Foliar Resorption Efficiency Does Not Change Along an Elevational Gradient in Two Dominant Peatbog Plant Species

Abstract

Plants adapted to nutrient-poor temperate peatlands exhibit relatively low foliar N and P contents and resorb N and P from ageing leaves very efficiently to minimize their nutrient losses through litter fall. Changes in nutrient resorption efficiency due to an expectable increase of temperature may affect nutrient cycling in peatlands. We used an elevational gradient as a proxy for the effect of ongoing climatic change and compared the foliar N and P resorption efficiencies (REN, REP) of two co-occurring typical plant dominants (Molinia caerulea and Vaccinium uliginosum) at four microsites of each of two acidic peatbogs in southern Bohemia, Czechia, at two elevations differing by ca 500 m. No significant difference in soil nutrient content was found between the two sites. Foliar N and P contents in mature leaves in both species did not depend on the elevational gradient and were mostly not correlated with the inorganic soil nutrients. The REN (70–78%) and REP values (61–70%) in Vaccinium were markedly lower than those in Molinia (84–85% and 92–94%, respectively). In line with literature data, the peatland dominants Molinia and Vaccinium possess different strategies of foliar N and P resorption from ageing leaves. High REN and REP in Molinia obviously underlie its strong dominance in unmanaged peatland habitats. No elevational difference in both REN and REP was found in either species, indicating that the resorption efficiencies of these species are not expected to change markedly under the projected scenario of increasing temperature and lengthening growing season.