It is impossible to continuously measure ecosystem-scale CH4 flux including both soil and plant-mediated CH4 emissions by the chamber technique. Lower GWL enhances peat aeration and potentially increases oxidative peat decomposition, which results in higher soil CO2 efflux. Mean annual total subsidence was 1. The aim of this study was to investigate temperature sensitivities of these processes and the effect of climate warming on the annual terrestrial net ecosystem CO2 exchange globally in the boreal and temperate regions. The differences in the relationship between PD and GWL indicate that separate estimations are required for each type of land. Thus, we have measured net ecosystem CH4 exchange FCH4 above a tropical peat swamp forest in Sarawak, Malaysia using the eddy covariance technique from February to July 18 months. Results showed that on the annual time scale, the intrinsic temperature sensitivity of GPP Q 10sG was higher than or equivalent to the intrinsic temperature sensitivity of RE Q 10sR. The difference in annual NEE between the two sites is attributable to higher leaf area index and less distinct seasonality in precipitation in this site. Moreover, our results suggest that PD can be enhanced by drainage both in forests and at burned sites. Keenan, DenniS Baldocchi, Margaret S. Optimum air temperature for tropical forest photosynthesis: mechanisms involved and implications for climate warming Zheng-Hong Tan, Jiye Zeng, Yong-Jiang Zhang, Martijn Slot, Minoru Gamo, Takashi Hirano, Yoshiko Kosugi, Humberto R. To clarify the effects of changes in land use on carbon dioxide emissions, wemeasured oxidative peat decomposition PD at different stages of disturbance at three sites in Central Kalimantan, Indonesia: an undrained peat swamp forest UF , a heavily drained peat swamp forest DF , and a drained and burned ex-forest DB. However, no report has described the applicability of C-LART in comparison with LB. Desai, Eugenie Euskirchen, Thomas Friborg, Daniele Gasbarra, Ignacio Goded, Mathias Goeckede, Martin Heimann, Manuel Helbig, Takashi Hirano, David Y. Using these relationships, we estimated annual PD from GWL data for and as and g C m -2 yr -1 at UF mean GWL: The annual PD was significantly higher in DF than in UF or DB, in both years. Clements, Sheema Abdul Aziz, Mark E. At UF and DF, PD and GWL showed significant quadratic relationships. This implies that root respiration was negligible in the FT plots. Morin, Mats B. Miller, Antonio O. In addition, ecosystems in these regions with different plant functional types should sequester more CO2 with climate warming. Annual CO2 emissions through both soil and heterotrophic respiration were smaller than those of other oil palm plantations on tropical peat, possibly due to the higher groundwater levels, land compaction, and continuous measurement of soil CO2 efflux in this study. Through the land conversion, peat carbon has become vulnerable and potentially changes to a great carbon dioxide CO2 source to the atmosphere. Richardson, Benjamin R, K. Goulden, Steven C. In conclusion, C-LART is not applicable to evaluate CO2 emissions through litter decomposition. The analysis of the current temperature sensitivities and net ecosystem production suggested that temperature rise might enhance the CO2 sink of terrestrial ecosystems both in the boreal and temperate regions. In conclusion, water management to raise groundwater levels would mitigate soil CO2 emissions from oil palm plantations on tropical peatland. Changes in microbial activity are probably caused by the alteration of material supply from the leaf litter layer to the soil by litter treatment the priming effect. Runkle, Youngryel Ryu, Torsten Sachs, Karina V, R. A database of site-years of ecosystem flux data at sites in the world was collected and analyzed. These data-driven estimates can provide a new opportunity to assess CO2 fluxes in Asia and evaluate and constrain terrestrial ecosystem models. Canadell, Marielle Saunois, Dario Papale, Housen Chu, Trevor F. Krauss, Lars Kutzbach, Annalea Lohila, Bhaskar Mitra, Timothy H. Owing to the huge soil carbon stock and high groundwater level GWL , tropical peatlands potentially represent a significant source of methane CH4 to the atmosphere. Hollinger, Hiroki Iwata, Minseok Kang, Janina Klatt, Ken W. Reba, Andrew D. The annual FCH4 was much higher than annual soil CH4 emissions from tropical peatlands, because the FCH4 included aboveground CH4 emissions mainly from tree stems. Annual soil respiration in the control plot was gC m -2 yr -1 , which was approximately twice as high as the mean of temperate evergreen forests in the world. C Elsevier B. Nilsson, Shuli Niu, Asko Noormets, Walter C. Manzi, Antonio D. Evaluation of spatially estimated NEE with net atmosphere-land CO2 fluxes of Greenhouse Gases Observing Satellite GOSAT Level 4A product shows that monthly variations of these data were consistent in Siberia and East Asia; meanwhile, inconsistency was found in South Asia and Southeast Asia. Evans, Mary Rose C. The negative annual NEE was equivalent to those of some tropical rain forests on mineral soil, but was more negative than g C m -2 yr -1 for an almost undrained PSF in Central Kalimantan, Indonesia Hirano et al. Torn, Ivan Mammarella, Carlo Trotta, Mika Aurela, Gil Bohrer, David I. Data-driven estimation was conducted by using a machine learning algorithm: support vector regression SVR , with remote sensing data for to period. The groundwater level GWL was a major controlling factor of PD at all sites. Annual FCH4 from March through February was 7. Furthermore, differences in the land CO2 fluxes from SVR-NEE and GOSAT Level 4A were partially explained by accounting for the differences in the definition of land CO2 fluxes. Temperature sensitivities of rates of RE and GPP were quantified with Q 10 , defined as the increase of RE or GPP rates with a temperature rise of 10 degrees C. Smith, Catherine M. This study investigated the factors controlling the CO2 efflux and quantified the annual cumulative CO2 emissions through soil respiration and heterotrophic respiration, which is equivalent to oxidative peat decomposition. Saleska, Michael L. PD exhibited seasonality, being less in the wet season and greater in the dry season. Posa, Paul H. Q 10sG was negatively correlated to the mean annual temperature MAT , whereas Q 10sR was independent of MAT. Nobre, Plinio B. Recently, it has been reported that some tree species growing in peat swamp forest emit CH4 from their stems. Oechel, Matthias Peichl, Olli Peltola, Michele L. The litter decomposition rate was 0. Tang, Masahito Ueyama, Rodrigo Vargas, Timo Vesala, Eric J. FCH4 was positively associated with GWL or soil moisture in a quadratic form. Daily mean CO2 efflux increased exponentially as the groundwater level or water-filled pore space decreased, indicating that oxidative peat decomposition and gas diffusion in the soil increased due to enhanced aeration resulting from lower groundwater levels. Anshari, Erik Meijaard, Jenny E. Goldstein, Susan Waldron, Kristell Hergoualc'h, Rene Dommain, Steve Frolking, Christopher D. Wofsy, Scott D. Saitoh, Kentaro Takagi, Andrej Varlagin, M. Monthly mean FCH4 was always positive during the 18 months, even in the driest month with mean GWL of —30 cm. All rights reserved. At DB, PD and GWL showed significant positive and negative relationships during the dry and wet seasons, respectively. However, a few studies of CH4 flux by the soil chamber technique have reported that annual CH4 emissions from tropical peat swamp forest were very low as compared to mid- and high-latitude peatlands. da Rocha, Scott R. In this study, we developed such a standardized database using 54 sites from various databases by applying consistent postprocessing for data-driven estimation of gross primary productivity GPP and net ecosystem CO2 exchange NEE. However, filed studies based on the ecosystem-scale monitoring of CO2 flux are quite limited. Thus, we began CO2 flux monitoring over a secondary PSF in Sarawak, Malaysia, by the eddy covariance technique in As a result, the seasonal difference in NEE between the two periods 0. Wijedasa, Jyrki Jauhiainen, Mari Kononen, Maija Lampela, Harri Vasander, Marie-Claire Leblanc, Stephanie Evers, Thomas E. Campbell, Alessandro Cescatti, Samuel Chamberlain, Jiquan Chen, Weinan Chen, Sigrid Dengel, Ankur R. Denial of long-term issues with agriculture on tropical peatlands will have devastating consequences Lahiru S. Harrison, Susan Cheyne, Gusti Z. Daily RE was significantly greater in the dry period mainly because of lower groundwater level GWL. It is essential to quantify the CO2 balance of the ecosystem and understand how the CO2 balance responds to environmental changes to predict the role of PSF in global carbon cycles. Yule, Helena Varkkey, Massimo Lupascu, Faizal Parish, Ian Singleton, Gopalasamy R. Mean annual gap-filled CO2 emissions were 1. The litter bag method LB and chamber method with litter addition and removal treatments C-LART have been used to quantify the litter decomposition rate and its resultant CO2 flux. Site-level evaluation of the estimated CO2 fluxes shows that although performance varies in different vegetation and climate classifications, GPP and NEE at 8days are reproduced e. The C-LART method measures soil CO2 fluxes in control, litter addition, and litter removal plots, and thereby decomposition rates are calculated from differences of the fluxes.
Knox, Robert Jackson, Benjamin Poulter, Gavin McNicol, Etienne Fluet-Chouinard, Zhen Zhang, Gustaf Hugelius, Philippe Bousquet, Josep G. Glaser, Nyoman Suryadiputra, Reza Lubis, Truly Santika, Rory Padfield, Sofyan Kurnianto, Panut Hadisiswoyo, Teck Wyn Lim, Susan E.
Carmelita Alberto, Jonas Ardoe, Eugenie S. The incredibly high decomposition was attributed to the enhanced or restricted microbial activities in the underlying mineral soil. Another approach must be used to compensate the priming effect for application of the chamber method. This study measured the litter decomposition rate and its resultant CO2 flux using C-LART and LB in a temperate evergreen forest in central Japan to assess the applicability of the two methods. However, the annual FCH4 was relatively low in comparison with those measured by the eddy covariance technique in mid- and high-latitude peatlands. In contrast, the decomposition rate of litter carbon ascertained using C-LART was greater than I 1. Euskirchen, Minseok Kang, Takashi Hirano, Joanna Joiner, Hideki Kobayashi, Luca Belelli Marchesini, Lutz Merbold, Akira Miyata, Taku M. Despite the very dry conditions, the annual PD values at these sites were much lower than those reported for tropical peat at plantations e.