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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Natural value assessments – can they predict the species richness of red listed and bioindicator fungi in Fennoscandian coniferous forests?

Samuelsson, Louise January 2017 (has links)
The thesis aims to examine how well two standardised methods in nature conservation, namely natural value assessment and key biotope inventory, perform in terms of recognising an area with a high amount of red listed and bioindicator fungi. The two methods are compared to see if any method is superior to find areas with high presence of red listed and bioindicator fungi and if a larger area automatically means a larger number of species. A natural value assessment inventory is conducted on study sites with a performed key biotope inventory, with an addition of an inventory on fungi. Statistical tests are completed to give information about occurring correlations. The results display that the key biotope inventory and the natural value assessment do not differ in their evaluations of an area. Analysis also shows that there is no relationship between the forest sites area and the assessment performed by the natural value assessment. However, if the assessment is performed by the key biotope inventory there exist a relationship with the forest sites area. Further on, there is no correlation between the area and its number of species. The tests also indicate that neither of the methods predict presence or the number of red listed and bioindicator species in a forest. Based on the results, the presence of bioindicator and red listed species alone are not good indicators of forest nature value. In order to give more credible answers to these questions, more studies with increased number of replicates should be conducted. / Avhandlingen syftar till att undersöka hur bra två standardmetoder inom naturvården (Skogsbiologernas naturvärdesbedömning och Nyckelbiotopsinventering) är på att upptäcka ett områdes förekomst av rödlistade svampar och signalarter. Metoderna jämförs för att upptäcka om någon metod är överlägsen den andra angående att finna områden med stor förekomst av rödlistade svampar och signalarter samt om ett större område automatiskt innebär fler arter. Detta undersöks genom att Skogsbiologernas naturvärdesbedömning utförs på områden som redan inventerats utifrån en Nyckelbiotopsinventering med tillägg av en svampinventering. Statistiska analyser genomförs därefter för att ge svar om förekommande samband. Analyser visar att Nyckelbiotopsinventeringen och Skogsbiologernas naturvärdesbedömning inte skiljer sig angående bedömningen av skogsområden. Utförda statistiska testerna tyder även på att det inte förekommer något samband mellan bedömda områdens areal och dess bedömning enligt Skogsbiologernas bedömning, däremot finns det ett samband mellan områdenas areal och Nyckelbiotopsinventeringens bedömning. Det förekommer dock inget art-area samband. Utförda tester indikerar även att ingen av metoderna kan förutsäga mängden rödlistade svampar samt signalarter i ett skogsområde. Baserat på detta resultat ger förekomsten av signalarter samt rödlistade svamparter ingen bra indikation på en skogs naturvärde. För att ge mer trovärdiga svar på dessa frågor krävs mer studier med en ökad mängd replikat.
2

Spatial pattern of occurrence of eleven epiphytic lichen species in a heterogeneous landscape

Muhammadi, Usman Haider January 2011 (has links)
Oaks (Quercus robur) are an important substrate for many epiphytic lichens, and with increasing age the bark of oaks becomes suitable for red-listed species. These species may respond to environmental and landscape factors differently, and at different spatial scales. We tested the effect of tree, environmental and land use factors on the occurrence and richness patterns of lichens species at various spatial scales (circles with radius ranging from 28 to 1225 m), in a heterogeneous landscape in South Eastern Sweden. The occurrence patterns of Cliostomum corrugatum and Chaenotheca phaeocephala were best explained by the density of oaks within radii of 400 and 302 m, respectively. In contrast, Ramalina baltica was best explained at smaller scale (263 m) as was species richness (302 m). This study shows that the most important factor for the occurrence and richness patterns of lichens was oak density at almost all the considered scales. Tree circumference also positively affected all four response variables.
3

Effects of site quality and surrounding landscape on bryophytes and brackets on logs in woodland key habitats

Dahlerup, Nina January 2010 (has links)
<p>A tool for management and conservation of valuable forests in Sweden are WKH:s. In this study WKH:s different in size, connectivity, amount of dead wood and quality of logs were investigated for species richness of bryophytes and brackets on coniferous logs. The aim was to clarify which scales and features that was important for the diversity of species as well as for individual species. The results showed that the amount of dead wood was most important on the site scale, and some species were affected at the landscape scale, a positive effect of valuable tracts. On the scale of individual logs, factors such as diameter, sun exposure, succession stage, contact with ground and ground bryophytes cover was most important. Red-listed species preferred logs with large diameter and late successional stages. The conclusion was that the quality of the substrate and the amount of dead wood was most important, but the amount of WKH:s on the landscape scale was also important for some species.</p>
4

Effects of site quality and surrounding landscape on bryophytes and brackets on logs in woodland key habitats

Dahlerup, Nina January 2010 (has links)
A tool for management and conservation of valuable forests in Sweden are WKH:s. In this study WKH:s different in size, connectivity, amount of dead wood and quality of logs were investigated for species richness of bryophytes and brackets on coniferous logs. The aim was to clarify which scales and features that was important for the diversity of species as well as for individual species. The results showed that the amount of dead wood was most important on the site scale, and some species were affected at the landscape scale, a positive effect of valuable tracts. On the scale of individual logs, factors such as diameter, sun exposure, succession stage, contact with ground and ground bryophytes cover was most important. Red-listed species preferred logs with large diameter and late successional stages. The conclusion was that the quality of the substrate and the amount of dead wood was most important, but the amount of WKH:s on the landscape scale was also important for some species.
5

Substratpreferenser hos Crossocalyx hellerianus i svenska barrskogar : är skoglig kontinuitet en viktig faktor?

Kvarnsudde, David January 2020 (has links)
In recent time, forests in Sweden have lost habitat quality in the loss of deadwood due to the practices in productions forestry. This means that substrates for epixylic species has decreased both in quality and quantity. The aim with this study was to find which preferences the epixylic liverwort, Crossocalyx hellerianus has on its substrate and environment. C. hellerianus requires coarse logs with rotten wood, which usually is more available in forests with long forest continuity. This study was performed to see if forest continuity, isolation of habitats and if the substrate was of significance for a demanding species such as C. hellerianus. The study was performed in six sites and in each site several 50x10 meter transects were surveyed for logs. Each log was measured for diameter, sun exposure, ground contact, stage of decay and if the log was colonized by C. hellerianus. The result showed that C. hellerianus preferred coarser logs and that the species only appeared on an intermediate or later stage of decay. A high forest continuity and low habitat isolation turned out to be positive factors for the abundance of C. hellerianus
6

Mosshumlan hjälper djuren : En barnbok om rödlistade djur som kan stödja förskollärare i undervisningen om hållbar utveckling / The moss bumblebee helps the animals : a children's book about red-listed animals that can support preschool teachers in teaching about sustainable development

Stark, Julia, Sjödin, Emilia January 2023 (has links)
Idag råder en global problematik i miljön och i det förändrade klimatet, vilket påverkar allt levande på vår planet. Det krävs därför att människan anpassar sina handlingar för att växla om till en hållbar utveckling. Förskolan är en institution som speglar samhället och där formas framtida generationer, det blir därför centralt hur lärare resonerar om och undervisar för en hållbar utveckling. Det framgår dock att förskolans undervisning om hållbar utveckling tenderar att mestadels handla om källsortering och att inte skräpa ned i naturen. I barnlitteratur som handlar om hållbar utveckling föreligger brister genom att innehållet inte når fram till barnen och att böckerna till största del likaså handlar om att sortera skräp, panta samt att inte slänga skräp i naturen. Därav skapades en barnbok som synliggör rödlistade djur och som kan stödja förskollärare i undervisningen, samt därmed avser främja barns lärande om hållbar utveckling. För att ta reda på bokens potential har sex förskollärare provat den i sin undervisning samt därefter återgett sina upplevelser av barnboken genom ett frågeformulär. I resultatet framgår det att förskollärarna upplever barnboken som ett värdefullt didaktiskt material i undervisningen samt att de upplever att boken främjar barns intresse och samtal för hållbar utveckling. Även bokens utvecklingsmöjligheter blir synligt i resultatet. Därmed är en slutsats att boken till stor del stödjer förskollärare samt bidrar till barns lärande om hållbar utveckling.
7

Long term restoration effects : Effects of restoration measures on restoration success in nature reserves in acidic fen, buffered fen, dry heather, wet heather, and wet grassland in Drenthe, Netherlands

Nyström, Erika January 2020 (has links)
Habitat degradation, fragmentation and loss are important factors causing loss in biodiversity and red listed species, and restoring habitats is essential in preventing this. However, there is a limited knowledge of the long term effects of restoration measures. This study focuses on analysing the long term restoration success of restoration measures carried out in a restoration program between the 1980's and early 2000's in locations of acidic fen, buffered fen, dry heather, wet heather, and wet grassland. The aim of the restoration program was to diminish the effects on ecosystems that were influenced by eutrophication, acidification, and dehydration. The locality species composition and Ellenberg values of nitrogen (EVN), moisture (EVM) and pH levels (EVpH) are analysed, by using previous and current restoration success scores from 54 locations in the province of Drenthe in the Netherlands. The dependence of restoration success score and Ellenberg values on change over time, habitat type, restoration method and EVN, EVM and EVpH are analysed. Restoration success depended on habitat type, with wet heather having significantly higher success compared to wet grasslands. The change in score over time, however, did not vary among habitats. Restoration success did not depend on restoration method(s), nor did change in restoration success. Ellenberg values varied among habitat types, and EVM changed significantly over time in dry heather, but was not significantly related to restoration success score. In conclusion, wet heather was shown to be doing quite well, but could benefit from additional restoration. Acidic fen, buffered fen, dry heather, and wet grassland have all shown poor long term restoration effects, indicating an overall need for further restoration measures. The results also highlight the importance of further studies into the effect of long term restorations, especially focused on finding successful restoration methods, and the importance of detailed data gathered in the field.

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