The background to the large-scale planting of Pinus contorta in northern Sweden is reviewed with an account of the distribution and characteristics ofPi nus contorta within its natural range in western North America. The threatsto successful planting of exotics are discussed in relation to the historicalbackground. Attention is also drawn to parasitic fungi which are infectingPi nus contorta in western Canada, and to the potential threat they representto the indigenous Pi nus sylvestris in Sweden.During a seven-year-period 100 provenances of Pi nus contorta have been investigatedannually with respect to different kinds of damage, primarilythose by parasitic fungi. The study indicates that damage to Pi nus contortaprimarily occurs during the first ten years after planting. Northern provenancesof Pi nus contorta are generally more resistant to pathogens than southernprovenances. Weather damage occurs almost every year among trees ofsouthern and coastal provenance. Even trees of northern provenance have sufferedfrom weather damage due to temperature oscillations during shoot elongation.Severe weather damage is a predisposing factor to infection by secondarypathogens primarily.Gremmeniella abietina. There is a minor correlation betweensevere weather damage and Phacidium infestans. Even northern provenancesof Pinus contorta are infected by Phacidi um infestans in high altitude standsin northern Sweden. Snow b light infection is, however, of a minor importanceto lodgepole pine than to Scots pine due to the rapid early growth of the former.The most productive plants of both Pinus contorta and Pinus sylvestrisare attacked by Phacidi um infestans. Plants not infected by snow b light havea lower height growth than those infected.Severe infection by Gremmeniella abietina has been recorded after voleattack, even among northern provenances of lodgepole pine. So far Pinus contortahas mainly been infected by the same fungi as Pinus sylvestris, with the |exception of Melampsora pinitorqua and Lophodermella sul ci gena. Pinus contorta iis, however more susceptible to infection by Gremmeniella abietina in connec- !tion with vole damage, depending on the more severe injuries to lodgepole pinethan to Scots pine.So far vole damage has been the most severe threat to Pinus contorta innorthern Sweden. Voles prefer lodgepole pine to Scots pine providing vole populationis moderate. At times of high vole populations even Scots pine suffersdamage. Voles attack Pinus contorta even 14 years after planting. The differencein frequency of vole damage among provenances strongly decreased with increasedvole population and repeated attacks from year to year.Tree tilting was first noted five to eight years after planting on sites exposedto strong winds and severe icing.In the central parts of northern Sweden most provenances of Pinus contortaare less attacked by pathogens than the indigenous Pinus sylvestris, and inorthern provenances of lodgepole pine are remarkably productive in thenorthernmost site, despite a relatively high frequency of Phacidium infestar^.Later investigations indicate, however, more severe damage to Pinuscontorta with increasing latitude and altitude in northern Sweden. / digitalisering@umu

Diss. (sammanfattning) Alnarp : Sveriges lantbruksuniversitet, 2009. / Härtill 5 uppsatser.

This thesis investigates the past extent, structure and dynamics of Mar Lodge Caledonian pine (Pinus sylvestris L.) woodland, near Braemar in the south-eastern Cairngorms. The geographical extent and Holocene history of the Scottish pinewoods are generally understood, but the Mar pinewoods are relatively obscure. This thesis is concerned with the Holocene history of the Mar pinewoods; the timing and reasons for first appearance, the increase in abundance of Pinus to become a dominant species, the spatial extent of the woodland and its structure and form. The investigation includes changes to the woodland assemblage during its fragmentation and disappearance in the late Holocene and possible influences on the woodland from people living in the area. At the heart of this thesis is an understanding of the factors underpinning the ecology of Pinus and the response of the species to competition with other taxa. This is related to the spatial and temporal changes in climate that contribute to the location and development of Pinus in Scotland and Mar Lodge. Areas comparable to Mar Lodge are defined as ‘core areas’ of pine woodland rather than ‘native areas’. This avoids the necessity of considering every short period of colonisation by Pinus in areas distal to large populations. The location, extent, form and behaviour of woodland according to macro sub-fossils and micro sub-fossils is used to define core woodland as those with a long presence of Pinus, often continuing to the present day. Areas with a long history but no extant population are regarded as peripheral areas. This thesis consists of extensive palaeoecological investigations of three peat sequences: from within extant pine woodland (Doire Bhraghad), from just beyond its edge (White Bridge) and from peat with sub-fossil pine stumps located 10km west of the modern range of Pinus (Geldie Lodge). A range of techniques, including loss of mass on ignition and colorimetric light transmission analysis are applied to the peat, but palynological techniques form the basis of the investigation. Stomatal counts are used in conjunction with pollen counts to explore the process of Pinus colonisation, and its increase in abundance to form woodland. Pinus percentage and influx, together with the ratio of arboreal to non-arboreal pollen and the percentage of Empetrum are used to define the density of the woodland canopy. The stability of the Doire Bhraghad assemblage confirms the area as core Pinus woodland. Pinus is present from c. 9600 cal BP and dominates woodland from c. 9150 cal BP. Woodland here is a closed, solely Pinus canopy from c. 8600 until 4000 cal BP. Arrival of Pinus at Geldie Lodge is undated but occurs before c. 7550 cal BP. Woodland is always more open; Pinus is co-dominant with Betula, showing affinity with other peripheral areas. Pinus woodland fragments at all Mar Lodge sites from c. 3900 cal BP, disappearing from Geldie Lodge by c. 2800 cal BP and White Bridge by c. 1900 cal BP. Calluna replaces Pinus as the dominant species at all three sites. The disappearance of Pinus is thought to relate to regional climatic change toward wetter conditions. At Geldie Lodge a prior Coleopteran study suggests Pinus growing on the mire surface to be small and short lived. These may not have been the only trees growing in the area but they perhaps contributed to the major fluctuations in arboreal and non-arboreal pollen. Early canopy fluctuations (c. 7550 to 6000 cal BP) at Geldie Lodge may be related to Mesolithic human activity; there is stronger evidence of human presence from c. 4000 cal BP, possibly including cereal cultivation. Evidence from Doire Bhraghad and White Bridge is indicative only of low intensity grazing activity. It is unlikely that human activity instigated the fragmentation and disappearance of woodland, but may have contributed to the process.

Effects of stand type on ground lichen height and species richness in boreal forests.   P. contorta as an alternative to P. sylvestris in terms of providing a suitable habitat   Maria Johansson     Abstract     Lichen-rich forests are essential to reindeer but up to 50 % of the lichen-rich areas in Sweden have been lost since the 1950s. Ground lichens thrive in pine-heaths and with an increasing area of plantations of the non-native tree species Pinus contorta, as an alternative to the native P. sylvestris, it is important to investigate if P. contorta can provide such an optimal habitat to ground lichens. The purpose of this study was to assess if forest characteristics, such as tree density, canopy cover and production capacity, affect the abundance and growth of five lichen species (Cladonia rangiferina, C. arbuscula/mitis, C. stygia, C. stellaris and Cetraria islandica) and whether these characteristics differ between forests dominated by P. contorta and forests dominated by P. sylvestris. Fieldwork was conducted in Norrbotten and Västerbotten on sample plots previously used by the Swedish National Forest Inventory (SNFI). The statistical analysis was based on data collected from 22 sample plots, 11 of each forest type, visited during July and September 2015. No statistical significant differences were found between forest characteristics of the two forest types, and none of the forest characteristics were found to relate to lichen height. Forest age did not seem to have an effect on ground lichens, while both canopy cover and production capacity were found to negatively relate to the proxy for lichen biomass as well as the abundance of the most common lichen species, C. rangiferina and C. arbuscula/mitis. The result suggests that a shadier canopy as well as a higher production capacity contributes to a reduced distribution of ground lichens.   Keywords: Ground lichens, Pinus contorta, Pinus sylvestris, forest characteristics, forestry, reindeer husbandry

Diss. (sammanfattning) Umeå : Sveriges lantbruksuniv., 2007. / Härtill 11 uppsatser.

Diss. (sammanfattning) Alnarp : Sveriges lantbruksuniversitet, 2005. / Härtill 4 uppsatser.

Diss. (sammanfattning). Umeå : Sveriges lantbruksUniversity. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2005. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2002. / Härtill 4 uppsatser.

Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 4 uppsatser.