4th, December 2018
Choi, J., Ko, J., Ng, C. T., Jeong, S., Tenhunen, J., Xue, W., & Cho, J. (2018). Quantification of CO2 fluxes in paddy rice based on the characterization and simulation of CO2 assimilation approaches. Agricultural and Forest Meteorology, 249, 348-366.
- Estimated rice paddy CO2 flux over 2-years with a closed-chamber system in Korea. Identified the green chlorophyll index explained around 60% of the GPP and NPP flux.
3rd, December 2018
Fernández-Martínez, M., Sardans, J., Chevallier, F., Ciais, P., Obersteiner, M., Vicca, S., ... & Piao, S. L. (2018). Global trends in carbon sinks and their relationships with CO 2 and temperature. Nature Climate Change, 1.
- Tropics holds half of the increased NEP although it is 22% of the global land. Since it would be the CO2 absorption area, it is important to understand the tropic forest. I could also know the needs of why we should identify the controlling factors.
2nd, December 2018
Bhattacharyya, P., Dash, P. K., Swain, C. K., Padhy, S. R., Roy, K. S., Neogi, S., ... & Mohapatra, T. (2019). Mechanism of plant mediated methane emission in tropical lowland rice. Science of The Total Environment, 651, 84-92.
- By comparing seven rice species they have identified significant variations in the methane emission among the species. The small number of the pore (aerenchyma) reduced the methane emission. To mitigate the methane from rice, genetic engineering or physiological manipulation should be considered.
1st, December 2018
Chen, Z., Xu, Y., Zhou, X., Tang, J., Kuzyakov, Y., Yu, H., ... & Ding, W. (2017). Extreme rainfall and snowfall alter responses of soil respiration to nitrogen fertilization: a 3‐year field experiment. Global change biology, 23(8), 3403-3417.
- Since I had trouble in understanding winter time rice paddy soil respiration, this paper helped a lot. In the winter time when snow appears, the soil gets frozen and decreases the soil respiration. However, when the soil or air temperature increases the soil gets defrost and release a high amount of CO2 into the atmosphere. Especially, the spring season is the right time for this phenomenon.
4th, November 2018
Fertitta-Roberts, C., Oikawa, P. Y., & Jenerette, G. D. (2018). Evaluating the GHG mitigation-potential of alternate wetting and drying in rice through life cycle assessment. Science of The Total Environment.
- The S1 scenario showed similar result with our rice paddy site in Korea (CRK). Methane decreased with the drainage events (dry-downs), but the response was not immediately and the magnitude was affected by the drainage timing, and severity. The S1 scenario mitigated methane emissions about 21% compared to the continuous flooding rice paddy.
3rd, November 2018
Shen, L., Ren, Y., Xiong, N., Li, H., & Chen, Y. (2018). Why small towns can not share the benefits of urbanization in China?. Journal of Cleaner Production, 174, 728-738.
- There have been various studies on how to develop small towns in China. However, this paper found out research has not provided a holistic picture on the barriers affecting the development of small towns in the process of urbanization. Thus, this paper identified four barriers, which includes institutional, economic, social, and ecologic.
2nd, November 2018
Wessely, J., Hülber, K., Gattringer, A., Kuttner, M., Moser, D., Rabitsch, W., ... & Essl, F. (2017). Habitat-based conservation strategies cannot compensate for climate-change-induced range loss. Nature Climate Change, 7(11), 823.
- The title was quite intense. By using the model this paper analyzed a 51 species habitat and the individual number until 2090 year. The result was the same as the title. However, since the model did not consider the vegetation, human effect, and climate extremes I do not feel confident with the result.
1st, November 2018
Anderegg, W. R., Kane, J. M., & Anderegg, L. D. (2013). Consequences of widespread tree mortality triggered by drought and temperature stress. Nature climate change, 3(1), 30.
- This article summaries the effect of tree mortality caused by drought and heat stress on ecosystem function, ecosystem services, and biosphere-atmosphere interactions. Although using 41 papers, there was a lack of studies about understory trees and soils.
4th, October 2018
Sakamoto, T., Gitelson, A. A., Wardlow, B. D., Verma, S. B., & Suyker, A. E. (2011). Estimating daily gross primary production of maize based only on MODIS WDRVI and shortwave radiation data. Remote Sensing of Environment, 115(12), 3091-3101.
- Since I am not an expert in this remote sensing field, the result seem very interesting. By only using the daily shortwave radiation and wide dynamic range vegetation index from MODIS they could model GPP variation accurately in both daily variation and seasonal patterns.
3rd, October 2018
Wang, W., Liao, Y., Wen, X., & Guo, Q. (2013). Dynamics of CO2 fluxes and environmental responses in the rain-fed winter wheat ecosystem of the Loess Plateau, China. Science of the Total Environment, 461, 10-18.
- This paper identified CO2 flux increased after the rainfall events in mid-growing season caused by the microbial activity. I think the CO2 flux increase pattern is maybe just caused by the plant growth. However, it was interesting to see the relationship between Pmax& LAI and NEE&PAR in different growing stage and weather situation.
2nd, October 2018
Lang, M., Nilson, T., Kuusk, A., Pisek, J., Korhonen, L., & Uri, V. (2017). Digital photography for tracking the phenology of an evergreen conifer stand. Agricultural and Forest Meteorology, 246, 15-21.
- Since my previous paper work emphasis the importance of exposure value, it was interesting to read the first conclusion of this paper ( camera exposure value doesn't influence gap faction when the readings are kept within the quarterfinal range). Also, I hope one day I could study with the hemispherical camera since digital cover photo (I have used) had narrow filed of view.
1st, October 2018
Zhang, Q., Chen, J. M., Ju, W., Wang, H., Qiu, F., Yang, F., ... & Wang, X. (2017). Improving the ability of the photochemical reflectance index to track canopy light use efficiency through differentiating sunlit and shaded leaves. Remote sensing of environment, 194, 1-15.
- To accurately estimate light use efficiency, this paper used tow leaf photochemical reflectance index method (sun and shad). The method showed good correlations of PRI and LUE (r2=0.8). However, as all field work are affected with weather, this method also had difficulty in rainy season. For me, it is still difficult to fully understand about the 'hotspot' concept.
4th, September 2018
Xin, F., Xiao, X., Zhao, B., Miyata, A., Baldocchi, D., Knox, S., ... & Li, X. (2017). Modeling gross primary production of paddy rice cropland through analyses of data from CO 2 eddy flux tower sites and MODIS images. Remote sensing of environment, 190, 42-55.
- Likewise the other four sites, CRK site GPP also increased as the air temperature rose. It was interesting to know that the GPP and both NDVI and EVI showed similar linear relationships in rice paddy site caused by the 1) unsaturated NDVI value (<0.8) and 2) surface reflection.
3rd, September 2018
Setyanto, P., Pramono, A., Adriany, T. A., Susilawati, H. L., Tokida, T., Padre, A. T., & Minamikawa, K. (2018). Alternate wetting and drying reduces methane emission from a rice paddy in Central Java, Indonesia without yield loss. Soil Science and Plant Nutrition, 64(1), 23-30.
- This study site have shown alternate wetting and drying system reduce CH4 without rice yield loss. The loss of water was also reduced compared to continuous flooding system. Also it was interesting that the amount of rice yield was very similar with our study site, since Indonesia is the largest rice producing country in the world.
2nd, September 2018
Huang, Y., Ryu, Y., Jiang, C., Kimm, H., Kim, S., Kang, M., & Shim, K. (2018). BESS-Rice: A remote sensing derived and biophysical process-based rice productivity simulation model. Agricultural and Forest Meteorology, 256, 253-269.
- Personally, it is great to read this paper since I was involved in manual data collection. The contents will be very helpful for my next research paper about the carbon and water flux at the same site (i.e. CRK). Back to the paper, it is interesting to see how well BESS-Rice simulates the flux tower measurements. However, since three different site is all located in Korea. I wonder how BESS-Rice could operate in other countries.
1st, September 2018
Andrew V. Gougherty,Stephen R. Keller,Anton Kruger,Cathlyn D. Stylinski,Andrew J. Elmore,Matthew C. Fitzpatrick. (2018). Estimating tree phenology from high frequency tree movement data. Agricultural and Forest Meteorology, 217-224.
- The idea of identifying tree phenology from the tree movement was interesting. As written in the paper, I am curious how could the sensor work in the less-wind area. The low co-relationship in the leaf fall season could be understood since there were some similar issues in other papers. The problem should be how can the sensor or the method to be developed.