Тип публикации: доклад, тезисы доклада, статья из сборника материалов конференций
Конференция: Международная молодежная школа и конференция по вычислительно-информационным технологиям для наук об окружающей среде; Томск; Томск
Год издания: 2015
Аннотация: Calculations of direct emissions of greenhouse gases from boreal wildfires remain uncertain due to problems with emission factors, available carbon, and imprecise estimates of burned areas. Even more varied and sparse are accurate in situ cal- culations of temporal changes in boreal forest carbon dynamics following fire. Linking siПоказать полностьюmultaneous instrumental atmospheric observations, GIS-based estimates of burned areas, and ecosystem carbon uptake calculations is vital to fill this knowledge gap. Since 2006 ZOTTO (www. zottoproject.org) a research platform for large-scale climatic observations is operational in Central Sibe- ria (60°48'N, 89°21'E). The data of ongoing green- house gases measurements at the tower are used in atmospheric inversions studies to infer the distribu- tion of carbon sinks and sources over central North- ern Eurasia. We present our contribution to reducing uncer- tainties in estimates of fire influence on atmospheric composition and post-fire ecosystem carbon uptake deduced from the large-scale fires that happened in 2012 in the tall tower footprint area. Assessment of air composition in fire plumes was based on time se- ries of CO/CO2/CH4 mixing ratios measured at 300 m a.g.l.. Burned areas were estimated from Landsat ETM 5,8 satellite images, while fires were detected from Terra/Aqua MODIS satellite data. The magni- tude of ecological change caused by fires was mea- sured and mapped with a Normalized Burn Ratio (NBR) index and further calibrated by a complemen- tary field based Composite Burn Index (CBI). Mea- sures of fire radiative power (FRP) index provided information on fire heat release intensity and on the amount and completeness of biomass combustion. Based on the analyzed GIS data, the system of study plots was established in the 5 dominating ecosystem types where the estimation of carbon pools and their mapping was organized with a laser-based field in- strumentation system. Based on the derived data set the biomass burning emissions from dominating eco- system types in Central Siberia were calculated. Esti- mations of direct emissions were supplemented by soil respiration measurements within the plots by an automated soil flux system (LI 8100A). The highest biomass burning emissions were found in pine forests (1300 - 1850 gC/m2). For mixed and dark forests fire emissions didn't exceed 550-600 gC/m2. In turn the maximal soil respiration rates (up to 3,2 ?molС/m2/s) were found in wet and less disturbed mixed forest stand and could be attributed to autotrophic respiration, and the lowest rates (1 - 1,2 ?molС/m2/s) of primarily heterotrophic origin were typical within the dry pine stands with the highest burn severity.
Номера страниц: 102-107
Издатель: Томский центр научно-технической информации