Studies on frost hardiness of Pinus contorta Dougl. seedlings grown in climate chambers

Pinus contorta populations from latitudes 47o to 63'N were cultivated in climate chambers and freeze tested at varying photoperiods. The results were compared with data from field trials comprising other populations from the same latitudinal range. A good agreement between our data on frost hardiness from the climate chambers and the ones front field trials was obtained. Breeding for frost hardiness in Pinus contorta ought to be done by early testing using the design developed in the present investigation. The longer the night length the greater the hardiness. Low temperature during the night promotes the development of hardiness. The more northern the origin the shorter the night length required to induce hardiness. Dry matter content of the upper 3 cm of the shoots and the lengthening of the secondary needles are strongly correlated with hardiness

Severity index and transfer effects on survival and volume production of Pinus sylvestris in northern Sweden

By means of results from provenance trials in northern Sweden, a map of severity index for various latitudes and altitudes was drawn up. The severity index is defined as the expected percentage plant mortality rate in the local population during the first 20 years after establishment of the plantation. By combining transfer effects based on data from all trials, a general trend of the transfer effect was calculated. The regression obtained showed that, at constant altitude, each degree of transfer southwards meant an increase in survival of 10.8 percentage units; at constant latitude, every 100 metres of downward transfer implied an increase in survival of 3.0 percentage units. By means of a graph combining severity index with transfer effects, it is shown how optimum transfer can be estimated. Optimum transfer is defined as the transfer giving maximum volume yield, which equals 70-80 per cent survival

Analys av trafiksäkerhetsutvecklingen 2012 : målstyrning av trafiksäkerhetsarbetet mot etappmålen 2020

Utvecklingen mot trafiksäkerhetsmålen för vägtrafiken år 2020 följs upp genom årliga rapporter. Denna rapport är den femte uppföljningen. I rapporten redovisas och analyseras trafiksäkerhetsutvecklingen under 2012. Liksom tidigare år analyseras utfallet i antalet dödade och skadade samt för ett antal utpekade indikatorer. Rapporten utgör underlag för 2013 års resultatkonferens i Stockholm den 24 april