Partitioning of ecosystem respiration in a paludified shallow-peat spruce forest in the southern taiga of European Russia

Abstract

Soil, tree stems, and ecosystem carbon dioxide fluxes were measured by chambers and eddy covariance methods in a paludified shallow-peat spruce forest in the southern taiga of European Russia (Tver region, 56 • N 33 • E) during the growing seasons of 2002-2012. The site was established in 1998 as part of the EUROSIBERIAN CARBONFLUX project, an international field experiment examining atmosphere-biosphere interaction in Siberia and European Russia. In all years the observed annual cumulative net ecosystem flux was positive (the forest was a source of carbon to the atmosphere). Soil and tree stem respiration was a significant part of the total ecosystem respiration (ER) in this paludified shallow-peat spruce forest. On average, 49% of the ER came from soil respiration. We found that the soil fluxes exhibited high seasonal variability, ranging from 0.7 to 10 µmol m −2 s −1 . Generally, the soil respiration depended on the soil temperature and ground water level. In drought conditions, the soil respiration was low and did not depend on temperature. The stem respiration of spruces grew intensively in May, had permanently high values from June to the end of September, and in October it dramatically decreased. The tree stem respiration in midsummer was about 3-5 µmol m −2 s −1 for dominant trees and about 1-2 µmol m −2 s −1 for subdominant trees. The respiration of living tree stems was about 10-20% of the ER.

Soil organic matter content controls gross nitrogen dynamics and N2O production in riparian and upland boreal soil

“…Boreal forests often have different zones in terms of soil type, vegetation, amount of SOM and soil water content (Högberg et al, 2006). In general, the upland zone away from the aquatic bodies has mature trees and, compared with the riparian zone, less soil moisture and SOM content (Kurbatova et al, 2013). The riparian zone is close to an aquatic system that is affected by changes in water level, and it is vegetated mainly by mosses that often form peat.…”

Radiative Entropy Production along the Paludification Gradient in the Southern Taiga

“…The towers are located in three adjacent ecosystems [29,[41][42][43][44]: dry spruce forest (DS), wet spruce forest (WS) and bog (B). DS site (32.9239° N, 56.4617° E, 265.00 m a.s.l.)…”

“…The height of trees reach 30-35 m. DS forest has the highest productivity among the all adjacent forest types in the CFBR and The data on short-wave and long-wave radiation were collected at three eddy covariance sites in the CFBR (Table 1), established in 1998 and 2000 as part of the EUROSIBERIAN CARBONFLUX project. The towers are located in three adjacent ecosystems [29,[41][42][43][44]: dry spruce forest (DS), wet spruce forest (WS) and bog (B). DS site (32.9239 • N, 56.4617 • E, 265.00 m a.s.l.)…”

“…Peat depth is 50 cm-1 m. The average tree height is about 23 m with maximum values of 27 m. The forest is low-productive; its habitus is similar to undisturbed vegetation of middle-northern taiga. Ground waters well up to the moss surface and above it after snow-melting [42], whereas in summer the ground water level sinks to 10-50 cm under the surface. In some very dry summers (2010, 2015) the ground water level at WS dropped lower than 120 cm.…”

Monitoring of Carbon Dioxide and Water Vapor Cycles at the “Log Tayozhny” Experimental Site (National Park “Valdaysky”)

“…То есть, заключение о характере углеродного баланса исследуемого ельника изменилось на противоположное -экосистема представляет собой заметный источник углерода для атмосферы. Добавим, что наиболее близкий по географическому положению ельник чернично-сфагновый Центрального лесного государственного заповедника (Тверская область), в котором проводится длительный мониторинг пульсационным методом, является устойчивым источником углерода для атмосферы в диапазоне 150-277 г С м -2 год -1 (Ольчев и др., 2009;Kurbatova et al, 2013). Функционирование лесной экосистемы как источника углерода для атмосферы не является исключительным случаем, хотя такие примеры и встречаются в литературе по пульсационному методу намного реже, чем регистрации стока углерода.…”