scholarly journals Development of Black Spruce Layers in Quebec and Ontario

1968 ◽  
Vol 44 (2) ◽  
pp. 25-28 ◽  
Author(s):  
W. Stanek

Black spruces of layer or seed origin develop into merchantable trees with similar growth in height, diameter and volume. Layerings tend to have a poorer stem form than seedlings, especially under adverse growing conditions. However, stem form of old layering trees is considerably better. The proportion of layerings and seedlings is influenced by stand history. Black spruce stands undisturbed for a long time consist largely of layerings. After fire, scarification, or exposure of mineral soil, stands regenerate mainly from seedlings. Stocking of black spruce is satisfactory where advance growth has been preserved after cutting, whether it is of layer or of seed origin.

2007 ◽  
Vol 37 (1) ◽  
pp. 62-73 ◽  
Author(s):  
Martin Lavoie ◽  
David Paré ◽  
Yves Bergeron

The surface of the soil in recently harvested or burned lowland black spruce (Picea mariana (Mill.) BSP) sites is composed of a fine mosaic of different bryophytes (mostly Sphagnum spp. and feathermosses), disturbed organic material originating mostly from mosses at different stages of decay, and exposed mineral soil. Growth substrates were compared in lowland black spruce stands regenerating after either careful logging or wildfire. The 3-year annual increment for black spruce seedlings was greatest with substrates of feathermosses, mainly Pleurozium schreberi (Brid.) Mitt., fibric material of P. schreberi origin, and a mixture of fibric P. schreberi and humic materials; it was least with fibric Sphagnum spp., mineral soil, and decaying wood substrates. The most favourable substrates for growth were characterized by better black spruce N and P foliar status. Our results also suggest that categories of growth substrates in the rooting zone reflect nutritional quality better than categories of growth substrates on the soil surface. To maintain or increase black spruce growth following careful logging of sites prone to paludification, we recommend fill-planting of seedlings in substrates originating from P. schreberi; management techniques that favour P. schreberi over Sphagnum mosses should also be developed.


1996 ◽  
Vol 13 (2) ◽  
pp. 68-72 ◽  
Author(s):  
Joanie Burns ◽  
Klaus J. Puettmann ◽  
Don Perala

Abstract Two different thinning methods were applied to three 6- or 7-yr-old black spruce stands in northern Minnesota which were measured after 20 yr. Overall, thinning improved the growing conditions for crop trees. Strip thinning with a 0.6 m leave strip and three widths of cleared strips (1.5 m, 2.1 m, and 2.7 m), and spacing to 1.5 m, 2.1 m, and 2.7 m resulted in reduced numbers of crop trees, but with larger diameters and, in the spacing thinned plots, greater heights. Because of these contradicting trends, stand volume was unaffected by thinning. Crop tree growth was not affected by the width of the cleared strip, but the distances between the leave trees in the square spacing were positively related to the increased growth response after thinning. The study is still too young to evaluate the economic feasibility of both thinning treatments, but shorter rotations or substantially increased volume seem possible by early thinnings of black spruce. North. J. Appl. For. 13(2):68-72.


2006 ◽  
Vol 86 (1) ◽  
pp. 1-9 ◽  
Author(s):  
N. Fenton ◽  
S. Légaré ◽  
Y. Bergeron ◽  
D. Paré

Globally, soil anoxia and water table rise play a role in the development of peatlands from forests. Cited causes have included a diversity of internal and external mechanisms, including Sphagnum and feather mosses, hardpan development, and peatland expansion. The objectives of this study were to examine water table depth in black spruce stands of the Clay Belt of Quebec and Ontario, and to associate changes with potential stand scale causal factors (primarily biological). A methodological issue, the link between oxygen zone and water table, was also addressed. Within stands less than 100 yr post-fire, oxygen zone and water table position were only loosely related, and no other potential factors were significantly correlated. Across a chronosequence of stands, while oxygen zone thickness in the soil profile was relatively constant, its position relative to the mineral soil changed, as it rose from the mineral soil into the forest floor. Forest floor thickness was the dominant explanatory factor in oxygen zone position, suggesting that in these forests other postulated mechanisms are less important. At the landscape level, the movement of the oxygen zone into the forest floor has important consequences for the long-term productivity of this intensively exploited forest region. Key words: Water table, black spruce, paludification, forest floor, Clay Belt, Sphagnum


2001 ◽  
Vol 79 (4) ◽  
pp. 420-428 ◽  
Author(s):  
Jean-François Giroux ◽  
Yves Bergeron ◽  
Jean J Veillette

Giant circular patterns of low tree density in black spruce (Picea mariana) stands were investigated in the Abitibi region of Quebec. We used dendrochronological techniques to test the hypotheses that ring patterns of low tree density are caused either by radial changes in spruce mortality or productivity. Seven circles were sampled. We found no gradient in the age of spruce along circle radii suggesting that rings of low tree density do not expand radially, that is, they are not spatially dynamic entities. The results indicate, however, that spruce trees were less dense and productive within the rings due to excessive moisture in the soil. Measurements of surface elevation, thickness of the organic layer and elevation of the mineral substrate across the circles revealed that a depression in the mineral soil beneath the rings traps the surface water and this area of poor drainage seems to prevent the establishment of black spruce within the rings. The origin of the ring-shaped depressions was attributed to geological or geomorphological causes.Key words: black spruce, Picea mariana, mortality, productivity, rings, geomorphology.


1976 ◽  
Vol 54 (7) ◽  
pp. 619-643 ◽  
Author(s):  
George H. La Roi ◽  
Muriel H. L. Stringer

The bryoflora of 34 white spruce – fir and 26 black spruce stands in the boreal forest subzone consisted of 100 mosses and 33 liverworts. Short turfs, smooth mats, threaded mats, and tall erect turfs were the most species-rich growth-forms; wefts were cover dominants. White spruce – fir stands had more species but lower cover than black spruce. The liverwort:moss species ratio in white spruce – fir increased with precipitation. Based on bryoflora and geography, stands were classified as follows: white spruce – fir, Hylocomium splendens – Pleurozium schreberi order (= three associations of western Ceratodon purpureus – Pylaisiella polyantha alliance and two associations of eastern Rhynchostegium serrulatum – Tetraphis pellucida alliance); black spruce, Pleurozium schreberi – Hylocomium splendens order (= three associations of western Drepanocladus uncinatus – Brachythecium salebrosum alliance and two associations of eastern Sphagnum – Hypnum pallescens alliance). Of the 32 most important species, 16 'preferred' wood, 7 needle litter, 6 mineral soil, and 3 bark. The ground cover hierarchy in white spruce – fir was weft mosses > detritus [Formula: see text] needles > wood > other bryophytes > lichens > bark > soil; in black spruce, wood and other bryophytes were reversed. Higher species richness of white spruce – fir stands was ascribed to higher productivity and greater age, which gives a greater diversity and quantity of woody substrates for microsuccessional species. Shortage of suitable substrate and competition from weft mosses may explain the consistently low abundance of most other bryophytes in the two community types.


2003 ◽  
Vol 33 (10) ◽  
pp. 1874-1879 ◽  
Author(s):  
Nicolas Bélanger ◽  
David Paré ◽  
Stephen H Yamasaki

The effect of different harvesting practices on soil acid–base status was evaluated in black spruce (Picea mariana (Mill.) BSP) forests of Quebec by comparing soil from five pairs of whole-tree and stem-only harvested plots 3 years after harvest. Stem-only harvesting contributed to the enrichment of the exchangeable base cation pool, particularly in the forest floors of the pairs where whole-tree harvested plots showed the highest exchangeable Al3+. In the mineral soil, divergence between treatments was low, perhaps because these acidic soils were strongly saturated with Al3+ (about 90%), which did not favour cationic exchange reactions. Although the effects of treatment may not persist over time, improved base cation nutrition may benefit stands during the early stages of development. Over a forest rotation of about 85 years, the estimated loss of alkalinity due to whole-tree harvesting was estimated to be low (less than 20%) when compared with the effect of acidic deposition.


Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 841
Author(s):  
Iveta Desaine ◽  
Annija Kārkliņa ◽  
Roberts Matisons ◽  
Anna Pastare ◽  
Andis Adamovičs ◽  
...  

The increased removal of forest-derived biomass with whole-tree harvesting (WTH) has raised concerns about the long-term productivity and sustainability of forest ecosystems. If true, this effect needs to be factored in the assessment of long-term feasibility to implement such a drastic forest management measure. Therefore, the economic performance of five experimental plantations in three different forest types, where in 1971 simulated WTH event occurred, was compared with pure, planted and conventionally managed (CH) Norway spruce stands of similar age and growing conditions. Potential incomes of CH and WTH stands were based on timber prices for period 2014–2020. However, regarding the economics of root and stump biomass utilization, they were not included in the estimates. In any given price level, the difference of internal rate of return between the forest types and selected managements were from 2.5% to 6.2%. Therefore, Norway spruce stands demonstrate good potential of independence regardless of stump removal at the previous rotation.


1994 ◽  
Vol 70 (2) ◽  
pp. 151-158 ◽  
Author(s):  
R. L. Fleming ◽  
D. S. Mossa

A series of spot seeding experiments was set out on coarse-textured upland sites in northwestern Ontario to investigate how black spruce (Picea mariana [Mill.] B.S.P.) seedling establishment and growth could be improved by site selection and seedbed preparation. Virtually all germination occurred within the first growing season. Annual seedling mortality rates were greatest during the first year, then declined steadily and stabilized at low levels (<10%) after the third year. The highest fifth-year establishment ratios (seedlings/viable seed sown) were found on seedbeds derived from materials near the mineral soil/humus interface. On wetter sites (i.e., higher Soil Moisture Regimes) the best seedbeds occurred closer to the soil surface. Mean fifth year establishment ratios for the best seedbeds were 0.032 on moderately fresh to fresh sites, 0.146 on very fresh to moderately moist sites, and 0.082 on moist to very moist sites. On adjacent lowland sites, slow-growing, compact Sphagnum mosses had a mean establishment ratio of 0.179. Mean fifth-year seedling heights on upland sites ranged from 12 to 14 cm, and were not strongly correlated with site or seedbed type. Key words: direct seeding, black spruce, seedbed, seedling establishment, site type and germination


1981 ◽  
Vol 11 (2) ◽  
pp. 259-274 ◽  
Author(s):  
Keith Van Cleve ◽  
Richard Barney ◽  
Robert Schlentner

Selected indices of structure and function were used to evaluate the effect of differing soil thermal regimes on soil-permafrost-dominated (muskeg) and permafrost-free (north-slope) black spruce ecosystems in interior Alaska. The poorly drained, permafrost site displayed cooler soil temperatures and higher soil moisture content than were encountered on the well-drained north slope. Mineral soil nutrient pools generally were largest on the permafrost site. However, low soil temperature acted as a negative feedback control, suppressing soil biological activity, nutrient mineralization, and tree primary production to lower levels on the soil-permafrost-dominated site as compared with the permafrost-free site. Forty percent larger accumulation of tree biomass and 80% greater annual tree productivity occurred on the warmer site.


Author(s):  
Matiashuk R. ◽  
Tkachenko I.

The sensitivity of the reproductive structures of Forsythiasuspensato the complex influence of undifferentiated environmental factors has been studied.The monitoring sites are located in 15 different park ecosystems in 6 administrative districts of Kyiv. Data from the Borys Sreznevsky Central Geophysical Observatory (air pollution index (API) and meteorological conditions for 2018-2020) were used to assess the conditions of the growthenvironment. The influence of a complex of ecologically important factors during the flowering offorsythia on the quality of the formedpollen is noted. Thus, growing plantsfor a long time in conditions with a low level of air pollution (APIup to 5.0) in abnormal weather conditions in 2020,40-50% less fertile grainswere formed. And forplants, which grow in areas with increasedlevel (API5.0-7.0) and high level (API7.0-14.0) of air pollution, the share of fertile grains in the pollen population decreased by 60-80%. In the closed bud,the pollen has higher resistance to a complex of exogenous growth factors. Forsythia plants, which are located in large parklands, lose less pollen quality in adverse weather conditions and affected byurbotechnogenic factors. F. suspensa is an acceptable indicator of the level of environmental pollution by the deviation of pollen fertility from the control value. In areas with high aerogenic load, for example, areas with large highways (Bus Station «Darnytsia»), as well as with a significant recreational load (HolosiivskyiPark, Recreation Park on the Olena Teliha Street) much smaller pollen is formed. Itis noted that the conditions of forsythia growth affect the quantitative indicators of the formed pollen not only in the flower but also in the closed bud, which confirms the chronic effect of the complex of ingredients of aerotechnogenic emissions on plants of this species. The coefficient of sterility of pollen (CS) was used to objectively compare the data of 2019 and 2020 on the condition of the generative organs of F. suspensa in the studied areas. The calculation of the CS confirmed that in the closedbud pollen has a higher resistance to exogenous factors. In areas with high and increased levels of air pollution,during budding and flowering of plants (March-May,) there is a much higher CS of pollen of F. suspensа. Significant parkland territoriesof the city (for example, HolosiivskyiPark, Botanical Garden named after O. V. Fomin) provide less stressful conditions for growth and development of plants, even with the "very high" level of air pollution (ISA above 14.0) observed in April 2020 on this territory.The study of the susceptibility of F. suspensаpollen to growing conditions will be continued, as the prospects of using this species for bioindication of ecological status and zoning of park ecosystems of Kyiv according to the gradient of anthropogenic impact have been revealed.Key words:forsythia, fertility, coefficient of sterility of pollen, bioindication. Проведене дослідження чутливості репродуктивних структур Forsythiasuspensaдо комплексного впливу недиференційованих факторів навколишнього середовища. Моніторингові ділянки розташовані в 15 різних паркових екосистемах 6 адміністративних районівКиєва. Для оцінки умов середовища вирощування рослин використані дані Центральної геофізичної обсерваторії імені Бориса Срезневського (індекс забруднення атмосферного повітря (ІЗА) та метеорологічні умови за 2018-2020 рр.). Відмічено вплив комплексу екологічно важливих факторів (за показниками відхилення від норми середньої місячної температури повітря та місячної кількості опадів у Києві) уперіод квітування форзиції на якість сформованого пилку. Так, за тривалої експозиції рослин в умовах з низьким рівнем забруднення повітря (ІЗА до 5,0) в аномальних погодних умовах 2020 р. сформувалось на 40-50% менше фертильних зерен. А у форзиції, яка росте на територіях з підвищеним (ІЗА 5,0-7,0) та високим (ІЗА 7,0-14,0) рівнями забруднення частка фертильних зерен в популяції пилку зменшилась на 60-80%. У закритому бутоні пилок має вищу стійкість до комплексу екзогенних факторів середовища зростання. Рослини форзиції, які розташовані у значних за площею паркових насадженнях, менше втрачають якість пилку за несприятливих погодних умов та дії урботехногенних чинників. За відхиленням показника фертильності пилку від контрольного значення F. suspensaє допустимим індикатором рівня забруднення середовища. На територіях з підвищеним аерогенним навантаженням, наприклад, ділянки з автотранспортними магістралями (Автостанція «Дарниця»), а також зі значним рекреаційним навантаженням (Голосіївський парк імені М. Рильського, Парк відпочинку по вул. Олени Теліги)формується значно дрібніший пилок. Відмічено, що умови росту позначаються на кількісних показниках сформованого пилку не лише в квітці, але й в закритому бутоні, що підтверджує хронічний вплив комплексу інгредієнтів аеротехногенних викидів нарослини цього виду. Для об’єктивного співставлення даних 2019 і 2020 рр. щодо стану генеративних органів F. suspensaна досліджених ділянках був використаний коефіцієнт стерильності (КС) пилку. Розрахунок КС підтвердив, що в закритому бутоні пилок має вищу стійкість до впливу екзогенних чинників. Вищий КС був у F. suspense, з ділянок, на яких в період бутонізації і квітування рослин (березень-травень) відмічений високий і підвищений рівень забруднення атмосфери. Значні за площею паркові насадження міста (наприклад, Голосіївський парк, Ботанічний сад ім.акад. О.В. Фоміна) забезпечують менш напружені умови росту і розвитку рослин навіть при відміченому в квітні 2020 р. «дуже високому» рівні забруднення повітря (ІЗА вище 14,0) на цих територіях. Дослідження чутливості пилку F. suspenseдо умов вирощування буде продовжене,оскільки виявлена перспективність використання цього виду для біоіндикації екологічного стану та зонування паркових екосистем Києва за градієнтом антропогенного впливу.Ключові слова: форзиція, фертильність, індекс стерильності, біоіндикація.


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