scholarly journals Dominating North American Forest Pathology Issues of the 20th Century

2003 ◽  
Vol 93 (8) ◽  
pp. 1039-1040 ◽  
Author(s):  
William L. MacDonald

The profession of forest pathology evolved in the early decades of the 20th century from a science describing microorganisms that infect trees to a discipline that was required to deal with numerous disease outbreaks. The foundations of the science were carried from Europe to the “New World” and initially dealt with decay and the resource losses it caused. The profession was forced to shift direction quickly because it was called upon to address major diseases caused by the introduction of pathogens from other continents; notably organisms inciting chestnut blight, Dutch elm disease, and white pine blister rust. Changes in natural ecosystems that resulted from a legacy of poor forest practice, land abuse, and an increase in plantation monocultures gave rise to other disease problems when host-pathogen balances in natural ecosystems were disturbed. Further, the need for large numbers of tree seedlings resulted in numerous nursery disease problems. Although many of the principles of general plant pathology had application to the study of forest diseases, the long-term nature of forests requires varied approaches to their study and management. Today, the science continues to evolve as the complexities of forest ecosystems unfold.

2000 ◽  
Vol 10 (3) ◽  
pp. 546
Author(s):  
Bohun B. Kinloch

After a century since introduction to North America from Europe, white pine blister rust, caused by Cronartium ribicola J.C. Fisch., is recognized as one of the catastrophic plant disease epidemics in history. It has not yet stabilized and continues to spread and intensify. Its nine native white pine hosts comprise major timber producers, important watershed protectors, keystone ecological species, and the oldest trees on earth. All are highly susceptible and some have been damaged severely in parts of their native range, as well as where they have been planted as exotics. Resistance, the most promising approach to control, requires understanding of genetic interactions between hosts and pathogen, a quest that has been ongoing for half a century. Unlike other hosts of spectacular exotic diseases, such as chestnut blight [caused by Cryphonectria parasitica (Murrill) M.E. Barr] and dutch elm disease [caused by Ophiostoma ulmi (Buisman) Nannf.], white pines (Pinus L.) exhibit a surprising number of resistance mechanisms to blister rust, if at only low frequencies. There are three main kinds:


1990 ◽  
Vol 66 (2) ◽  
pp. 127-132 ◽  
Author(s):  
Denis Lachance

Losses due to diseases are an important part of forest pest depletion, therefore much is expected from forest pathology research. Examples of recent accomplishments in forest disease protection include a vastly increased knowledge in the field of root and butt rots as well as in control methodologies and in the predictability of such problems; the development of control strategies for scleroderris canker through increased surveys, improved diagnostic methodologies and new control techniques; the establishment of white pine blister rust hazard zones; and the publication of user-friendly technical bulletins. As the pool of forest pathology researchers has changed little in recent years, the task ahead is enormous when compared to expectations. However, acquired knowledge, the application of new technologies, and the more common acceptance of the integrated pest management (IPM) concept should allow for significant strides forward in forest disease control. Finally, it is suggested that forest pathologists take the lead in promoting a concept of forest health to promote better integration of forest disease protection with forest stand productivity and survival.


2008 ◽  
Vol 38 (5) ◽  
pp. 982-995 ◽  
Author(s):  
Cyndi M. Smith ◽  
Brendan Wilson ◽  
Salman Rasheed ◽  
Robert C. Walker ◽  
Tara Carolin ◽  
...  

In 2003–2004, we examined 8031 whitebark pine ( Pinus albicaulis Engelm.) trees and 3812 seedling-establishment sites in 170 plots for mortality and incidence of white pine blister rust ( Cronartium ribicola A. Dietr.). We found blister rust in all but four plots (98%), and 57% of all trees assessed for blister rust were either already dead or showed signs of blister rust infection. Mean percentage of trees infected was highest in the southern Canada – United States border area (∼73%), decreasing to a low in the northern region of Banff National Park, Alberta (∼16%), and then rising (∼60%) in the northern end of the study area in Jasper National Park, Alberta. Stands with higher infection, mortality, and canopy kill of trees and higher presence of rust on seedlings tended to be located on the western side of the Continental Divide. In the eight stands in Waterton Lakes National Park, Alberta, that had been previously assessed in 1996, infection levels increased from 43% to 71%, and mortality increased from 26% to 61%, whereas no change was apparent in Glacier National Park, Montana, stands. The impacts of high mortality and infection levels, high crown kill, and reduced regeneration potential, suggest that the long-term persistence of whitebark pine in the southern part of the study area is in jeopardy.


1967 ◽  
Vol 06 (01) ◽  
pp. 8-14 ◽  
Author(s):  
M. F. Collen

The utilization of an automated multitest laboratory as a data acquisition center and of a computer for trie data processing and analysis permits large scale preventive medical research previously not feasible. Normal test values are easily generated for the particular population studied. Long-term epidemiological research on large numbers of persons becomes practical. It is our belief that the advent of automation and computers has introduced a new era of preventive medicine.


2011 ◽  
Author(s):  
Amanda Crump ◽  
William R. Jacobi ◽  
Kelly S. Burns ◽  
Brian E. Howell

2008 ◽  
Author(s):  
Kelly S. Burns ◽  
Anna W. Schoettle ◽  
William R. Jacobi ◽  
Mary F. Mahalovich

Buildings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 27
Author(s):  
Klara Kroftova

An urban residential building from the second half of the 19th century and the start of the 20th century, the so-called tenement house, is a significant representative of the architecture of the developing urban fabric in Central Europe. The vertical and horizontal load-bearing structures of these houses currently tend to show characteristic, repeated defects and failures. Their knowledge may, in many cases, facilitate and speed up the design of the historic building’s restoration without compromising its heritage value in this process. The article presents the summary of the most frequently occurring defects and failures of these buildings. The summary, however, is not an absolute one, and, in the case of major damage to the building, it still applies that, first of all, a detailed analysis of the causes and consequences of defects and failures must be made as a basic prerequisite for the reliability and long-term durability of the building’s restoration and rehabilitation. An integral part of the rehabilitation of buildings must be the elimination of the causes of the appearance of their failures and remediation of all defects impairing their structural safety, health safety and energy efficiency.


2015 ◽  
Vol 12 (103) ◽  
pp. 20141184 ◽  
Author(s):  
Konstans Wells ◽  
Barry W. Brook ◽  
Robert C. Lacy ◽  
Greg J. Mutze ◽  
David E. Peacock ◽  
...  

Infectious diseases can exert a strong influence on the dynamics of host populations, but it remains unclear why such disease-mediated control only occurs under particular environmental conditions. We used 16 years of detailed field data on invasive European rabbits ( Oryctolagus cuniculus ) in Australia, linked to individual-based stochastic models and Bayesian approximations, to test whether (i) mortality associated with rabbit haemorrhagic disease (RHD) is driven primarily by seasonal matches/mismatches between demographic rates and epidemiological dynamics and (ii) delayed infection (arising from insusceptibility and maternal antibodies in juveniles) are important factors in determining disease severity and local population persistence of rabbits. We found that both the timing of reproduction and exposure to viruses drove recurrent seasonal epidemics of RHD. Protection conferred by insusceptibility and maternal antibodies controlled seasonal disease outbreaks by delaying infection; this could have also allowed escape from disease. The persistence of local populations was a stochastic outcome of recovery rates from both RHD and myxomatosis. If susceptibility to RHD is delayed, myxomatosis will have a pronounced effect on population extirpation when the two viruses coexist. This has important implications for wildlife management, because it is likely that such seasonal interplay and disease dynamics has a strong effect on long-term population viability for many species.


1994 ◽  
Vol 1 (3) ◽  
pp. 214 ◽  
Author(s):  
Colin J. Yates ◽  
Richard J. Hobbs ◽  
Richard W. Bell

Woodlands dominated by Eucalyptus salmonophloia occur both in the fragmented landscapes of the Western Australian wheatbelt and in the adjacent unfragmented goldfields area. We examined the responses of the unfragmented woodlands to landscape-scale disturbances caused by fire, floods, windstorms and drought. Sites known to have experienced disturbances of these types over the past 50 years all had cohorts of sapling-stage E. salmonophloia and other dominant Eucalyptus species. Sites disturbed either by fire, flood or storm during 1991-92 displayed adult tree mortality and extensive seedling establishment, although rates of establishment and survival varied between sites. No regeneration was observed at equivalent undisturbed sites. These results indicate that landscape-scale disturbances of several types are important drivers of the dynamics of these semi-arid woodlands. Lack of regeneration of fragmented woodlands in the wheatbelt is likely to be due to changed disturbance regimes coupled with altered physical and biotic conditions within remnants. We argue that it may be difficult to identify processes which are important for the long-term persistence of natural ecosystems in fragmented landscapes without reference to equivalent unfragmented areas.


2016 ◽  
Vol 214 (5) ◽  
pp. 571-586 ◽  
Author(s):  
Elisa Herawati ◽  
Daisuke Taniguchi ◽  
Hatsuho Kanoh ◽  
Kazuhiro Tateishi ◽  
Shuji Ishihara ◽  
...  

Multiciliated cells (MCCs) promote fluid flow through coordinated ciliary beating, which requires properly organized basal bodies (BBs). Airway MCCs have large numbers of BBs, which are uniformly oriented and, as we show here, align linearly. The mechanism for BB alignment is unexplored. To study this mechanism, we developed a long-term and high-resolution live-imaging system and used it to observe green fluorescent protein–centrin2–labeled BBs in cultured mouse tracheal MCCs. During MCC differentiation, the BB array adopted four stereotypical patterns, from a clustering “floret” pattern to the linear “alignment.” This alignment process was correlated with BB orientations, revealed by double immunostaining for BBs and their asymmetrically associated basal feet (BF). The BB alignment was disrupted by disturbing apical microtubules with nocodazole and by a BF-depleting Odf2 mutation. We constructed a theoretical model, which indicated that the apical cytoskeleton, acting like a viscoelastic fluid, provides a self-organizing mechanism in tracheal MCCs to align BBs linearly for mucociliary transport.


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