Energy and mass exchange and the productivity of main Siberian ecosystems (from Eddy covariance measurements). 2. carbon exchange and productivity

Abstract

Direct measurements of CO2 fluxes by the eddy covariance method have demonstrated that the examined middletaiga pine forest, raised bog, true steppe, and southern tundra along the Yenisei meridian (~90° E) are carbon sinks of different capacities according to annual output. The tundra acts as a carbon sink starting from June; forest and bog, from May; and steppe, from the end of April. In transitional seasons and winter, the ecosystems are a weak source of carbon; this commences from September in the tundra, from October in the forest and bog, and from November in the steppe. The photosynthetic productivity of forest and steppe ecosystems, amounting to 480–530 g C/(m2 year), exceeds by 2–2.5 times that of bogs and tun dras, 200–220 g C/(m2 year). The relationships between the heat balance structure and CO2 exchange are shown. Possible feedback of carbon exchange between the ecosystems and atmosphere as a result of climate warming in the region are assessed

Siberian carbon sink reduced by forest disturbances

“…In response to warmer temperatures, a longer growing season 3 and widespread 'greening' seen by optical remote-sensing data 4,5 have been reported. These changes are generally interpreted as increases in above-ground biomass carbon (AGC) 6 and CO2 uptake 7,8 , and the prevailing view is that Siberian forests have acted as a net sink for atmospheric CO2 during recent decades [9][10][11][12][13] .…”

Thesis of N.A. Shnyrev: I. Micrometeorology and other notes

“…В связи с этим, вывод автора о том, что «Такое сильное варьирование результатов в зависимости от способов технической реализации метода (отбора проб) и обработки результатов порождает неопределенность оценки не меньшую, чем в случае непосредственных замеров потоков камерными методами и ставит под сомнение тезис о якобы более точной (адекватной) оценке газовых потоков и углеродного баланса территории указанными дорогостоящими способами» кажется просто следствием его порочной методологии (придумывание данных вместо анализа результатов реальных измерений) и вообще недостаточной проработки им данной темы. И в отечественной [Минаева и др., 2003;Tchebakova et al, 2015;Бурба и др., 2016, с. 6], и в зарубежной литературе [Baldocchi, 2003;Lee et al, 2006, р.…”

Fixação e alocação de carbono em plantações clonais de eucalipto sob diferentes densidades de plantio

“…A técnica "Eddy covariance (EC)" é considerada uma das formas mais diretas e adequadas para medir e calcular fluxos turbulentos de CO2 em escala local (BURBA, 2013) e tem sido amplamente aplicada para uma variedade de ecossistemas, incluindo florestas, pastagens e terras agrícolas, etc. (BALDOCCHI, 2003;NOUVELLON et al, 2012;LIU et al, 2015;TCHEBAKOVA et al, 2015), tornando-se uma ferramenta indispensável para a compreensão e o acompanhamento do ciclo global do carbono (FRIEND et al, 2007).…”