Early colonization of Populus wood by saproxylic beetles (Coleoptera)

2001 ◽  
Vol 31 (7) ◽  
pp. 1175-1183 ◽  
Author(s):  
H E. James Hammond ◽  
David W Langor ◽  
John R Spence

The early colonization of newly created coarse woody material (CWM) by beetles was studied in aspen mixedwood forests at two locations in north-central Alberta. Healthy trembling aspen (Populus tremuloides Michx.) trees, in old (>100 years) and mature (40–80 years) stands, were cut to provide three types of CWM: stumps, bolts on the ground (logs), and bolts suspended above the ground to simulate snags. Over 2 years, 1049 Coleoptera, representing 49 taxa, were collected. Faunal structure differed little between the two locations. Species diversity was higher in old than in mature stands, and higher in stumps and logs than in suspended bolts; however, these "snags" tended to have higher abundance when compared with stumps and logs. Overall beetle abundance and the catch of wood-boring beetles was significantly higher in the first year post-treatment, mainly because of the ambrosia beetle (Trypodendron retusum (LeConte)) and one of its predators, Rhizophagus remotus LeConte; however, beetle diversity was higher in the second year, suggesting that early wood-boring species may "precondition" the wood for a number of succeeding species. The high turnover rate of taxa and spatial or temporal variation in faunal structure suggests that effort focused on habitat classification of CWM will facilitate management to conserve saproxylic faunal diversity.

2018 ◽  
Vol 18 (1) ◽  
pp. 99-111
Author(s):  
Alberto Prieto ◽  
José Manuel Díaz-Cao ◽  
Pablo Díaz ◽  
Ana Pérez-Creo ◽  
Gonzalo López-Lorenzo ◽  
...  

Abstract The objective of this study was to assess the implementation of a three-year Mycobacterium avium subsp. paratuberculosis monitoring programme using pooled faecal culture in small and mediumsized dairy herds to classify them as infected or non-infected and apply proper hygiene and biosecurity measures. Over a three-year period, 35 dairy herds were analysed annually by faecal culture of ten pooled samples. In addition, proper hygiene and biosecurity protocols were implemented in the farms after the first testing round. Considering a herd as infected with at least one culture positive in any of the three years, the accumulated percentage of infected herds was 25.7%, 40% and 45.7%, for each year respectively. Assuming that all infected herds had been detected at the end of the study, the percentage of infected herds detected each year was 56.25% and 87.5% for the first and second year, respectively. Using frequentist and Bayesian approaches, the estimated individual prevalence revealed a downward trend from 3.30-3.65% in the first year to 1.66-1.86% in the third year. The results of this study indicate that pooled faecal culture allowed for proper classification of the herds and can be a useful tool for monitoring dairy herds against paratuberculosis. In addition, statistical analysis of pooled faecal culture results can be used to evaluate the evolution of individual prevalence in the population and therefore the function of the implemented control programmes.


2009 ◽  
Vol 85 (4) ◽  
pp. 631-638 ◽  
Author(s):  
Alison D Lennie ◽  
Simon M Landhäusser ◽  
Victor J Lieffers ◽  
Derek Sidders

Trembling aspen regeneration was studied in 2 types of partial harvest systems designed to harvest mature aspen but protect immature spruce and encourage natural aspen regeneration. Two partial harvest systems, where the residual aspen was either left in strips or was dispersed uniformly, were compared to traditional clearcuts. After the first and second year since harvest, aspen sucker density and growth was similar between the 2 partial harvests, but was much lower than in the clearcuts. However, in the partial cuts the regeneration density was very much dependent on the location relative to residual trees. The density of regeneration was inversely related to the basal area of residual aspen; however, sucker height was inversely related to the basal area of the residual spruce. Although there were adequate numbers of suckers after partial harvest, their viability and contribution to the long-term productivity of these mixedwood stands is not clear. Key words: silvicultural systems, forest management, residual canopy, white spruce, Populus tremuloides, Picea glauca, traffic


2004 ◽  
Vol 19 (04) ◽  
pp. 297-306 ◽  
Author(s):  
Shigeru Sokejima ◽  
Yoshimi Nakatani ◽  
Kazuomi Kario ◽  
Kazunori Kayaba ◽  
Masumi Minowa ◽  
...  

AbstractIntroduction:No epidemiological data exist concerning the influence of an earthquake on the risk of stroke. Whether the incidence of cerebrovascular stroke increased after the 1995 Hanshin-Awaji earthquake (EQ) in Japan and whether seismic intensity affected stroke risk dose-dependently was examined.Methods:A retrospective cohort study was conducted among residents, who were living in two towns on the island of Awaji and were participants of the National Health Insurance (NHI) program. The two towns were divided into 11 districts and their respective damage and socioeconomic states were investigated. Reviewing the NHI documents issued before and after the EQ, people who had strokes (9th International Classification of Diseases, codes 430–431 or 433–434.9) were identified. Risk of stroke in relation to the seismic intensities, was assessed with the Cox proportional hazard model.Results:Among subjects aged 40 to 99 years, 45 of 8,758 (0.514%) had a stroke the year before the EQ, 72 of 8,893 (0.810%) had a stroke in the first year following the EQ, and 49 of 8,710 (0.566%) had a stroke in the second year following the EQ. In districts where the earthquake's intensity was ≤9.5 on the modified Mercalli intensity (MMI), compared with the year prior to the EQ, the relative risk (RR) of stroke was 2.4 (95% confidence interval (CI) 1.1, 5.0) in the first year following the EQ, after adjusting for age, gender, and income. In that year, compared with MMI of <8.5–9.0, RRs for 9.0–9.5 and ≥9.5 were 1.6 (CI 0.9, 2.1) and 2.0 (CI 1.1, 3.7), respectively (pfor trend 0.02). No trend for the RR was observed in the year before the EQ or in the second year following the EQ.Conclusion Stroke increased in the first year following the EQ. The increase was associated with seismic intensity in a dose-response manner. Results suggest a potential threshold for RR of >2.0 in areas near 9.5 on the MMI scale.


2005 ◽  
Vol 35 (9) ◽  
pp. 2141-2150 ◽  
Author(s):  
EH (Ted) Hogg ◽  
Ross W Wein

The valleys of southwestern Yukon have a continental climate with average annual precipitation of <300 mm. In 1958, fires burned large areas of mature mixedwood forests dominated by white spruce (Picea glauca (Moench) Voss) in the valleys near Whitehorse. Since then, the burned areas have shown poor regeneration of spruce, but have been colonized by scattered clones of trembling aspen (Populus tremuloides Michx.) interspersed by grassland. The objective of the study was to examine the influence of climatic variation on forest growth and regeneration in the 1958 burn and the adjacent unburned forests. Tree-ring analysis was conducted on 50 aspen and 54 white spruce in 12 mature stands where these species were codominant, and on 147 regenerating aspen in the 1958 Takhini burn. The mature stands were uneven-aged and the patterns of growth variation for the aspen and spruce between 1944 and 2000 were similar. Growth of both species was most strongly related to variation in precipitation. The regenerating aspen had a wide age-class distribution (1959–2000) and their growth was also positively related to precipitation. The results indicate that these forests have been slow to regenerate after fire, and are vulnerable if the climate becomes drier under future global change.


1978 ◽  
Vol 54 (1) ◽  
pp. 24-28 ◽  
Author(s):  
Roy F. Sutton

Environmentally safe, yet potent in controlling herbs, grasses, and woody species, with possibilities for selective use, glyphosate (Roundup®) has great potential usefulness in forestry.In the small study reported here, twelve.01 ha plots were established in August, 1973 in dense 6-year-old shrub and hardwood post-fire regrowth near Chapleau, Ontario. In each plot, 16 rising 3 + 0 white spruce (Picea glauca [Moench] Voss) were planted centrally at.9 m ×.9 m spacing. Six treatments with two replications were applied at random the next day: 1, control; 2, all woody vegetation cut off at ground level; 3, all woody vegetation cut off in central planted area of plot; 4, sprayed with 60 mL glyphosate in 1.892 L of water; 5, sprayed with double strength glyphosate; 6, sprayed with sextuple strength glyphosate. Eight trees in each plot were shielded during the spraying. Browsing affected 16% of the spruce after 2 weeks, 96% by spring. Half of each plot was replanted with eight white spruce (four of them caged against browsing) in May, 1974.The objectives were to observe the effect of glyphosate on hardwood and shrub competition, to assay this effect by white spruce outplantings, and to evaluate the resistance to glyphosate of newly planted white spruce. Glyphosate was highly effective in killing trembling aspen (Populus tremuloides Michx.), white birch (Betula papyrifera Marsh.), and beaked hazel (Corylus cornuta Marsh.): pin cherry (Prunus pensylvanica L. f.) resprouted with moderate vigor. White spruce responded significantly (P.01) to first-year non-herbicide (i.e., immediate) weed control, but second-year height increment was significantly (P.001) less than that of the first year: second-year height increment in the glyphosate treatments was significantly (P.001) greater than in the non-herbicide treatments. Growth and survival were both affected by non-treatment disturbances, but shielding during spraying improved second-year survival significantly (P.001).


2020 ◽  
Vol 5 (1) ◽  
pp. 74-89
Author(s):  
Hugh Crago

In a seminal 1973 paper, Robert Clark described the very different “cultures” of the first and second year students in a four year clinical psychology PhD programme. The author applies Clark’s template to his own experiences as trainee or trainer in five different counsellor education programmes, one in the US and four in Australia. Each of the programmes, to varying degrees, demonstrates key features of the pattern identified by Clark, where the first year is “therapeutic” and other-oriented, the second is “professional” and self-focused. The author concludes that all the surveyed programmes exhibited some level of “second year crisis”, in which a significant number of students felt abandoned, dissatisfied, or rebellious. The author extends and refines Clark’s developmental analogy (first year = childhood; second year = adolescence) to reflect recent neurological research, in particular, the shift from a right hemisphere-dominant first year of life, prioritising affiliative needs, to a left hemisphere-dominant second year, prioritising autonomy and control. This shift is paralleled later by a more gradual move from a protective, supportive childhood to necessary, but sometimes conflictual, individuation in adolescence. The first two years of a counsellor training programme broadly echo this process, a process exacerbated by the second year internship/placement, in which students must “leave home” and adjust to unfamiliar, potentially less nurturing, authority figures. Finally, the author suggests introducing more rigorous “academic holding” into the first year, and greater attention to “therapeutic holding” of dissident students in the second, hopefully decreasing student dropout, and achieving a better balanced training experience.


Author(s):  
Umar Iqbal ◽  
Deena Salem ◽  
David Strong

The objective of this paper is to document the experience of developing and implementing a second-year course in an engineering professional spine that was developed in a first-tier research university and relies on project-based core courses. The main objective of this spine is to develop the students’ cognitive and employability skills that will allow them to stand out from the crowd of other engineering graduates.The spine was developed and delivered for the first time in the academic year 2010-2011 for first-year general engineering students. In the year 2011-2012, those students joined different programs, and accordingly the second-year course was tailored to align with the different programs’ learning outcomes. This paper discusses the development and implementation of the course in the Electrical and Computer Engineering (ECE) department.


2020 ◽  
Author(s):  
Jennifer McDonald ◽  
Rebecca Merkley ◽  
Jacqueline Mickle ◽  
Lisa Collimore ◽  
Daniel Ansari

Research in cognitive development has highlighted that early numeracy skills are associated with later math achievement, suggesting that these skills should be targeted in early math education. Here we tested whether tools used by researchers to assess mathematical thinking could be useful in the classroom. This paper describes a collaborative project between cognitive scientists and school board researchers/educators implementing numeracy screeners with kindergarten students over the course of three school years. The Give-A-Number task (Wynn, 1990) was used with first-year kindergarten students and the Numeracy Screener [BLINDED] with second-year kindergarten students. Results indicated that educators (N = 59) found the tools feasible to implement and helpful for exploring their students’ thinking and targeting instruction. The Educators’ feedback also helped inform improvements to the implementation of the tools and future directions for both the schools and the researchers. This work emphasizes the importance of transdisciplinary collaboration to address the research-practice gap.


2016 ◽  
Vol 3 (3) ◽  
Author(s):  
ARVIND KUMAR ◽  
POOJA KHULBE

Influence of abiotic factors and hosts on population dynamics of green lacewing, Chrysoper lacarnea (Stephens) was studied in sunflower, Helianthus annus (Linn.).The maximum number of C. carnea population was found during mid March –mid April in the first year and mid April – mid May in the second year in sunflower crop. The maximum number of host population viz. egg and larva of Helicoverpa armigera and Myzuspe rsicae population were found during mid March –mid April in both the year and correlation studies revealed the positive and significant correlation between larval population of H. armigera, M. persicae and predator C. carnea. While there was no significant relationship found between eggs of H. armigera and C. carnea. The C. carnea population on H. annus during both the year was positively correlated with maximum temperature and found significant,while negatively correlated with relative humidity.However, no significant correlation of C. carnea was found with minimum temperature in both the year.


1955 ◽  
Vol 47 (5) ◽  
pp. 224-228 ◽  
Author(s):  
James H. Torrie ◽  
Earle W. Hanson
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document