Research Information System
UFRO Research Group 7.01.00, International Conference Biological Reactions of Forests to Climate Change and Air Pollution, Kaunas, Lithuania, 21 - 24 May 2015, pp.218, (Summary Text)
In terrestrial environments, nutrient budget of a catchment hydrologic system involves the cycling of water and nutrients. In systems approach; atmospheric and other sources are taken as inputs while export of nutrients via stream ow represents the output in catchments. We mostly bene t this approach if our objective is the estimation of output (nutrient or water yield) or identi cation of catchment system behaviour. The disadvantage of the approach is the need to monitor at least the deposition inputs and stream ow outputs and also the climatic variability which can be offset by paired watershed approach.
Experimental studies are conducted in small sized catchments and the results are scaled into larger ones for practical applications. Many management strategies have been proposed based on this approach during the last century. Therefore, small sized experimental catchments have been instrumented for this purpose. On the other hand, upscaling of the results has been widely discussed in hydrology because of many con icting results at different sized catchments.
In this paper we analyze the input-output relationship of 3 adjacent catchments different in size (17.5, 71.9, 77.5 hectares) in relation with hydrology. The vegetation cover remained unchanged during a period of 5 years and no forestry treatments were performed. The only variation source was in the climatic parameters.
According to the results smallest catchment was more responsive to precipitation in winter months compared to larger ones but larger catchments have summer ows due to longer system memories. However, the runoff coef cients of the experimental catchments always remained under 0.2 indicating a strong vegetation evapotranspiration. We also calculated ionic inputs and outputs to compare and discuss on the catchment size.