Erratum: Effects of fertilization on decomposition rate of Populus tremuloides foliar litter in a boreal forest

2000 ◽  
Vol 30 (3) ◽  
pp. 519
Author(s):  
C E Prescott ◽  
R Kabzems ◽  
L M Zabek
1999 ◽  
Vol 29 (3) ◽  
pp. 393-397 ◽  
Author(s):  
C E Prescott ◽  
R Kabzems ◽  
L M Zabek

Rates of mass loss of foliar litter of trembling aspen (Populus tremuloides Michx.) were measured for 4 years after a single fertilization with N at 200 kg N/ha or a mix of N, P, K. Ca, Mg, S, and B. Foliar litter from fertilized plots had higher N concentrations than litter from control plots; litter from the nutrient-mix plots had higher concentrations of N, P, and Ca. The average rate of mass loss of aspen foliar litter was 60% after 4 years. The higher concentrations of nutrients in litter from fertilized plots did not affect the rate of decomposition. There was some difference in rates of decomposition of litter incubated in plots of the three treatments. Mass loss was significantly slower in the nutrient-mix plots after 12 and 18 months compared with control plots. This experiment provided no evidence that fertilization of boreal aspen forests will increase rates of litter decomposition.


1988 ◽  
Vol 66 (10) ◽  
pp. 1940-1947 ◽  
Author(s):  
Barry R. Taylor ◽  
Dennis Parkinson

Freshly fallen leaf litter was collected from a stand of trembling aspen (Populus tremuloides Michx.) in the Rocky Mountains of Alberta each autumn from 1981 through 1984. Leaves from 1981 and 1982 were yellow, waxy, and strong. Leaves from 1983 were pale brown and very brittle, and almost 1% of them suffered symmetrical deformities. Leaves from 1984 were composed of 80% yellow leaves and 20% green leaves, which apparently abscissed before senescence. Green and yellow 1984 leaves were distinctly different with respect to total (3 days) leaching loss, leachate conductivity, and proportions of ash, cellulose, and labile material. Green 1984 leaves contained twice as much nitrogen as yellow ones (13.1 vs. 6.5 mg∙g−1) and significantly more phosphorus (1.6 vs. 1.3 mg∙g−1). Leaves of different years varied widely with respect to leaf mass, water absorption rate, mass and conductivity of leachate, and proportions of cellulose, labiles, lignin, and ash, but there was no consistent ordering among years; leaves of different colouration (especially 1981 and 1983) were often physicochemically similar, while leaves identical in appearance were often chemically different. Small but significant differences in N and P concentrations among years were removed by 2 h leaching. Leaves of 1981 decomposing in laboratory microcosms at 26 °C lost less mass than either 1982 or 1983 leaves after 1 month, but not after 2 months. Ability of the cuticle to resist water absorption was probably responsible for the difference in initial decomposition rate.


2010 ◽  
Vol 40 (1) ◽  
pp. 37-47 ◽  
Author(s):  
Xavier Cavard ◽  
Yves Bergeron ◽  
Han Y.H. Chen ◽  
David Paré

This study investigates the potential of mixed forest stands as better aboveground carbon sinks than pure stands. According to the facilitation and niche complementarity hypotheses, we predict higher carbon sequestration in mature boreal mixedwoods. Aboveground carbon contents of black spruce ( Picea mariana (Mill.) Britton, Sterns, Poggenb.) and trembling aspen ( Populus tremuloides Michx.) mixtures were investigated in the eastern boreal forest, whereas jack pine ( Pinus banksiana Lamb.) and trembling aspen were used in the central boreal forest. No carbon gain was found in species mixtures; nearly pure trembling aspen stands contained the greatest amount of aboveground carbon, black spruce stands had the least, and mixtures were intermediate with amounts that could generally be predicted by linear interpolation with stem proportions. These results suggest that for aspen, the potentially detrimental effect of spruce on soils observed in other studies may be offset by greater light availability in mixtures. On the other hand, for black spruce, the potentially beneficial effects of aspen on soils could be offset by greater competition by aspen for nutrients and light. The mixture of jack pine and trembling aspen did not benefit any of these species while inducing a loss in trembling aspen carbon at the stand level.


2011 ◽  
Vol 77 (10) ◽  
pp. 3351-3359 ◽  
Author(s):  
Elizabeth Bent ◽  
Preston Kiekel ◽  
Rebecca Brenton ◽  
D. Lee Taylor

ABSTRACTThe role of common mycorrhizal networks (CMNs) in postfire boreal forest successional trajectories is unknown. We investigated this issue by sampling a 50-m by 40-m area of naturally regenerating black spruce (Picea mariana), trembling aspen (Populus tremuloides), and paper birch (Betula papyrifera) seedlings at various distances from alder (Alnus viridissubsp.crispa), a nitrogen-fixing shrub, 5 years after wildfire in an Alaskan interior boreal forest. Shoot biomasses and stem diameters of 4-year-old seedlings were recorded, and the fungal community associated with ectomycorrhizal (ECM) root tips from each seedling was profiled using molecular techniques. We found distinct assemblages of fungi associated with alder compared with those associated with the other tree species, making the formation of CMNs between them unlikely. However, among the spruce, aspen, and birch seedlings, there were many shared fungi (including members of thePezoloma ericae[Hymenoscyphus ericae] species aggregate,Thelephora terrestris, andRussulaspp.), raising the possibility that these regenerating seedlings may form interspecies CMNs. Distance between samples did not influence how similar ECM root tip-associated fungal communities were, and of the fungal groups identified, only one of them was more likely to be shared between seedlings that were closer together, suggesting that the majority of fungi surveyed did not have a clumped distribution across the small scale of this study. The presence of some fungal ribotypes was associated with larger or smaller seedlings, suggesting that these fungi may play a role in the promotion or inhibition of seedling growth. The fungal ribotypes associated with larger seedlings were different between spruce, aspen, and birch, suggesting differential impacts of some host-fungus combinations. One may speculate that wildfire-induced shifts in a given soil fungal community could result in variation in the growth response of different plant species after fire and a shift in regenerating vegetation.


1996 ◽  
Vol 76 (3) ◽  
pp. 373-385 ◽  
Author(s):  
W. Z. Huang ◽  
J. J. Schoenau

The forms, amounts and distribution of carbon (C), nitrogen (N), phosphorus (P) and sulfur (S) were assessed in soil profiles under trembling aspen (Populus tremuloides Michx.) stands in the southern boreal forest of Saskatchewan, Canada. The total mass of organic C storage in the LFH horizon and mineral soil to a depth of 1 m ranged from 95 352 to 103 430 kg ha−1, with an average of 99 220 kg ha−1. Organic C and N in the LFH horizon accounted for the greatest proportion of the total storage (47.3% of C and 34.2% of N), followed by the B horizon (22.4% of C and 32.7% of N) the A horizon (17.3% of C and 18.3% of N) and the C horizon (13.0% of C and 14.8% of N). Unlike C and N, more than 96% of the total P was found in the mineral soil and only 3.5% in the LFH horizon. Much of the P stored in the mineral horizons is contained in non-labile primary minerals forms. The greatest proportion (36.5%) of organic S was found in the C horizon with 26.6% in the LFH horizon. The contribution of the LFH horizon to total organic C and N stored in boreal forest soils should not be neglected in global nutrient cycling models. Key words: Forest floor, litter, nutrient storage, organic matter


1998 ◽  
Vol 28 (3) ◽  
pp. 375-389 ◽  
Author(s):  
Scott J Goetz ◽  
Stephen D Prince

Variability in carbon exchange, net primary production (NPP), and light-use efficiency were explored for 63 boreal forest stands in northeastern Minnesota using an ecophysiological model. The model was initialized with extensive field measurements of Populus tremuloides Michx. and Picea mariana (Mill.) BSP stand properties. The results showed that the proportion of total carbon assimilation expended in autotrophic respiration (i.e., the respiration to assimilation ratio, R/A) was significantly different for the two tree species and this explained much of the variability in the amount of net production per unit absorbed photosynthetically active radiation (APAR), referred to as PAR utilization ( epsilonn). This is the first known study to directly link variability in respiratory costs to epsilonn. Total assimilation per unit APAR ( epsilong) was much less variable than epsilonn and was not significantly different between species. Greater stomatal control on some moisture stressed sites accounted for most of the variability in epsilong. The lack of a simple relationship between light harvesting and net carbon gain indicates that estimation of net primary production with satellite remote sensing requires additional information on respiration costs; however, evidence for convergence in epsilong can be used to simplify the remote sensing of gross primary production over large areas.


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