Fire history in the southern boreal forest of northwestern Quebec

1993 ◽  
Vol 23 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Pierre-René Dansereau ◽  
Yves Bergeron
Keyword(s):  
Physical Environment ◽  
Fire History ◽  
Age Determination ◽  
Historical Reconstruction ◽  
Fire Scars ◽  
Future Studies ◽  
Fire Cycle ◽  
Large Fires ◽  
Observation Period

Age determination of post-fire forests and the analysis of fire scars on surviving trees have allowed for the historical reconstruction and mapping of fires in a forest area of 11 715 ha in northwestern Quebec, south of Lake Abitibi. Most of the study area was burnt by two large fires (>1000 ha) in 1760 and 1923. All the other fires recorded (1797, 1823, 1870, 1907, 1919) were smaller in extent and occurred in a restricted part (1984 ha) of the study area, characterized by the fragmentation of the forest landscape by water bodies. The compilation of data concerning area burnt per type of surficial material confirms that the physical environment exerts a stronger control on the delimitation of these smaller fires. The data do not allow for the estimation of the fire cycle owing to the small size of the study area and possible temporal changes during the observation period. However, methodological observations are formulated for future studies covering a larger area in the bioclimatic region.

Fire disturbance of larch woodlands in string fens in northern Québec

2005 ◽  
Vol 83 (6) ◽  
pp. 599-609 ◽  
Author(s):  
Daniel Busque ◽  
Dominique Arseneault
Keyword(s):  
Boreal Forest ◽  
Fire History ◽  
Wood Decay ◽  
Complete Removal ◽  
Tree Density ◽  
Fire Disturbance ◽  
Tree Cover ◽  
Larix Laricina ◽  
Fire Scars ◽  
Large Fires

In this study, dendrochronology was used to reconstruct the fire history and associated dynamics of the last 350 years in three larch (Larix laricina [Du Roi] K. Koch) woodlands in string fens of the northern boreal forest of Quebec. Fire scars were also sampled to reconstruct the fire history across the surrounding uplands. Our results show that string fens are more likely to experience partial disturbance than complete removal of the tree cover during fire. Although large fires burned across the studied landscape in 1733, 1787, 1865, and 1941, no stand-replacing fire has occurred in any of the studied woodlands. At all sites, the oldest larch trees became established around 1640–1680, and several individuals survived each fire identified across the uplands. However, partial disturbance during the most recent 1941 fire, which was associated with severe fire weather, decreased tree density and released the growth of several trees. Although signs of previous fire may have been lost through wood decay, no fire impacted larch growth as severely as the 1941 fire, further emphasizing the modest influence of fire in string fens as compared with uplands. The low fire influence in these minerotrophic peatlands helps explain the high occurrence of the fire-sensitive eastern larch.Key words: boreal forest, fire disturbance, larch woodland, Larix laricina, northern Quebec, string fen.

Fire history of a central Nevada pinyon–juniper woodland

2009 ◽  
Vol 39 (8) ◽  
pp. 1589-1599 ◽  
Author(s):  
John M. Bauer ◽  
Peter J. Weisberg
Keyword(s):  
Great Basin ◽  
Fire History ◽  
Fire Regime ◽  
Climatic Conditions ◽  
Spatial And Temporal Variation ◽  
Fire Scars ◽  
Survivorship Analysis ◽  
Fire Cycle ◽  
Superposed Epoch Analysis ◽  
Fire Exclusion

Our study reconstructed fire history (1445–2006) from tree rings for a Great Basin single-needle pinyon pine ( Pinus monophylla Torr & Frém.) – Utah juniper ( Juniperus osteosperma (Torr.) Little) woodland. Information from multiple lines of evidence, including dateable fire scars (n = 83), tree demography, and charred coarse woody debris, was used to quantify fire frequency, severity, and extent. Fire cycle models were developed using survivorship analysis of time-since-fire estimates. We investigated the spatial and temporal variation in historical fire regime, addressing the plausibility of postsettlement fire exclusion as an explanation for increased woodland area and density since the late 1800s. Historical fire regime was characterized by infrequent, small, high-severity fires. Estimated fire cycle (1570–1880) was 427 years, with no evidence of postsettlement stand-replacing fires. Topographic analyses indicated that in this drought-prone landscape, more mesic conditions favor continuous fuels that lead to more frequent or extensive fire. Superposed epoch analysis showed increased fire occurrence during drought years but with no influence of antecedent climatic conditions. More frequent grassland and shrubland fires were recorded by fire scars near valley floors. Thus, anthropogenic fire exclusion in adjacent, shrub-dominated communities presents a plausible mechanism for woodland expansion in the study area. However, there is little ecological justification for reintroducing fire to areas of historic woodland, where effects of fire exclusion have been minimal.

Analysis of Fibronectin and TGF-β1 Immunoexpression to Determination of Wound Vitality in Wistar Rats (Rattus norvegicus)

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Nita Novita ◽  
Hasrayati Agustina ◽  
Bethy S. Hernowo ◽  
Abdul H. Hassan
Keyword(s):  
Rattus Norvegicus ◽  
Wistar Rats ◽  
Age Determination ◽  
Scientific Field ◽  
Wound Age ◽  
Forensic Practice ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
Tgf Β1

Wound examination is indispensable in forensic practice. The scientific field of wound age determination has advanced progressively during recent years.The purpose of this study was to determine the differences of fibronectin and TGF-β1 expression in both antemortem and postmortem wounds. This study was an experimental with completely randomized design.  The skin wounds (vital and postmortem) were taken from fourty Wistar rats and divided into 10 groups of rats. Immunohistochemical staining was performed to determine the differences between antemortem and postmortem wounds. The result showed that in 30 minutes after antemortem wound infliction, all of samples showed weak reactivity for fibronectin and TGF-β1 (100%).  In first hour after wound infliction, 3 samples (75%) showed weakly positive and 1 sample (25%) strongly positive for fibronectin and TGF-β1.  In 2 hour after wound infliction, 1 sample (25%) showed weakly positive and 3 sample (75%) strongly positive for fibronectin and TGF-β1.  In 3 and 4 hour after wound infliction, all of samples strongly positive for fibronectin and TGF-β1.  In postmortem wound, all of samples showed negativity for fibronectin and TGF-β1. In conclusion, fibronectin and TGF-β1 may be useful in the determination of wound vitality. Keywords: wound, fibronectin, TGF-β1, vitality

scholarly journals Directly ageing the Caribbean spiny lobster, Panulirus argus with validated band counts from gastric mill ossicles

2018 ◽  
Vol 76 (2) ◽  
pp. 442-451 ◽  
Author(s):  
Gaya Gnanalingam ◽  
Mark J Butler ◽  
Thomas R Matthews ◽  
Emily Hutchinson ◽  
Raouf Kilada
Keyword(s):  
Spiny Lobster ◽  
Age Determination ◽  
Florida Keys ◽  
Panulirus Argus ◽  
Gastric Mill ◽  
Coefficients Of Variation ◽  
The Caribbean ◽  
First Time ◽  
Reader Experience

Abstract In crustaceans, ecdysis was long believed to result in the loss and replacement of all calcified structures, precluding the use of conventional ageing methods. However, the discovery of bands in the gastric ossicles of several crustaceans with some correlation with age suggests that direct age estimation may be possible. We applied this method to a tropical spiny lobster, Panulirus argus, one of the most iconic and economically valuable species in the Caribbean. The presence of growth bands was investigated using wild lobsters of unknown age and was validated with captive reared lobsters of known age (1.5–10 years) from the Florida Keys, Florida (USA). Bands were consistently identified in ptero- and zygo-cardiac ossicles of the gastric mill and did not appear to be associated with moulting. Validation with known age animals confirms that bands form annually. Counts between independent readers were reproducible with coefficients of variation ranging from 11% to 26% depending on reader experience and the structure used. This study demonstrates, for the first time, that direct age determination of P. argus is possible.

Using the isotope dating of endocontact hybrid rocks for the age determination of mafic rocks (southern Siberian craton)

2013 ◽  
Vol 54 (11) ◽  
pp. 1340-1351 ◽  
Author(s):  
D.P. Gladkochub ◽  
T.V. Donskaya ◽  
M.T.D. Wingate ◽  
A.M. Mazukabzov ◽  
S.A. Pisarevsky ◽  
...  
Keyword(s):  
Siberian Craton ◽  
Age Determination ◽  
Mafic Rocks ◽  
Isotope Dating

Age determination of the African lion (Panthera leo)

2009 ◽  
Vol 185 (1) ◽  
pp. 115-146 ◽  
Author(s):  
G. L. Smuts ◽  
J. L. Anderson ◽  
J. C. Austin
Keyword(s):  
Age Determination ◽  
Panthera Leo ◽  
African Lion

scholarly journals Age determination of chum salmon using scales and otoliths

2017 ◽  
Vol 83 (5) ◽  
pp. 758-763
Author(s):  
YURIKO KANETO ◽  
SATOSHI KATAYAMA ◽  
MASAYA IIDA
Keyword(s):  
Chum Salmon ◽  
Age Determination

A Technique for Age Determination of Juvenile White-Tailed Ptarmigan

1979 ◽  
Vol 43 (2) ◽  
pp. 508 ◽  
Author(s):  
Kenneth M. Giesen ◽  
Clait E. Braun
Keyword(s):  
Age Determination
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