No abstract

From 1987–1991, conditions in 110 conventional plantings of introduced lodgepole pine (Pinuscontorta Dougl. ex Loud.) were investigated in northern Sweden. Severe damage by Scleroderris canker, caused by the fungus Gremmeniellaabietina (Lagerb.) Morelet, was recorded at high elevations in 1987. Damage was related to a period with extreme weather conditions. The disease was initially severe in low lying areas, from where it quickly spread throughout the plantations during 1988. Temperatures above average during 1988–1990 favoured tree vigour, which in turn slowed the spread of the disease. The frequency of stem cankers increased in seriously infected areas during 1989, and new severe damage was recorded locally in 1990 and in 1992. A strong correlation was found between disease severity and the temperature sum at the site. Lodgepole pine planted on spruce sites was often severely affected. A negative correlation was found between the frequency of G. abietina and the abundance of birch thicket. In large areas in northern Sweden with a more favourable climate, lodgepole pine plantations were healthy and productive up to 1991. However, instability, leading to increased susceptibility to disease, has become a problem of great concern in some of these areas during the 1990s.

Survival, height, and health status of Pinus sylvestris and Pinus contorta were studied in a randomized factorial experiment in northern Sweden. Treatments studied per species were no scarification (control), patch scarification, and mounding. The experiment was evaluated 18 years after planting. For both species, survival was higher in mounded plots than in control plots. Pinus contorta was 11% higher than P. sylvestris in the treatment with highest survival, but this difference was not significant. Ninety-three per cent of the P. contorta trees were infected and 22% killed by Gremmeniella abietina compared with 21% and 5% for P. sylvestris. Eighty-three per cent of the P. sylvestris trees were infected and 24% killed by Phacidium infestans compared with 8% and 2% for P. contorta. Leaning P. contorta trees were more severely damaged by G. abietina than those not leaning. Mounding reduced the mortality caused by G. abietina in P. contorta and by Ph. infestans in P. sylvestris. Due to the increasing mortality of P. contorta during the past 6 yrs, and the high frequency of G. abietina, the number of surviving trees of the two species are approaching equality. Significantly more P. contorta than P. sylvestris trees were leaning and had poor stem quality. Regardless of species, mounded plots showed the highest frequency of broken tops. Results suggest that more than 20 yrs need to elapse before regeneration efforts with these two species in harsh areas can be evaluated reliably.

In a randomized block factorial experiment, 1200 seedlings from four provenances, each of Pinus sylvestris, Pinus eontorta and Picea abies were inoculated with conidia (2 x lO'' and 1 x 10'' conidia/seedling) of Gremmeniella abietina {Bruncborstia pinea), isolated from P. eontorta plantations in northern Sweden. A further 600 seedlings were left as controls. The occurrence of symptoms and the extension of dead tissues on the annual shoots were recorded 13 months after inoculation. Only the higher spore dose resulted in significant infection. P. sylvestris and P. eontorta seedlings were equally susceptible (53% infected), and significandy more infected than P. abies secdlinsrs (39%). The annual shoots of P. sylvestris and P. abies were affected to 43% and 37% of their length, which was significantly more than 15% of the length oiP. eontorta shoots. The frequency of affected seedlings differed between the most southern and northern provenances of P. sylvestris and P. abies, and between the northwestern and the south-eastern provenance of P. eontorta. Twenty-six months after inoculation, a higher proportion of P. eontorta seedlings than P. sylvestris and P. abies seedlings had recovered, and a lower proportion of P. eontorta than P. sylvestris and P. abies seedlings had died. This paper discusses why P. sylvestris was found to be more susceptible to G. abietina than P. eontorta in this experiment, while the reverse is found in plantations in northern Sweden.

PurposeThis study aims to explore behavioural differences between women and men in managerial positions and suggest explanations for differences and similarities.Design/methodology/approachIn order to eliminate any effects of organizational differences on leadership behaviour, this study had public managers responding to questionnaires that measured their leadership style, decision‐making style, and motivation profile.FindingsStatistical analyses of data from three groups of Swedish public managers (n=385) revealed virtually no significant differences in behaviour between female and male managers. Regardless of whether there is a female or male majority of employees or a female or male majority of managers, no effect on leadership behaviour occurs.Originality/valueA number of studies indicate that managers' behaviour is different in different types of organizations. This study suggests, therefore, that, independent of gender, organizational and demographic characteristics modify leadership behaviours, thus explaining similarities in leadership behaviour.