The effect of prescribed burning on some physical soil properties of jack pine sites in southeastern Manitoba

1976 ◽  
Vol 6 (1) ◽  
pp. 58-68 ◽  
Author(s):  
H. P. Sims

The effect of prescribed burning on physical soil properties of clear-cut areas originally supporting jack pine (Pinusbanksiana Lamb.) was studied in southeastern Manitoba.Average temperatures recorded during three burns ranged from <52 °C at 5-cm depth to 300 °C at the mineral soil – humus interface. The most severe burn increased the weight of organic horizons by 7% because of deposition of fuel residues, while the least severe burn produced a 31% reduction in the weight of the organic mantle.Soils at 3.8 and 7.6 cm under burned seedbeds reached permanent wilting point at days 9 and 23 respectively during a 30-day rain-free period. Moisture contents at similar depths on an adjacent scarified area were significantly higher than on the burn, were much less variable, and remained above permanent wilting point for the duration of the 30-day period. Burning did not significantly affect percolation rate.

1989 ◽  
Vol 19 (2) ◽  
pp. 239-243 ◽  
Author(s):  
Z. Chrosciewicz

Moisture contents of organic forest-floor materials were studied by strata on a clear-cut jack pine (Pinusbanksiana Lamb.) site in relation to slash distribution and changes in both duff moisture code and fine fuel moisture code, the two weather-based components of the Canadian Forest Fire Weather Index System. The best-fitting curvilinear regression (Y = a + b/X) of the duff moisture code showed distinctive patterns of variation, so that both the surface and subsurface forest-floor strata were consistently moister under slash cover than in slash openings, and for each of these two slash conditions, the subsurface forest-floor strata were consistently moister than the surface strata. Combinations of these materials down to mineral soil showed intermediate moisture contents both in slash openings and under slash cover. The straight line regression (Y = a + bX) of the fine fuel moisture code was the best-fitting moisture content relationship for the surface forest-floor materials, but only in slash openings; under slash cover, the curvilinear regression (Y = a + b/X) of the duff moisture code was more suitable. The coefficients of correlation, r, as derived from these varied regressions, were all very highly significant at P < 0.001.


1989 ◽  
Vol 19 (11) ◽  
pp. 1483-1487 ◽  
Author(s):  
Z. Chrosciewicz

Moisture contents of organic forest-floor materials were studied by strata in a semimature jack pine (Pinusbanksiana Lamb.) stand in relation to their within-stand locations and changes in both duff moisture code and fine fuel moisture code, the two weather-based components of the Canadian Forest Fire Weather Index System. The resulting best-fitting curvilinear regressions (Y = aebX) of the duff moisture code showed distinctive patterns of variation so that both the surface and subsurface forest-floor strata were consistently more moist in stand openings than under stand canopy. An initial moisture inversion between the surface and subsurface forest-floor materials manifested itself near the start of the regressions wherever live Schreber's moss (Pleuroziumschreberi (Brit.) Mitt.) and litter were the combined surface materials; otherwise, pure surface litter was consistently drier than the subsurface materials. Combinations of all these materials down to mineral soil showed intermediate moisture contents both in stand openings and under stand canopy. In contrast, the best-fitting regressions of the fine fuel moisture code just for surface forest-floor strata were of the straight line (Y = a + bX) category and had generally lower r2 values than those for the corresponding curvilinear regressions (Y = aebX) of the duff moisture code.


2015 ◽  
Vol 12 (22) ◽  
pp. 6737-6749 ◽  
Author(s):  
J. B. Richardson ◽  
A. J. Friedland

Abstract. Climatic changes in the northeastern US are expected to cause coniferous stands to transition to deciduous stands over the next hundred years. Mercury (Hg) sequestration in forest soils may change as a result. In order to understand potential effects of such a transition, we studied aboveground vegetation and soils at paired coniferous and deciduous stands on eight mountains in Vermont and New Hampshire, USA. Organic horizons at coniferous stands accumulated more total Hg (THg; 42 ± 6 g ha−1) than deciduous stands (30 ± 4 g ha−1). Total Hg pools in the mineral horizons were similar for coniferous (46 ± 8 g ha−1) and deciduous stands (45 ± 7 g ha−1). Soil properties (C, % clay, and pH) explained 56 % of the variation in mineral soil Hg concentration when multiply regressed. Foliar and bole wood Hg concentrations were generally greater for coniferous species than deciduous species. Using allometric equations, we estimated that aboveground accumulation of Hg in foliage and woody biomass was similar between vegetation types but that coniferous stands have significantly smaller annual litterfall fluxes (0.03 g ha−1 yr−1) than deciduous stands (0.24 g ha−1 yr−1). We conclude that organic horizon Hg accumulation is influenced by vegetation type but mineral horizon Hg accumulation is primarily controlled by soil properties. Further investigations into the effect of vegetation type on volatilization, atmospheric deposition, and leaching rates are needed to constrain regional Hg cycling rates.


1999 ◽  
Vol 9 (3) ◽  
pp. 195 ◽  
Author(s):  
Luc C. Duchesne ◽  
Suzanne Wetzel

Mass losses of litter bags containing leaf litter of Pinus banksiana Lamb., Quercus rubra L., Pteridium aquilium (L.) Kuhn, and Populus tremuloides Mchx. were compared in a jack pine ecosystem after clear-cutting, clear-cutting plus prescribed burning, and clear-cutting plus disk trenching scarification. Controls consisted of litterbags left in undisturbed plots. Mass losses were significantly affected by treatment types and litter types. The greatest differences among treatments were observed after 1 year of field incubation whereas there were considerably fewer differences among treatments after 3 years of incubation in the field. Initial decomposition of P. tremuloides and Q. rubra litter was greatest in the control plots. Scarified plots showed the slowest decomposition rates. Mass losses were not significant among treatments and litter types after 3 years incubation except for P. aquilinum litter on clear-cut and scarified plots.


1997 ◽  
Vol 73 (6) ◽  
pp. 711-714
Author(s):  
Luc C. Duchesne ◽  
Renée Tellier

The nutrient (N, P, K, Mg, and Ca) content of the aboveground living non-crop vegetation of a jack pine (Pinus banksiana Lamb.) clear-cut in eastern Ontario was investigated for two years after site preparation, which consisted of prescribed burning under different fire intensities and disk trencher scarification. Total plant nutrient content generally followed biomass accumulation with higher levels of plant N, P, Ca, and K in clear-cuts and scarified sites than in burned-over sites. In the first growing season, concentrations of N, P, and K were higher in the vegetation of burned-over plots than in scarified and clear-cut plots. Mg concentrations were greater in burned-over and scarified plots than in the clear-cut plots. Ca concentrations did not differ among the treatments. Concentration of P and K and the total amount of N, P and K in aboveground non-crop vegetation were correlated well with fire intensity at the end of the first growing season whereas only K concentration and quantities were correlated to fire intensity within two years after treatment. Key words: prescribed burning; disk trenching scarification; fire; Pinus banksiana; nutrients


2015 ◽  
Vol 12 (14) ◽  
pp. 11463-11498 ◽  
Author(s):  
J. B. Richardson ◽  
A. J. Friedland

Abstract. Climatic changes in the northeastern US are expected to cause coniferous stands to transition to deciduous stands over the next hundred years. Mercury (Hg) sequestration in forest soils may change as a result. In order to understand potential effects of this transition, we studied aboveground vegetation and soils at paired coniferous and deciduous stands on eight mountains in Vermont and New Hampshire, US. Organic horizons at coniferous stands accumulated more Total Hg (THg) (42 ± 6 g ha−1) than deciduous stands (30 ± 4 g ha−1). Total Hg pools in the mineral horizons were similar for coniferous (46 ± 8 g ha−1) and deciduous stands (45 ± 7 g ha−1). Soil properties (C, % clay, and pH) explained 56 % of the variation in mineral soil Hg concentration when multiple regressed. Foliar and bole wood Hg concentrations were generally greater for coniferous species than deciduous species. We estimated Hg mean residence time (MRT) in the organic and mineral horizons at coniferous and deciduous stands using a simple two-box model. Organic horizon MRT were longer at coniferous stands (183 ± 44 yr) than deciduous stands (65 ± 15 yr). Mineral soil horizon MRT values were also longer for coniferous stands (386 ± 57 yr) than for deciduous stands (188 ± 27 yr). We concluded that organic horizon Hg accumulation is influenced by vegetation type but mineral horizons are primarily affected by soil properties. Further investigations into the effect of vegetation type on volatilization, atmospheric deposition, and leaching rates are needed to constrain regional Hg cycling rates.


1998 ◽  
Vol 78 (1) ◽  
pp. 115-126 ◽  
Author(s):  
R. L. Fleming ◽  
T. A. Black ◽  
R. S. Adams ◽  
R. J. Stathers

Post-harvest levels of soil disturbance and vegetation regrowth strongly influence microclimate conditions, and this has important implications for seedling establishment. We examined the effects of blading (scalping), soil loosening (ripping) and vegetation control (herbicide), as well as no soil disturbance, on growing season microclimates and 3-yr seedling response on two grass-dominated clearcuts at different elevations in the Southern Interior of British Columbia. Warmer soil temperatures were obtained by removing surface organic horizons. Ripping produced somewhat higher soil temperatures than scalping at the drier, lower-elevation site, but slightly reduced soil temperatures at the wetter, higher-elevation site. Near-surface air temperatures were more extreme (higher daily maximums and lower daily minimums) over the control than over exposed mineral soil. Root zone soil moisture deficits largely reflected transpiration by competing vegetation; vegetation removal was effective in improving soil moisture availability at the lower elevation site, but unnecessary from this perspective at the higher elevation site. The exposed mineral surfaces self-mulched and conserved soil moisture after an initial period of high evaporation. Ripping and scalping resulted in somewhat lower near-surface available soil water storage capacities. Seedling establishment on both clearcuts was better following treatments which removed vegetation and surface organic horizons and thus enhanced microclimatic conditions, despite reducing nutrient supply. Such treatments may, however, compromise subsequent stand development through negative impacts on site nutrition. Temporal changes in the relative importance of different physical (microclimate) and chemical (soil nutrition) properties to soil processes and plant growth need to be considered when evaluating site productivity. Key words: Microclimate, soil temperature, air temperature, soil moisture, clearcut, seedling establishment


1987 ◽  
Vol 17 (4) ◽  
pp. 340-345 ◽  
Author(s):  
Roy C. Sidle ◽  
Charles G. Shaw III

Sitka spruce (Piceasitchensis (Bong.) Carr.) seedlings colonized by the ectomycorrhizal fungi Laccarialaccata (Scop. ex Fr.) Berk and Br., Hebelomacrustuliniforme (Bull, ex St. Amans) Quel., or Cenococcumgeophilum Fr. and a noninoculated control were planted on rotten wood, undisturbed duff, undisturbed duff on the north side of large stumps, and exposed mineral soil in an area recently clear-cut on Chichagof Island, southeast Alaska. Uptake and concentrations of N, P, K, Ca, Mg, and several micronutrients in foliage, stems, and roots were determined 2 years after outplanting. There were no significant interactions between fungal treatments and microsite types for uptake or concentration of any nutrient. Uptake and concentrations of N and P in foliage and roots did not differ significantly among fungal treatments. Foliar K and Cu concentrations were significantly higher in control seedlings than in those with L. laccata ectomycorrhizae. Calcium was the only nutrient analyzed that was present in higher concentrations in seedlings inoculated with H. crustuliniforme than in controls. Concentrations of foliar P, Mn, and Zn were significantly greater in seedlings grown on undisturbed duff (protected north side) than in seedlings grown on exposed mineral soil. However, foliar concentrations of all nutrients tested were not significantly different between seedlings grown on undisturbed duff (unprotected sites) and those grown on mineral soil. Seedlings grown on rotten wood had significantly greater concentrations of foliar Ca than seedlings grown on either exposed mineral soil or undisturbed duff. The on-site colonization of control seedlings after outplanting indicates that resident ectomycorrhizal fungi readily establish and appear to provide equal if not improved nutrient benefits compared to inoculated seedlings. Greater nutritional benefits were derived by planting on certain microsite types (duff and protected duff) than by inoculating with specific ectomycorrhizal fungi.


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