Browsing by Subject "Pohjois-Pohjanmaa"

The aim of this study was to make a quantitative map inventory of the amount of temporal and spatial changes in meadow area in Finland during 1925-1992 and to make an estimation of the total amount of meadows in Finland in 1980’s and in the beginning of 1990’s. The environmental factors were also evaluated in the same areas. Initially this reseach was a part of FIBRE program. In the temporal study the area values of meadows and environmental factors were studied in three time steps: in 1930’s, 1960’s and 1980’s The oldest data from 1930’s were collected from black and white parish maps 1:20 000 and the two younger phases from base maps 1:20 000. The study area of the temporal change study was 7 500 km² and the mean areal coverage was 4,4% of the 11 studied provincial areas. North Karelia, Kainuu and Lappland were not included in this temporal change study as there were not available the oldest parish maps in these areas. The studied areas were Uusimaa, Lounais-Suomi, Häme, Pirkanmaa, Etelä-Savo, Pohjois-Savo, Keski-Suomi, Länsi-Suomi, Pohjois-Pohjanmaa and Åland. In the larger sample study of the meadow area in 1980’s in Finland the aim was to get an estimate of the total meadow area in Finland that time and also search for the differencies between different areas – which areas still contain most meadow hectares and which is the proportion between meadow hectares and studied surface area or proportion between the land area and meadow area or the relation between acricultural field hectares to meadow hectare amount. This larger study contained 14 provincial areas and the study area was 26 000 km² and the mean study coverage was 12 %. In the study 315 base maps 1.20 000 were inventoried – the meadows were counted hectare by hectare from the maps. The results showed that the largest changes in meadow area hectares took place already between 1930 and 1960. The biggest proportional declines were in the areas were the initial hectare amounts were highest at the start. A significant result was that the total area of meadows in Finland was not so low as estimations have given reason to expect. In this large study many areas had still left a third of the 1930 meadow hectares, in the best areas even 40% in the 1980’s and in the beginning of 1990’s. Although also in this study there were places were 99% of the original hectares of meadows were all vanished – from the hundreds of hectares were left only 2-10 hectares. Of the studied areas the most rich in meadows was Åland throughout all the three studied time steps. Other meadow high areas were Lounais-Suomi, Pirkanmaa and Keski-Suomi in the 1930’s, Pirkanmaa, Pohjois-Pohjanmaa and Häme in the 1960’s and Länsi-Suomi, Uusimaa and Lounais-Suomi. For the total amount of meadow hectares in Finland this study gives estimates: 680 000 – 980 000 hectares in the 1930’s, 330 000 – 475 000 hectares in the 1960’s and 275 000 hectares in the 1980’s.

Improving land management to mitigate climate change is important, especially in agriculture on soils with high organic content. Many studies have found evidence that increasing diversity can help to improve plant biomass production and soil carbon storage. This is attributed to complementarity which consists of more efficient resource use due to niche differences and facilitative interactions. For the total climate impact, the effect of greenhouse gas emissions from the soil needs to be considered. To find out if adding more species to a grass mixture could have similar benefits in boreal zone grass cultivation in Finland, an experiment was set up with four different species mixtures, and three levels of species richness were established under a nurse crop. It was additionally of interest if these effects can counter the emissions of cultivation on organic soils. Biomass samples were collected both before the nurse crop was removed and at the end of the growing season. Both species richness and Shannon diversity index were considered as explanatory factors. Carbon exchange, divided into respiration and photosynthetic capacity, as well as nitrous oxide and methane fluxes, were monitored monthly. There was no strong evidence that species richness affects biomass or greenhouse gas fluxes during the first year. The effect of species richness on the biomass was clearer when the diversity index was considered. These results were significant when the lowest biomass values were excluded from the analysis, probably because complementary resource use needs enough biomass to have an effect. The differences in carbon flux measurements may be sensitive to timing within the growing season since the results closest to significant were obtained at the start of the season. At the time, the measurement conditions were good and the nurse crop biomass was small enough not to obscure the effects of grass mixture. When it comes to other greenhouse gases, species richness had most impact on early nitrous oxide emissions, while methane flux probably needs significantly more time for any changes to appear. Overall, the effect of species richness needs to be studied over the full grass cultivation cycle to find out the full effect. Based on current results, increasing species richness may be an option when other methods cannot be used to reduce emissions and improve carbon sink of agriculture.