C/N/P stoichiometry of forest soil in relation to the tree species and slope position in the Carpathian Mountains

The aim of our study was to determine the C/N/P stoichiometry of forest soils in relation to the tree species and slope position in the Carpathian Mountains. Ecological stoichiometry is used as an effective approach to the analysis of feedback and relation between the different components of an ecosystem. Knowledge about the distribution of C, N and P as well as their stoichiometry allows for a better understanding of ecosystem function and stability. C/N/P ratio reflects natural changes in ecosystems as well as those resulting from the management methods or caused by human activity. We assume that tree species and altitude influence the quantity and quality of soil organic matter in forest soils and in turn the C/N/P stoichiometry. The study was carried out in the Jalowiec Massif in Beskid Zywiecki of southern Poland (49 degrees 39'64"N; 19 degrees 28'67"E). Study plots were located along altitudes at 600, 800 and 1000 m a.s.l. in a beech stand Fagus sylvatica and fir stand Abies alba. The enzymatic activity, content of C, N and P were recorded in testing soil samples. The C/N/P stoichiometry was calculated for reflecting the nutrient availability in soil along altitude gradient. Our study confirmed the role of climatic condition and tree species in shaping the stoichiometry C/N/P of mountain soils. Soils under influence of fir stands are characterized by a wider C/N/P ratio compared to soils under influence of beech stand. The higher content of soil organic matter that is less decomposed was noted in higher locations as a result of the impact of fir stand. The activity of four out of six tested enzymes decreased with height, which confirms the limitation of biological activity of soils in higher positions. We found that the enzymatic stoichiometry depend on the altitude. The type of tree species had no effect on enzymatic ratios. The altitude influenced the temperature and moisture which are related to microorganisms activity, which results in differences in the stoichiometry of soil enzymes. Our study support the use of enzymatic stoichiometry for reflecting the nutrient cycle in mountain forest ecosystem.