The importance of traffic corridors as urban habitats for plants in Finland

Abstract

Traffic corridors have been recognized as floristically rich with endangered and rare species included. The aim of this study is to treat traffic corridors as habitats and estimate their importance for diversity of vascular plants on municipal level. The material is derived from the comprehensive studies of urban floras in the cities of Vantaa, Kerava and Järvenpää during the 1990s in southern Finland. The material consists of over 190,000 species records (704-771 species). The material was divided in two groups: the ones with occurrences in traffic corridors (TC) and the others with no occurrences (NTC). The percentage of the traffic corridor plants of the total flora is almost the same in all the three cities: two thirds in traffic corridors and one third not in traffic corridors. The explanation may be the general floristic similarity of the cities. The two groups differ ecologically from each other. The association of plants with traffic corridors varies according to the ecology of the species. About 100 plants have more than 50% of their occurrences in traffic corridors. In Järvenpää, a group of four Carex-species was intensively mapped. 46 occurrences out of 50 were found in traffic corridors. A case study showed the difficulties in management of endangered species on a roadside site. The usual extensive management techniques were not sustainable for the survival of the species. Instead, a much more intensive management was needed.

Floristic analysis of a high-speed railway embankment in a Mediterranean landscape

“…Further, as already found in central and north Europe (TIKKA et al 2000;2001, TINNER and SCHUMACHER 2004, RANTA 2008, LOSOSOVA and LANIKOVA 2010, in the Mediterranean region too railway sides can act as a substitute habitat for species from natural and semi-natural communities. However, the ecological role of railway sides in the temperate and boreal regions -where road and railway verges are among the few surviving examples of dry and mowed habitats -is quite different compared to the Mediterranean countries.…”

“…71 (2), 2012229 1979BRANDES 1983BRANDES , 1993BRANDES , 2008CORNELINI and PETRELLA 1996;SCHOENENBERGER et al 2002;NOWI¼SKA and CZARNA 2008). Some works have focused on the negative role of rail lines as dispersal pathways for alien species (SCHOENENBERGER et al 2002, CHRISTEN and MATLACK 2006, RANTA 2008, TRET'YAKOVA 2010 -although due to the decrease in grain and livestock rail transportation in the last few decades, railways have nowadays a less rich alien flora than observed in the first half of the 20th century (BRANDES 1983: 38, CORNELINI and PETRELLA 1996, TINNER and SCHUMACHER 2004.…”

“…SARGENT 1984, BRANDES 1993, TIKKA et al 2000, SCHAFFERS and SYKORA 2002, WITTIG 2002, TINNER and SCHUMACHER 2004, RANTA 2008. A floristic survey of the Dutch railway network found a total of 1,026 species, i.e.…”

“…In highly transformed landscapes, on the other hand, rail and road sides -being a relatively undisturbed habitat compared to the surrounding areas (MESSENGER 1968, BRANDES 1993) -may act as corridors for the survival and dispersal of plant populations from endangered natural or semi-natural communities (TIKKA et al 2001, RANTA 2008, especially if the railway verges are managed according to biodiversity-oriented criteria (PARR and WAY 1988;CORNELINI et al 1990;CORNELINI 1994a, b;TIKKA et al 2000TIKKA et al , 2001.…”

Plant diversity and grassland naturalness of differently managed urban areas of Torino (NW Italy)

“…In particular, the interest in the evaluation of habitat diversity in urban grasslands has greatly increased over the last years, since these ecosystems display a pivotal ecological role for both human and wildlife well-being, and they represent an important habitat for a wide number of plant and animal species (Angold et al, 2006;Ranta, 2008;Tikka et al, 2000). Compared to semi-natural grasslands, urban grasslands are exposed to more frequent and intense disturbance regimes by periodic cutting (McKinney, 2002).…”