Boreal Forest Of Quebec Research Articles

Comparative ecology of Quebec boreal forests: a numerical approach to modelling

Climatic and species–environmental models for seven regions of Quebec boreal and boreal-transition forest were developed using principal components factor analysis. Climatic models based on growth-relevant meteorological parameters indicated that despite large geographical distances, all regions were very similar. The first principal component in the climatic model accounted for 73% of the total variation in the original climatic variables. Two regions were relatively dissimilar, coinciding with differences in predominant air mass during the growth season.Analytical models of tree species and tree species with environmental variables were based on 1668 forest plots. Compositional and environmental models were similar as were major ecological species–environment relationships among the seven regions. Air and moisture drainage related to catena, natural stand disturbances related to specific edaphic parameters, and microclimate related to slope aspect accounted for 29.7%, 21.5%, and 17.4% of the variance on first, second, and third principal components, respectively. Validity of the models and problems for further investigation are discussed.

LIFE HISTORY AND BEHAVIOR OF PODISUS MODESTUS (HEMIPTERA: PENTATOMIDAE) IN BOREAL FOREST IN QUEBEC

AbstractPodisus modestus (Dallas) has one generation per year in the boreal forest of Quebec. Adults hibernate in the litter and soil from mid-autumn to late spring. Overwintered adults were found in the field until the latter part of August. Adults mated shortly after emergence from hibernation. Females mated an average of three times during the summer; the maintenance of a supply of highly fertile eggs apparently required this periodic mating. Young adults, which emerge from August to October, neither mated nor laid eggs before hibernation.The preoviposition period after first mating was 10 to 19 days. Females laid an average of 7.9 egg masses (average of 16.7 eggs per mass) at intervals of 1 to 25 days on jack pine, and on Kalmia and Vaccinium spp.Eighty per cent of the eggs hatched successfully after a mean incubation period of 15.3 days; 12% did not develop while 8% developed and were destroyed, during hatching, by other first-instar nymphs in the brood. Maturing nymphs spent an average of 7.7, 7.7, 7.8, 11.9, and 23.8 days in each of the five respective stadia, and required 59 days from hatching to adult emergence. A logistic curve describes the relationship between developmental time and temperature. First-instar nymphs required no animal food, but during each of the last four instars animal food was required for maturation. The hunting and feeding behavior, food consumption, abundance and mortality of P. modestus are also described.

Free Amino-acid Content in Needles of Abies balsamea and Picea mariana growing on Different Sites

THE abundance of tyrosine among the free amino-acids of ligneous plants of the lesser forest vegetation has been emphasized1. Because this amino-acid may be significant in lignin synthesis and in resistance to frost2, the present investigation was undertaken to test the relative abundance of tyrosine in the free amino-acids of the needles of balsam fir (Abies balsamea (L.)) and black spruce (Picea mariana (Mill.)), which grow in widely separated areas of the Quebec boreal forest region3.

The fungal flora of a Boreal forest raw humus.

The fungi present in the raw humus under black spruce in the boreal forest of Quebec were studied by the soil-washing technique. Penicillium, Pullularia, and yeasts together comprised 75–94% of isolates from the washings and 42–77% of those from the washed particles. There was evidence that Penicillium spp. existed to a significant extent in the mycelial state. Aspergillus and Tricho-derma spp. were absent or rare. The possible ecological significance of the high incidence of Pullularia and yeasts is discussed.