Browsing by Subject "perennat"

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  • Nieminen, Noora (Helsingfors universitet, 2010)
    Puu-Käpylä (“Wooden Käpylä”), a neighbourhood of Helsinki, is the earliest example of the Garden City Movement in Finland. The suburb of valuable wooden architecture was built between 1920 and 1925, with the aim to provide a healthy housing area for working-class families with many children. The houses were erected by a co-operative (Käpylän kansanasunnot, “People?s Dwellings”) and they are protected by the city plan since 1960?s. However, the historical value of the sheltered courtyards has not been investigated. The aim of this study was to survey the garden flora of Puu-Käpylä and to evaluate the authenticity of the courtyard gardens. The survey covered the area of one residential quarter (1.2 ha) with twelve 2-storey semi-detached timber houses arranged around a common yard, which was originally appointed for the tenants? vegetable gardens. The houses are still rented, and each flat is allowed a small lot of the courtyard for cultivation. A complete list was made of all perennial, ornamental plant taxa present in the quarter. Spring bulbs were missed due to the timing of the survey. Generally, the plants were recorded on species level, with the exception of common lilacs, shrub roses, irises and peonies that were thoroughly studied for cultivar identification. It was assumed that plants initially grown in the courtyard could be distinguished by studying Finnish garden magazines, books and nursery catalogues published in the 1920?s and by comparing the present vegetation to surviving documents from the quarter. The total number of ornamental plant taxa identified was 172, of which 17 were trees, 47 shrubs, 7 climbers and 101 herbaceous perennials. The results indicated that a major part of the shrubs, climbers and perennials presumably originated from the 1970?s or later, whereas ca. 70 % of the tree specimens were deemed as original. The survey disclosed a heritage variety of common lilac, resembling cultivar „Prince Notger?, a specific peony taxon, Paeonia humilis Retz., cultivated in Nordic countries since long ago, and a few historic iris varieties. Well-preserved design elements included front gardens on one side of the quarter, a maple alley on another side as well as trees at the garden gates. Old garden books and magazines did not shed much light on the Finnish garden flora commonly used in the period when Puu-Käpylä was built. However, they gave a valuable picture of contemporary planting design. Nursery catalogues offered insight into the assortment of ornamental plants traded in the 1920?s. Conclusions on the authenticity of the current flora were mainly drawn on the basis of old photographs and a vegetation survey map drawn in the 1970?s. This study revealed a need for standardization of syrvey methods applied when investigating garden floras. Uniform survey techniques would make the results comparable and enable a future compilation of data from e.g. historic gardens.
  • Tommila, Tero (Helsingfors universitet, 2010)
    The herbaceous vegetation of Viikinoja naturalistic rain garden in Viikinojanpuisto, Helsinki, was mapped about 10 years after construction. Viikinoja garden is a brooklike reworking of a part of an old main ditch and can be classified as an enhanced wetland. In the garden area, 28 species of herbaceous perennials were planted in 1999, 23 of them within the actual wetland area. The aim of the study was to evaluate the success of planted herbaceous perennials in the wetland area and to compare this data to the life history traits of these species. In addition, the spontaneous herbaceous vegetation in the area was surveyed and the success of some of these species was compared to their life history traits. Species' success was assessed by their proportional presence, general coverage and local coverage. Of the 23 species planted in the wetland area, 19 had survived and of these, ten can be called succesfull. Spontaneous species were identified from over 80 genera. The combined coverage of the planted species in the study area was 57 %, while that of spontaneous species exceeded 90 %. Both groups were dominated by graminoid species (Phragmites australis and other grasses, Typha latifolia, Scirpus sylvaticus and Carex species). Of the life history traits, competitiviness, maximum height and lateral spreading ability had a positive effect on species' success, especially with respect to perennials at their planting sites. Ruderality had a negative effect on the success of perennials. It was concluded that the vegetation of Viikinoja is entering competitor-dominated phase. Future long-term development depends largely on park management practices regarding mowing, dredging and cutting of willows.