Studiens syfte är att undersöka arterna Buxbaumia viridis och Nowellia curvifolia för att kunna förutse var man hittar dessa signalarter. Detta gjordes genom att död liggande ved undersöktes i Ycke naturreservat samt en närliggande brukas skog, Östergötlands län. Resultaten visar att faktorerna som är avgörande för B. virids är markkontakt och nedbrytningsklass. B. viridis föredrar att växa på lågor i de högre nedbrytningsklasserna (4-7) och med stor andel markkontakt, över 80 %. N. curvifolia beror på diameter (över 60cm), nedbrytningsklass (3-4) och längd (över 30m). Baserat på dessa resultat, kan signalarter lättare upptäckas utan en fullskalig inventering av skogen. / Young trees dominate Swedish forests, which today have a shortage of downed dead wood, key biotopes, and an overall lack of high natural values. By using the mosses Buxbaumia viridis and Nowellia curvifolia the general state of a forest can be assessed. These species indicate high natural values, with a continuity of dead wood in different stages of decay. By investigating ground-lying dead wood, one can predict if the mosses occur in the area or not. This is useful for maintenance of the forests and the preservation of biological diversity. The purpose of this study was to study the species B. viridis and N. curvifolia in Ycke natural reserve in Östergötland, southern Sweden, and learn how to predict where these species occur. The results showed that ground contact (over 80 %) and stage of decay (stage 4-6) of logs were important to B. viridis, with test values 30- 50 times as high as the other test values. To N. curvifolia, the diameter of the logs was the most important. Decay stage and length of the log were also important factors to N. curvifolia. Based on these results, these indicator species can more easily detected without a full scale inventory of the forest.

<p>Biodiversity in forests depends on long canopy continuity and existence of different elements which function as substrates for varying organisms. Bryophytes often occupy specific substrates with a patchy distribution. The aim of this thesis was to increase the ecological knowledge about two threatened moss species; <i>Buxbaumia viridis</i>, inhabiting decaying wood, and <i>Neckera pennata</i>, inhabiting bark of base-rich deciduous trees. </p><p>Establishment from spores was investigated in <i>Buxbaumia viridis</i> and <i>Neckera pennata</i> and models were created to predict germination of spores as a function of pH and water potential. The effects of pH, phosphorus and nitrogen concentration were studied in <i>Buxbaumia viridis</i>, both on spore germination and on sporophyte occurrences in the field. Colony growth in relation to precipitation and microhabitat variables was studied in <i>Neckera pennata</i>, and a model was used to predict growth of colonies over time. Metapopulation dynamics of <i>Buxbaumia viridis</i> were analyzed as an effect of precipitation, habitat quality and patch quantity. A spatial explicit patch occupancy model was constructed to simulate metapopulation sizes and extinction risk over 100 years.</p><p>The quality of the substrate was very important for spore establishment. Germination success increased with increasing pH in both species. <i>Buxbaumia viridis</i> was less sensitive to low pH than <i>Neckera pennata</i> when water was freely available. However, there was a strong interaction between pH and water potential in prediction of the final cumulative germination: the spores reacted positively to one factor only when the other factor was in a favourable range.</p><p>Precipitation, moisture holding capacity and interference competition were the main factors affecting colony growth of <i>Neckera pennata</i>. <i>Buxbaumia viridis</i> showed large fluctuations in number of occupied patches among years. Both colonizations and extinctions were highly related to precipitation. Spore germination and sporophyte occurrences in the field were positively related to phosphorus concentration and pH of the substrate.</p>

Biodiversity in forests depends on long canopy continuity and existence of different elements which function as substrates for varying organisms. Bryophytes often occupy specific substrates with a patchy distribution. The aim of this thesis was to increase the ecological knowledge about two threatened moss species; Buxbaumia viridis, inhabiting decaying wood, and Neckera pennata, inhabiting bark of base-rich deciduous trees. Establishment from spores was investigated in Buxbaumia viridis and Neckera pennata and models were created to predict germination of spores as a function of pH and water potential. The effects of pH, phosphorus and nitrogen concentration were studied in Buxbaumia viridis, both on spore germination and on sporophyte occurrences in the field. Colony growth in relation to precipitation and microhabitat variables was studied in Neckera pennata, and a model was used to predict growth of colonies over time. Metapopulation dynamics of Buxbaumia viridis were analyzed as an effect of precipitation, habitat quality and patch quantity. A spatial explicit patch occupancy model was constructed to simulate metapopulation sizes and extinction risk over 100 years. The quality of the substrate was very important for spore establishment. Germination success increased with increasing pH in both species. Buxbaumia viridis was less sensitive to low pH than Neckera pennata when water was freely available. However, there was a strong interaction between pH and water potential in prediction of the final cumulative germination: the spores reacted positively to one factor only when the other factor was in a favourable range. Precipitation, moisture holding capacity and interference competition were the main factors affecting colony growth of Neckera pennata. Buxbaumia viridis showed large fluctuations in number of occupied patches among years. Both colonizations and extinctions were highly related to precipitation. Spore germination and sporophyte occurrences in the field were positively related to phosphorus concentration and pH of the substrate.