Someone the other day made a statement that some recent work was one of the most important papers on the N cycle published in the last 5 years. Statements like that are hard to refute, but I wondered what that list would like.
I had a short list in my head of papers I could think of. There has been a lot of work on N limitation, new developments in our understanding of microbial processes, and continued advances in the consequences of N deposition.
I did a search for “nitrogen” and “cycle” and sorted by number of times cited. Then did a search for “nitrogen” in Science, Nature, or PNAS and sorted by # times cited and then relevance. For each I looked at the top 100 papers. I then pulled papers relevant to terrestrial N cycling, but left out reviews and anything with my name on it. I didn’t try to judge 2012 papers.
Here are the 12 papers I came up with for the "Top Ten" list…
Effects of nitrogen deposition
Clark, C. M. and D. Tilman. 2008. Loss of plant species after chronic low-level nitrogen deposition to prairie grasslands. Nature 451:712-715.
Janssens, I. A., W. Dieleman, S. Luyssaert, J. A. Subke, M. Reichstein, R. Ceulemans, P. Ciais, A. J. Dolman, J. Grace, G. Matteucci, et al. 2010. Reduction of forest soil respiration in response to nitrogen deposition. Nature Geoscience 3:315-322.
Mulholland, P. J., A. M. Helton, G. C. Poole, R. O. Hall, S. K. Hamilton, B. J. Peterson, J. L. Tank, L. R. Ashkenas, L. W. Cooper, C. N. Dahm, et al. 2008. Stream denitrification across biomes and its response to anthropogenic nitrate loading. Nature 452:202-U246.
Thomas, R. Q., C. D. Canham, K. C. Weathers, and C. L. Goodale. 2010. Increased tree carbon storage in response to nitrogen deposition in the US. Nature Geoscience 3:13-17.
Global patterns of N cycling
Houlton, B. Z., Y.-P. Wang, P. M. Vitousek, and C. B. Field. 2008. A unifying framework for dinitrogen fixation in the terrestrial biosphere. Nature 454:327-330.
Davidson, E. A. 2009. The contribution of manure and fertilizer nitrogen to atmospheric nitrous oxide since 1860. Nature Geoscience 2:659-662.
Clarisse, L., C. Clerbaux, F. Dentener, D. Hurtmans, and P. F. Coheur. 2009. Global ammonia distribution derived from infrared satellite observations. Nature Geoscience 2:479-483.
Nitrogen limitation to productivity
Elser, J. J., M. E. S. Bracken, E. E. Cleland, D. S. Gruner, W. S. Harpole, H. Hillebrand, J. T. Ngai, E. W. Seabloom, J. B. Shurin, and J. E. Smith. 2007. Global analysis of nitrogen and phosphorus limitation of primary producers in freshwater, marine and terrestrial ecosystems. Ecology Letters 10:1135-1142.
LeBauer, D. S. and K. K. Treseder. 2008. Nitrogen limitation of net primary productivity in terrestrial ecosystems is globally distributed. Ecology 89:371-379.
Soil N cycling advances
Di, H. J., K. C. Cameron, J. P. Shen, C. S. Winefield, M. O'Callaghan, S. Bowatte, and J. Z. He. 2009. Nitrification driven by bacteria and not archaea in nitrogen-rich grassland soils. Nature Geoscience 2:621-624.
Manzoni, S., R. B. Jackson, J. A. Trofymow, and A. Porporato. 2008. The global stoichiometry of litter nitrogen mineralization. Science 321:684-686.
Morford, S. L., B. Z. Houlton, and R. A. Dahlgren. 2011. Increased forest ecosystem carbon and nitrogen storage from nitrogen rich bedrock. Nature 477:78-81.
Summary of these papers:
N deposition causes loss of species even at low levels, it reduces soil CO2 production, increases stream denitrification, and increases C sequestration in trees.
Nitrogen isn’t fixed in cold places because of enzymatic limitations, nitrous oxide concentrations have been driven by anthropogenic N, and India produces a lot of ammonia.
N and P are limiting everywhere, N is limiting everywhere.
Archaea aren’t important in nitrification, microbes are less efficient with C in high C:N litter, plants can get N from rocks.
Which of these is the most important? Probably not necessary to try and answer.
Did I miss any?
2 counter-intuitive nitrogen issues =ReplyDelete
(!)Re-phrasing context of nitrification:
(2011)"Ammonia concentration determines differential growth of ammonia-oxidising archaea (AOA) and bacteria (AOB) in soil microcosms"
"In soil, AOA and AOB have been demonstrated to exhibit some level of functional redundancy.
However, growth of AOB, and not of AOA, has been linked to nitrification activity following amendment with high levels of ammonium, either directly as mineral fertiliser or as urea, which is rapidly hydrolysed to ammonium.
In contrast, growth of AOA is associated with nitrification in soils with continual supply of ammonia at low concentration through mineralisation of organic matter."
(!!)location, location, location:
(2012)"New evidence that high potential nitrification rates occur in soils during dry seasons: Are microbial communities metabolically active during dry seasons?"
Soil Biology and Biochemistry,Vol.53, 2012 (Oct.), pg. 28–31
"...challenging existing paradigms of nitrogen (N) cycling in arid and semiarid ...chemically and physically distinct soils along a three million year substrate age gradient in Arizona.
Potential nitrification rates were as high or higher in the dry season than in the wet season."