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1993
Harrington, J.B., Flannigan, M.D.
Long dry spells (sequences of dry days) are rare events, but they are important because they correlate significantly with the area burned during bad wildfire years. Previous attempts to model the frequency of dry spells have been successful for spells of short duration, but have failed for...
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Characterizing the performance of ecosystem models across time scales: A spectral analysis of the North American Carbon Program site-level synthesis
Download2011
Black, T.A., Izaurralde, R.C., Lokupitiya, E., Munger, J.W., Schaefer, K., Weng, E., Richardson, A.D., Altaf Arain, M., Luo, Y., Ciais, P., Ricciuto, D.M., Stoy, P.C., Dietze, M.C., Poulter, B., Barr, A.G., Liu, S., Hollinger, D., Tian, H., Suyker, A.E., Verbeeck, H., Price, D.T., Grant, R.F., Peng, C., Baker, I.T., Vargas, R., Anderson, R.S., Tonitto, C., Sahoo, A.K., Chen, J.M., Flanagan, L.B., Riley, W.J., Wang, W., Lafleur, P., Gough, C.M., Verma, S.B., Kucharik, C.J.
Ecosystem models are important tools for diagnosing the carbon cycle and projecting its behavior across space and time. Despite the fact that ecosystems respond to drivers at multiple time scales, most assessments of model performance do not discriminate different time scales. Spectral methods,...
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Differential growth and rooting of upland and peatland black spruce, Picea mariana, in drained and flooded soils
Download2007
A reciprocal experiment was analyzed to determine whether 30 open-pollinated families of peatland and upland populations of black spruce [Picea mariana (Mill.) B.S.P.] sampled from a single area in north-central Alberta, Canada, performed consistently when grown in either flooded or well-drained...
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Diurnal and annual exchanges of mass and energy between an aspen-hazelnut forest and the atmosphere: testing the mathematical model ecosys with data from the BOREAS experiment
Download1999
Russell, C., den Hartog, G., Grant, R.F., Berry, J.A., Yang, P.C., Neumann, H.H., Blanken, P.D., Black, T.A., Gower, S.T.
There is much uncertainty about the net carbon (C) exchange of boreal forest ecosystems, although this exchange may be an important part of global C dynamics. To resolve this uncertainty, net C exchange has been measured at several sites in the boreal forest of Canada as part of the Boreal...
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2007
Chang, S. X., Bhatti, J., Choi, W. J.
Abstract: The lowering of the water table resulting from peatland drainage may dramatically alter C and N cycling in peatland ecosystems, which contain one-third of the total terrestrial C. In this study, tree annual ring width and C (delta C-13) and N (delta N-15) isotope ratios in soil and...
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Ecological controls on net ecosystem productivity of a mesic arctic tundra under current and future climates
Download2011
Dimitrov, D. D., Grant, R. F., Lafleur, P. M., Humphreys, E. R.
Abstract: Changes in arctic C stocks with climate are thought to be caused by rising net primary productivity (NPP) during longer and warmer growing seasons, offset by rising heterotrophic respiration (Rh) in warmer and deeper soil active layers. In this study, we used the process model ecosys to...
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Effects of variable nitrogen fertilization on growth, gas exchange, and biomass partitioning in black spruce and tamarack seedlings.
Download2005
Macdonald, S. Ellen, Islam, M. Anisul
In order to compare the ability of black spruce (Picea mariana (Mill.) BSP) 1 and tamarack (Larix laricina (Du Roi) K. Koch) to adjust to variable edaphic conditions, 2 as found in natural peatlands, we varied nitrogen (N) fertilization of seedlings in a growth 3 chamber experiment over two...
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2012
For much of the history of Alberta’s tar sands, a series of visual conventions have shaped Canadian imaginaries of the resource, the emergence of the non-conventional oil industry, and the mining of oil. We introduce a series of archival images dating from 1880 until the opening of Great Canadian...
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2012
Desai, A., Grant, R.F., Sulman, B.
Responses of wetland productivity to changes in water table depth (WTD) are controlled by complex interactions among several soil and plant processes, and hence are site-specific rather than general in nature. Hydrological controls on wetland productivity were studied by representing these...