5. CONCLUSIONS
Our results indicated that the alpine wetland in this study was a weak
carbon source. Our findings indicate that aggregated growing season
degree day and soil temperature were the most important controlling
factors for the seasonal variations of CO2 fluxes. The
hydrothermal conditions especially during the non-growing season played
an important role in determining inter-annual variations of
CO2 fluxes. The results of our study highlighted the
importance of the non-growing season CO2 emissions for
the variation of CO2 dynamics, which was few focused by
previous studies. According to our study results, we speculate that
under the context of global warming, especially in the non-growing
seasons, which will exacerbate carbon loss in the alpine wetlands of the
QTP.
Our alpine wetland was a carbon source, which agrees well with the
earlier reports. However, the swamps in Northern Tibetan Plateau (NTP)
and Qinghai Lake (QL) are strong carbon sink (Cao et al., 2017; Niu et
al., 2017). The stronger GPP in NTP and lower RES in QL accounted for
the discrepancy, respectively. Our results showed that the estimation of
carbon sequestration capacity of alpine wetland should be more cautious.