Browsing by Subject "viherrakentaminen"

In Arboretum Mustila, the most significant private tree species collection in Finland, cultivation of exotic conifer species began in the 1910s. Finnish research on exotic conifers stems from the interests of commercial forestry although the focus of cultivating these conifers has shifted to horticultural and landscaping use in practice. This study is an inventory aiming to produce knowledge on the performance of conifer plantations in Mustila Arboretum. In addition, the results of the inventory are usable in targeting the selection of reproduction material in the Arboretum and they enable further discussion on benefits and possibilities of breeding exotic conifers. 41 tree species from genera Abies, Chamaecyparis, Cuprsessus, Larix, Picea, Pinus, Pseudotsuga, Thuja and Tsuga were included in the study. Yield parameters, tree quality, tree damages and phenotypic variability in important properties to horticultural landscaping use were assessed in forest stands and tree groups. 1-4 permanent circular plots were established to each forest stand for measurements and additionally phenotypic variance was estimated visually. Results of the inventory are available for the Arboretum and every single tree can be tracked even after decades. Most of the Arboretums exotic conifer plantations are suitable sources for reproduction of trees for gardens and parks. Abies balsamea, Abies koreana, Abies nephrolepis, Larix gmelinii var. japonica, Larix sibirica, Pinus peuce and Pseudotsuga menziesii var. glauca were most vital of the studied species. Stand volume exceeded 500 m3/ha within 16 species. Results of the inventory indicate that more exotic species perform well in Southern Finnish conditions than former studies have shown.

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.