Dynamique de la régénération d'une pessière à lichen dans la zone de la pessière noire à mousses, nord du Saguenay–Lac-Saint-Jean (Québec)

1996 ◽  
Vol 26 (8) ◽  
pp. 1504-1509 ◽  
Author(s):  
Stéphane Riverin ◽  
Réjean Gagnon
Keyword(s):  
Black Spruce ◽  
Adult Population ◽  
Climatic Conditions ◽  
Population History ◽  
Taiga Zone ◽  
Forest Zone ◽  
Dating Method ◽  
Different Populations ◽  
Cross Dating ◽  
Open Forests

Regeneration dynamics have been studied in three open lichen–spruce woodlands located in the black spruce feather-moss forest zone. Black spruces (Piceamariana (Mill.) BSP) belonging to the adult stratum originated from a fire that occurred in 1877. Population history and ecology has been studied on the basis of the establishment period of individuals. The age of black spruces belonging to the regeneration stratum was calculated by using the cross-dating method. The establishment period of the seedlings was determined by the age structure. The black spruces of these open forests belong to two different populations. The adult population originated from the 1877 fire whereas the regeneration population seems to have established itself following another fire that occurred in 1922–1923. Black spruce seedlings of the regeneration stratum are very old (60 years-old on average) in spite of a low height (mean height of 96 cm). Although these open forests are under favourable climatic conditions, they have dynamics similar to lichen–spruce woodlands of the taiga zone. In the last 45 years, no seedlings have settled in these sparse forests.

Light Rings in Subarctic Conifers as a Dendrochronological Tool

1986 ◽  
Vol 26 (2) ◽  
pp. 272-279 ◽  
Author(s):  
Louise Filion ◽  
Serge Payette ◽  
Line Gauthier ◽  
Yves Boutin
Keyword(s):  
Black Spruce ◽  
Volcanic Eruptions ◽  
Growing Season ◽  
Climatic Conditions ◽  
Climatic Effect ◽  
Growth Variability ◽  
Growing Seasons ◽  
Cell Layers ◽  
Cross Dating ◽  
Light Ring

Light rings are characterized by one or a very few latewood-cell layers, an indication of shortened growing seasons, and are particularly frequent in black spruce (Picea mariana (Mill.) BSP) at the treeline in Québec. The construction of a light-ring chronology spanning the period AD 1398–1982 showed that the highest frequency (>25%) of light rings among 160 trees and krummholz occurred in 1593, 1620, 1634, 1784, 1816, 1817, 1853, 1969, and 1972. These diagnostic rings be a useful cross-dating tool for dendroecologists working with living and dead krummholz with a low-growth variability. About two-thirds of the 65 light-ring years coincide with years (or triads) of major volcanic eruptions. The climatic conditions (low temperature) occurring at the end of the growing season, in part induced by the climatic effect of volcanism, seem to initiate light rings.

Croissance juvénile comparée de deux générations successives de semis d'épinette noire issus de graines après feu en forêt boréale, Québec

2002 ◽  
Vol 32 (8) ◽  
pp. 1478-1490 ◽  
Author(s):  
Natalie Fantin ◽  
Hubert Morin
Keyword(s):  
Black Spruce ◽  
Choristoneura Fumiferana ◽  
Height Growth ◽  
Climatic Conditions ◽  
Juvenile Growth ◽  
Mature Trees ◽  
Soil Enrichment ◽  
Terminal Bud ◽  
Cross Dating ◽  
The 19Th Century

The objective of this study was to compare juvenile (0–12 years) height growth pattern of dominant mature trees from two virgin black spruce (Picea mariana (Mill.) BSP) forests established during the 19th century (1870) to that of young dominant black spruce seedlings newly regenerated following a 1983 fire on the same sites. The pattern was reconstructed by measuring the distance between terminal bud scars on young seedlings, and by precise counting of growth rings by cross-dating from the collar, which was identified by anatomical features, for mature trees. New seedlings growth was significantly higher than that of mature trees. Seedlings were almost twice as high as mature trees after 12 years of juvenile growth. Assuming that mature trees were dominant during their juvenile growth phase, we put forward the hypothesis that juvenile height growth of mature trees would have been affected by the combined action of spruce budworm (Choristoneura fumiferana (Clem)) and colder climatic conditions than those presently observed. Also, young seedlings juvenile height growth may have been favored by nitrogen soil enrichment along with more favourable climatic conditions.

Peculiarities of the course of the postpartum period in domestic reindeer females, its morphophysiology and behavioral reactions in the North-East of Russia (Republic of Sakha)

2020 ◽  
pp. 99-105
Author(s):  
V. Fedorov ◽  
E. Sleptsov ◽  
K. Plemyashov
Keyword(s):  
Postpartum Period ◽  
Reproductive Function ◽  
Complex Problem ◽  
Climatic Conditions ◽  
Taiga Zone ◽  
Behavioral Reactions ◽  
North East ◽  
The North ◽  
The Republic ◽  
Mountain Taiga

A growth in the number of deer and an increase in their productivity are closely related to the solution of the complex problem of reproduction and rational use of deer females. Significant damage to reindeer husbandry is caused by the barrenness of northern domestic deer, the level of which has been quite high in recent years. So, in the Republic of Sakha, on 01.01.2020, the number of domesticated reindeer was 152,068, of which female deer and heifers — 71,818, offspring per 100 females — 59, business yield amounted to 52 fawns per 100 females. The causes of infertility are very diverse, as the natural and climatic conditions of the breeding zones have a significant influence on the reproductive function of reindeer. In Yakutia, the main population of northern domestic deer is bred in mountain taiga and tundra natural-climatic zones, so there are about 55 thousand deer in the mountain taiga zone and more than 65 thousand deer in the tundra zone. In this regard, the study of the peculiarities of the postpartum period course in domestic reindeer females, its morphophysiology, and behavioral reactions depending on the natural and climatic conditions of breeding is of great importance.

scholarly journals Climatic Variation of Supercooling Point in the Linden Bug Pyrrhocoris apterus (Heteroptera: Pyrrhocoridae)

Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 144 ◽  
Author(s):  
Tomáš Ditrich ◽  
Václav Janda ◽  
Hana Vaněčková ◽  
David Doležel
Keyword(s):  
Cold Tolerance ◽  
Minimum Temperature ◽  
Climatic Conditions ◽  
Climatic Variation ◽  
Strongly Correlated ◽  
Supercooling Point ◽  
Pyrrhocoris Apterus ◽  
Winter Minimum Temperature ◽  
Different Populations ◽  
Insect Fitness

Cold tolerance is often one of the key components of insect fitness, but the association between climatic conditions and supercooling capacity is poorly understood. We tested 16 lines originating from geographically different populations of the linden bug Pyrrhocoris apterus for their cold tolerance, determined as the supercooling point (SCP). The supercooling point was generally well explained by the climatic conditions of the population’s origin, as the best predictor—winter minimum temperature—explained 85% of the average SCP variation between populations. The supercooling capacity of P. apterus is strongly correlated with climatic conditions, which support the usage of SCP as an appropriate metric of cold tolerance in this species.

scholarly journals Signs of gathering and fishing on the monuments of the Late Neolithic - Early Eneolithic of Karelia (based on the settlement of Vigainavolok I)

2019 ◽  
Vol 8 (3) ◽  
pp. 150-157
Author(s):  
Tatyana Anatolyevna Vasilyeva
Keyword(s):  
Large Body ◽  
Climatic Conditions ◽  
Stone Age ◽  
Late Neolithic ◽  
The West ◽  
Forest Zone ◽  
Lake Onega ◽  
Study Results ◽  
Determining Factors

The paper presents the study results of Vigainavolok I materials. This settlement is located on the west of Lake Onega in Karelia. The monument was investigated by G.A. Pankrushev in 1963-1966. Its area was 8,000 m. 26 buildings remains were revealed. The area of 2748 m was studied. The inventory collection includes more than 25 thousand pieces of ceramics and about 7 thousand pieces of stone, clay and metal. The buildings served as dwellings and workshops. The collection includes sinkers that are marked as direct signs of fishing. Favorable climatic conditions for the development in the forest zone, confined to the coast of a large body of water, settlement equipment, osteological materials of the Stone Age monuments characterize fishing as one of the determining factors in the life of the population.

scholarly journals Raising Hereford breed in the conditions of the Republic of Tuva

2020 ◽  
Vol 50 (4) ◽  
pp. 66-71
Author(s):  
B. M. Ludu ◽  
B. K. Kan-ool
Keyword(s):  
Beef Cattle ◽  
Animal Husbandry ◽  
Steppe Zone ◽  
Climatic Conditions ◽  
Forest Steppe ◽  
High Mountain ◽  
Taiga Zone ◽  
Research Information ◽  
Peasant Farm ◽  
The Republic

The paper presents the results of the research into the condition, number and concentration of beef cattle of Hereford breed, adapted to the natural and climatic conditions of the East Siberian region. The methodological basis of the study was formed by the methods of systematization, logical and comparative statistical analysis. The research information was based on the official materials of the Ministry of Agriculture and Food of the Republic of Tuva on animal husbandry. Out of the total number of livestock in the region (180 748 heads), Herefords amount to 2869 heads. A comparative analysis of livestock in farms of different forms of ownership and different natural and climatic zones was carried out. The largest population of Herefords (48.94%) is concentrated in the central agricultural and livestock zone with forest-steppe and steppe subzones (by the number of animals Piy-Khem kozhuun ranks first, 19.1%). In the southern zone of dry steppes, there are 27.43% of Herefords (by the number of livestock in the Republic, Tes-Khem kozhuun ranks second, 14.7%). In the western mountain-steppe zone there are 23.63% of Herefords, the largest number is in Barun-Khemchik (7.4%) and in Bai-Taiginsky (7%) kozhuun. Specialized beef cattle have not been brought to the high-mountain Mongun-Taiginsky kozhuun of the western zone or to the eastern high-mountain taiga zone. According to the results of the analysis, taking into account the category of farms, 56.4% of Herefords are kept in peasant farm enterprises, 19.7% – in agricultural production cooperatives, 29.7% – in other agricultural enterprises. All farms practise year-round grazing. Differences in the number of Hereford cattle by districts depend on the capacities of farms and climatic breeding zones. The monitoring which was carried out will allow to determine the prospects for raising purebred cattle of a specialized type, taking into account the terrain and zone of the breeding work in the conditions of year-round grazing in the Republic of Tuva.

Dendroecological analysis of black spruce in lichen—spruce woodlands of the closed-crown forest zone in eastern Canada

Ecoscience ◽  
2011 ◽  
Vol 18 (3) ◽  
pp. 279-294 ◽  
Author(s):  
François Girard ◽  
Serge Payette ◽  
Réjean Gagnon
Keyword(s):  
Black Spruce ◽  
Eastern Canada ◽  
Forest Zone ◽  
Crown Forest

CHEMOSYSTEMATIC STUDIES IN THE GENUS PICEA (PINACEAE): II. THE LEAF OIL OF PICEA GLAUCA AND P. MARIANA

1967 ◽  
Vol 45 (9) ◽  
pp. 1703-1714 ◽  
Author(s):  
E. Von Rudloff
Keyword(s):  
Liquid Chromatography ◽  
Distribution Pattern ◽  
Picea Glauca ◽  
Black Spruce ◽  
Gas Liquid Chromatography ◽  
Oil Composition ◽  
Eastern Canada ◽  
Leaf Oil ◽  
Different Populations ◽  
Ecological Differences

The leaf oils from white and black spruce obtained from different locations in Western and Eastern Canada, Michigan, and Minnesota, have been analyzed by gas liquid chromatography. Both species were found to have a remarkably consistent and distinctive distribution pattern of the leaf oil terpenes. The quantitative variations encountered in samples of the same species from different populations are relatively small and ecological differences are not found to affect the leaf oil composition. Hence, analysis of spruce leaf oils appears to be highly suitable for a study of introgression and hybridization.

Formation of honey bees modern look and their reproduction in the republic of Dagestan

10.12737/6540 ◽  
2014 ◽  
Vol 9 (3) ◽  
pp. 117-119
Author(s):  
Гасанов ◽  
Alibulat Gasanov ◽  
Абакарова ◽  
Muslimat Abakarova
Keyword(s):  
Honey Bees ◽  
Wing Length ◽  
Climatic Conditions ◽  
High Mountains ◽  
Mountainous Areas ◽  
The Third ◽  
Different Populations ◽  
Natural Breeding ◽  
The Republic ◽  
Natural Dispersal

Grey mountain Caucasian bees are of great interest for the selection, as a valuable gene pool of different populations of this race is supported by high mountains and inaccessible gorges of Dagestan, while serving as an isolated mountainous natural breeding areas. The studies were conducted in three different climatic conditions of the republic: the plains, foothills and mountainous areas. In the area of natural dispersal of gray mountain Caucasian bees in Dagestan released several local populations and different backgrounds. Characteristics of the main morphological features of honey bees are the length of proboscis, wing and width of the third tergite and others. These features bees vary, depending on the habitat population. Numerous studies of Dagestan honeybees showed, that the longest proboscis inherent in bees of mountain zone (6.85 ± 0.03 mm). The plain bees have a smaller proboscis (up to 6.71 ± 0.01 mm), and in the foothills bees the proboscis occupies an intermediate position (from 6.69 ± 0.01 to 6.83 ± 0.01 mm). Two other peculiarities (wing length and the third tergite) are subject to variation, depending on the altitude above sea level.

Lightning-Caused and Human-Induced Forest Fires as Evidenced By Pteridium Spores in Selected Quaternary Records from Poland

2013 ◽  
Vol 30 (1) ◽  
pp. 29-40 ◽  
Author(s):  
Krzysztof Bińka ◽  
Jerzy Nitychoruk
Keyword(s):  
Forest Fires ◽  
Indirect Evidence ◽  
Climatic Conditions ◽  
Forest Zone ◽  
Lightning Strikes ◽  
The Holocene ◽  
Middle Holocene ◽  
Natural Fires ◽  
Long Time ◽  
Successional Stages

Abstract The occurrence of Pteridium spores - the common fire-adapted plant - was observed in Poland’s Pleistocene (three interglacials and numerous interstadials) and Holocene pollen sequences. Until the onset of the middle Holocene, bracken was recorded relatively rarely. This marks climatic conditions with sporadic wildfires, followed by quick re- moval of the clones (or maintenance of the clones in a suppressed state) in the subsequent, post fire successional stages. In each interglacial we can also identify short periods (most often synchronous) of somewhat higher frequency of Pteridium, indicating a possible increase in natural fires as an effect of stormy conditions. These short periods are placed mainly within phases dominated by coniferous woodlands. The very high content of bracken found from a reanalysis of the long Saalian sequence at Ossówka as three regular culminations just above three non-tree phases, eastern Poland is the unique exception. To explain this we found the close modem analogue of the above phenomenon in the Alaskan region, at the boundary between the tundra and the boreal zone where in a very narrow forest zone, especially with the continental signature, lightning-initiated fires are very frequent (the edge effect). Pleistocene records of bracken during forest periods might indicate that thunderstorms and lightning strikes were responsible for its higher content. This is not to exclude the possibility that interglacial fires were set by Palaeolithic humans. However, it is more likely that the wildfires were utilized and to some extent controlled, especially at Ossówka, where the palaeolake existed for a long time after the interglacial; and this surely attracted the attention of game and humans. Our investigations show that rare, more abundant Pteridium in the Pleistocene sequences can be traced throughout the corresponding periods even at distant sites. This might be indirect evidence of a climatic pattern that promote stormy conditions and fires at that time. In the Holocene, different factors seem to be responsible for the long-term dynamics in Pteridium clones. Both in Poland and in adjacent areas bracken peaked in the middle Holocene from 8000 to 5000 BP, when this territory was occupied by deciduous woodlands. There is agreement that this is due to burning of forests by the hunter-gatherer societies of the Late Mesolithic. However, in spite of increased clearings in the subsequent phases bracken substantially decreased in abundance. This means first of all that fires rather than clearings were responsible for the rise in Pteridium spores in the Holocene pollen sequences.

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