Net Primary Production of Carbon in Pine Forests on European North-East of Russia (Republic of Komi)

Abstract

The accumulation of carbon of organic matter by forest phytocenoses during photosynthesis is their most important function, mitigating climate change on the Earth. The literature provides data that the territory of the Russian Federation is a large sink of atmospheric carbon. However, the estimates of the sink, as well as the values ​​of the net primary production (NPP) of forest ecosystems, vary widely. This paper presents materials describing the net carbon production of phytomass in pine forests of different types of growing conditions in the northern and middle taiga of the Komi Republic. Premature, mature, and old-growth pine forests of green moss, lichen, and sphagnum types have been studied at forest stations. The carbon sequestration by the forest stand is assessed by biological productivity using sample trees. The regression equations for the dependence of the increments of individual organs of a sample tree on the stem diameter at a height of 1.3 m are composed. A statistically significant relationship is found between these parameters, characterized by high trend approximation values ​​varying from 0.44 to 0.99 (at 95% significance level). It is calculated that, under the conditions of the European Russian northeast, the NPP of carbon in pine phytocenoses varies within the range of 1.9–4.5 t C ha–1 year–1. It is established that the tree stand accounts for 32–73% of the total NPP. With increasing soil moisture and moving northward, the participation of plants in the ground vegetation increases in the total NPP. It is noted that a significant part of the NPP of carbon of the tree layer of pine forests is formed by the photosynthetic apparatus and the stem wood. Based on these data, the conversion relations between NPP and wood volume/carbon stock in the stand for pine forests of the northern and middle taiga are derived.