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Restoration of endangered epiphytic lichens in fragmented forest landscapes

the importance of habitat quality and transplantation techniques

Lidén, Marlene (2009). Restoration of endangered epiphytic lichens in fragmented forest landscapes. Diss. (sammanfattning/summary) Umeå : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2009:82
ISBN 978-91-576-7429-6
[Doctoral thesis]

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In a situation with increasingly rapid changes in landscape mosaics, driven by large-scale forestry and future climate change, a number of epiphytic lichens are now becoming threatened. Many of these species are limited either by dispersal or the subsequent processes of immobilisation on the substrate and germination. Overcoming the bottleneck of dispersal and/or reproduction may therefore constitute a key factor in species conservation. The main aim of this thesis is to evaluate different strategies to optimise efficiency in restoration of populations of endangered epiphytic lichens in fragmented forest landscapes, with a special emphasis on the importance of habitat quality and transplantation techniques. The thesis includes the development of a modeling tool for habitat evaluation in relation to photosynthetic performance of individual species (III); exploration of underlying causes for habitat restrictions in hydrophilic lichens (IV); and identification of habitat and substrate characteristics that 1) are associated with high vitality in natural populations of hydrophilic lichens (II), 2) are beneficial for establishment during active transplantation of thallus fragments (I) or isidia (V), and 3) are beneficial for photosynthetic activity in adult thalli (III, IV). The occurrence of pronounced photosynthetic activation time lags among hydrophilic species, with full activity for some species being reached first 24 h after hydration, is reported for the first time in the present study and may be one of the physiological causes explaining habitat restrictions in rare hydrophilic lichens (IV). Using a dynamic water and activity model, we assessed the capacities of four hydrophilic (Bryoria bicolor, Lobaria amplissima, Platismatia norvegica and Usnea longissima) and a generalist species (Platismatia glauca) to rehydrate and activate photosynthesis by liquid water and humid air available in natural habitats (III). Simulations show that for three of the four studied hydrophilic species, species-specific PSII activation time lags can, in combination with microclimatic differences, control photosynthetic performance in a most dramatic manner (III, IV). The distribution patterns of hydrophilic lichens coincide very well with habitat features that generate high realised activity among the slowly activated species studied here (II, III, IV). Both close proximity to streams and the presence of turbulent water had a consistent strong positive impact on realised activity among the studied species (IV). The occurrence of activation time lags may explain both the higher abundances in oceanic core habitats, and the affinity for stream habitats and turbulent water displayed by marginal populations of suboceanic lichens such as P. norvegica (II). Further, we have shown that transplantations of fragments (using Evernia divaricata and Ramalina dilacerata) or isidia (using P. norvegica) can constitute a valuable tool for restoration of endangered lichen populations, and that both habitat characteristics (I) and the mode of transplantation (I, V) is of vital importance to fragment vitality. In Paper V, where isidia of P. norvegica were transplanted into six sites in the regions of Jämtland and Trøndelag in Central Scandinavia, we have shown that preparation of transplant surfaces with an adhesive Ac-Di-Sol® solution may constitute a highly efficient tool for enhancing the outcome of restorative transplantations targeting epiphytic lichens (V). However, in order to enhance the possibilities for long-term viability and persistence of the population, it is essential that restoration efforts are concentrated to habitats and substrates that can be viewed as optimal for the species in question (I-V). The model developed in Paper III and used in Paper IV may provide a tool for identifying such suitable habitats. Further, this thesis highlights the importance of fringe populations for conservation of endangered suboceanic lichens in Scandinavia (II), and also underscores the importance of separating the processes of dispersal, immobilisation and establishment, when studying lichen distributional patterns (I, II, V).

Authors/Creators:Lidén, Marlene
Title:Restoration of endangered epiphytic lichens in fragmented forest landscapes
Subtitle:the importance of habitat quality and transplantation techniques
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :2009
Number of Pages:46
ALLI. Lidén, M., Pettersson, M., Bergsten, U., Lundmark, T., 2004. Artificial dispersal of endangered epiphytic lichens: a tool for conservation in boreal forest landscapes. Biological Conservation 118(4), 431-442. II. Lidén, M., Hilmo, O. 2005. Population characteristics of the suboceanic lichen Platismatia norvegica in core and fringe habitats: relations to macroclimate, substrate, and proximity to streams. The Bryologist 108(4), 506-517. III. Jonsson Čabrajić, A., Lidén, M., Ottosson-Löfvenius, M., Lundmark, T., Palmqvist, K. 2009. Modelling hydration and PSII activation in relation to in situ rain and humidity patterns - a tool to compare performance of rare and generalist epiphytic lichens. Submitted. IV. Lidén, M., Jonsson Čabrajić, A., Ottosson-Löfvenius, M., Palmqvist, K., Lundmark, T. 2009. Species-specific activation time lags can explain habitat restrictions in hydrophilic lichens. Submitted. V. Lidén, M., Hilmo, O., Bergsten, U., Lundmark, T. 2009. Effects of substrate manipulation and microsite quality on immobilisation and establishment of isidia in restorative transplantations of Platismatia norvegica.
Place of Publication:Umeå
ISBN for printed version:978-91-576-7429-6
Publication Type:Doctoral thesis
Full Text Status:Public
Agrovoc terms:lichenes, epiphytes, habitats, nature conservation, resource management, endangered species
Keywords:Conservation management, hydrophilic epiphytic lichens, habitat restrictions, photosynthetic activation time lags, water relations, modelling, restoration, transplantation, macroclimate, stream evaporation, substrate, isidia, Ac-Di-Sol®, Bryoria bicolor, Evernia divaricata, Lobaria amplissima, Platismatia glauca, Platismatia norvegica, Ramalina dilacerata, Usnea longissima.
Permanent URL:
ID Code:2138
Department:(S) > Dept. of Forest Ecology and Management
Deposited By: Marlene Lidén
Deposited On:21 Oct 2009 00:00
Metadata Last Modified:02 Dec 2014 10:16

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