The introduced lodgepole pine (Pinus contorta) occupies more than 650 000 hectares in Sweden. There are some differences between lodgepole pine and Scots pine (Pinus sylvestris) forests which could affect bird assemblages, for example differences in canopy density and ground vegetation. Birds were surveyed in 14 localities in northern Sweden, each characterized by one middle-aged stand of lodgepole pine next to a stand of Scots pine. The two paired stands in each locality were planted by the forestry company SCA at the same time and in similar environment to evaluate the potential of lodgepole pine in Sweden. In those 14 localities, one to three point count stations were established in both the lodgepole pine and the Scots pine stand, depending on the size of the area.

Productivity of Norway spruce (Picea abies) and Scots pine (Pinus sylvestris) was studied on 12 sites in coastal areas of northern Sweden. On each site, sample plots were placed in adjacent Norway spruce and Scots pine stands with similar ages in between. Basal area, tree height, Site Index, volume production, simulated maximum mean annual increment (MAImax) and tree vitality were compared for the two species. Average basal area at the time of measurement was 30.4% larger for Scots pine stands than for Norway spruce stands. The difference between the two species in basal area increment during the last 10 years was related to stand age.

In the 1970´s the North American lodgepole pine (Pinus contorta) was introduced to Sweden in large scale. The lodgepole pine affects its new environment different from Scots pine (P. sylvestris), leading to a change in biological diversity. Forestry today affects the ground beetle fauna (Carabidae). Habitat specialists associated with older forests are first affected. When the canopy closes again after a clear-cutting species that prefer open habitats reduces and those who prefer mature/closed forests increase. In this study we compare differences in diversity and community structure of ground beetles in stands of lodgepole pine and Scots pine.

The third most common conifer in Sweden is Pinus contorta (lodgepole pine). It originates from the western part of North America and was brought here in the end of the 1920s. The lodgepole pine is today allowed for commercial plantations in central and northern Sweden, excluding high altitude locations. Since 1979 only plantations with scientific purpose are allowed in south-central and south Sweden. This document is focused on how lodgepole pine manage perform compared with Pinus sylvestris (Scots pine) in the southernmost part of Sweden, Götaland. The idea came from the fact that the Swedish government is evaluating a notification from the National Forest Agency that suggests lodgepole pine to be allowed for commercial plantation even in southern Sweden.

Swedish forests are dominated by just two conifer species Norway spruce and Scotch pine. They are not able to achieve the highest possible production or fulfill industry demands for raw materials. The introduction of exotic conifers can potentially meet these shortcomings and present a relevant solution. This study was conducted in a block experiment with ten blocks planted in 1987 by SCA in North Sweden. The objective of the block experiment was to study if Black spruce is an appropriate alternative to Lodgepole pine, Norway spruce and Scotch pine on different site classes.

The aim of the study was to compare how the population of pine (Pinus sylvestris) and spruce (Picea abies) have changed between 1927 and 2013 in the oak landscape south of Linköping. A field study was carried out in 22 two kilometre lines which also had been studied in 1927. In these lines, which where ten meters broad and had a direction from west to east, the pines and spruces were counted, measured and classified by steam diameter. The obtained result was that the basal steam area (m²/ha) had increased for pine (44%) and spruce (57%) between 1927 and 2013. The amount of trees had increased in all diameter classes except thinner pine and spruce with a diameter of 5-10cm.

The Swedish Cellulosa Companiy, SCA, has today 280 000 ha planted with lodgepole pine (Pinus contorta var. latifolia) (?C?) which is equivalent to 14 % of its total forest area. Exotic lodgepole pine has in previous experimental stands shown a superior growth than the native Scots pine (Pinus sylvestris L.) (?S?).But also the comparison could be questioned because stand histories were was unknown and also differences in age between C and S existed.

The purpose of this study was to compare naturally regenerated Scots pine (Pinus sylvestris (L.)) against seeded Scots pine in terms of benefits and differences. An inventory was performed at a number of different sites, 4 ? 6 years after soil scarification and data on the number of new established plants, their height growth as well as ground-line diameter was collected. Information about site conditions such as altitude, quarter exposure and frost risk was also collected. A review of previous studies was conducted in addition to the field study.

Pine twisting rust (Melampsora pinitorqua) is a parasitic rust fungus found all across Sweden causing damage resulting in lower quality and reduced tree growth in pine stands. In Sweden, the fungus is dependent on two alternate hosts; European aspen (Populus tremula) and Scots pine (Pinus sylvestris). Pine twisting rust has five different spore stages, two of them (uredinio- and teliospores) on the leaves of aspen. Injures on aspen caused by pine twisting rust is not extensive. On the other hand, when it infects the annual shoots of Scots pine it often results in a bent steam or even a top shoot breakage.

In the 1970?s it was predicted that in the beginning of the 21st century there would be a timber shortage in Sweden and a large scale introduction of the exotic tree species lodgepole pine started. An introduction of a foreign tree species means a risk of a negative influence on the forests ecosystem. Today, the stands that were established in the 70?s are middle-aged and the effect on the forest floor vegetation can be studied.

Over the past 40 years 600 000 ha of lodgepole pine (Pinus contorta ssp. latifolia (Engelm.) Critchf.) has been planted in Sweden (280 000 ha on SCA's forest land alone which represents about 15% of the company's total forest land area). In the early 70's SCA situated a number of experimental stands in order to investigate different aspects of the exotic tree, primarily growth rate. To be able to compare the two species plots with scots pine (Pinus sylvestris L.), this species was also planted at the same time and under the same conditions. A number of questions should always be raised when exotic species are introduced in an ecosystem. Invasiveness, the pathogen situation and purely ethical issues should be discussed.

In this study, pollen contamination (measured by the number of seeds pollinated by pollen not belonging to any of the clones on the seed orchard) is compared between open pollination and isolated pollination environments in a Scots pine (Pinus sylvestris) seed orchard called Västerhus, located outside Önsköldsvik. In this seed orchard a tent experiment is taking place. Skogforsk has built six large tents covering 12-14 trees with each tent. Fertilization patterns were compared between one tree in a tent with a supplementation of pollen from five clones not represented in the tent and another tree of the same clone subject to open pollination outside the tents. By using DNA markers the paternity was determined for 48 seeds from each tree.

In this study, pollen contamination (measured by the number of seeds pollinated by pollen not belonging to any of the clones on the seed orchard) is compared between open pollination and isolated pollination environments in a Scots pine (Pinus sylvestris) seed orchard called Västerhus, located outside Önsköldsvik. In this seed orchard a tent experiment is taking place. Skogforsk has built six large tents covering 12-14 trees with each tent. Fertilization patterns were compared between one tree in a tent with a supplementation of pollen from five clones not represented in the tent and another tree of the same clone subject to open pollination outside the tents. By using DNA markers the paternity was determined for 48 seeds from each tree.

Prescribed burning was commonly used for site preparation in Sweden to establish new forests until the 1960?s, when mechanical scarification was introduced. During recent decades the interest in prescribed burnings has increased again, mainly due to certifications of forestry stating that 5% of the regeneration areas should be burned on dry and mesic soils. The objective of the study was to evaluate actual influence of prescribed burning compared to other site preparation on stand stem density, growth parameters and tree damages for Scots pine (Pinus sylvestris L.) after direct seeding and planting. The study also attempts to simulate growth until first thinning.

För att växter ska växa bra krävs det en mix av olika näringsämnen där de två viktigaste näringsämnena normalt sett är kväve (N) och fosfor (P). Det är viktigt att mixen av olika näringsämnen passar växtens behov samt att näringsämnena är möjliga för växten att ta upp. Det får inte heller vara för mycket av ett näringsämne då detta kan leda till förgiftning. Denna studie är gjord med syfte att klargöra hur algbiomassa av grönalger i blandad mix fungerar som gödslingsmedel för små plantor av tall (Pinus sylvestris) och gran (Picea abies). Samt att hitta förklaringar över varför algerna påverkar plantornas tillväxt.