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Boxing for biodiversity: a long-term follow up of an artificial dead wood environmentCarlsson, Staffan January 2015 (has links)
Today many saproxylic species are threatened because of habitat decline in Europe. Hollow trees represent a great part of the habitats that saproxylic species use. Since hollows takes a long time to develop, management actions are needed to prevent the extinction of saproxylic species. The aim of this study was to investigate the succession of saproxylic beetle species in artificial habitats in the form of wooden boxes. Wooden boxes were filled with a potential substrate and placed at different distances (0-1800 m) from oak hollow hot spots. In addition to the start mixture, four different additional substrates were added. In total, 4510 specimens of 114 saproxylic beetle species were sampled in 43 boxes over ten years. The specimens of tree-hollow species, wood rot species and nest species increased with 38% from the fourth to the final year but species richness decline from 47 to 29, respectively. A dead hen had a tendency for attracting more species but the small effect of different added substrates diminished over the years and had no significant effect on species richness after ten years. There was a higher similarity in species richness after ten years between the boxes and real hollow oaks. In conclusion, the artificial habitat developed into a more hollow like environment, with fewer but more abundant wood mould specialists, during ten years. This study clearly shows that the wooden boxes are used as habitats for saproxylic species as the boxes seems to develop into a more hollow-like habitat with time.
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Evaluation of artificial habitats for saproxylic oak invertebrates: Effects of substrate, composition and distance from dispersal sourceLarsson, Anna January 2008 (has links)
<p>Saproxylic species living in old hollow trees have low dispersal rate. Many of the species are threatened since their micro habitats are rare. To prevent some of these species from going extinct their habitats have to have the right management. In some areas artificial environment could be a solution. The aim of this study was to investigate if the insects that are dependent on tree cavities with wood mould would colonize an artificially created habitat: large wooden boxes filled with artificial wood mould placed on tree trunks. The boxes were filled with substrates like oak saw dust, oak leaves, dead hens, hen excrements, medicago (Medicago falcata flour) or potatoes. Over three years, 136 species and 10 380 specimens were caught in 47 boxes. The groups classified as specialists were in general statistically significant more often than groups classified as generalists. Dead hen was the substrate with the highest number of species, although differences were small. In conclusion, a large number of species, including red listed ones and saproxylic specialists used the boxes. A dead hen in the box gave some extra species and 1800 meters was too long for some of the species to disperse. Hence, the prospects for using artificial environments are good especially to reduce habitat availability gaps in time and space.</p>
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Evaluation of artificial habitats for saproxylic oak invertebrates: Effects of substrate, composition and distance from dispersal sourceLarsson, Anna January 2008 (has links)
Saproxylic species living in old hollow trees have low dispersal rate. Many of the species are threatened since their micro habitats are rare. To prevent some of these species from going extinct their habitats have to have the right management. In some areas artificial environment could be a solution. The aim of this study was to investigate if the insects that are dependent on tree cavities with wood mould would colonize an artificially created habitat: large wooden boxes filled with artificial wood mould placed on tree trunks. The boxes were filled with substrates like oak saw dust, oak leaves, dead hens, hen excrements, medicago (Medicago falcata flour) or potatoes. Over three years, 136 species and 10 380 specimens were caught in 47 boxes. The groups classified as specialists were in general statistically significant more often than groups classified as generalists. Dead hen was the substrate with the highest number of species, although differences were small. In conclusion, a large number of species, including red listed ones and saproxylic specialists used the boxes. A dead hen in the box gave some extra species and 1800 meters was too long for some of the species to disperse. Hence, the prospects for using artificial environments are good especially to reduce habitat availability gaps in time and space.
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Boxes with artificial habitats support saproxylic beetles in green areas near and within citiesRyding, Caroline January 2020 (has links)
The highest terrestrial biodiversity in Sweden is connected to old grown deciduous trees with tree trunk hollows and dead wood, such as oak and maple. A reduction of deciduous forest and old grown trees from anthropological activities has left many habitats wanting in size and fragmented. Many saproxylic species that are dependent on old grown trees with tree trunk hollows are now threatened. The aim of this study was to further develop artificial habitats (boxes) used for conservation of saproxylic beetles. The boxes were made larger, placed in cities’ green areas and filled with produce from the surrounding areas. The study assessed the effectiveness of these boxes, regarding species richness and composition, compared with earlier studies and tree trunk hollows. The study also aimed to assess what variables might affect the species richness and family and species composition. During April to August 2019, 3454 individuals of 105 saproxylic species were collected in 55 boxes. Of the species dependent on tree trunk hollows, 45% were found in the boxes, compared with tree trunk hollows. Of the variables included shading of the box, the amount of buildings surrounding the box and the amount of forest surrounding the box were found to affect species richness. More shading and a larger forest area increased the species richness in the boxes, and a higher concentration of buildings decreased species richness in the boxes. Conclusively, this study showed that boxes placed in cities’ green areas could act as an alternative habitat for saproxylic beetles.
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Skillnader i mulmvolymer mellan fem trädslag i Östergötlands eklandskap / Differences in wood mould volumes among five tree species in the oak landscape of ÖstergötlandCarlsson, Staffan January 2013 (has links)
Old hollow trees of oak contain a large amount of wood mould. Unfortunately, these trees have in the last century been greatly reduced in numbers. It has resulted in that species that depend on these habitats, saproxylic species, have become at risk to decrease in numbers or die out regionally. Previous studies have shown that the volume of wood mould is an important factor for occurrence and population size of saproxylic organisms. The aim of the present study was to examine how the volume of wood mould varies among ash (Fraxinus excelsior), lime (Tilia sp.), maple (Acer platanoides), aspen (Populus tremula) and oak (Quercus robur). The measurements were wood mould depth, internal cavity diameter, internal cavity height, circumference, and if white or brown rot was the dominating mould fungus. In total 23 ashes, 20 limes, 24 maples, 24 aspens and 21 oaks in the vicinity of Motala (Östergötland) were measured. The results show that there were significant differences between tree species concerning the volumes of wood mould. The oak accommodated larger volumes than the other species. The ash, however, had a larger volume than oak at the same circumference. The study shows ash could be a complement to the oak in conservation plans. Since the ash generally holds a larger volume then the oak at the same circumference, this implies the possibility that the ash can be suitable for saproxylic organisms at an earlier stage. In the isolated fragments of the landscape the possibility for survival may then increase for species that are dependent of these habitats. / Gamla hålträd av ek hyser ofta en stor mängd mulm. Tyvärr har dessa träd det senaste århundradet minskat i antal. Det har fått till följd att arter som är beroende av dessa habitat riskerar att minska eller dö ut regionalt. Tidigare studier har visat att volymen av mulm i ett träd är en viktig faktor för förekomst och populationsstorlek. Syftet med denna studie var att undersöka hur mulmvolymer varierar mellan olika trädslag. Mulmvolymen mättes därför hos ask ( Fraxinus excelsior), lind (Tilia sp.), lönn (Acer platanoides), asp (Populus tremula) och ek (Quercus robur). På varje träd mättes mulmdjup, invändig håldiameter, invändig hålhöjd, omkrets samt om trädet hade vitröta eller brunröta. Sammanlagt mättes 23 askar, 20 lindar, 24 lönnar, 24 aspar och 21 ekar runt Motala (Östergötland) med omnejd. Resultaten visar att det finns signifikanta skillnader mellan trädslagen gällande mulmvolymer. Eken hyser större volymer än de övriga, men ask och lönn har även de relativt stora volymer mulm. Asken har dock större volym mulm än vad eken har vid samma omkrets. Studien visar att man vid naturvårdsplaneringar bör ta med ask som ett komplement till eken i ett fragmenterat landskap. Eftersom asken kan generera större volymer mulm än eken vid samma omkrets medför detta möjligheten att asken kan fungera som habitat i ett tidigare skede. I isolerade fragment av landskapet kan då chansen för överlevnad möjligtvis öka för de arter som är beroende av mulmhabitat.
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