Armillaria species on small woody plants, small woody debris, and root fragments in red pine stands

2005 ◽  
Vol 35 (6) ◽  
pp. 1487-1495 ◽  
Author(s):  
K W Kromroy ◽  
R A Blanchette ◽  
D F Grigal
Keyword(s):  
Woody Plants ◽  
Woody Debris ◽  
Red Pine ◽  
Stand Age ◽  
Soil Core ◽  
Large Numbers ◽  
Pine Stands ◽  
The Individual ◽  
Small Woody Debris ◽  
Armillaria Species

The incidence of Armillaria on small woody plants, small woody debris, and root fragments was estimated in red pine (Pinus resinosa Ait.) stands in northeastern Minnesota. Soil core samples 10 cm in diameter, and extending to a depth of either 16 or 25 cm, were collected from 13 stands belonging to three age-classes. Half of the youngest stands had been treated using herbicide. Mycelial fans or rhizomorphs of Armillaria were observed on 13% of the small woody plants and isolated from 8% of them. Including small woody debris and root fragments, 38% of 0–16 cm deep samples had Armillaria. Armillaria was observed on 3% and isolated from 1% of individual substrate units from 0 to 25 cm deep samples. Within a single stand, 0%–67% of the samples and 0%–9% of the individual units had evidence of Armillaria. All but one isolate were Armillaria ostoyae (Romagn.) Herink. Herbicide-treated and untreated red pine stands had similar Armillaria incidence, and there was a trend of incidence inversely related to stand age-class. Large numbers of small woody plants, woody debris, and root fragments were found in red pine stands; varying percentages of these substrates were contributing to the survival of Armillaria and could also be serving as sources of root disease inoculum.

Woody debris volumes and carbon accumulation differ across a chronosequence of boreal red pine and jack pine stands

2013 ◽  
Vol 43 (8) ◽  
pp. 768-775 ◽  
Author(s):  
Joshua Allard ◽  
Andrew Park
Keyword(s):  
Pinus Banksiana ◽  
Dead Wood ◽  
Woody Debris ◽  
Jack Pine ◽  
Carbon Accumulation ◽  
Red Pine ◽  
Stand Age ◽  
Data Set ◽  
C Storage ◽  
Pine Stands

Boreal forests are thought to store more than 30% of the world’s terrestrial carbon (C), much of it in the form of dead wood. Harvesting, stand transformation, and climate change the storage capacity of this carbon pool and improved quantification of C storage is needed to improve the accuracy and coverage of C accounting in Canadian forests. In this study, we compared wood volumes and C storage in coarse woody debris (CWD), fine woody debris (FWD), and standing dead wood (snags) in a 94-year chronosequence of jack pine (Pinus banksiana Lamb.) and red pine (Pinus resinosa Ait.) stands in the Sandilands Provincial Forest, southeastern Manitoba. In our data set of 20 jack pine and 17 red pine stands, jack pine stands supported higher volumes of CWD, snags, and sparsely distributed FWD than red pine stands. Mean CWD volume and C mass were, respectively, 18.6 m3·ha−1 and 2.6 tonnes (t)·ha−1 for jack pine and 11.3 m3·ha−1 and 1.1 t·ha−1 for red pine. Snag volumes and C mass were, respectively, 1.8 m3·ha−1 and 0.25 t·ha−1 for jack pine and 0.26 m3·ha−1 and 0.04 t·ha−1 for red pine. CWD loads in jack pine stands followed a U-shaped distribution with stand age, and snag loads in jack pine increased linearly with time. No such significant trends for CWD or snags were observed in red pine. Our results confirm that stand conversion from fire-origin jack pine to red pine plantations has the potential to significantly reduce and alter temporal patterns of dead wood accumulation across the landscape.

Estimation de la production de jeunes plantations de pin rouge et de pin gris du sud du Québec

1976 ◽  
Vol 6 (4) ◽  
pp. 478-486 ◽  
Author(s):  
H. A. Bolghari
Keyword(s):  
Multiple Regression ◽  
Jack Pine ◽  
Red Pine ◽  
Pine Plantations ◽  
Regression Equations ◽  
Pine Plantation ◽  
South Shore ◽  
Pine Stands ◽  
Natural Stands ◽  
St Lawrence River

Multiple regression equations have been developed to predict yield from young red pine and jack pine plantations. Data from 446 sample plots representing young red pine and jack pine stands located on the south shore of the St. Lawrence River between Quebec and Montreal were analysed. The red pine plantation yielded more than the jack pine. However, in plantation both species yield more than in natural stands. Taking into account the age and spacing of the sampled plantations, the equation obtained can provide information on yield of red pine and jack pine stands the maximum spacing of which is 3 × 3 m, up to the age of 45 and 35 years respectively. The equations will allow the construction of preliminary yield tables for both species.

Autonomy and non-autonomy in Drosophila mesoderm determination and morphogenesis

Development ◽  
1994 ◽  
Vol 120 (4) ◽  
pp. 853-859 ◽  
Author(s):  
M. Leptin ◽  
S. Roth
Keyword(s):  
Cell Shape ◽  
Shape Change ◽  
Developmental Program ◽  
Cell Shape Change ◽  
Ventral Furrow ◽  
Large Numbers ◽  
The Individual ◽  
Mutant Cells ◽  
Transplantation Experiments ◽  
Shape Changes

The mesoderm in Drosophila invaginates by a series of characteristic cell shape changes. Mosaics of wild-type cells in an environment of mutant cells incapable of making mesodermal invaginations show that this morphogenetic behaviour does not require interactions between large numbers of cells but that small patches of cells can invaginate independent of their neighbours' behaviour. While the initiation of cell shape change is locally autonomous, the shapes the cells assume are partly determined by the individual cell's environment. Cytoplasmic transplantation experiments show that areas of cells expressing mesodermal genes ectopically at any position in the egg form an invagination. We propose that ventral furrow formation is the consequence of all prospective mesodermal cells independently following their developmental program. Gene expression at the border of the mesoderm is induced by the apposition of mesodermal and non-mesodermal cells.

Evolution of mutation rate and virulence among human retroviruses

1994 ◽  
Vol 346 (1317) ◽  
pp. 333-343 ◽  
Keyword(s):  
Immune System ◽  
Mutation Rate ◽  
Hiv Infections ◽  
Molecular Data ◽  
Mutation Rates ◽  
Rapid Progression ◽  
Human T Cell ◽  
Large Numbers ◽  
The Individual ◽  
Multicellular Organisms

High mutation rates are generally considered to be detrimental to the fitness of multicellular organisms because mutations untune finely tuned biological machinery. However, high mutation rates may be favoured by a need to evade an immune system that has been strongly stimulated to recognize those variants that reproduced earlier during the infection, hiv infections conform to this situation because they are characterized by large numbers of viruses that are continually breaking latency and large numbers that are actively replicating throughout a long period of infection. To be transmitted, HIVS are thus generally exposed to an immune system that has been activated to destroy them in response to prior viral replication in the individual. Increases in sexual contact should contribute to this predicament by favouring evolution toward relatively high rates of replication early during infection. Because rapid replication and high mutation rate probably contribute to rapid progression of infections to aids, the interplay of sexual activity, replication rate, and mutation rate helps explain why HIV-1 has only recently caused a lethal pandemic, even though molecular data suggest that it may have been present in humans for more than a century. This interplay also offers an explanation for geographic differences in progression to cancer found among infections due to the other major group of human retroviruses, human T-cell lymphotropic viruses (HTLV). Finally, it suggests ways in which we can use natural selection as a tool to control the aids pandemic and prevent similar pandemics from arising in the future.

scholarly journals Short-term effects of fertilizer application on soil respiration in red pine stands

2012 ◽  
Vol 35 (4) ◽  
pp. 307-311 ◽  
Author(s):  
Choonsig Kim ◽  
Jaeyeob Jeong ◽  
Nanthi S. Bolan ◽  
Ravi Naidu
Keyword(s):  
Soil Respiration ◽  
Fertilizer Application ◽  
Red Pine ◽  
Short Term ◽  
Pine Stands ◽  
Short Term Effects

Canada's oldest permanent sample plots — thinning in white and red pine

1998 ◽  
Vol 74 (4) ◽  
pp. 606-616 ◽  
Author(s):  
Darwin Burgess ◽  
Craig Robinson
Keyword(s):  
Woody Debris ◽  
Basal Area ◽  
Wildlife Habitat ◽  
Red Pine ◽  
Major Influence ◽  
Residual Volume ◽  
Annual Increment ◽  
Permanent Sample Plots ◽  
Stand Management ◽  
Set Up

Two of the oldest permanent sample plots (PSPs) in Canada were set up at Petawawa, Ontario (45° 57′ N, 77° 34′ W) to examine the effect of thinning on the development of natural white (Pinus strobus L.) and red pine (Pinus resinosa Ait). Field data were collected periodically, starting in 1918 when the stand was 40 years old and continuing for 71 years. Six thinning treatments were completed, beginning in 1918, and then in 1933, 1941, 1959, 1969 and 1989. The intensity of thinning varied through time with 14, 27, 38, 8, 30, and 7% of the basal area removed. The sawlog volume mean annual increment for the thinned plot remained stable at about five m3 ha−1 yr−1, but the sawlog volume periodic annual increment for the control declined markedly during the last 10-year measurement period to less than 2 m3 ha−1 yr−1. The residual volume was higher in the control; but, if the harvested sawlog volume (264.5 m3 ha−1) was added to the residual sawlog volume (301.3 m3 ha−1) for PSP one, then the sawlog production on the thinned plot has been about the same and its residual volume concentrated on fewer, larger and more valuable trees. The level of natural mortality in the control plot (129.7 m3 ha−1 of sawlog volume) was greater than 10 times that in the thinned plot, thereby adding more coarse woody debris to improve wildlife habitat. These two approaches had a major influence on stand development. The approach used will depend on specific stand-level management objectives. Key words: white pine, red pine, natural stand management, shelterwood system, permanent sample plots.

Epilepsy

2013 ◽  
pp. 155-173 ◽  
Author(s):  
Ian Brown ◽  
Martin C. Prevett
Keyword(s):  
Epileptic Seizures ◽  
Shop Floor ◽  
Common Condition ◽  
Insurance Cover ◽  
Large Numbers ◽  
Working People ◽  
History Of ◽  
Education And Employment ◽  
The Individual ◽  
Available Information

Epilepsy is a common condition that affects large numbers of working people. In about one-third, epilepsy is the only condition, and in others there are additional neurological, intellectual, or psychological problems. Uncontrolled epileptic seizures can lead to injury and may impact on education and employment, but antiepileptic drug (AED) treatment is effective in approximately 70 per cent of people with epilepsy. Many people do not disclose a history of epileptic seizures when applying for a job or during a routine examination at the workplace. This may cause major problems for the individual and the employer and, on occasions, inadvertently contravene the HSW Act or invalidate insurance cover. However, the disability provisions of the Equality Act 2010 now confer some protection on those with epilepsy. The unenlightened attitudes of some employers have led to secrecy or denial by those affected. The possibility of dangerous situations arising at work, or dismissal without recourse to appeal, may be the consequence. A competent occupational health service, trusted by both shop-floor and management, can be invaluable in resolving conflicts and giving advice. Responsibility for the employment and placement of a person with epilepsy rests with the employer and they should take appropriate medical advice. Each case must be judged on its merits in light of the available information, which must include a sound and complete understanding of the requirements of the job. Employees with epilepsy must be regularly reviewed. The development of good rapport and mutual trust will encourage employees to report any changes in their condition or treatment that have arisen.

Subsampling Reduces Sorting Effort for Waterfowl Foods in Salt-Marsh Core Samples

2014 ◽  
Vol 5 (2) ◽  
pp. 380-386 ◽  
Author(s):  
Mark C. Livolsi ◽  
Kevin M. Ringelman ◽  
Christopher K. Williams
Keyword(s):  
Salt Marsh ◽  
Food Availability ◽  
Carrying Capacity ◽  
Processing Time ◽  
Soil Core ◽  
Habitat Types ◽  
Core Samples ◽  
Large Numbers ◽  
Significant Difference ◽  
Time Savings

Abstract Waterfowl researchers often use soil core samples to estimate food availability in foraging habitats, and these estimates are needed for bioenergetic models of carrying capacity. However, core sampling is frequently a time- and resource-intensive process, and some researchers have suggested that subsampling may be a valuable way to reduce processing time. We evaluated whether 10% and 25% by mass subsampling are appropriate techniques for reducing core-sorting effort while maintaining precision for samples taken in six separate habitat types along the Delaware bayshore. We found no significant difference between biomass found in 100% sorted cores and estimated biomass obtained by 10% and 25% subsampling. We found that 10% subsampling offered the greatest time savings, reducing mean sorting times by 77% (from 13.7 hours to 3.3 hours) from 100% sorted cores. We recommend that researchers consider subsampling to reduce core-sorting effort and cost, particularly when processing large numbers of cores.

scholarly journals Some Relationships Between Silvicultural Treatments and Symmetry of Stem Growth in a Red Pine Stand

1998 ◽  
Vol 15 (2) ◽  
pp. 90-93 ◽  
Author(s):  
Bruce C. Larson ◽  
W. Keith Moser ◽  
Vijay K. Mishra
Keyword(s):  
Growth Patterns ◽  
Red Pine ◽  
Mixed Stand ◽  
Stand Age ◽  
Pure Stand ◽  
White Pine ◽  
Silvicultural Treatments ◽  
Growth Increments ◽  
Crown Shape ◽  
Asymmetric Growth

Abstract Variations in spacing and the distribution of removed trees have been assumed to affect the pattern of growth on tree boles. Changing crown shapes were believed to affect the symmetry of the stems. This study examined the change of growing space resulting from differential species' growth in a mixed stand. A red pine (Pinus resinosa Ait.) plantation in southern New Hampshire was planted at 2 × 2 m spacing in 1917. At one end of the stand every second row was planted with white pine (Pinus strobus L.), whereas the other end of the stand was pure red pine. In the mixed portion of the stand, the red pine outgrew the white pine, overtopping and often killing it. The mixed stand was thinned in the 1970s and the pure stand in the 1980s for a variety of products which opened more crown room for some of the trees. We compared growth increments along perpendicular axes to determine if asymmetry was consistent at different bole heights. The study did not show asymmetric boles at age 50 and did not have asymmetric growth patterns attributable to the earlier history up to stand age 70. When current crown shape was compared to current growth there was no relationship between asymmetric crowns and asymmetric growth. Provided the asymmetry is not maintained throughout the entire rotation, silvicultural treatments which greatly affect the stand spatial pattern may not have a lasting effect on the symmetry of the boles. North. J. Appl. For. 15(2):90-93.

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