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Modelling of atmospheric nitrogen deposition effects to polish terrestrial ecosystems for various emission scenarios until the target year 2020

Pecka T., Mill W.

Environment Protection Engineering

2012

Vol. 38, nr 3

133--143

Biogeochemical effects to Polish terrestrial ecosystems resulting from atmospheric nitrogen deposition were forecasted until the target year 2020. To this end recently updated critical loads of nutrient nitrogen were applied and the nitrogen deposition projections for the sequence of decades from 1980 until the target year 2020, based on the Current Legislation (CLE) and Maximum Feasible Reductions (MFR) emission scenarios. The predictions were done by use of the Very Simple Dynamic (VSD) Model developed within the Working Group on Effects of the UN ECE Convention on the Long-Range Transboundary Air Pollution CLRTAP. The calculations were done for three main forest ecosystems and three selected semi-natural ecosystems encompassing the whole territory of Poland with the spatial resolution defined by a grid cell of 1*1 km size. The study concluded with maps of CLnut(N) exceedances and expected nitrogen concentrations in soil as chemical criterion, assigned to different eutrophication risk categories for each deposition scenario. The obtained results show that in spite of the realistic (CLE scenario) and extreme (MFR) nitrogen emission reductions until 2020, more than 99% and 80% of total area of terrestrial ecosystems of Poland, respectively, willbe exposed to excessive nitrogen deposition. Results of this study as well as studies done on the European scale reveal that the nitrogen emission reductions determined by the Gothenburg Protocol are still insufficient and may lead to negative ecological effects including loss of ecosystems biodiversity. This substantiates a demanding need for the revision of the CLRTAP Gothenburg Protocol.

Znaczenie procesu biologicznego wiązania azotu atmosferycznego w rolnictwie ekologiczym

Martyniuk S.

Journal of Research and Applications in Agricultural Engineering

2008

Vol. 53, nr 4

9-14

Zdolność do biologicznego wiązania azotu atmosferycznego (BWAA) jest do szeroko rozpowszechniona w przyrodzie, ale tylko wśród bakterii - mikroorganizmów prokariotycznych. Proces ten przeprowadzany jest przez różne grupy fizjologiczne bakterii. Pod względem ekologicznym wyróżniane są : wolno żyjące asymilatory N2 występujące w glebie i zbiornikach wodnych (Azotobacter, Clostridium, Nostoc), bakterie wiążące azot w asocjacjach z korzeniami roślin (Azospirillum) oraz bakterie wiążące N2 w ścisłych układach symbiotycznych z roślinami (Rhizobium - rośliny motylkowate, Frankia - olsza). W referacie omówiono ww. systemy BWAA oraz ich przyrodnicze i gospodarcze znaczenie.

It has been estimated that annually over 100x106 tons of atmospheric nitrogen is introduced into the global nitrogen cycle as a result of biological nitrogen fixation (BNF). Until 90s BNF was the largest source of biologically available nitrogen in the biosphere. The assessments performed in the last decade of the XX century indicate that the amounts of anthropogenically fixed nitrogen exceed those of fixed by the biological process. Ability to fix atmospheric nitrogen is quite common in nature but it occurs only within prokaryotic microorganisms. Different physiological groups of bacteria are engaged in this process. From ecological point of view there are: free-living N2 fixers (Azotobacter, Clostridium, Anabaena, Nostoc), bacteria (Azospirillum) that fix atmospheric N in close associations with roots of some plants and bacteria fixing N2 in symbiotic systems with plants (Rhizobium - legumes or Frankia - alder symbioses). In this review different symbiotic systems have been characterised as well as their ecological and agronomic importance, particularly in organic (ecological) agriculture.