scholarly journals National Geochemical Reconnaissance Lake Sediment and Water Data, Thunder Bay Region, northwestern Ontario [NTS 52b]

1990 ◽  
Author(s):  
P W B Friske ◽  
E H W Hornbrook ◽  
J J Lynch ◽  
M W McCurdy ◽  
H Gross ◽  
...  
1990 ◽  
Author(s):  
P W B Friske ◽  
E H W Hornbrook ◽  
J J Lynch ◽  
M W McCurdy ◽  
H Gross ◽  
...  

1995 ◽  
Vol 71 (2) ◽  
pp. 219-227 ◽  
Author(s):  
R. L. Fleming ◽  
D. S. Mossa

Temporal changes in black spruce (Picea mariana [Mill.] B.S.P.) seedbed coverage and seedbed receptivity were investigated on coarse-textured upland sites near Thunder Bay (48°25′N 89° 15′W), in northwestern Ontario. Sowing was completed in May for three consecutive years following summer scarification at each of 12 sites. Infilling by organic debris reduced the proportion of receptive soil strata three to five years after scarification by 50–95%. Receptive seedbed coverage declined more quickly on fresh Soil Moisture Regimes with a variety of deciduous trees and shrubs than on moist Soil Moisture Regimes dominated by eracaceous shrubs. Pioneer mosses, which are also good seedbeds, invaded moist sites more readily than fresh sites, and mitigated losses in seedbed coverage. Compact Sphagnum seedbeds in lowland depressions maintained good areal coverage much longer than did receptive upland soil strata. Seedling establishment ratios varied greatly among seeding years, seedbeds and sites, but there was an underlying trend of decreasing seedbed receptivity with time since scarification. Seedlings originating from the first seeding year were taller at age 7–10 than those originating from the second or third seeding years. Key words: direct seeding, seedbed coverage, seedbed receptivity, scarification, black spruce, Picea mariana


1983 ◽  
Vol 61 (6) ◽  
pp. 1573-1579 ◽  
Author(s):  
William H. Parker ◽  
P. Knowles ◽  
F. Bennett ◽  
A. Gray ◽  
T. Krickl

To determine whether local site differences corresponded to any morphological or chemical differentiation in Picea mariana, 10 cone-bearing trees were sampled from each of three semiadjacent stands near the Matawin River, Thunder Bay District, Ont.: (i) an upland forest on well-drained alluvial soil, (ii) an abandoned pasture on heavy soil, and (iii) a wet sphagnum bog. Nine cone characters and eight needle and twig characters were scored and analyzed. Differences among sites were generally small. Principal-components analysis demonstrated two major, independent trends of variation, one attributable mainly to cone characters and the other to needle characters. Bog trees tended to be more variable than the others with respect to cone characters but had similar levels of variation for needle and twig characters. Further comparisons were made based on foliar flavonoids of the 30 trees and isozyme characteristics of an expanded sampling of 60 trees. Flavonoid analysis indicated that a fraction of the bog trees possessed flavonoid diglycosides not present in the other trees. Five polymorphic enzyme systems were detected in electrophoretic analysis. Trees from the three sites had similar isozyme patterns with the exception of three bands that were unique to the bog site trees. Thus, the bog trees were more variable for cone, flavonoid, and isozyme characters but exhibited no greater variability for needle and twig characters. However, none of the data gave an indication of discrete ecotypes of black spruce corresponding to upland and lowland sites.


1991 ◽  
Author(s):  
P W B Friske ◽  
E H W Hornbrook ◽  
J J Lynch ◽  
M W McCurdy ◽  
H Gross ◽  
...  

1991 ◽  
Author(s):  
P W B Friske ◽  
E H W Hornbrook ◽  
J J Lynch ◽  
M W McCurdy ◽  
H Gross ◽  
...  

1998 ◽  
Vol 28 (10) ◽  
pp. 1579-1585 ◽  
Author(s):  
F M Moola ◽  
A U Mallik

This study reports on the phenology of 180 vegetative and 180 reproductive shoots of lowbush blueberry (Vaccinium angustifolium Ait.) and velvet leaf blueberry (Vaccinium myrtilloides Michx.) in a young black spruce (Picea mariana (Mill.) BSP) plantation near Thunder Bay, northwestern Ontario. Leaves of both species emerged in mid-May and remained uniformly green until mid-August. By late August, the majority of tagged shoots had turned red and were beginning to deteriorate. Approximately 30% of tagged shoots lost their leaves by 25 September in both V. angustifolium and V. myrtilloides. Patterns of leaf development in V. angustifolium and V. myrtilloides suggest that Vaccinium spp. may be less susceptible to foliar-applied herbicides if applications are made during or following the period of leaf senescence (i.e., between late August and late September). However, delayed treatment may be impractical in conifer plantations, since the time of leaf senescence and abscission of blueberry coincides with that of many target species.


1991 ◽  
Author(s):  
P W B Friske ◽  
E H W Hornbrook ◽  
J J Lynch ◽  
M W McCurdy ◽  
H Gross ◽  
...  

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