Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2022
Authors
Palingamoorthy Gnanamoorthy Qinghai Song Junbin Zhao Yiping Zhang Jing Zhang Youxing Lin Liguo Zhou Sadia Bibi Chenna Sun Hui Yu Wenjun Zhou Liqing Sha Shusen Wang S. Chakraborty Pramit Kumar Deb BurmanAbstract
The rapid conversion of tropical rainforests into monoculture plantations of rubber (Hevea brasiliensis) in Southeast Asia (SEA) necessitates understanding of rubber tree physiology under local climatic conditions. Frequent fog immersion in the montane regions of SEA may affect the water and carbon budgets of the rubber trees and the plantation ecosystems. We studied the effect of fog on various plant physiological parameters in a mature rubber plantation in southwest China over 3 years. During the study period, an average of 141 fog events occurred every year, and the majority occurred during the dry season, when the temperature was relatively low. In addition to the low temperature, fog events were also associated with low vapor pressure deficit, atmospheric water potential, relative humidity and frequent wet-canopy conditions. We divided the dry season into cool dry (November-February) and hot dry (March-April) seasons and classified days into foggy (FG) and non-foggy (non-FG) days. During the FG days of the cool dry season, the physiological activities of the rubber trees were suppressed where carbon assimilation and evapotranspiration showed reductions of 4% and 15%, respectively, compared to the cool dry non-FG days. Importantly, the unequal declines in carbon assimilation and evapotranspiration led to enhanced crop water productivity (WPc) on cool dry FG days but insignificant WPc values were found between FG and non-FG days of the hot dry season. Our results suggest that, by regulating plant physiology, fog events during the cool dry season significantly reduce water demand and alleviate water stress for the trees through improved WPc.
Authors
Christophe MoniAbstract
No abstract has been registered
Authors
M. Helbig T. Živković P. Alekseychik M. Aurela T. S. El-Madany E. S. Euskirchen L. B. Flanagan T. J. Griffis P. J. Hanson J. Hattakka C. Helfter T. Hirano E. R. Humphreys G. Kiely R. K. Kolka T. Laurila P. G. Leahy A. Lohila I. Mammarella M. B. Nilsson A. Panov Frans-Jan W. Parmentier M. Peichl J. Rinne D. T. Roman O. Sonnentag E.-S. Tuittila M. Ueyama T. Vesala P. Vestin Simon Weldon P. Weslien S. ZaehleAbstract
Peatlands have acted as net CO2 sinks over millennia, exerting a global climate cooling effect. Rapid warming at northern latitudes, where peatlands are abundant, can disturb their CO2 sink function. Here we show that sensitivity of peatland net CO2 exchange to warming changes in sign and magnitude across seasons, resulting in complex net CO2 sink responses. We use multiannual net CO2 exchange observations from 20 northern peatlands to show that warmer early summers are linked to increased net CO2 uptake, while warmer late summers lead to decreased net CO2 uptake. Thus, net CO2 sinks of peatlands in regions experiencing early summer warming, such as central Siberia, are more likely to persist under warmer climate conditions than are those in other regions. Our results will be useful to improve the design of future warming experiments and to better interpret large-scale trends in peatland net CO2 uptake over the coming few decades.
Authors
Liang Wang Maria N.P. Olsen Christophe Moni Alba Diuegez-Alonso Jose Maria de la Rosa Marianne Stenrød Xingang Liu Liangang MaoAbstract
Production of biochar from corn cob and corn stalk has gained great interest for efficient waste management with benefits of improving soil properties, increasing crop productivity, and contributing to carbon sequestration. This study investigated slow pyrolysis of corn cob and corn stalk at 600 °C to characterize yields and properties of products, with focus on solid biochar. Spruce wood, a rather well studied woody biomass, was also included for comparison purposes. It was observed that yields of biochar and condensates from corn cob, corn stalk, and spruce wood were comparable. However, gas release profiles and yields from the three biomasses were quite different, which is mainly related to the different chemical compositions (i.e., hemicellulose, cellulose, lignin, and inorganic species) of the studied raw feedstocks. The produced biochars were analyzed for proximate analysis, CHNS-elemental analysis, specific surface area and specific pore volume for pores in the nm-range, inorganic composition, solid functional groups, and aromaticity. The corn cob and corn stalk biochar presented significantly higher concentration of inorganic elements, especially P and K, favoring soil application. The SEM analysis results showed that the spruce wood biochar has different microstructure than corn cob and corn stalk biochars. Condensates and light gases, as by-products from biochar production, contained over 50% of the energy and 40% of the total carbon of the initial biomass. Utilization of the condensates and light gases as valuable resources is therefore critical for improving environmental and energy benefits of the biochar production process.
Authors
Daniel RasseAbstract
No abstract has been registered
Authors
Daniel RasseAbstract
No abstract has been registered
Authors
Shu Zhang Lingbo Meng Jian Hou Xiaodan Liu Abiola O. Ogundeji Zeyu Cheng Tengjiao Yin Nicholas Clarke Baozhong Hu Shumin LiAbstract
No abstract has been registered
Authors
Daniel Liptzin Jens Boy John L. Campbell Nicholas Clarke Jean-Paul Laclau Roberto Godoy Sherri L. Johnson Klaus Kaiser Gene E. Likens Gunilla Pihl Karlsson Daniel Markewitz Michela Rogora Stephen D. Sebestyen James B. Shanley Elena Vanguelova Arne Verstraeten Wolfgang Wilcke Fred Worrall William H. McDowellAbstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
Heat Field Deformation (HFD) is a widely used method to measure sap flow of trees based on empirical relationships between heat transfer within tree stems and the sap flow rates. As an alternative, the Linear Heat Balance (LHB) method implements the same instrumental configuration as HFD but calculates the sap flow rates using analytical equations that are derived from fundamental conduction-convection heat transfer theories. In this study, we systematically compared the sap flow calculated using the two methods based on data that were recorded using the same instrument. The measurements were conducted on four Norway spruce trees. We aimed to evaluate the discrepancies between the sap flow estimates from the two methods and determine the underlying causes. Diurnal and day-to-day patterns were consistent between the sap flow estimates from the two methods. However, the magnitudes of the estimated sap flow were different between them, where LHB resulted in much lower estimates in three trees and slightly higher estimates in one compared to HFD. We also observed larger discrepancies in negative (reversed flow) than in positive sap flow, where the LHB resulted in lower reversed flow than HFD. Consequently, the seasonal budget estimated by LHB can be as low as ∼20% of that estimated by HFD. The discrepancies can be mainly attributed to the low wood thermal conductivities for the studied trees that lead to substantial underestimations using the LHB method. In addition, the sap flow estimates were very sensitive to the value changes of the empirical parameters in the calculations and, thus, using a proper case-specific value is recommended, especially for the LHB method. Overall, we suggest that, despite the strong theoretical support, the correctness of LHB outputs depends largely on the tree individuals and should be carefully evaluated.