Effects of Windfall on Soil Surface Carbon Emission and Fine Root Stocks in the Central Sikhote-Alin

Eurasian Soil Science. 2022. Vol. 55. No. 10. P. 1405–1413.

Ivanov A. V., Salo M. A., Tolstikova V. Y., Bryanin S. V., Zamolodchikov D.

The effect of a large-scale windfall as a result of the Lionrock typhoon (2016), which caused complete destruction of forest plantations on the area of 36 000 ha within the Sikhote–Alin Nature Reserve, on carbon emission from the soil surface and on fine root stocks was considered. Sample areas on windfall and control sites were in Siberian pine and birch forests. Emission from the soil surface on the windfall site in the birch forest was 5.52 ± 1.12 t C/(ha yr}, which was 25% lower in comparison with the emission on the control plot because of the weakened root respiration. The annual carbon flux from soil at the windfall site in the Siberian pine forest was 8.02 ± 1.50 t C/(ha yr); in contrast to the birch forest, it was 29% higher than on the control plot. This can be explained by intensive decomposition of fine roots on the windfall in the Siberian pine forest during the measurement period, while birch roots predominantly decomposed before the start of measurements. The stock of fine roots after the windfall decreased by 20% in the Siberian pine forest and by 37% in the birch forest, while the stock of dead roots was 58% higher at the windfall site of the Siberian pine forest and 28% lower at the windfall site of the birch forest site as compared to the control. It was determined that windfall significantly increased soil moisture (p < 0.001). Temperature dependences of emission were plotted. Estimates of annual emission values obtained using data from the Ternei weather station were close to the values calculated from logger temperatures on sample plots. Our work experimentally showed a significant contribution of fine roots to soil emission on the windfall site. Against the background of large carbon losses from fires and logging, the territory of the Ternei forestry of Primorskii region became a powerful source of carbon.

Keywords: carbon, CO2 emissions, windfall, stock, fine roots