Fire history and the establishment of oaks and maples in second-growth forests

2008 ◽  
Vol 38 (5) ◽  
pp. 1184-1198 ◽  
Author(s):  
Todd F. Hutchinson ◽  
Robert P. Long ◽  
Robert D. Ford ◽  
Elaine Kennedy Sutherland
Keyword(s):  
Cross Sections ◽  
Fire History ◽  
Direct Relationship ◽  
Fire Occurrence ◽  
Fire Control ◽  
Second Growth ◽  
History Of ◽  
Stand Thinning ◽  
Large Pulse ◽  
Cut Stumps

We used dendrochronology to examine the influence of past fires on oak and maple establishment. Six study units were located in southern Ohio, where organized fire control began in 1923. After stand thinning in 2000, we collected basal cross sections from cut stumps of oak (n = 137) and maple (n = 204). The fire history of each unit was developed from the oaks, and both oak and maple establishment were examined in relation to fire history. Twenty-six fires were documented from 1870 to1933; thereafter, only two fires were identified. Weibull median fire-return intervals ranged from 9.1 to 11.3 years for the period ending 1935; mean fire occurrence probabilities (years/fires) for the same period ranged from 11.6 to 30.7 years. Among units, stand initiation began ca. 1845 to 1900, and virtually no oak recruitment was recorded after 1925. Most maples established after the cessation of fires. In several units, the last significant fire was followed immediately by a large pulse of maple establishment and the cessation of oak recruitment, indicating a direct relationship between fire cessation and a shift from oak to maple establishment.

scholarly journals Reconstructing fire history in central Mongolia from tree-rings

2012 ◽  
Vol 21 (1) ◽  
pp. 86 ◽  
Author(s):  
Amy E. Hessl ◽  
Uyanga Ariya ◽  
Peter Brown ◽  
Oyunsannaa Byambasuren ◽  
Tim Green ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Cross Sections ◽  
Fire History ◽  
Test Case ◽  
Fire Occurrence ◽  
Central Mongolia ◽  
Targeted Sampling ◽  
In Fire ◽  
Use Factors

Rising temperatures are expected to increase wildfire activity in many regions of the world. Over the last 60 years in Mongolia, mean annual temperatures have increased ~2°C and the recorded frequency and spatial extent of forest and steppe fires have increased. Few long records of fire history exist to place these recent changes in a historical perspective. The purpose of this paper is to report on fire history research from three sites in central Mongolia and to highlight the potential of this region as a test case for understanding the relationships between climate change, fire and land use. We collected partial cross-sections from fire-scarred trees and stumps at each site using a targeted sampling approach. All three sites had long histories of fire ranging from 280 to 450 years. Mean Weibull fire return intervals varied from 7 to 16 years. Fire scars at one protected-area site were nearly absent after 1760, likely owing to changes in land use. There is limited synchrony in fire occurrence across sites, suggesting that fire occurrence, at least at annual time scales, might be influenced by local processes (grazing, human ignitions, other land-use factors) as well as regional processes like climate. Additional data are being collected to further test hypotheses regarding climate change, land use and fire.

scholarly journals Long-term fire resilience of the Ericaceous Belt, Bale Mountains, Ethiopia

2019 ◽  
Vol 15 (7) ◽  
pp. 20190357 ◽  
Author(s):  
Graciela Gil-Romera ◽  
Carole Adolf ◽  
Blas M. Benito ◽  
Lucas Bittner ◽  
Maria U. Johansson ◽  
...  
Keyword(s):  
Fire History ◽  
Time Perspective ◽  
Negative Impact ◽  
Current Knowledge ◽  
Landscape Management ◽  
Fire Occurrence ◽  
Controlled Burning ◽  
History Of ◽  
Grazing Systems

Fire is the most frequent disturbance in the Ericaceous Belt ( ca 3000–4300 m.a.s.l.), one of the most important plant communities of tropical African mountains. Through resprouting after fire, Erica establishes a positive fire feedback under certain burning regimes. However, present-day human activity in the Bale Mountains of Ethiopia includes fire and grazing systems that may have a negative impact on the resilience of the ericaceous ecosystem. Current knowledge of Erica –fire relationships is based on studies of modern vegetation, lacking a longer time perspective that can shed light on baseline conditions for the fire feedback. We hypothesize that fire has influenced Erica communities in the Bale Mountains at millennial time-scales. To test this, we (1) identify the fire history of the Bale Mountains through a pollen and charcoal record from Garba Guracha, a lake at 3950 m.a.s.l., and (2) describe the long-term bidirectional feedback between wildfire and Erica, which may control the ecosystem's resilience. Our results support fire occurrence in the area since ca 14 000 years ago, with particularly intense burning during the early Holocene, 10.8–6.0 cal ka BP. We show that a positive feedback between Erica abundance and fire occurrence was in operation throughout the Lateglacial and Holocene, and interpret the Ericaceous Belt of the Ethiopian mountains as a long-term fire resilient ecosystem. We propose that controlled burning should be an integral part of landscape management in the Bale Mountains National Park.

scholarly journals COMPARAÇÃO ENTRE O PERFIL DOS INCÊNDIOS FLORESTAIS DE MONTE ALEGRE, BRASIL, E DE PINAR DEL RÍO, CUBA

FLORESTA ◽  
2013 ◽  
Vol 43 (2) ◽  
pp. 231 ◽  
Author(s):  
Marcos Pedro Ramos Rodríguez ◽  
Ronaldo Viana Soares ◽  
Antonio Carlos Batista ◽  
Alexandre França Tetto ◽  
Luis Wilfredo Martínez Becerra
Keyword(s):  
Forest Fires ◽  
Fire History ◽  
Fire Season ◽  
Burned Area ◽  
Fire Occurrence ◽  
Fire Control ◽  
Spatial And Temporal Distributions ◽  
Del Rio ◽  
Pinus Spp ◽  
Control Service

 É importante se determinar onde, quando e porque ocorrem os incêndios florestais, com vistas a estruturar os serviços de prevenção e combate dentro de limites economicamente viáveis. Esta pesquisa foi desenvolvida com o objetivo de comparar o comportamento histórico dos incêndios florestais ocorridos no período de 2002 a 2011 no Distrito Florestal de Monte Alegre, estado do Paraná, Brasil, e nas empresas florestais da Província de Pinar del Río, Cuba. Foram consideradas as distribuições temporal e espacial dos incêndios, tendo sido analisada também a eficiência do serviço de proteção. Os registros de ocorrência de incêndios foram fornecidos pela Klabin S/A e pelo Corpo de Guardabosques de Pinar del Río. Os resultados mostraram um maior número de ocorrências e uma menor área queimada em Monte Alegre. Os incêndios se concentraram nos meses de agosto a outubro (77,97% do total) em Monte Alegre e de março a maio (86,80%) em Pinar del Río. A cobertura vegetal mais afetada nas duas regiões foi “Pinus spp.” e a principal causa foi “incendiário” (71,66% do total) em Monte Alegre e “raios” (39,26%) em Pinar del Río. Conclui-se que há uma similaridade no perfil dos incêndios para os dois lugares, com exceção da época de incêndios.Palavras-chave: Estatísticas de incêndios; época de incêndios; prevenção de incêndios. AbstractComparison between the forest fires statistics in Monte Alegre, Brazil, and Pinar del Río, Cuba. It is important to determine where, when and why forest fires occur in order to structure the prevention and suppression within economically viable limits. This research was developed in order to compare the historical behavior of forest fires in the period 2002 to 2011 in the Forest District of Monte Alegre, Paraná State, Brazil, and forestry companies in the province of Pinar del Río, Cuba. Spatial and temporal distributions of fire occurrence were considered and the efficiency of fire control service was analyzed. Records of fire occurrence were provided by Klabin S/A and the Forest Department of Pinar del Río. The results revealed a higher number of occurrences and a lower burned area in Monte Alegre. The fires were concentrated from the month of August to October (77.97% of total) in Monte Alegre and March-May (86.80%) in Pinar del Río. The most affected vegetation in both regions was "Pinus spp" and the main cause of the occurrence was "incendiary" (71.66% of total) in Monte Alegre and "lightning" (39.26%) in Pinar del Río. There was a similarity in the fire profile for the two regions, except in the fire season.Keywords: Fire statistics; fire history; fire season; fire prevention.

Streptococcus pluranimalium meningoencephalitis in a horse

2021 ◽  
pp. 104063872110234
Author(s):  
Dah-Jiun Fu ◽  
Akhilesh Ramachandran ◽  
Craig Miller
Keyword(s):  
Ribosomal Rna ◽  
Cross Sections ◽  
Nucleotide Sequencing ◽  
Formalin Fixed Paraffin ◽  
Quarter Horse ◽  
Formalin Fixed Paraffin Embedded ◽  
History Of ◽  
The Brain ◽  
Gram Positive Cocci ◽  
Formalin Fixed

A 3-y-old, female Quarter Horse with a history of acute neurologic signs was found dead and was submitted for postmortem examination. Areas of petechial and ecchymotic hemorrhage were present on cross-sections of the cerebrum, cerebellum, and brainstem. Histologic examination of the brain revealed severe, purulent meningoencephalitis and vasculitis with a myriad of intralesional gram-positive cocci. Streptococcus pluranimalium was identified from formalin-fixed, paraffin-embedded tissue obtained from sites with active lesions by PCR and nucleotide sequencing of bacterial 16S ribosomal RNA. S. pluranimalium should be considered as a cause of meningoencephalitis in a horse.

scholarly journals Nucleotide Variation at theCHALCONE ISOMERASELocus inArabidopsis thaliana

Genetics ◽  
2000 ◽  
Vol 155 (2) ◽  
pp. 863-872 ◽  
Author(s):  
Helmi Kuittinen ◽  
Montserrat Aguadé
Keyword(s):  
Nucleotide Diversity ◽  
Direct Relationship ◽  
Selective Sweep ◽  
Balancing Selection ◽  
Neutral Theory ◽  
Low Frequency ◽  
The Other ◽  
Nucleotide Variation ◽  
Rapid Population Growth ◽  
History Of

AbstractAn ~1.9-kb region encompassing the CHI gene, which encodes chalcone isomerase, was sequenced in 24 worldwide ecotypes of Arabidopsis thaliana (L.) Heynh. and in 1 ecotype of A. lyrata ssp. petraea. There was no evidence for dimorphism at the CHI region. A minimum of three recombination events was inferred in the history of the sampled ecotypes of the highly selfing A. thaliana. The estimated nucleotide diversity (θTOTAL = 0.004, θSIL = 0.005) was on the lower part of the range of the corresponding estimates for other gene regions. The skewness of the frequency spectrum toward an excess of low-frequency polymorphisms, together with the bell-shaped distribution of pairwise nucleotide differences at CHI, suggests that A. thaliana has recently experienced a rapid population growth. Although this pattern could also be explained by a recent selective sweep at the studied region, results from the other studied loci and from an AFLP survey seem to support the expansion hypothesis. Comparison of silent polymorphism and divergence at the CHI region and at the Adh1 and ChiA revealed in some cases a significant deviation of the direct relationship predicted by the neutral theory, which would be compatible with balancing selection acting at the latter regions.

Morphometrics of the aerial roots of Kingia australis (Liliales)

1981 ◽  
Vol 29 (1) ◽  
pp. 81 ◽  
Author(s):  
B Lamont
Keyword(s):  
Fire History ◽  
Dead Zone ◽  
Dry Weight ◽  
Root Primordia ◽  
Stem Apex ◽  
Primary Roots ◽  
Aerial Roots ◽  
History Of ◽  
Lateral Branches ◽  
Potential Height

Kingia australis, common in the heaths and forests of south-western Australia, is distinguished from all other grass trees in Australia by the presence of a mantle of concealed aerial roots. A ring of up to 50 root primordia is initiated in winter from the stem apex. In plants more than 1 m high, initiation and commencement of elongation of the primary roots are no longer annual but dependent on the fire history of the plant. These roots descend between the stem and persistent leaf bases at about 2 cm per growing month, sending many lateral branches among the leaf bases. Aerial roots gradually replace the space occupied by the leaf bases until they may account for 45% of the dry weight of the aerial caudex. The caudex of one 6-m-high specimen bore up to 27 roots per cm2 transection of the root mantle, with about 3000 primary roots entering the soil. All underground primary roots (except the initial contractile roots) have an aerial origin and are concentrated vertically under the canopy. After 300-400 years the stem starts to die back from the base, and the aerial roots attached to that portion disintegrate. By propping up the stem and bridging the dead zone of the stem, the living aerial roots greatly extend the potential height and longevity of the plant. In addition, the hairy laterals are ideally located to absorb water and nutrients directly from the leaf bases. Protective and aerating functions are also indicated.

Holocene stand-scale vegetation dynamics and fire history of an old-growth spruce forest in southern Finland

2015 ◽  
Vol 24 (6) ◽  
pp. 731-741 ◽  
Author(s):  
Jennifer L. Clear ◽  
Heikki Seppä ◽  
Niina Kuosmanen ◽  
Richard H. W. Bradshaw
Keyword(s):  
Vegetation Dynamics ◽  
Fire History ◽  
Spruce Forest ◽  
Old Growth ◽  
History Of

CHARMONIUM PRODUCTION IN Pb–Pb COLLISIONS AT ALICE: FROM SUPPRESSION TO REGENERATION?

2013 ◽  
Vol 28 (21) ◽  
pp. 1330018 ◽  
Author(s):  
ENRICO SCOMPARIN
Keyword(s):  
Phase Transition ◽  
Cross Sections ◽  
Short Review ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Alice Experiment ◽  
Model Calculations ◽  
Ion Collisions ◽  
Quark Production ◽  
History Of

Heavy quarkonium states are considered as one of the key observables for the study of the phase transition from a system made of hadrons towards a Quark–Gluon Plasma (QGP). In the last 25 years, experiments at CERN and Brookhaven have studied collisions of heavy ions looking for a suppression of charmonia/bottomonia, considered as a signature of the phase transition. After an introduction to the main concepts behind these studies and a short review of the SPS and RHIC results, I will describe the results obtained in Pb – Pb collisions by the ALICE experiment at the LHC. The ALICE findings will be critically compared to those of lower energy experiments, to CMS results, and to model calculations. The large cross-sections for heavy-quark production at LHC energies are expected to induce a novel production mechanism for charmonia in heavy-ion collisions, related to a recombination of [Formula: see text] pairs along the history of the collision and/or at hadronization. The occurrence of such a process at the LHC will be discussed. Finally, prospects for future measurements will be shortly addressed.

Genetic variation in allozymes of western larch

1986 ◽  
Vol 16 (5) ◽  
pp. 1013-1018 ◽  
Author(s):  
Lauren Fins ◽  
Lisa W. Seeb
Keyword(s):  
Genetic Variation ◽  
Genetic Drift ◽  
Fire History ◽  
Glacial History ◽  
Geographic Proximity ◽  
Electrophoretic Variation ◽  
Inland Empire ◽  
Genetic History ◽  
Expected Heterozygosity ◽  
History Of

Seed samples from 19 stands of Larixoccidentalis Nutt. were analyzed for electrophoretic variation at 23 loci. Because sample sizes consisted of only 9 or 10 trees per stand (18–20 alleles per locus per stand), samples were grouped by geographic proximity into four larger samples. For all measures of variation, this species scored lower than most, but within the range observed for other western conifers. Most of the variation was found within rather than between the population groups. The single southern sample appeared to be genetically distinct from the others. Although some variation was observed between individual stand samples in expected heterozygosity, the consistently low values for all samples suggest that genetic drift has played a major role in the genetic history of the species in the Inland Empire, both through its glacial history in postulated refugia and through fire history in recent times.

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