Increasing the plant species selection in traffic environment
Traffic environment, like roadsides and central reservations, when considering their total area and netlike structure, provide a good opportunity to increase ecosystem services by green infrastructure. This potential is unexploited because of limited plant species selection. We tested low-growing herbaceous perennials, ornamental grasses and shrubs in a city center traffic area to attain visually good, diverse urban greenspace with low maintenance needs. We also tested local growing media containing composted digestate of sewage sludge and biochar made of deciduous wood. The test site was in the central reservation of a busy highway in the city of Turku, southern Finland. The selected plant species were 16 perennial herbaceous species, 6 grass species and 7 shrubs. Some of the species were native, others garden varieties. The perennials and ornamental grasses were planted as pre-grown mats (total area 450 m2) and the shrubs were planted as container plants (total area 385 m2). During two growing seasons, the growth, health, overwintering, ornamental value and tolerance of plants to the stress factors caused by the traffic were observed. The results gave indications about the success of some species and vulnerability of others in traffic environment. During the two first growing seasons, biochar did not affect the growth of the shrubs.
Tuhkanen, E.M., Juhanoja, S., Myllymäki, T. and Haakana, A.M. (2018). Increasing the plant species selection in traffic environment. Acta Hortic. 1215, 259-262
biochar, low-maintenance, perennial, shrub, urban landscaping