scholarly journals Palynologie des sédiments de la fin de l’optimum climatique de l’interglaciaire sangamonien, île aux Coudres, estuaire du Saint-Laurent, Québec

2007 ◽  
Vol 49 (2) ◽  
pp. 291-304 ◽  
Author(s):  
Martine Clet ◽  
Serge Occhietti
Keyword(s):  
Picea Abies ◽  
Picea Mariana ◽  
Pinus Banksiana ◽  
Alnus Crispa ◽  
Forêt Mixte

RÉSUMÉ Des silts sableux prodeltaïques, des sables deltaïques et des silts et sables stratifiés ont été excavés sous l'estran et à la base des falaises de la côte nord-ouest de l'île aux Coudres, dans l'estuaire moyen du Saint-Laurent. L'analyse sporopollinique à maille serrée de ces unités révèle une suite d'associations végétales du Sangamonien observée pour la première fois dans la vallée du Saint-Laurent. À la base, la phase prodeltaïque est contemporaine d'une forêt boréale régionale à Picea mariana, Pinus banksiana et, en proportion décroissante, à Abies. Cette phase est suivie d'un épisode deltaïque puis d'un optimum climatique de type interglaciaire caractérisé par une forêt régionale mixte à Picea et Quercus (17%). Au-dessus, la succession pollinique représente la transition entre la fin d'un optimum interglaciaire et un épisode glaciaire. La forêt mixte est remplacée progressivement par une sapinière (Picea, Abies, Betula), une pessière (Picea, Pinus), puis par une toundra arbustive (Betula, Alnus crispa). Des sables stériles puis des varves glaciolacustres, déjà connus, complètent cette séquence de refroidissement. Les unités pleistocenes de l'île aux Coudres introduisent de nouveaux éléments de corrélation entre les séquences du lac Ontario, de la vallée du Saint-Laurent et celles du golfe du Saint-Laurent. Le lit à Quercus abondant représente, sur une faible épaisseur, un optimum climatique du Sangamonien très probablement équivalent de la fin du sous-stade isotopique 5e. Il confirme l'âge pré-sangamonien et du début du Sangamonien des sédiments détectés par sismique réflexion jusqu'à —160 m sous le niveau actuel de l'estuaire du Saint-Laurent. L'optimum climatique est suivi d'un refroidissement caractérisé par une évolution végétale semblable à celle observée en Nouvelle-Ecosse pendant la transition du 5e au 5d.

РАЗЛИЧИЕ ЭКОЛОГИЧЕСКИХ СТРАТЕГИЙ ХВОЙНЫХ ПОРОД В ЕВРОПЕЙСКИХ И КАНАДСКИХ БОРЕАЛЬНЫХ ЛЕСАХ: МОДЕЛЬНЫЙ АНАЛИЗ

2015 ◽  
Vol 7 (3) ◽  
pp. 328 ◽  
Author(s):  
О.Г. Чертов ◽  
А.С. Комаров ◽  
С.С. Быховец ◽  
Дж.С. Бхатти
Keyword(s):  
Picea Abies ◽  
Pinus Sylvestris ◽  
Picea Mariana ◽  
Pinus Banksiana ◽  
Biological Productivity

Обсуждается роль распределения по органам (аллокации) биологической нетто-продуктивности (net biological productivity, NBP)деревьев как параметра, отражающего их экологическую стратегию. Использование индивидуально-имитирующей пространственнораспределенной модели «дерево-почва» EFIMOD для европейских и североамериканских бореальных лесов выявило существенные отличия экологических параметров европейских сосны (Pinus sylvestris L.) и ели (Picea abies L. [Karst.]) от североамериканских сосны Банкса (Pinus banksiana Lamb.) и ели черной (Picea mariana Mill.). Были обнаружены сильные различия между этими древесными породами по аллокации NBP между хвоей и тонкими корнями. У североамериканских хвойных пород в сравнении с европейским изначительно большая часть NBP расходуется на образование тонких корней. Для исследования влияния аллокации NBP на компоненты баланса углерода и продукцию древесины был поставлен вычислительный эксперимент. Дополнительно был использован параметр «емкость круговорота» (turnover capacity, ТС), представляющий собой сумму NBP, дыхания почвы и потерь биомассы с рубкамии пожарами. Сравнение североамериканских и европейских хвойных пород проводилось в двух вариантах. В первом модельная имитация с изменением аллокации NPP проводилась при «произрастании» деревьев в их естественных условиях (канадские в Канаде, европейские в России). Во втором варианте «рост» канадских видов имитировался в условиях русского климата и почв, а европейских – в соответствующих канадских условиях. Результаты выявили существенные различия роста деревьев, изменения почв и параметров баланса углерода в зависимости от типов распределения NBP. Породы с высокой долей NBP, расходуемой на рост тонких корней, показали меньшую скорость роста даже при достаточно высокой емкости биологического круговорота в более мягком климате европейской России. Породы с более выравненным «европейским» распределением NBP росли лучше канадских даже в более континентальном холодном климате центральной Канады. Были идентифицированы два уровня производительности древостоев в зависимости от перераспределения NBP и от емкости круговорота экосистем. Эти уровни ясно показывают, что производительность древостоев (прирост древесины) может существенно различаться при одинаковых значениях NBP и емкости круговорота, если древесные породы имеют различные типы реаллокации. Это отражает адаптацию североамериканских хвойных пород к суровым климатическим условиям сочень холодными почвами на севере и очень сухими на юге бореальных лесов центральной Канады. Предложен индекс распределения NBP (отношение NBP листьев к NBP тонких корней) в качестве показателя устойчивости деревьев к стрессу, адаптации к суровым климатическим условиям и экологической стратегии.

Forest floor mass and nutrients in two chronosequences of plantations: Jack pine vs. black spruce

1998 ◽  
Vol 78 (1) ◽  
pp. 77-83 ◽  
Author(s):  
Helmut Krause
Keyword(s):  
Nutrient Cycling ◽  
Picea Mariana ◽  
Forest Floor ◽  
Pinus Banksiana ◽  
Forest Cover ◽  
Black Spruce ◽  
Jack Pine ◽  
Pine Plantations ◽  
Nutrient Concentrations ◽  
Natural Forests

The purpose of this study was to determine whether change of forest cover had an effect on the development of the organic surface horizons, particularly on those variables that influence nutrient cycling and forest productivity. Jack pine (Pinus banksiana Lamb.) and black spruce (Picea mariana [Mill.] B.S.P.) plantations were selected from among the youngest to oldest (2–16 yr) within a 100 km2 area in southeastern New Brunswick. Natural forests were also included as benchmark sites. The forest floor and tree foliage was sampled and trees measured on 0.05-ha plots. The forest floor samples were used to determine organic mass, nutrient contents and pH. In pine plantations, organic matter accumulated rapidly during the period of exponential tree growth, but leveled off at about 45 Mg ha–1. This was within the range of benchmark sites with mixed conifer-hardwood cover. In spruce plantations, the forest floor mass ranged upward to 77 Mg ha–1. Development was strongly influenced by the nature of the previous forest. Spruce forest floors were on average more acid and had lower nutrient concentrations, particularly N and Ca. The observed differences suggest that nutrients are recycled more rapidly in the pine plantations, partly explaining the superior growth of the latter. Key words: Forest floor, Kalmia angustifolia L., Picea mariana (Mill.) B.S.P., Pinus banksiana Lamb., nutrient cycling, plantation forest

Responses of boreal conifers to climate fluctuations: indications from tree-ring widths and carbon isotope analyses

1998 ◽  
Vol 28 (4) ◽  
pp. 524-533 ◽  
Author(s):  
J Renée Brooks ◽  
Lawrence B Flanagan ◽  
James R Ehleringer
Keyword(s):  
Climate Change ◽  
Boreal Forest ◽  
Carbon Isotope ◽  
Tree Ring ◽  
Picea Mariana ◽  
Pinus Banksiana ◽  
Annual Growth ◽  
Climate Change Scenarios ◽  
Southern Boundary ◽  
The North

Spatial distribution and species composition of the boreal forest are expected to change under predicted climate change scenarios. Current research indicates that water limitations control the southern boundary of the central Canadian boreal forest and temperature limitations control the northern boundary. As part of Boreal Ecosystem - Atmosphere Study (BOREAS), we examined this idea by comparing annual variation in tree-ring widths and carbon isotope ratios ( delta 13C) of tree-ring cellulose with annual climatic parameters in the northern and southern boreal forest. Contrary to expectations, climate correlations with ring widths at the northern and southern sites were similar in black spruce (Picea mariana (Mill.) BSP). Annual growth was favored by cooler and wetter conditions. For jack pine (Pinus banksiana Lamb.), increased temperature and spring precipitation favored annual growth at both sites. In the north, annual growth was negatively correlated with winter precipitation. The delta 13C - climate correlations in Pinus banksiana followed current distribution theories. In the south, potential evapotranspiration explained significant annual delta 13C variation, whereas in the north, winter and growing season precipitation influenced annual delta 13C variations. Our data support the concept that moisture limits the southern range of Pinus banksiana and cold soil temperatures limit the northern extent. However, colder, wetter conditions favored growth of Picea mariana throughout its range. These observations strengthen the concept that species respond individually to climate change, not as a cohesive biome.

Short-term effects of cut-to-length versus full-tree harvesting on conifer regeneration in jack pine, mixedwood, and black spruce forests in Manitoba

2004 ◽  
Vol 34 (9) ◽  
pp. 1938-1945 ◽  
Author(s):  
Isobel Waters ◽  
Steven W Kembel ◽  
Jean-François Gingras ◽  
Jennifer M Shay
Keyword(s):  
Picea Mariana ◽  
Picea Glauca ◽  
Pinus Banksiana ◽  
Black Spruce ◽  
Abies Balsamea ◽  
Jack Pine ◽  
Tree Regeneration ◽  
Understorey Vegetation ◽  
Advance Regeneration ◽  
The Impact

This study compares the effects of full-tree versus cut-to-length forest harvesting methods on tree regeneration in jack pine (Pinus banksiana Lamb.), mixedwood (Picea glauca (Moench) Voss – Populus tremuloides Michx. – Abies balsamea (L.) Mill.), and black spruce (Picea mariana (Mill.) BSP) sites in southeastern Manitoba, Canada. We surveyed tree regeneration densities, disturbance characteristics, and understorey vegetation in replicated control and harvested plots in each site type preharvest (1993) and 1 and 3 years postharvest (1994, 1996). In jack pine sites, the full-tree harvest method promoted regeneration of Pinus banksiana through increased disturbance of soil and the moss layer, and decreased slash deposition relative to the cut-to-length method. Conversely, in mixedwood sites the cut-to-length method resulted in less damage to advance regeneration and proved better at promoting postharvest regeneration of Abies balsamea and Picea glauca relative to the full-tree method. In black spruce sites, there were few differences in the impact of the two harvesting methods on regeneration of Picea mariana, which increased in frequency and density after both types of harvesting.

The influence of light quality and carbon dioxide enrichment on the growth and physiology of seedlings of three conifer species. I. Growth responses

1996 ◽  
Vol 74 (3) ◽  
pp. 383-390 ◽  
Author(s):  
John Hoddinott ◽  
Rickey Scott
Keyword(s):  
Growth Rates ◽  
Picea Mariana ◽  
Picea Glauca ◽  
Pinus Banksiana ◽  
Light Quality ◽  
Flux Ratio ◽  
Growth Period ◽  
Growth Responses ◽  
Relative Growth ◽  
Relative Growth Rates

Plant growth responds to light quality, as evaluated by the red/far-red (R/FR) quantum flux ratio, and to the level of CO2. Pinus banksiana, Picea mariana and Picea glauca seedlings were raised at 350, 700, or 1050 μL∙L−1 CO2 and high or low R/FR ratios and growth was measured over a 16-week growth period. Far-red rich light enhanced the whole plant and height relative growth rates of Pinus banksiana. The three species showed species specific responses in plant organ relative growth rates and partitioning ratios. On the basis of their biomass partitioning the species would be ranked Pinus banksiana < Picea mariana < Picea glauca for shade tolerance. In commercial operations, seedlings grown for outplanting are selected, in part, on the basis of plant form as described by the stem height/diameter ratio. More desirable ratios were obtained at ambient CO2 concentrations for Pinus banksiana and Picea mariana in red rich light and for Picea glauca in far-red rich light. Keywords: seedling growth, light quality, CO2 enrichment.

Individual height–diameter models for young black spruce (Picea mariana) and jack pine (Pinus banksiana) plantations in New Brunswick, Canada

2009 ◽  
Vol 85 (1) ◽  
pp. 43-56 ◽  
Author(s):  
Xiangdong Lei ◽  
Changhui Peng ◽  
Haiyan Wang ◽  
Xiaolu Zhou
Keyword(s):  
New Brunswick ◽  
Picea Mariana ◽  
Pinus Banksiana ◽  
Black Spruce ◽  
Jack Pine ◽  
Tree Level ◽  
Forest Stands ◽  
Tolerance Intervals ◽  
Group I ◽  
Group Ii

Historically, height–diameter models have mainly been developed for mature trees; consequently, few height–diameter models have been calibrated for young forest stands. In order to develop equations predicting the height of trees with small diameters, 46 individual height–diameter models were fitted and tested in young black spruce (Picea mariana) and jack pine (Pinus banksiana) plantations between the ages of 4 to 8 years, measured from 182 plots in New Brunswick, Canada. The models were divided into 2 groups: a diameter group and a second group applying both diameter and additional stand- or tree-level variables (composite models). There was little difference in predicting tree height among the former models (Group I) while the latter models (Group II) generally provided better prediction. Based on goodness of fit (R2and MSE), prediction ability (the bias and its associated prediction and tolerance intervals in absolute and relative terms), and ease of application, 2 Group II models were recommended for predicting individual tree heights within young black spruce and jack pine forest stands. Mean stand height was required for application of these models. The resultant tolerance intervals indicated that most errors (95%) associated with height predictions would be within the following limits (a 95% confidence level): [-0.54 m, 0.54 m] or [-14.7%, 15.9%] for black spruce and [-0.77 m, 0.77 m] or [-17.1%, 18.6%] for jack pine. The recommended models are statistically reliable for growth and yield applications, regeneration assessment and management planning. Key words: composite model, linear model, model calibration, model validation, prediction interval, tolerance interval

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

1975 ◽  
Vol 51 (2) ◽  
pp. 53-54
Author(s):  
W. Stanek
Keyword(s):  
Nutrient Solution ◽  
Picea Mariana ◽  
Concentration Gradient ◽  
Pinus Banksiana ◽  
Black Spruce ◽  
Jack Pine ◽  
Height Growth ◽  
Distilled Water ◽  
Pine Seedlings ◽  
Water Height

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.

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