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1	Ecology of lichens in boreal coniferous forests with reference to spatial and temporal patterns Esseen, Per-Anders January 1983 (has links) The thesis deals with the ecology of lichens in two contrasting types of forest, epiphytic lichens in old Picea abies forest of the fi re-refugia type and epigeic as well as epixylic lichens in a successional sequence of fire- susceptible Pinus sylvestris forests. Results in five separate papers form the basis for a discussion of general patterns of dispersal, succession and life strategies in lichens. The study sites were located in Medelpad and Västerbotten, in the central and northern part of Sweden, respectively. Special attention has been paid to the rare, pendulous, spruce-1ichen Usnea longissima and the coexisting lichen species. U. longissima is largely restricted to north-facing hill slopes covered with old, mesic spruce forest that is characterized by a very long continuity not disturbed by fire. A marked decline in the number of sites with U. longissima was found. The decline was mainly due to the effect of different forestry practices as the species is very sensitive to environmental disturbances. The epiphytic lichen vegetation of six tree species occurring in the spruce forest is described. Clear successional trends with increasing tree size were • obtained for Alectoria sarmentosa, Bryoria fuscescens coll., B. nadvornikiana, Usnea filipendula' and U. subflorida'na, to a lesser extent for Bryoria capii-“" laris while U. longissima had no relationship to tree size or age. TTstudy of the litterfall of macrofragments of epiphytic lichens showed that thallus fragments were dispersed throughout the year with late autumn, winter and early spring as the most critical periods. It is suggested that dispersal through thallus fragmentation is more important in fruticose than in foliose species and that U. longissima has a shorter range of propagule transport than the other species of Alectoria, Bryoria and Usnea studied. The latter proposition was supported through a study of the horizontal patterns of lichen occurrence in the spruce forest. It is shown that the diversity in ground vegetation, after an initial increase, declines with succession in the pine forests. A mechanism of succession in ground vegetation is presented which suggest that variations in habitat heterogeneity, i.e. the diversity of substrates caused by the initial disturbance and the stand development, largely determines diversity changes during succession. Trends of increasing thallus size, increasing size of asexual reproductive propagules and increased competitive ability with succession formed the basis for recognizing three types of strategies in Cladonia» It is concluded that lichens have features that are compatible with the r-K continuum and that they are variously adapted to both the stability of the substrates and that of the forest as a whole. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1983, härtill 5 uppsatser</p> / digitalisering@umu Lichens epiphytes Alectoria Bryoria Cladonia Usnea Picea abies Pinus sylvestris dispersal litterfall succession diversity spatial patterns
2	Förekomst och spridning av hänglavar från äldre skogar till unga tidigare avverkade områden i Västerbottens inland Maksimova, Emma January 2023 (has links) The Swedish forestry and the use of clearcutting models has resulted in great losses of older forests in Sweden, resulting in several species being affected negatively. Hair lichens are important organisms that are providing several ecological functions in forest ecosystems and are declining due to being associated with older forests with high continuity. This study investigates the occurrence and dispersal ability of the genus Alectoria, Bryoria and Usnea between older forests and young secondary forests in three different areas in Storuman municipality, Västerbotten county. Bryoria were found on all trees in all forest patches, both in the old and young forest patches, while Alectoria had much lower occurrence in the young secondary forest. Usnea had no observed pattern in occurrence between the different areas. The average length of the lichens, here used as a proxy for lichen biomass, showed a statistical difference in biomass between areas for genera Bryoria and Usnea. The genera Alectoria showed a difference in biomass between areas, distance to closest older forest and the interaction between these two. Therefore, this study suggests that Alectoria is limited in dispersal in these areas. Some of the results could be explained by distribution and dispersal ability of the studied genera. To further evaluate the differences seen in occurrence and biomass between the genera and the different areas more studies are needed. This could provide important information for sustainable forestry that favors lichens and benefits reindeer husbandry. Lichens Dispersal Picea abies Pinus sylvestris Epiphytic Hair lichens Alectoria Bryoria Usnea Ecology Ekologi
3	Modelling forest landscape dynamics in Glen Affric, northern Scotland Hope, Joseph C. E. January 2003 (has links) Consideration of forest management at the landscape scale is essential if commitments to the conservation of biodiversity are to be upheld. The ecosystem management approach, developed largely in North America, has made use of various landscape modelling tools to assist in planning for biodiversity maintenance and ecological restoration. The roles of habitat suitability models, metapopulation models, spatially explicit population models (SEPMs) and forest landscape dynamics models (FLDMs) in the planning process are discussed and a review of forest dynamics models is presented. Potential is identified for developing landscape models in the UK for both landscape restoration projects and semi-natural woodland management. Glen Affric, in northern Scotland contains a large area of native pine and birch woodland and is the subject of a long-term restoration project. A new model, GALDR (Glen Affric Landscape Dynamics Reconstruction) is introduced and is believed to be the first FLDM developed for British woodland. The theory behind the model is described in detail and preliminary results and sensitivity analyses are presented. Furthermore, GALAM (Glen Affric Lichen Abundance Model), a new SEPM for the rare epiphytic lichen Bryoria furcellata is also described. Results of simulations from the linked GALDR and GALAM models are presented which shed light on the role of landscape heterogeneity in determining the dynamics of lichen habitats and populations. It is concluded that, whilst much work will be required to develop a management-oriented decision support system from the GALDR model, the modelling process may aid researchers in the identification of knowledge gaps in ecological theory relevant to management and restoration. 581.7
4	Manganese as a site factor for epiphytic lichens / Mangan als Standortfaktor für epiphytische Flechten Paul, Alexander 27 April 2005 (has links) No description available. 580 Pflanzen (Botanik) WWH 000 WVR 200 WHA 000 Mathematics and Natural Science Flechtenökologie Hypogymnia physodes Lecanora conizaeoides Bryoria fuscescens Alectoria sarmentosa Lobaria pulmonaria Nephroma helveticum Leptogium saturninum Mangan Schwermetalltoleranz Ultrastruktur Trebouxia Nostoc Röntgenmikroanalyse Chlorophyllfluoreszenz lichen ecology Hypogymnia physodes Lecanora conizaeoides Bryoria fuscescens Alectoria sarmentosa Lobaria pulmonaria Nephroma helveticum Leptogium saturninum manganese heavy metal tolerance ultrastructure Trebouxia Nostoc X-ray microanalysis chlorophyll fluorescence 42.44 42.48 42.51 42.41

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