Phytosociology and ecology of old hay meadows in Hordaland, western Norway in relation to management

Abstract

Well-drained mown hay meadows in Hordaland, western Norway, were investigated. The hay meadows are either managed in a traditional or in a semi-traditional way. Traditional management in the area involves little or no use of manure or fertilizer, mowing once or twice a year with a first cut later than June 23, clearing in spring and intensive grazing for short periods in spring and autumn. Semi-traditional management involves use of small to medium quantities of commercial fertilizer, often in addition to manure. Grazing may be irregular, light or lacking.Eight units of hay meadow vegetation are described, all assigned to the class Molinio-Arrhenatheretea, orderArrhenatheretalia; four units to the Atlantic alliance Cardaminion pratensis, association CardaminopratensisConopodietum majoris (with three subassociations); one unit to the alliance Arrhenatherion elatioris, three units are provisionally grouped as Galium uliginosum-Knautia arvensis meadows.Continuous management of these meadows has resulted in characteristic species compositions, which vary along a west-east climatic gradient, and are related to the amount of commercial fertilizer used and the natural mineral-content of the soil.These hay meadows seem to be best maintained by continuing the traditional management regime. Grazing in spring and in autumn reduces fast growing dominants and creates openings for new seedlings of annuals and biennials. A late first cut allows for ripening of the seeds and creates openings for light for the species of the lower field layer. A list of species characteristic of traditionally managed permanent hay meadows is presented, and possible effects of present changes in management on the species composition of the meadows are discussed.The amount of organic matter in the topsoil is small in most stands. The pH values are between 4.0 and 5.6. The highest values were recorded in soil where little or no commercial fertilizer is used, and where the subsoil is naturally rich in minerals. A tendency to Mg impoverishment in the best fertilized stands is demonstrated. Species-rich stands on Ca-rich soils are poor in P.The expected changes in vegetation, future use, and conservation of permanent hay meadows in Hordaland are discussed.

Dispersal, Recruitment and Site Occupancy of Grassland Plants in Fragmented Habitats

“…Due to changes in the traditional land-use related to agriculture, many areas have been converted to arable land or tree plantations and others have been fertilised (e.g. Losvik 1988, Bengtsson-Lindsj6 et al 1991, Ihse 1995. Apart from being suitable targets for studies of Table 2.…”

Response of sowed, flowering herbaceous communities suitable for anthropic Mediterranean areas under different mowing regimes

“…Mowing early in the season favors late flowering plants without rosettes (Losvik, 1988) and in fact, in the second year, we found that E. californica* had 6.7 plants per square meter in the early season mowed plots versus 3.3 and 1.7 plants per square meter in the mid and in the late-season mowed plots, respectively.…”

“…Lateseason mowing not only enabled the species to produce seeds, but presumably also enabled the perennials to allocate nutrients to below-ground reserves (Huhta, Rautio, Tuomi, & Laine, 2001). A late cut in fact enables the seeds to ripen and creates light for the species in lower field layers (Losvik, 1988).…”

Thick moss layers and high cover of grasses: Potential threats to herb diversity in hay meadows in Norway

“…The mean temperature in January is 0.58C, and the mean annual temperature is 7.28C (Aune 1993). The soil is rich in minerals (base saturation: 54 Á76%), and poor in organic matter (carbon: 2.3 Á3.8%, nitrogen: 0.31 Á0.47%, and phosphorus: 0.2 Á0.5mg/100 g dry matter), while the pH varies between 5.1 and 5.6 (Losvik 1988).…”