Carbon Dioxide Fluxes Of A Young Deciduous Afforestation Under The Influence Of Seasonal Precipitation Patterns And Frequent Typhoon Occurrence

Afforestation is considered a major tool for climate change mitigation with high potential particularly in the tropics. In this study we analyzed CO2 fluxes of an afforested former sugar cane plantation in southern Taiwan, as this forest had been planted with the goal of sequestering CO2 to help mitigate climate change. The plantation is exposed to a monsoon climate with dry but warm winter seasons, heavy precipitation during the summers and experiences a rather high frequency of typhoons (0.7 per year). The aim of this study is to quantify the net ecosystem exchange (NEE), ecosystem respiration (ER), gross primary production (GPP) and increment in above-ground biomass (AGB) at the site. Specifically, we aim to analyze the influence of the distinct wet and dry seasonality and the frequent typhoon impact on these fluxes. We estimated the CO2 fluxes for two years using the eddy covariance approach. In 2010 and 2016 the forest sequestered carbon from the atmosphere with a NEE of -116 g C m(-2) year(-1) and -322 g C m(-2) year(-1), respectively. Between 2011 and 2014, the yearly increment in AGB increased with a mean increment of 509 +/- 181 (SD) g C m(-2) year(-1). We observed high seasonal difference in CO2 fluxes particularly in ER and GPP, and conclude that high winter precipitation enhances CO2 uptake. Furthermore, frequent typhoons reduced the CO2 uptake and increment in AGB, such as in 2016, when a very strong typhoon passed the forest.