scholarly journals Importance de la predation des cones de l epinette noire (Picea mariana) par l ecureuil roux (Tamiasciurus hudsonicus)

1994 ◽  
Author(s):  
Josée Potvin
Keyword(s):  
Picea Mariana ◽  
Tamiasciurus Hudsonicus ◽  
Epinette Noire

SEASONAL DAMAGE BY INSECTS AND SQUIRRELS TO FEMALE REPRODUCTIVE STRUCTURES OF BLACK SPRUCE, PICEA MARIANA (MILL.) B.S.P.

1988 ◽  
Vol 120 (12) ◽  
pp. 1113-1121 ◽  
Author(s):  
Y.H. Prévost ◽  
J.E. Laing ◽  
V.F. Haavisto
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Choristoneura Fumiferana ◽  
Tamiasciurus Hudsonicus ◽  
Red Squirrel ◽  
Red Squirrels ◽  
Reproductive Structures ◽  
Cone Axis ◽  
Viable Seeds ◽  
Cone Growth

AbstractThe seasonal damage to female reproductive structures (buds, flowers, and cones) of black spruce, Picea mariana (Mill.) B.S.P., was assessed during 1983 and 1984. Nineteen insects (five Orders) and the red squirrel, Tamiasciurus hudsonicus (Erxleben), were found feeding on these reproductive structures. Collectively, these organisms damaged 88.9 and 53.5% of the cones in 1983 and 1984, respectively. In the 2 years, Lepidoptera damaged 61.8% of the cones in 1983 and 44.4% of the cones in 1984. The spruce budworm, Choristoneura fumiferana (Clem.), and the spruce coneworm, Dioryctria reniculelloides Mut. and Mun., were the most important pests. Cones damaged by Lepidoptera could be classed into three categories: (a) severe, yielding no seeds; (b) moderate, yielding 22.3 seeds per cone; and (c) light, yielding 37.5 seeds per cone. Undamaged cones yielded on average 39.9 seeds per cone. Red squirrels removed 18.8% of the cones in 1983 and none in 1984. The spruce cone axis midge, Dasineura rachiphaga Tripp, and the spruce cone maggot, Lasiomma anthracinum (Czerny), caused minor damage in both years. Feeding by spruce cone axis midge did not reduce cone growth significantly or the number of viable seeds per cone, but feeding by the spruce cone maggot did. During both years new damage by insects to the female reproductive structures of the experimental trees was not observed after mid-July. In 1983 damage by red squirrels occurred from early to late September. In 1984 damage to cones on trees treated with dimethoate was 15.6% compared with 53.5% for untreated trees, without an increase in the number of aborted cones.

Effets du drainage sur la croissance et le statut nutritif d’un peuplement d’épinette noire de structure inéquienne : résultats de 10 ans

2005 ◽  
Vol 81 (4) ◽  
pp. 516-524 ◽  
Author(s):  
Marcel Prévost ◽  
Daniel Dumais ◽  
André P Plamondon
Keyword(s):  
Picea Mariana ◽  
Stand Structure ◽  
Black Spruce ◽  
Tree Height ◽  
Nutrient Content ◽  
Medium Size ◽  
Diameter Growth ◽  
Growth Increase ◽  
Epinette Noire ◽  
Forest Drainage

We present the 10-year results of a forest drainage experiment conducted in a pre-mature uneven-aged black spruce (Picea mariana [Mill.] BSP) stand, in Bas-Saint-Laurent, Québec, Canada. The set up included 20, 30, 40, 50 and 60 m ditch spacings, and the data were pooled in three diameter classes, ≤ 4 cm (small stems), 6–10 cm (medium-size stems) and ≥ 12 cm (large stems), in order to take into account stand structure in the analysis. The diameter growth of large stems (dominant cover, height ~ 8–12 m) was not improved by drainage. Medium-size stems (intermediate story, ~ 4–8 m) showed a better growth at a 5–10 m distance from the ditches, while small stems (understory ~ 1–4 m) reacted well to drainage, proportionally to ditch closeness. Generally, growth and gain attributable to drainage increased with the live crown ratio, from one third of the total tree height. We did not detect any effect of drainage or distance from the nearest ditch on the nutrient content of the current year foliage of the large stems. For small stems, even the individuals located at 25–30 m from the ditches showed a growth increase compared to the control, although the understory did not benefit from full light conditions. Results suggest that drainage aiming at correcting watering-up following harvesting could permit a rapid growth increase of advance growth. Key words: diameter growth, foliar analysis, forest drainage, black spruce, Picea mariana, forested peatland

Sign in / Sign up

Export Citation Format

Share Document