can pick up and deposit a great deal of material. Our aim was to explore thepotential for motor vehicles to maintain the functional connectivity of the landscape inthe absence of free-ranging livestock. We collected manure samples from grazers onsemi-natural grassland pastures, and mud from the cars and tractors of five farmsduring the outdoor grazing season in a 10 km 2 landscape in southern Sweden, andgrew them in a greenhouse to assess their seed content. 31 713 seedlings of 109species emerged from 31 manure samples, while 12 675 seedlings of 111 speciesemerged from 49 samples of mud removed from motor vehicles. Both sets ofsamples were dominated by the genera Agrostis and Poa, which together stood for43% and 77% of the seedlings emerging from motor vehicle and manure samplesrespectively. Otherwise, manure samples contained several grassland specialists,whereas, despite the occasional grassland species, widespread ruderal speciesmade up the majority of the rest of the seeds dispersed by motor vehicles. Ourresults indicate that motor vehicles do not provide an effective link for the dispersal ofgrassland species through the rural landscape, and that the movement of grazersbetween fragmented grasslands should be encouraged to improve functionalconnectivity and biodiversity in the rural landscape.
Place, publisher, year, edition, pages
IdentifiersURN: urn:nbn:se:su:diva-66323OAI: oai:DiVA.org:su-66323DiVA: diva2:467455
Frontiers in Historical Ecology, Zürich, Switzerland, 30/8-2/9 2011