Regular research paper

Ground vegetation carbon and its relation to climate and species richness

Jerzy Solon, Ewa Roo-Zielińska

Institute of Geography and Spatial Organization, Polish Academy of Science 00-818 Warsaw, Twarda 51/55; e-mail: j.solon@twarda.pan.pl, e.roo@twarda.pan.pl

Abstract: 

     Ten pine forest sites located along the transect between 50^o28’ and 70^o09’ N were studied. The purposes of the present paper are: 1) to determine the volume of the organic carbon pool in selected layers of the analysed forest ecosystems (shrubs, herb layer, mosses and lichens, litter, and the humus horizon of the soil); and 2) to elaborate the correlation-based prediction models relating the organic carbon pools in these layers with the selected variables characterising the climate and the species richness of the pine forests. The results indicate a clear horizontal heterogeneity of the ground layer in the pine forests considered. This is reflected, in particular, through the differentiation of the carbon pool in particular places within the ecosystem. There is a distinct geographical variability in the carbon pool among the sites in particular layers, with the average annual and January temperatures having the largest influence on this variability. However, in different cases there are different combinations of the factors describing these relations in the best way. The relations between the carbon pool and the species richness of the sites along the transect show that either the minimal carbon pool occurs at sites of an average species richness, or there is no relation between these variables. The analysis implies that there are two points of the transect at which various characteristics of the system undergo an abrupt shift. The first of them is equivalent to the passage of the annual +1^oC isotherm, while the second at approximately 5–6^oC. There is the possibility that these regularities occur within the entire range of the pine forests.

Key words: carbon pool, biomass, species richness, dwarfshrubs, mosses, lichens, climate factors, geographical variability