French Associates Institute for Agriculture and Biotechnology of Drylands
Jacob Blaustein Institutes for Desert Research
Ben-Gurion University of the Negev
Sede Boqer Campus, 849900, Israel
I am an ecosystem ecologist and the general aim of my research is to understand processes that regulates terrestrial biogeochemical cycles of nitrogen and carbon on multiple scales. The specific emphasis of my research is on understanding consequences of changes in climate, land-use and management on N and C cycles and their interactions.
In my lab we are studying N availability and loss, N and C transformations, and soil emissions of trace gases with the goal to understand how C and N dynamics affecting environmental impact and sustainability of managed ecosystems. Together with work at the ecosystem scale to understand system-level impacts we perform experiments at plant and microbial scales to understand processes that leading to system-level changes.
Currently I am looking for M.Sc. and Ph.D. students, contact me if you are interested.
Effect of management on the environmental impact of agroecosystems
To determine the environmental impact of agroecosystems I am estimating ecosystem-level balances of nitrogen. For this end I am measuring pools and flows (fluxes) of nitrogen in ecosystems. I am also measuring nitrogen transformations in soils (N fixation, N mineralization, nitrification, and denitrification), emissions of gaseous N forms (ammonia, nitrous, and nitric oxides) from soils to the atmosphere, and leaching of nitrogen beneath plants root zone.
Impacts of environmental and land-use changes on linkages between C and N cycles in agroecosystems
Environmental change does not have just а gradual effect on mean environmental conditions but also affect the variability of weather such as frequency and intensity of extreme events, including droughts and heavy precipitation. In general, I am interested in pulse events and their effects on soil biogeochemistry as well as on whole ecosystem functioning. Specifically, I am interested in understanding what effects drought/rewetting cycles have on the biogeochemistry of soil greenhouse gas emissions in systems under different management. Some particular questions I am asking are: Are soils that experience repetitive drying/rewetting cycles developing biogeochemical responses differently from soils experiencing prolonged droughts and infrequent wetting? How will soil management affect soil and ecosystem N and C biogeochemistry under changing frequencies of drying/rewetting cycles? These questions are being answered by rain addition experiments where I measure soil greenhouse gas emissions and N transformations (e.g., mineralization, nitrification) in fields with different soil organic carbon contents and identical management but differing land-use histories and in mesacosm studies.
Controls on soil trace gases emissions
Land use change and management are the most common features of today's landscapes and both have large influences on the C cycle, which is tightly connected to the N cycle. In my research, I am exploring linkages between the two cycles by asking: How do soil C availability, dominant N forms (i.e. NH4+ or NO3-), and N availability interact to affect soil emissions of the N-oxides (N2O/NOx)? To answer this question, I am using ecosystem-level measurements of trace gas exchanges with eddy covariance towers, coupled with ground-based static flux chambers and detailed measurements of N cycling processes in soils. Often, I combine ground measurements with data-mining to assess the importance of different drivers to soil trace gas emissions.
19. Gelfand I, Shcherbak I, Millar N, Kravchenko AN, Robertson GP (2016) Long-term nitrous oxide fluxes in annual and perennial agricultural and unmanaged ecosystems in the upper Midwest USA. Global Change Biology DOI:10.1111/gcb.13426
18. Abraha M, Gelfand I, Shao C, Su Y-J, Hamilton SK, Robertson GP, Chen J. (2016) Land use history, ecosystem type and species composition drive water use efficiency in annual maize and perennial grasslands in a humid temperate climate. Ecosystems DOI:10. 1007/ s10021-016-9981-2
17. Gelfand I, Cui M, Tang J, Robertson GP. (2015) Short-term drought response of N2O and CO2 emissions from mesic agricultural soils in the US Midwest. Agriculture, Ecosystems, and Environment 212:127-133.
16. Oates LG, Duncan DS, Gelfand I, Millar N, Robertson GP, Jackson RD. (2015) Nitrous oxide emissions during establishment of eight alternative cellulosic bioenergy cropping systems in the North Central U.S. GCB Bioenergy 8(3):539-549.
15. Zenone T, Zona D, Gelfand I, Gielen B, Camino Serrano M, Ceulemans R. (2015) The offset of CO2 uptake by CH4 and N2O emissions in poplar short-rotation coppice. GCB Bioenergy 8(3):524-538.
14. Gelfand I and Robertson GP. (2014) A reassessment of the contribution of soybean biological nitrogen fixation to reactive N in the environment. Biogeochemistry 123:175-184.
13. Sahajpal R, Xuesong Z, Izzauralde CR, Gelfand I, Hurtt GC. (2014) Identifying representative crop rotation patterns and grassland loss in the US Western Corn Belt. Computers and Electronics in Agriculture 108:173-182.
12. Gelfand I, Sahajpal R, Zhang X, Izzauralde CR, Gross KL, Robertson GP. (2013) Sustainable bioenergy production from marginal lands in the US Midwest. Nature 493: 514-517. Recommended by F1000.
11. Zenone T, Gelfand I, Chen J, Hamilton SK, Robertson GP. (2013) From set-aside grassland to annual and perennial cellulosic biofuel crops: Effects of land use change on carbon balance. Agricultural and Forest Meteorology 182-183: 1-12.
10. Gelfand I, Grünzweig JM, Yakir D. (2012) Slowing of nitrogen cycling and increasing nitrogen use efficiency in semi-arid afforestation. Oecologia 168(2): 563-75.
9. Gelfand I, Zenone T, Jasortia P, Chen J, Hamilton SK, Robertson GP. (2011) Carbon debt of a Conservation Reserve Program (CRP) grassland converted to bioenergy production. Proceedings of the National Academy of Sciences (USA) 108: 13864-13869.
8. Gelfand I, Snapp SS, Robertson GP. (2010) Energy efficiency of conventional, organic, and alternative cropping systems at a site in the US Midwest. Environmental Science and Technology 44: 4006-4011.
7. Gelfand I, Feig G, Meixner FX, Yakir D. (2009) Afforestation of semi-arid shrubland reduces biogenic NO emission from soil. Soil Biology & Biochemistry 41: 1561-1570.
6. Gelfand I and Yakir D. (2008) Influence of nitrite accumulation in association with seasonal patterns and mineralization of soil nitrogen in a semi-arid pine forest. Soil Biology & Biochemistry 40: 415-424.
5. Grünzweig JM, Gelfand I, Fried Y, Yakir D. (2007) Biogeochemical factors contributing to enhanced carbon storage following afforestation of a semi-arid shrubland. Biogeosciences 4: 891-904.
4. Cytryn E, Minz D, Gelfand I, Neori A, Gieseke A, de Beer D, van Rijn J. (2005) Sulfide-oxidizing activity and bacterial community structure in a fluidized bed reactor from a zero-discharge mariculture system. Environmental Science and Technology 39(6): 1802-1810.
3. Gelfand I, Barak Y, Even-Chen Z, Cytryn E, Krom M, Neori A, van Rijn J. (2003) A novel zero-discharge intensive seawater recirculating system for the culture of marine fish. Journal of World Aquaculture Society 34 (3): 344-358.
2 .Cytryn E, Gelfand I, Barak Y, van Rijn J, Minz D. (2003) Diversity of microbial communities correlated to physiochemical parameters in digestion basin of a zero-discharge mariculture system. Environmental Microbiology 5(1): 55-63.
1. Barak Y, Cytryn E, Gelfand I, Krom M, van Rijn J. (2003) Phosphorus removal in a marine prototype recirculating aquaculture system. Aquaculture 220(1-4):313-326.
Gelfand I and Robertson GP. (2015) Mitigation of greenhouse gases in agricultural ecosystems. In: Hamilton SK, Doll JE, Robertson GP. Eds. “The ecology of agricultural landscapes: Long-term research on the path to sustainability", pp. 310-338. Oxford Univ. Press.