Professor

EDUCATION        

2011.09-2015.09  Ph.D. in Soil Science, University of Alberta, Canada           

Thesis title: Coarse Woody Debris Effects on Biogeochemistry of Two Reconstructed Soils in the Athabasca Oil Sands Region, Canada

2007.03-2009.02  M.Sc. in Soil Science, Chonnam National University, South Korea

Thesis title: Isotope and Chemical Composition of Soil and Plant Samples  of Red Pine Forests as Indicators of Acid Precipitation Disturbance

2001.03-2007.02  B.Ag. in Agricultural Engineering, Chonnam National University, South Korea       

 

POSTDOCTORIAL WORK        

2017.09 – 2019.08     Resilient Reclaimed Land and Water Systems, Future Energy Systems (FES), University of Alberta, Canada

Research topic: Developing novel materials for land reclamation: biochar

 

2017.01 – 2017.08     Forest Soils Research Group, University of Alberta, Canada

Research topic: Beneficial management practices to enhance carbon sequestration and reduce greenhouse gas emissions from agroforestry systems

  

2015.10 – 2016.12     Land Reclamation International Graduate Studies, University of Alberta, Canada

Research topic: Effects of ten years of elevated nitrogen and sulfur depositions on soil biogeochemistry (gross nitrogen transformation rates, enzyme and microbial activities, and microbial biomass), tree growth parameters (tree ring width, ring chemistry including carbon and nitrogen concentrations and their isotope ratio, and cation concentrations), and understory species diversity

RESEARCH EXPERIENCES       

• Using carbon and nitrogen isotope ratio techniques for diverse environmental studies

• Effects of coarse woody debris on soil biogeochemistry, such as nitrogen cycling, enzyme activities, greenhouse gas emission, in reclaimed cover soils in oil sands landscape

• Evaluation of historical climate and environment changes using tree ring growth and chemistry including carbon and nitrogen concentration and their isotope ratio, and cation concentrations.

• Effects of simulated nitrogen and sulfur depositions on soil nitrogen cycling, annual tree growth and ring chemistry, and understory species diversity

• Best management practices to enhance carbon sequestration and reduce greenhouse gas emissions from agroforestry systems

• Developing biochar using different feedstocks under different pyrolysis conditions and developing relationships among feedstock type, pyrolysis condition, biochar properties and metal sorption capacity

• Paddy rice growth and nutrient use efficiency under elevated temperature and CO2 concentration

• Ammonia volatilization and Chinese cabbage growth by co-application of compost and urea

 

PUBLICATIONS (peer reviewed)

 

First and Corresponding Authorship (23 articles; 20 SCI journals and 2 Korean journals)

• Lim, S. S., Yang, H. I., Park, H. J., Seo, B. S., Lee, K. S., Lee, S. H., Lee, S. M., Kim, H. Y., Ryu, J. H., Kwak, J. H., Choi, W. J. 2019. Land-use management for sustainable rice production and carbon sequestration in reclaimed coastal tideland soils for South Korea: a review. Soil Science and Plant Nutrition 66: 60-75 DOI: https://doi.org/10.1080/00380768.2019.1674121 (Co-corresponding author)

• Kwak, J. H., Islam, M. S., Wang, S., Messele, S. A., Chang, S. X., Naeth, M. A., Gamal El-Din, M., 2019. Biochar properties and lead(II) adsorption depend on feedstock type, pyrolysis temperature, and steam activation. Chemosphere 231: 393-404 DOI: 10.1016/j.chemosphere.2019.05.128

• Lee, D. S., Lim, S. S., Park, H. J., Yang, H. I., Park, S. I., Kwak, J. H., Choi, W. J., 2019. Fly ash and zeolite decrease metal uptake but do not improve rice growth in paddy soils contaminated with Cu and Zn. Environment International 129: 551-564 DOI: 10.1016/j.envint.2019.04.032 (Co-corresponding author)

• Wang, Q., Kwak, J. H., Choi, W. J., Chang, S. X., 2019. Long-term N and S addition and changed litter chemistry do not affect trembling aspen leaf litter decomposition, elemental composition and enzyme activity in a boreal forest. Environmental Pollution 250: 143-154. DOI: 10.1016/j.envpol.2019.04.007 (Co-first author)

• Kwak, J. H., Lim, S. S., Baah-Acheamfour, M., Choi, W. J., Fatemi, F., Carlyle, C, N., Bork, E. W., Chang, S. X., 2019. Introducing trees to agricultural lands increases greenhouse gas emission during spring thaw in Canadian agroforestry systems. Science of the Total Environment 652: 800-809. DOI: 10.1016/j.scitotenv.2018.10.241

• Kwak, J. H., Chang, S. X., Naeth, M. A. 2018. Eleven years of simulated deposition of nitrogen but not sulfur changed species composition and diversity in the herb stratum in a boreal forest in western Canada. Forest Ecology and Management 412: 1-8. DOI: 10.1016/j.foreco.2018.01.049.

• Kwak, J. H., Naeth, M. A., Chang, S. X. 2018. Microbial activities and gross nitrogen transformation unaffected by ten-year nitrogen and sulfur addition. Soil Science Society of America Journal 82: 362–370. DOI:10.2136/sssaj2017.11.0384

• Yang, H. I., Lee, K. S., Lim, S. S., Park, H. J., Kwak, J. H., Lee, S. I., Chang, S. X., Choi, W. J. 2018. δ13C, δ15N, N concentration, C/N, and Ca/Al of Pinus densiflora foliage in Korean cities of different precipitation pH and atmospheric NO₂ and SO₂ levels. Ecological Indicators 88: 27-36. (Co-corresponding author) DOI: 10.1016/j.ecolind.2018.01.020

• Jung, K., Kwak, J. H., Gilliam, F. S., Chang, S. X. 2017. Simulated N and S deposition affected soil chemistry and understory plant communities in a boreal forest in western Canada. Journal of Plant Ecology. 11: 511-523. (Co-first author) DOI: 10.1093/jpe/rtx030

• Lim, S. S., Park, H. J., Hao, X., Lee, S. I., Jeon, B. J., Kwak, J. H., Choi, W. J. 2017. Nitrogen, carbon, and dry matter losses during composting of livestock manure with two bulking agents as affected by co-amendments of phosphogypsum and zeolite. Ecological Engineering 102: 280-290. (Co-corresponding author) DOI: 10.1016/j.ecoleng.2017.02.031

• Choi, W. J., Kwak, J. H., Lim, S. S., Park, H. J., Chang, S. X., Lee, S. M., Arshad, M. A., Yun, S. I., Kim, H. Y. 2017. Synthetic fertilizer and livestock manure differently affect δ15N in the agricultural landscape: A review. Agriculture, Ecosystems and Environment 237: 1-15. (corresponding author) DOI: 10.1016/j.agee.2016.12.020

• Kwak, J. H., Chang, S. X., Naeth, M. A., Schaaf, W. 2016. Nitrogen transformation rates are affected by cover soil type but not coarse woody debris application in reclaimed oil sands soils. Restoration Ecology 24: 506-516. DOI: 10.1111/rec.12344

• Lim, S. S., Lee, D. S., Kwak, J. H., Park, H. J., Kim, H. Y., Choi, W. J. 2016. Fly ash and zeolite amendments increase soil nutrient retention but decrease paddy rice growth in a low fertility soil. Journal of Soils and Sediments 16: 756-766. DOI: 10.1007/s11368-015-1294-0 (corresponding author)

• Kwak, J. H., Chang, S. X., Naeth, M. A., Schaaf, W. 2016. Coarse woody debris effects on greenhouse gas emission rates depend on cover soil type in oil sands reclamation. Applied Soil Ecology 100: 124-134. DOI: 10.1016/j.apsoil.2015.12.006.

• Kwak, J. H., Lim, S. S., Lee, K. S., Viet, H. D., Matsushima, M., Lee, K. H., Jung, K., Kim, H. Y., Lee, S. M., Chang, S. X., Choi, W. J. 2016. Temperature and air pollution affected tree ring δ¹³C and water-use efficiency of pine and oak trees under rising CO₂ in a humid temperate forest. Chemical Geology 420: 127-138. DOI: 10.1016/j.chemgeo.2015.11.015

• Kwak, J. H., Chang, S. X., Naeth, M. A., Schaaf, W. 2015. Coarse woody debris increases microbial community functional diversity but not enzyme activities in reclaimed oil sands soils. PLOS ONE DOI: 10.1371/journal.pone.014385.

• Kwak, J. H., Chang, S. X., Naeth, M. A., Schaaf, W. 2015. Coarse woody debris extract decreases nitrogen availability in two reclaimed oil sands soils in Canada. Ecological Engineering 84: 13-21. DOI: 10.1016/j.ecoleng.2015.07.012

• Kwak, J. H., Lee, K. S., Lim, S. S., Matsushima, M., Lee, K. H., Lee, S. M., Choi, W. J. 2013. Historical response of Quercus variabilis growth to environmental changes in southern Korea: Evidence from tree ring width and δ¹³C. Journal of Korean Society of Applied Biological Chemistry 56: 583-590.

• Kwak, J. H., Lim, S. S., Chang, S. X., Lee, K. H., Choi, W.J. 2011. Potential use of δ¹³C, δ¹⁵N, N concentration, and Ca/Al of Pinus densiflora tree rings in estimating historical precipitation pH. Journal of Soils and Sediments 11: 709-721. DOI: 10.1007/s11368-011-0355-2

•  Kwak, J. H., Choi, W. J., Lim, S. S., Arshad, M. A. 2009. δ¹³C, δ¹⁵N, N concentration, and Ca-to-Al ratios of forest samples from Pinus densiflora stands in rural and industrial areas. Chemical Geology 264: 385-393. DOI: 10.1016/j.chemgeo.2009.04.002

• Kwak, J. H., Lim, S. S., Park, H. J., Lee, S. I., Lee, K. H., Kim, H. Y., Chang, S. X., Lee, S. M., Ro, H. M., Choi, W. J. 2009. Relating tree ring chemistry of Pinus densiflora to precipitation acidity in an industrial area of South Korea. Water Air and Soil Pollution 199: 95-106. DOI: 10.1007/s11270-008-9862-1

• Kwak, J. H., Lim, S. S., Park, H. J., Lee, S. I., Lee, D. S., Lee, K. H., Han, G. H., Ro, H. M., Choi, W. J. 2009. Isotope ratio of mineral N in Pinus desiflora forest soils in rural and industrial areas: potential indicator of atmospheric N deposition and soil N loss. Korean Journal of Soil Science and Fertilizer 42: 46-52.

• Kwak, J. H., Choi, W. J., Lim, S. S., Lee, S. H., Lee, S. M., Chang, S. X., Jung, J. W., Yoon, K. S., Choi, S. M. 2008. Sources and transformations of N in reclaimed coastal tidelands in Korea: Evidence from soil δ¹⁵N data. Environmental Geology 53: 1331-1338. DOI: 10.1007/s00254-007-0741-7

 

Co-authorship (39 articles; 31 SCI journals and 8 Korean journals)

• Park, S. I., Yang, H. I., Park, H. J., Seo, B. S., Jeong, Y, J., Lim, S. S., Kwak, J. H., Kim, H. Y., Yoon, K. S., Lee, S, M., Choi, W. J., 2021. Rice straw cover decreases soil erosion and sediment-bound C, N, and P losses but increases dissolved organic C export from upland maize fields as evidenced by δ¹³C. Science of the Total Environment 753: 142053 https://doi.org/10.1016/j.scitotenv.2020.142053

• Choi, W. J., Kwak, J. H., Park, H. J., Yang, H. I., Park, S. I., Xu, Z., Lee, S. M., Lim, S. S., Chang, S. X., 2020. Land use type, and land management and disturbance affect soil δ¹⁵N: A review. Journal of Soils and Sediments 20: 3283–3299 DOI: https://doi.org/10.1007/s11368-020-02708-x

• Park, H. J., Lim, S. S., Yang, H. I., Lee, K. S., Kwak, J. H., Park, S. I., Kim, H. Y., Lee, S. M., Choi, W. J., 2020. Nitrogen effects on quantity, chemistry, and decomposability of Pinus densiflora and Quercus variabilis litters under elevated CO₂ and warming. Forest Ecology and Management 473: 118315. https://doi.org/10.1016/j.foreco.2020.118315

• Park, H. J., Lim, S. S., Kwak, J. H., Lee, K. S., Yang, H. I., Kim, H. Y., Lee, S. M., Choi, W. J., 2020. Biomass, chemical composition, and microbial decomposability of rice root and straw produced under co-elevated CO₂ and temperature. Biology and Fertility of Soils 56:991–1005 https://doi.org/10.1007/s00374-020-01471-y

• Choi, W. J., Chang, S, X., Kwak, J. H., 2020. Comment on: Inorganic N addition replaces N supplied to switchgrass (Panicum virgatum) by arbuscular mycorrhizal fungi. Ecological Applications https://doi.org/10.1002/eap.2270

• Wang, S., Kwak, J. H., Islam, M.S., Naeth, M.A., Gamal El-Din, M., Chang, S., 2020. Biochar surface complexation and Ni(II), Cu(II), and Cd(II) adsorption in aqueous solutions depend on feedstock type. Science of the Total Environment 712: 136538 DOI: https://doi.org/10.1016/j.scitotenv.2020.136538

• Li, J., Liu, G., Kwak, J. H., Chang, S. X., Gao, H., Wu, Q., Yang, J., Chen, J., 2020. Reclamation of desert land to continuous cotton cropping affects soil properties and microbial communities in the desert-oasis ecotone of Xinjiang, China. Journal of Soils and Sediments 20: 862-873 DOI: https://doi.org/10.1007/s11368-019-02469-2

• Wu, Q., Kwak, J. H., Chang, S. X., Han, G., Gong X., 2020. Cattle urine and dung additions differently affect nitrification pathways and greenhouse gas emission in a grassland soil. Biology and Fertility of Soils 56: 235-247 DOI: https://doi.org/10.1007/s00374-019-01415-1

• Park, H. J., Lim, S. S., Yang, H. I., Lee, K. S., Park, S. I., Kwak, J. H., Kim, H. Y., Oh, S. W., Choi, W. J., 2020. Co-elevation of CO2 and temperature with changed soil water availability do not change litter quantity and quality of pine and oak. Agricultural and Forest Meteorology 280: 107795 DOI: 10.1016/j.agrformet.2019.107795

• Park, H. J., Park, H. J., Yang, H. I., Park, S. I., Lim, S. S., Kwak, J. H., Lee, G. T., Lee, S. M., Park, M., Choi, W. J. 2019. Sorption of Pb in chemical and particle-size fractions of soils with different physico-chemical properties. Journal of Soils and Sediments 19: 310-321. DOI: 10.1007/s11368-018-1978-3

•  Park, H. J., Lim, S. S., Kwak, J. H., Yang, H. I., Lee, K. S., Lee, Y. H., Choi, W. J., 2018. Elevated CO₂ concentration affected pine and oak litter chemistry and the respiration and microbial biomass of soils amended with these litters. Biology and Fertility of Soils 54: 583-594. DOI: 10.1007/s00374-018-1282-9

• Wang, Q., Kwak, J. H., Choi, W. J., Chang, S. X., 2018. Decomposition of trembling aspen leaf litter under long-term nitrogen and sulfur deposition: Effects of litter chemistry and forest floor microbial properties. Forest Ecology and Management 412: 53-61. DOI: 10.1016/j.foreco.2018.01.042

• Dinh, V. H., Nguyen, T. K., Kwak, J. H., Choi, W. J., 2018. Warming increased nitrogen availability and tree growth during the last five decades as revealed by annual ring data of Pinus merkusii in central Vietnam. Communications in Soil Science and Plant Analysis 49: 416-425. DOI: 10.1080/00103624.2018.1427265

• Pokharel, P., Kwak, J. H., Ok, Y. S., Chang, S. X. 2018. Pine sawdust biochar reduces GHG emission by decreasing microbial and enzyme activities in forest and grassland soils in a laboratory experiment.  Science of The Total Environment 625: 1247-1256. DOI https://doi.org/10.1016/j.scitotenv.2017.12.343

• Pokharel, P., Kwak, J. H., Chang, S. X. 2017. Growth and nitrogen uptake of jack pine seedlings in response to exponential fertilization and weed control in a reclaimed soil. Biology and Fertility of Soils 53: 701-713. DOI: 10.1007/s00374-017-1213-1

• Lee, S. I., Choi, W. J., Kwak, J. H., Lim, S. S., Park, H. J., Chang, S. X., Kim, H. Y. 2016. The chloroform fumigation efficiency in water-saturated soils increases by mixing sand and decreasing packing thickness. European Journal of Soil Biology 75: 88-96. DOI: 10.1016/j.ejsobi.2016.05.001

• Park, H. J., Lim, S. S., Kwak, J. H., Baek, W. J., Yoon, K. S., Choi, S. M., Choi, W. J. 2015. Nitrogen inputs with different substrates quality modified pH, Eh, and N dynamics of a paddy soil incubated under waterlogged conditions. Communications in Soil Science and Plant Analysis 46: 2234-2248. DOI: 10.1080/00103624.2015.1069324

• Jung, J. W., Lim, S. S., Kwak, J. H., Park, H. J., Yoon, K. S., Kim, H. Y., Baek, W. J., Choi, W. J. 2015. Further understanding of the impacts of rainfall and agricultural management practices on nutrient loss from rice paddies in a monsoon area. Water Air and Soil Pollution 226: 283. DOI: 10.1007/s11270-015-2551-y

• Lim, S. S., Kwak, J. H., Lee, K. S., Chang, S. X., Yoon, K. S., Kim, H. Y., Choi, W. J. 2015. Soil and plant nitrogen pools in paddy and upland ecosystems have contrasting δ¹⁵N. Biology and Fertility of Soils 51: 231-239. DOI: 10.1007/s00374-014-0967-y

• Lee, S. I., Lim, S. S., Kwak, J. H., Choi, W. J., Matsushima, M. 2015. Sand mixing improved chloroform fumigation efficiency in the determination of microbial biomass carbon of water-saturated soils. Communications in Soil Science and Plant Analysis 46: 271-276. DOI: 10.1080/00103624.2014.967864

• Nam, H. S., Kwak, J. H., Lim, S. S., Choi, W. J., Lee, S. I., Lee, D. S., Lee, K. S., Kim, H. Y., Lee, S. M., Matsushima, M. 2013. Fertilizer N uptake of paddy rice in two soils with different fertility under experimental warming with elevated CO₂. Plant and Soil 369: 563-575. DOI: 10.1007/s11104-013-1598-z

• Viet, H. D., Kwak, J. H., Lee, K. S., Lim, S. S., Matsushima, M., Chang, S. X., Lee, K. H., Choi, W. J. 2013. Foliar chemistry and tree ring δ¹³C of Pinus densiflora in relation to tree growth along a soil pH gradient. Plant and Soil 363: 101-112. DOI: 10.1007/s11104-012-1301-9

• Lee, K. S., Lee, D. S., Lim, S. S., Kwak, J. H., Jeon, B. J., Lee, S. I., Lee, S. M., Choi, W. J. 2012. Nitrogen isotope ratio of dissolved organic nitrogen in wet precipitation in a metropolis surrounded by agricultural area in southern Korea. Agriculture, Ecosystem & Environment 159: 161-169. DOI: 10.1016/j.agee.2012.07.010

• Lim, S. S., Lee, K. S., Lee, S. I., Lee, D. S., Kwak, J. H., Hao, X., Ro, H. M., Choi, W. J. 2012. Carbon mineralization and retention of livestock manure composts with different substrate qualities in three soils. Journal of Soils and Sediments 12: 312-322. DOI: 10.1007/s11368-011-0458-9

• Kim, H. Y., Lim, S. S., Kwak, J. H., Lee, S. I., Lee, D. S., Hao, X., Yoon, K. S., Choi, W. J. 2011. Soil and compost type affect phosphorus leaching from Inceptisol, Ultisol, and Andisol in a column experiment. Communications in Soil Science and Plant Analysis 42: 2188-2199. DOI: 10.1080/00103624.2011.602450

• Kim, H. Y., Lim, S. S., Kwak, J. H., Lee, D. S., Lee, S. M., Ro, H. M., Choi, W. J. 2011. Dry matter and nitrogen accumulation and partitioning in rice (Oryza sativa L.) exposed to experimental warming with elevated CO₂. Plant and Soil 342: 59-71. DOI: 10.1007/s11104-010-0665-y

• Lee, K. S., Viet, H. D., Kwak, J. H., Lim, S. S., Lee, K. H., Choi, W. J. 2011. Tree ring Ca/Al as an indicator of historical soil acidification of Pinus densiflora forest in southern Korea. The Korean Society of Environmental Agriculture 30: 229-233.

• Lee, S. I., Lim, S. S., Kwak, J. H., Jung, J. W., Ro, H. M., Choi, W. J. 2011. Kinetic responses of soil carbon dioxide emission to increasing urea application rate. The Korean Society of Environmental Agriculture 30: 99-104.

• Lim, S. S., Kwak, J. H., Lee, S. I., Lee, D. S., Park, H. J., Hao, X., Choi, W. J. 2010. Compost type effects on nitrogen leaching from Inceptisol, Ultisol, and Andisol in a column experiment. Journal of Soils and Sediments 10: 1517-1526. DOI: 10.1007/s11368-010-0263-x

• Matsushima, M., Lim, S. S., Kwak, J. H., Park, H. J., Lee, S. I., Lee, D. S., Choi, W. J. 2009. Interactive effects of synthetic nitrogen fertilizer and composted manure on ammonia volatilization from soils. Plant and Soil 325: 187-196. DOI: 10.1007/s11104-009-9967-3

• Lim, S. S., Park, H. J., Lee, S. I., Lee, D. S., Kwak, J. H., Choi, W. J. 2009. The role of organic amendments with different biodegradability in ammonia volatilization during composting of cattle manure. The Korean Society of Environmental Agriculture 28: 20-24 (in Korean).

• Kim, Y. J., Choi, W. J., Lim, S. S., Kwak, J. H., Chang, S. X., Kim, H. Y., Yoon, K. S., Ro, H. M. 2008. Changes in nitrogen isotopic compositions during composting of cattle feedlot manure: Effects of bedding material type. Bioresource Technology 9: 5452-5458. DOI: 10.1016/j.biortech.2007.11.012

• Jung, J. W., Yoon, K. S., Choi, W. J., Choi, W. Y., Joo, S. H., Lim, S. S., Kwak, J. H., Lee, S. H., Kim, D. H., Chang, N. I. 2008. Improvement measures of pollutants unit-loads estimation for paddy fields. Journal of Korean Society on Water Environment 24: 291-296 (in Korean).

• Lim, S. S., Kwak, J. H., Park, H. J., Lee, S. I., Lee, D. S., Kim, Y. J., Yun, B. K., Kim, S. W., Choi, W. J. 2008. Analysis of nutrient cycling structure of a Korean beef cattle farm combined with cropping as affected by bedding material types. Korean Journal of Soil Science and Fertilizer 41: 354-361 (in Korean).

• Lim, S. S., Choi, W. J., Kwak, J. H., Jung, J. W., Chang, S. X., Kim, H. Y., Yoon, K. S., Choi, S. M. 2007. Nitrogen and carbon isotope responses of Chinese cabbage and chrysanthemum to the application of liquid pig manure. Plant and Soil 295: 67-77. DOI: 10.1007/s11104-007-9262-0

• Choi, W. J., Chang, S. X., Kwak, J. H., Jung, J. W., Lim, S. S., Yoon, K. S., Choi, S. M. 2007. Nitrogen transformations and ammonia volatilization losses from 15N-urea as affected by the co-application of composted pig manure. Canadian Journal of Soil Science 87(5): 485-493. DOI: 10.4141/CJSS07002

• Choi, W. J., Kwak, J. H., Jung, J. W., Yoon, K. S., Jang, N. I., Huh, Y. J. 2007. Application of simple regression models for pollutants load estimation of paddy to Yeongsan and Seomjin river watersheds. Journal of the Korean Society of Agricultural Engineers 49: 89-97 (in Korean).

• Jung, J. W., Choi, W. J., Yoon, K. S., Kim, H. Y., Kwak, J. H., Lim, S. S., Chang, N. I., Huh, Y. J. 2007. Response of total nitrogen and phosphorus concentrations of paddy floodwater to fertilization under rain-shielding conditions. Korean National Committee on Irrigation and Drainage 14: 66-73.

• Choi, W. J., Lee, S. M., Han, G. H., Yoon, K. S., Jung, J. W., Lim, S. S., Kwak, J. H. 2006. Available organic carbon controls nitrification and immobilization of ammonium in an acid loam-textured soil. Agricultural Chemistry and Biotechnology 49: 28-32.

 

 PUBLICATIONS (non-peer reviewed, 2 articles)    

• Kwak, J. H., Ojekanmi, A., Duan, M., Chang, S. X., Naeth, M. A., 2017. Mine Site Reclamation in Canada: Overview and Case Studies. In: Bolan, N., Ok, Y., Kirkham, M. B., (Eds.). Spoil to Soil: Mine Site Rehabilitation and Revegetation. CRC Press, Taylor & Francis Group. Boca Raron, FL, USA. pp 291-308.

• Choi, W. J., Lim, S. S., Kwak, J. H., Kim, T. W., Yoon, B. K., 2010. Nutrient management manual for natural recycling agriculture. Chonnam National University Press. South Korea. ISBN 978-89-6381-032-4 93520 (in Korean)

 

PRESENTATIONS

 

Oral presentations

• Kwak, J. H.*, Islam, M. S., Wang, S., Chang, S. X., Naeth, M. A., Gamal El-Din, M., 2019. Biochar property and lead(II) adsorption capacity depend on feedstock type, pyrolysis temperature, and steam activation. November 10-14, 2019. IBI Biochar World Congress 2019. Seoul. South Korea

•  Kwak, J. H.*, Islam, M. S., Wang, S., Chang, S. X., Naeth, M. A., Gamal El-Din, M., 2019. Effects of feedstock type, pyrolysis temperature, and steam activation on biochar properties and lead(II) adsorption. October 10-11, 2019. The Korean Society of Agricultural Engineering, Hongchun, South Korea.

• Kwak, J. H.*, Islam, M. S., Wang, S., Messele, S.A., Chang, S. X., Naeth, M. A., Gamal El-Din, M., 2019. Effects of feedstock type, pyrolysis temperature, and steam activation on biochar properties and lead(II) adsorption. June 12-15, 2019. The 3rd International Conference on Bioresources, Energy, Environment, and Materials Technology 2019 (BEEM2019). Hong Kong

• Kwak, J. H.*, Islam, M. S., Wang, S., Chang, S. X., Naeth, M. A., Gamal El-Din, M., 2019. Effects of feedstock type, pyrolysis temperature, and steam activation on biochar properties and lead(II) adsorption. February 19-21, 2019. Alberta Soil Science Workshop. Calgary, Alberta, Canada

• Kwak, J. H.*, Chang, S. X., Naeth, M. A., Gamal El-Din, M., 2019. Developing novel materials for reclamation and remediation of land and water. January 6-9, 2019. SSSA International Soils Meeting. "Soils Across Latitudes". San Diego, USA

• Chang, S. X.*, Kwak, J. H., Islam, M. S., Wang, S., Ok, Y. S., Naeth, M. A., Gamal El-Din, M., 2018. Characterizing and optimizing biochars for contaminant removal from process water. The 4th Asia Pacific Biochar Conference (APBC 2018), November 3-8, 2018. Foshan City, Guangdong Province, China

• Kwak, J. H.*, Chang, S. X., Naeth, M. A., 2016. Elevated nitrogen and sulfur depositions affect nitrogen transformation rates in a boreal mixedwood forest in northern Alberta. Joint Annual Meeting of the Canadian Society of Soil Science and Pacific Regional Society of Soil Science. May 14-19. Kamloops, British Columbia, Canada.

• Kwak, J. H.*, Chang, S. X., Naeth, M. A., Schaaf, W., 2015. Coarse woody debris increased microbial activity but did not affect soil enzyme activity in cover soils for oil sands reclamation. Alberta Soil Science Workshop. February 17-19. Edmonton, Alberta, Canada.

• Kwak, J. H.*, Chang, S. X., Naeth, M. A., Schaaf, W., 2014. Effect of coarse woody debris extract on N transformation rates on reclaimed soils in the Athabasca oil sands region in Alberta, Canada. 20th World Congress of Soil Science. June 8-13. Jeju, South Korea.

• Jung, K., Kwak, J. H.*, Chang, S. X. 2013. Understory plant community was changed by seven years of simulated N and S deposition in the Athabasca oil sands region in Alberta. 50th Alberta Soil Science Workshop. February 19-21. Lethbridge, Alberta, Canada.

 Poster presentations (recent 5 years)

• Kwak, J. H.*, Chang, S. X., Naeth, M. A, Gamal El-Din, M.,, 2018. Developing novel materials for reclamation and remediation of land and water. Alberta Soil Science Workshop. February 20-22. Edmonton, Alberta, Canada.

• Pokharel, P.*, Kwak, J. H., Chang, S. X., Ok, Y. S., 2018. Effect of pine sawdust biochar on greenhouse gas emission from forest and grassland soils under laboratory condition. Alberta Soil Science Workshop. February 20-22. Edmonton, Alberta, Canada. (Best poster award)

• Wang, Q.*, Kwak, J. H., Chang, S. X., Choi, W. J., 2018. Decomposition of trembling aspen leaf litter under long-term nitrogen and sulfur decomposition: Effects of litter chemistry and forest floor microbial properties. Alberta Soil Science Workshop. February 20-22. Edmonton, Alberta, Canada.

•  Kwak, J. H., Chang, S. X.*, Naeth, M. A. 2017. Eleven years of nitrogen but not sulfur deposition changed understory species composition in a boreal forest. BIOGEMON 9th International Symposium on Ecosystem Behavior. August 20-24. Litomyšl Chateau, Czech Republic

• Kwak, J. H.*, Naeth, M. A., Chang, S. X. 2017. Ten years of elevated nitrogen and sulfur deposition did not affect microbial and enzyme activities and nitrogen transformation in a boreal mixedwood forest. 11th North American Forest Ecology Workshop. June 19-22. Edmonton, Alberta, Canada

• Wang, Q.*, Kwak, J. H., Choi, W. J., Chang, S. X. 2017. Decomposition of leaf litter from a mixedwood boreal forest under nitrogen and sulfur deposition is mediated by lignin concentration and soil microbial properties: a microcosm study. 11th North American Forest Ecology Workshop. June 19-22. Edmonton, Alberta, Canada

• Lim, S. S., Baah-Acheamfour, M., Choi, W. J., Arshad, M. A., Carlyle, C. N., Bork, E. W., Fatemi, F., Banerjee, S., Kwak, J. H.*, Chang, S. X., 2017. Soil organic carbon dynamics of agroforestry systems: from surface organic to deeper mineral layers. Alberta Soil Science Workshop. February 15-17. Lethbridge, Alberta, Canada

• Wang, Q.*, Kwak, J. H., Chang, S. X., 2016. Long-term nitrogen and sulfur depositions affect leaf litter decomposition in a mixedwood boreal forest in northern Alberta. Alberta Soil Science Workshop. February 16-18. Grande Prairie, Alberta, Canada

• Kwak, J. H.*, Chang, S. X., Naeth, M. A., Schaaf, W., 2015. Coarse woody debris increased microbial activity but did not affect soil enzyme activity in cover soils for oil sands reclamation. Canadian Society of Soil Science Annual Meeting. July 5-10. Montreal, Quebec, Canada.

• Pokharel, P.*, Ibsen, S., Kwak, J. H., Jamro, G. M, Lou, K., Chang, S. X., 2015. Nursery nutrient loading promotes growth of jack pine seedlings planted on reclaimed soils. Canadian Land Reclamation Association and Manitoba Soil Science Society Joint Conference. June 15-18. Winnipeg, Manitoba, Canada.

• Kwak, J. H.*, Chang, S. X., Naeth, M. A., Schaaf, W., 2014. CO2 emission rates were affected by soil type but not by coarse woody debris in reclaimed oil sands soils. ASA, CSSA & SSSA International Annual Meeting. November 2-5. Long Beach, CA, USA.

• Kwak, J. H.*, Chang, S. X., Naeth, M. A., Schaaf, W., 2014. Coarse woody debris effects on CO2 emission rates in reclaimed oil sands soils depend on cover soil type. 4th Helmholtz-Alberta Innovative Science Forum. September 29-October 1. Edmonton, Alberta, Canada.

• Lee, K. S.*, Kwak, J. H., Viet, H. D., Lim, S. S., Mathushima, M., Chang, S. X., Choi, W. J., 2014. Pine and oak trees had contrasting water use responses to environmental changes caused by industrialization in southern Korea: evidence from tree ring δ13C. 20th World Congress of Soil Science. June 8-13. Jeju, South Korea. (Best poster award)