Vegetation–soil relationships along a spruce forest transect in interior Alaska

1979 ◽  
Vol 57 (23) ◽  
pp. 2644-2656 ◽  
Author(s):  
C. T. Dyrness ◽  
D. F. Grigal

Five distinct forest communities were recognized along a 3-km transect. These are, listed in order of decreasing elevation: (i) open black spruce/feathermoss - Cladonia, (ii) closed black spruce/feathermoss, (iii) open black spruce/Sphagnum, (iv) black spruce woodland/Eriophorum, and (v) white spruce/alder/Calamagrostis (restricted to a narrow band adjacent to a stream). Several techniques of ordination were used to recognize these five forest communities plus two intergrades: (open black spruce/feathermoss - Cladonia) - (Sphagnum) and open black spruce/Sphagnum - woodland/Eriophorum.The distribution of two-thirds of the plant species was highly correlated with vegetation–slope zones. Results of the fit of Gaussian curves also suggest that vegetation boundaries were well placed. The distribution of the four soil series in the area was well correlated with vegetation–slope zones: three were limited to one zone each. Permafrost, absent from the soil on the ridgetop and upper slope, was generally within 40 to 50 cm of the surface elsewhere and tended to be at shallower depths as elevation decreased. The most striking differences in forest floor properties were found in the white spruce zone compared with the six black spruce dominated zones. The white spruce forest floor was markedly thinner and had higher levels of nutrients. In the six black spruce dominated zones, forest floor thickness and concentrations of N and Mg tended to increase with distance downslope, and P and K decreased.

Ecosystems ◽  
2003 ◽  
Vol 6 (3) ◽  
pp. 248-260 ◽  
Author(s):  
Kari E. B. O'Connell ◽  
Stith T. Gower ◽  
John M. Norman

Ecosystems ◽  
2003 ◽  
Vol 6 (3) ◽  
pp. 236-247 ◽  
Author(s):  
Kari E. B. O'Connell ◽  
Stith T. Gower ◽  
John M. Norman

1989 ◽  
Vol 19 (11) ◽  
pp. 1389-1396 ◽  
Author(s):  
C. T. Dyrness ◽  
K. Van Cleve ◽  
J. D. Levison

Soil chemical properties were studied after a wildfire in stands of white spruce (Piceaglauca (Moench) Voss), black spruce (Piceamariana (Mill.) B.S.P.), paper birch (Betulapapyrifera Marsh.), and quaking aspen (Populustremuloides Michx.). Samples of the forest floor and surface 5 cm of mineral soil were collected from burned sites and unburned controls and analyzed soon after the fire. With the exception of soil pH, effects of the fire on soil chemistry differed among the four forest types. Generally, amounts of exchangeable K, Ca, and Mg did not appreciably increase in the forest floor and surface mineral soil except in heavily burned areas in white spruce and black spruce. Fire reduced amounts of N by about 50% in white spruce, aspen, and birch forest floors. In black spruce, quantities of N were slightly higher in heavily burned locations. Forest floor C:N ratios were substantially lower in heavily burned locations in white spruce and black spruce than in unburned controls. Burning did not have a marked influence on supplies of available P in the forest floor, except in heavily burned black spruce, where average amounts were 12.50 g/m2 versus only 0.46 g/m2 in the control. Burning caused more moderate gains in available P in surface mineral soils under aspen and white spruce. We concluded that fire caused marked short-term changes in soil chemistry in the four forest types. How long these changes will persist is unknown.


2009 ◽  
Vol 6 (3) ◽  
pp. 5507-5548 ◽  
Author(s):  
O. Bergeron ◽  
H. A. Margolis ◽  
C. Coursolle

Abstract. This study reports continuous automated measurements of forest floor carbon (C) exchange over feathermoss, lichen, and sphagnum micro-sites in a black spruce forest in eastern North America during snow-free periods over three years. The response of soil respiration (Rs-auto) and forest floor photosynthesis (Pff) to environmental factors was determined. The seasonal contributions of scaled up Rs-auto adjusted for spatial representativeness (Rs-adj) and Pff (Pff-eco) relative to that of total ecosystem respiration (Re) and photosynthesis (Peco), respectively, were also quantified. Shallow soil temperature explained 67–86% of the variation in Rs-auto for all ground cover types, while deeper soil temperatures were related to Rs-auto only for the feathermoss micro-sites. Base respiration was consistently lower under feathermoss, intermediate under sphagnum, and higher under lichen during all three years. The Rs-adj/Re ratio increased from spring through autumn and ranged from 0.85 to 0.87 annually for the snow-free period. The Rs-adj/Re ratio was negatively correlated with the difference between air and shallow soil temperature and this correlation was more pronounced in autumn than summer and spring. Maximum photosynthetic capacity of the forest floor (Pffmax) saturated at low irradiance levels (~200 μmol m−2 s−1) and decreased with increasing air temperature and vapor pressure deficit for all three ground cover types, suggesting that Pff was more limited by desiccation than by light availability. Pffmax was lowest for sphagnum, intermediate for feathermoss, and highest for lichen for two of the three years. Pff normalized for light peaked at air temperatures of 5–8°C, suggesting that this is the optimal temperature range for Pff. The Pff-eco/Peco ratio varied seasonally from 13 to 24% and reached a minimum in mid-summer when both air temperature and Peco were at their maximum. On an annual basis, Pff-eco accounted for 17–18% of Peco depending on the year and the snow-free season totals of Pff-adj were 23–24% that of Rs-adj.


2009 ◽  
Vol 6 (9) ◽  
pp. 1849-1864 ◽  
Author(s):  
O. Bergeron ◽  
H. A. Margolis ◽  
C. Coursolle

Abstract. This study reports continuous automated measurements of forest floor carbon (C) exchange over feathermoss, lichen, and sphagnum micro-sites in a black spruce forest in eastern North America during snow-free periods over three years. The response of soil respiration (Rs-auto) and forest floor photosynthesis (Pff) to environmental factors was determined. The seasonal contributions of scaled up Rs-auto adjusted for spatial representativeness (Rs-adj) and Pff (Pff-eco) relative to that of total ecosystem respiration (Re) and photosynthesis (Peco), respectively, were also quantified. Shallow (5 cm) soil temperature explained 67–86% of the variation in Rs-auto for all ground cover types, while deeper (50 and 100 cm) soil temperatures were related to Rs-auto only for the feathermoss micro-sites. Base respiration was consistently lower under feathermoss, intermediate under sphagnum, and higher under lichen during all three years. The Rs-adj/Re ratio increased from spring through autumn and ranged from 0.85 to 0.87 annually for the snow-free period. The Rs-adj/Re ratio was negatively correlated with the difference between air and shallow soil temperature and this correlation was more pronounced in autumn than summer and spring. Maximum photosynthetic capacity of the forest floor (Pff-max) saturated at low irradiance levels (~200 μmol m−2 s−1) and decreased with increasing air temperature and vapor pressure deficit for all three ground cover types, suggesting that Pff was more limited by desiccation than by light availability. Pff-max was lowest for sphagnum, intermediate for feathermoss, and highest for lichen for two of the three years. Pff normalized for light peaked at air temperatures of 5–8°C, suggesting that this is the optimal temperature range for Pff. The Pff-eco/Peco ratio varied from 13 to 24% over the snow-free period and reached a minimum in mid-summer when both air temperature and Peco were at their maximum. On an annual basis, Pff-eco accounted for 17–18% of Peco depending on the year and the snow-free season totals of Pff-eco were 23–24% that of Rs-adj.


1993 ◽  
Vol 23 (11) ◽  
pp. 2389-2394 ◽  
Author(s):  
R.D. Blew ◽  
D.R. Iredale ◽  
D. Parkinson

Rates of transfer of nitrogen in throughfall were measured in a Piceaglauca (Moench) Voss forest in southwest Alberta, Canada. Total annual flux of N in throughfall was estimated to be 6.8 kg•ha−1•year−1. The highest rates of N deposition in throughfall occurred during the spring. The pattern of seasonal variation of N in throughfall suggested that different processes of N accumulation in and loss from the canopy may have been operating at different times of the year. Annual leaching of N from the canopy was estimated to be 4.09 kg•ha−1•year−1 and represented 24% of the total amount of N returned to the forest floor (leachates plus litter fall).


2014 ◽  
Vol 184 ◽  
pp. 25-35 ◽  
Author(s):  
D. Gaumont-Guay ◽  
T.A. Black ◽  
A.G. Barr ◽  
T.J. Griffis ◽  
R.S. Jassal ◽  
...  

2010 ◽  
Vol 40 (4) ◽  
pp. 822-826 ◽  
Author(s):  
Kevin J. Kemball ◽  
A. Richard Westwood ◽  
G. Geoff Wang

Mineral soils exposed by fire are often covered by a layer of ash due to complete consumption of the forest floor (litter and duff). To assess the possible effects of ash on seed germination and viability of jack pine ( Pinus banksiana Lamb.), black spruce ( Picea mariana (Mill.) Britton, Sterns, Poggenb.), white spruce ( Picea glauca (Moench) Voss), and balsam fir ( Abies balsamea (L.) Mill.), a laboratory experiment was conducted using ash derived from three types of forest floor samples. The samples represented areas of high conifer concentration, high aspen concentration, and mixed aspen and conifer and were collected from five mature aspen ( Populus tremuloides Michx.) – conifer mixedwood stands in southeastern Manitoba. Ash derived from each forest floor type neither prohibited nor delayed conifer germination, except that of balsam fir. Balsam fir had significantly less germination on ash derived from forest floor samples with high aspen concentration. When corrected for seed viability, balsam fir had significantly less germination on all three ash types compared with jack pine, black spruce, and white spruce. However, the impact of ash on balsam fir is unlikely to have meaningful ecological implications, as balsam fir is a climax species and will establish in undisturbed mature forests.


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