title: Effects of roads on adjacent plant community composition and ecosystem function: An example from three calcareous ecosystems.
abstract: Roads and exhaust emissions can affect plant communities directly, for example via direct foliar uptake of exhaust products, or indirectly via changes to soil biogeochemistry and hydrology. A transect study adjacent to roads of different traffic densities was carried out at three species-rich calcareous grasslands in south eastern England. Measured annual NO(2) concentrations and modelled NH(3) concentrations increased towards the roads and with higher traffic densities, and there was evidence of increased soil moisture, pH and heavy metal concentrations at roadsides. Increases in the abundance of nitrogen (N) tolerant species and grasses at roadsides were associated with N enrichment from vehicle exhausts at two of the sites. In contrast plant species richness, the abundance of forb and moss species declined at roadside locations. As vehicle usage spreads across the world, it is increasingly important to understand the effects of road traffic on adjacent ecosystems to inform traffic and conservation management policies.
authors.affiliation: Division of Biology, Imperial College London, Silwood Park Campus, Ascot, Berkshire, SL5 7PY, UK. mark.lee07@imperial.ac.uk
authors.forename: Mark A
authors.initials: MA
authors.lastname: Lee
authors.forename: Linda
authors.initials: L
authors.lastname: Davies
authors.forename: Sally A
authors.initials: SA
authors.lastname: Power
mesh_terms: D000393:Air Pollutants / Q000032:analysis; D000641:Ammonia / Q000032:analysis; D002119:Calcium Carbonate / Q000032:analysis*; D017753:Ecosystem; D004777:Environment; D004784:Environmental Monitoring; D019216:Metals, Heavy / Q000032:analysis; D009584:Nitrogen / Q000032:analysis; D009585:Nitrogen Dioxide / Q000032:analysis; D012989:Soil Pollutants / Q000032:analysis*; D014186:Transportation
chemical_list: D000393:Air Pollutants; D019216:Metals, Heavy; D012989:Soil Pollutants; D000641:Ammonia; D002119:Calcium Carbonate; D009584:Nitrogen; D009585:Nitrogen Dioxide