ABSTRACT Seven islands in the lake Kolsnaren have been investigated. I have inventoried saproxylic insects and investigated what characters on dead wood and characters at the islands that have affected species number of beetles (Coleoptera) and true bugs (Hemiptera). This study shows a relatively low number of species of beetles and true bugs but the study was too small to estimate a proper result. Probably there is many more species, especially more rare/threatened species. The characters vary between islands, but even the individual islands had different tree species, thickness, degradation stage and sun exposure of dead wood. Therefore there were favourable conditions for many different saproxylic species that have different demands of the habitat to find suitable substrate. The islands are partly isolated by water but no longer distances. With that in mind it was important that there is plenty of dead wood with varying characters around Kolsnaren so they get the opportunity to disperse and recolonise the islands when even the habitats are changing in time. The dead woods thickness and degradation stage was the characters with most impact of the number of species. / SAMMANFATTNING Sju öar i Kolsnaren har undersökts. Jag har inventerat vedlevande insekter och undersökt vilka karaktärer på död ved (art, grovlek, rötstadie och solexponering) samt karaktärer på öarna (storlek, avstånd till land, ljusinsläpp, trädarter samt mängden död ved) som påverkar artantalet av skalbaggar (Coleoptera) och halvvingar (Hemiptera). Denna studie visade på ett relativt lågt artantal av skalbaggar och halvvingar men troligen finns det många fler arter, framförallt fler sällsynta liksom hotade arter. Öarnas karaktärer varierade mellan varandra men även på de enskilda öarna var det variationer i form av olika trädarter, grovlek, rötstadier och solexponering av den döda veden. Därför finns det goda förutsättningar för en mängd olika vedlevande arter med varierande habitatkrav att finna lämpligt substrat. Öarna är delvis isolerade av vatten men det utgör inget större hinder för de flesta skalbaggar. Däremot är det viktigt att det finns gott om död ved med varierande karaktärer runt omkring Kolsnaren så att vedlevande skalbaggar får möjlighet att sprida sig och återkolonisera öarna då även habitaten ändras med tiden. Den döda vedens grovlek och rötstadie var de karaktärerna som hade störst inverkan på antalet arter.

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Död ved i skogen har en viktig betydelse för den biologiska mångfalden. I Sverige är över 6000 arter knutna till död ved. När skogen utsätts för många störningar av oss människor påverkas artrikedomen relaterad till död ved. Volymen död ved har minskat och dess komposition förändrats, till följd av ett intensivt skogsbruk. Mängden död ved i framförallt brukade skogar är väsentligt mindre än vad som är hållbart för den biologiska mångfalden. Denna studie har inventerat död ved och vedlevande signalarter i barrdominerade skogar ägda av Skövde kommun. Detta för att visa på hur sambandet mellan volymen död ved och artrikedom ser ut inom och mellan naturreservat och brukade skogar. Resultatet visade att mängden död ved är större i naturreservat än i brukade skogar. Genomsnittet av volymen död ved i brukade skogar ägda av Skövde kommun är större jämfört med genomsnittet för Västra Götaland och landet som helhet. Ett starkt samband hittades mellan volymen död ved och artrikedom för mycket nedbruten ved men inte för hård ved eller mindre nedbruten ved. Detta kan delvis förklaras av de arter som användes för mått på artrikedom, mossor och lavar, främst prefererar ved i senare nedbrytningsstadie. Denna studie visar på att tillförsel av väl nedbruten ved är ger ett starkt utslag för artrikedomen i brukade skogar och framförallt i naturreservat. Det styrker vikten av att kontinuerligt tillföra död ved och låta den brytas ned, då olika arter är beroende av olika nedbrytningstadier.

The military area Skillingaryds skjutfält is considered to harbor a great amount of value for saproxylic beetles, despite the fact that no inventory has been made, because of the high amount of dead wood. After the storms Gudrun (2005) and Per (2007) the County Administrative Board of Jönköping decided to leave a large amount of dead wood in the area to promote biodiversity. During the summer of 2016 the area was surveyed with window traps that were emptied three times. 121 species of saproxylic beetles belonging to 41 families were found during this time. Of these species there were three red listed: Uloma culinaris, Pseudanidorus pentatomus and Orchesia minor. Aside from the red listed species one species that indicate high nature values, Necydalis major, was found and four rare species from the genus Hylis sp. which are rare due to intense forestry. In comparison to other studies Skillingaryds skjutfält exhibit a less interesting fauna than expected. The reason for this is believed to be overgrowth, lack of variation and canopy closure that limits sun exposure. The summer of 2016 was quite mediocre in both temperature and sunny days which also may have affected the results. Since there hasn’t been any previous study of the saproxylic fauna in the area it is impossible to say if the windthrow from the big storms has affected the fauna in any direction. But since it is a known fact that storms generate dead wood it can be concluded that the increase of dead wood should have affected the fauna. This study is the start-up of a proposed continual survey and to draw any conclusions, comparison to other similar studies has been made. It should be emphasized that this study does not give the full picture of the saproxylic fauna and that there probably are more species living in the area than presented here.

Den globala biologiska mångfalden minskar på grund av kraftig mänsklig exploatering av resurser. Ett sådant exempel är diversitetens nedgång i Fennoskandias skogar. Denna studie sökte att undersöka om skogsbruket negativt påverkar mångfalden i en svensk skog i förhållande till dess vedlevande lavar och mossor, med hjälp av träsubstratets kvaliteter som jämförelse och oberoende variabel. 21 vedlevande mossor och lavar var grunden för dessa jämförelser. Studien jämförde två ursprungligen likadana produktionsskogar, där den ena blev ett naturreservat för nästan 100 år sedan. De ligger sydost om Linköping stad, nära BjärkaSäby. Tio 300 m2transekter med slumpmässigt genererade startpunkter och riktningar etablerades i varje skog. Kvantiteten av, deras diameter, deras höjd/längd och deras arttillhörighet för levande och döda träd över en meter i höjd noterades. Nedbrytningsstadier för liggande död ved bredare än 5 centimeter noterades. Ett Wilcoxon-rank-summa-test avslöjade signifikant högre medelvärden av förekomster för vedlevande arter inuti reservatet. Oparade t-tester avslöjade signifikant högre medelvärden för de vedlevande arternasarttäckning och för volymen död ved i reservatet. Pearsons chi-två test avslöjade signifikanta fördelningsskillnader hos levande tallars och lövträdsdiametrar mellan de två områdena men inte mellan fördelningen av nedbrytningsstadier eller hos diametrarna för levande granar. Logistiska regressioner avslöjade att de flesta av de vedlevande arterna med över 10 förekomster i båda områdena över lag hade åtminstone en signifikant korrelation med dess substrats egenskaper. Fynden tyder på att modernt skogsbruk påverkar vedlevande arter negativt, främst på grund av den lilla mängden substrat tillgängligt i produktionsskogen snarare än på grund av substratens variation av egenskaper. / Global biodiversity is declining due to human exploitation, such as seen with its decline within Fennoscandian forests. This study aimed to see if forestry negatively impacts diversity in a Swedish forest in relation to its wood-living lichens and mosses, using the wooden substrate qualities as a point of comparison. 21 saproxylic mosses and lichens formed the basis of these comparisons. The study compared two originally equal production forests, where one became a reserve almost 100 years ago. They are located south-east of Linköping City, near Bjärka-Säby. Ten 300 m2 transects with randomly generated placements and directions were established in each forest. The quantity, diameter, height/length, and species of living and deadtrees over one meter tall were noted. Decay stages for lying dead wood broader than 5 centimeters was noted. A Wilcoxon-rank-sum-test revealed significantly higher meanoccurrences of saproxylic species in the reserve. Unpaired t-tests revealed significantly higher means of saproxylic species coverage and volume of dead wood in the reserve. Pearson’s chi-square test revealed significant distribution differences of living pines and deciduous tree diameters between the two areas but not in the distribution of wood decay stages or in the diameters of living spruces. Logistic regressions revealed that most of the saproxylic specieswith over 10 occurrences in both areas over all had at least one significant correlation with its substrate’s properties. Findings indicate that modern forestry negatively impacts wood-dwelling species mostly due to the small amount of substrate in the managed forest rather than due to their variety

This pilot study was conducted to test if there are differences in occurrence of red-listed xylophagous fungi in forests dependent on degrees of human impact on the forests. Three main degrees of human impact was investigated: little impact (natural forest); medium impact (semi-natural forest) and high impact (monoculture plantation). These forests were compared in three geographically distinct areas within the same municipality, Vindeln. Within each forest type, three experimental plots were randomly selected, resulting in a total of 27 research plots. The study was conducted in northern Sweden, Västerbotten county in the following locations: Svartberget, Skatan and Kulbäcksliden. The pilot study found significant differences between natural forests and monoculture plantations. The natural forests harboured the most red-listed species, followed by the semi-natural forests, while the monoculture plantations had the fewest. The semi-natural was closer to the natural forest but did not yield significant differences when comparing the various areas. Despite the small dataset, the results are clear that the natural forests harbour the highest abundance of red-listed xylophagous fungi when comparing the degree of human impact in three different forest ecosystems.

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

The biodiversity of saproxylic organisms and in the case of this study, saproxylic beetles, is dependent on the amount and quality of course woody debris (CWD) in the environment. Over the past decades the quantity of CWD in Swedish forests has increased, yet the quality has decreased, forests are managed and exploited, and old-growth forests are rarer. To counteract this, fauna depots, artificial piles of dead wood, can be placed to increase the amount and quality of habitat for saproxylic organisms. This study measured fauna depots of aspen CWD placed in Uppsala municipality to find which combination of qualities resulted in the highest species richness and abundance (diversity). A total of 242 beetles across 26 species were sampled using a bark sifter and Tullgren extraction funnels. The CWD qualities; number of logs, log diameter, sun exposure and decomposition level were measured. Log diameter was confirmed to be positively correlated with species richness supporting previous research. Decomposition was also positively correlated with species richness, but this not supported by previous research. Some qualities, like sun exposure, were unexpectedly not correlated and number of logs was negatively correlated. Only one red-listed species was found across all samples. Overall results were somewhat inconclusive but provide hints towards better practice in saproxylic beetle conservation, such as placing larger logs in the depots.