Black Spruce Seedlings Research Articles

Reproduction de l'épinette noire (Piceamariana) après coupe à blanc de superficie réduite

Small clear-cuttings (elliptical, circular, and strip) were made in the commercial boreal forest in Quebec to improve black spruce (Piceamariana (Mill.) B.S.P.) reproduction.Five years after cutting, black spruce layers were as numerous as black spruce seedlings and total softwood reproduction averaged 26 710 stems per hectare (10 810 stems per acre) with 90% stocking. In some cases, white birch stems tripled between the 1st and 5th year after cutting, which may have an important effect on stand composition.Strip cuts gave more stems per hectare than circular or elliptical cuts but stocking was lower. Strips 40 m wide (130 ft) gave better results than those 80 m wide (260 ft).Stocking, although adequate in all these small clear-cuttings, appears to be a more critical factor in the success of softwood reproduction than is density.

Height growth of black spruce and jack pine seedlings in flooded flats

Black spruce (Picea mariana [Mill.] B.S.P.) and jack pine (Pinus banksiana Lamb.) seedlings were grown in a green-house on peat-filled flats flooded with nutrient solution or distilled water. None was aerated. However, an O2 concentration gradient existed across the flats, 3.0 – 3.7 ppm along the edges, and 1.4 – 1.9 ppm in the centers. After 4½ months seedlings of both species grew taller with nutrient solution than with distilled water. In flats supplied with nutrient solution, seedlings of both species grew taller along the edges than in the centers, whereas in flats supplied with distilled water height differential did not develop. Jack pine grew taller than black spruce under similar conditions.

The Role of Free Growth in the Differentiation of Provenances of Black Spruce Piceamariana (Mill.) B.S.P.

Two distinct phases of needle initiation contributed to the annual complement of needles of 4-year-old black spruce seedlings. The first phase occurred during development of the overwintering bud, and was expressed in predetermined growth. The second phase occurred in the same season as the overwintering bud was flushed, and was expressed in free growth. Ten black spruce provenances were flushed under conditions favorable or unfavorable for free growth. Variation in needle complements for overwintering buds was small and did not correlate with variation in height growth of provenances. Good correlation occurred between growth and needle complements when these included foliage initiated during any subsequent free growth. Fast growth of southern provenances grown at Chalk River, Ont. (46°00′N, 77°26′W), was interpreted as a result of less stringent requirements for free growth. Free growth potential was reduced or disappeared when the local photoperiod was shorter than that at the origin of the provenance. Free growth is characteristic of seedlings only, but advantages thus obtained by southern provenances in the first few years of growth probably establish lasting gains in height.

Methods for Successful Afforestation of a Weed Infested Clay Soil

The effects of plowing and tilling, fertilization, and chemical weed control on survival and height growth of newly planted seedlings of black locust, silver maple, white ash, white pine, and white spruce were investigated in a non-replicated study in southern Ontario. Cost-benefit relationships of treatments were computed. Plowing and tilling improved growth of all species with average increases ranging from 37 per cent for white spruce to 750 per cent for white ash. Plowing and tilling plus weed control greatly improved growth of all hardwood species and resulted in the most favourable growth-cost relationship. Fertilization improved growth of locust, ash, and maple by 200, 500, and 700 per cent respectively, but failed to increase conifer growth. Application of 12 pounds of simazine increased ash mortality by 67 per cent. White spruce was subject to severe frost heaving following complete weed control.

Influence of Manganese on Growth of Jack Pine and Black Spruce Seedlings

Analyses of foliage from natural stands of jack pine and black spruce confirmed earlier observations that levels of Mn were much higher in foliage of black spruce than in that of jack pine. Levels of Fe in jack pine foliage were greater than in black spruce.In a growth chamber experiment with spruce and pine seedlings and Mn supplied at 0, 0.1, 1, 10 and 100 ppm, both species grew best at the 0.1 ppm level and there was no evidence of difference in tolerance to high Mn levels. In this experiment, no marked species difference in foliar Mn concentrations was observed like that existing in natural stands. Possible reasons for this lack of difference are discussed.

Nitrogen deficiency in the york river burn, gasp�, Quebec

Visual symptoms of malnutrition associated with the unsatisfactory development of natural and planted black spruce seedlings in a 20-year-old burn suggested low supply and uptake of nitrogen, phosphorus, and possibly other nutrients as the primarily adverse factors.

A TEN-YEAR TEST FOR TRANSPLANTED WILD BLACK AND RED SPRUCE

Wild black and red spruce seedlings were lifted at the Acadia Forest Experiment Station and planted at Green River, New Brunswick in 1950. By 1960 survival averaged 38 per cent for the two species and they had reached an average height of six feet.