Country-scale mapping of ecosystem services provided by semi-natural grasslands.

Semi-natural grasslands harbour high biodiversity and play a key role in the supply of ecosystem services (ES). However, abandonment, changes in traditional management practices and agricultural intensification constitute a major threat to these grasslands worldwide and these practices have led to declines in species diversity. In this paper the multi-functionality of semi natural-grasslands is assessed from the ES perspective, within a range of common semi-natural grassland types throughout Estonia. The analysis follows a stepwise approach based on the ES cascade model. Firstly, analyses of the relationships between plant species distribution patterns and environmental factors are described. Secondly, the effect of grassland abandonment on plant species diversity, as well as on the presence of rare and protected plant species is tested. In order to overcome the lack of data on ES at the national scale, plant species diversity and soil organic carbon are tested as surrogate indicators for five ESS: pollination, herbs for traditional medicinal use, nutrient cycling, nutrient retention and biomass production. In the final step, the spatial distribution of ES is assessed, based on an ES hotspots map obtained by detecting areas where high levels of plant species diversity and soil organic carbon overlap. The results show that the majority of ES hotspots are present in wooded meadows and pastures. However, there is an important threat to these hotspots because 45% are not eligible for agri-environmental support.

Nitrogen and phosphorus accumulation and biomass production by Scirpus sylvaticus and Phragmites australis in a horizontal subsurface flow constructed wetland.

We studied plant biomass production and nutrient accumulation by wood club-rush (Scirpus sylvaticus) and reed (Phragmites australis) in a horizontal subsurface flow constructed wetland in 2001 and 2002. The wetland consists of two beds, one with dry and another with wetter conditions. From both beds, 5 above-ground, below-ground, and litter samples were taken in the summer, during the maximum flowering period of the dominant species. The average dry biomass of whole plant and litter was considerable higher in 2002 (3071 g m(-2)) than in 2001 (620 g m(-2)) due to the climatic conditions. The average dry weight biomass of 5 plots in 2001 was 513 g m(-2) in the dry bed and 729 g m(-2) in the wet bed. In 2002 these values were 2,520 and 3,765, respectively. Variations in biomasses will also appear in values for nutrient accumulation, in all cases the N and P accumulation was higher in 2002. The average nitrogen accumulation by plants was 16.6 g m(-2) in the wet and 10.7 g m(-2) in the dry bed in 2001, and 51.7 and 83.5 g m(-2) in 2002 respectively. Phosphorus accumulation was higher in the wet bed during 2001--2.8 g m(-2), in the dry bed this value was 1.9 g m(-2). In 2002, the phosphorus accumulation was higher in the dry bed--12.8 g m(-2), in the wet bed it was 12.43 g m(-2). The total biomass at the same conditions in the wet bed was slightly higher in case of wood club-rush--765 g m(-2) in 2001 and 3846 g m(-2) in 2002, same values for reed were 674 g m(-2) and 3,646, respectively.

Alternative filter media for phosphorous removal in a horizontal subsurface flow constructed wetland.

During the study period from 1997 to 2002 the purification efficiency of phosphorus in the horizontal subsurface flow (HSSF) constructed wetland (CW) in Kodijärve, has been quite high (63-95%). However, slowly increasing trend in outlet P concentrations and decreasing annual P removal rate are obviously the indicators that show possible saturation processes in filter media. To search for potential filter media with high phosphorus sorption capacity, sorption characteristics and particle size distribution of several local sands, gravels, glauconite-sandstone, LWA, and calcareous waste products from oil-shale industry were investigated. The average P sorption capacity for best materials (crashed ash block, oil, shale fly ash and the sediment from oil shale ash plateau) was higher than 96% and estimated design capacity was around 4-5 g P kg(-1). According to results, sediment from oil shale ash plateau was considered as perspective filter media for P retention. In Summer 2002 experimental sedimentation filter, filled with the sediment from oil shale ash plateau, was installed in the outlet from the Kodijärve HSSF CW. According to preliminary results the average P removal in the sedimentation filter was 52%.