| 1. |
- Wittwer, Torben, et al.
(author)
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Does one community shape the other? Dragonflies and fish in Swedish lakes
- 2010
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In: Insect Conservation and Diversity. - London : Wiley. - 1752-4598 .- 1752-458X. ; 3:2, s. 124-133
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Journal article (peer-reviewed)abstract
- 1. Freshwater communities are often structured by predation. In permanent lentic freshwater habitats dragonfly larvae are major predators which, in return, suffer predation by fish. Antipredator traits vary between the dragonfly species, and the dragonfly communities are therefore shaped by the presence of fish. But fish communities vary, and as different fish species affect dragonflies in different ways, the species composition of the fish community may affect the composition of the dragonfly community. 2. We sampled dragonfly larvae in 24 lakes with a known fish stock in south-western Sweden, and explored the impact of fish as well as vegetation structure on dragonfly communities by means of multivariate analyses. 3. We found that the presence of four fish species affected the community structure of dragonflies. The impact strength depended mainly on the abundance of Perca fluviatilis, with which most dragonfly species were negatively correlated. Many dragonfly species were also positively correlated with the occurrence of at least one fish species, which may reflect similar habitat requirements or imply indirect positive effects of these fish species. 4. Of the 24 recorded dragonfly species, four did not occur in lakes dominated by P. fluviatilis, whereas only one species was lacking in lakes dominated by Rutilus rutilus. The dragonfly species diversity was higher in R. rutilus lakes than in P. fluviatilis lakes. 5. Our results suggest that the fish species composition is a major determinant of the dragonfly community, which in turn will influence the lower trophic levels.
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| 2. |
- Haaland, Christine
(author)
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Sown wildflower strips for insect conservation: a review
- 2011
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In: Insect Conservation and Diversity. - : Wiley. - 1752-458X .- 1752-4598. ; 4, s. 60-80
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Research review (peer-reviewed)abstract
- 1. Sown wildflower strips are increasingly being established in European countries within agri-environmental schemes to enhance biodiversity, especially in intensively used agricultural areas. 2. The regulations vary between countries regarding the seed mixture, intensity of management and period of time over which subsidies are given. Insects in particular are intended to benefit from these schemes. 3. This review treats studies of insect diversity and abundance in sown wildflower strips. Schemes on wildflower strips in several countries in Central and Northern Europe are compared. 4. In a significant majority of studies, sown wildflower strips support higher insect abundances and diversity than cropped habitats. In general, numbers and diversity also tend to be higher than in other margin types such as sown grass margins and natural regeneration, but pollen- and nectar-rich flower mixtures may outperform them. 5. Common species are the main beneficiaries of the establishment of wildflower strips, although some studies point out the presence of rare or declining insect species. 6. Insect groups respond differently to particular characteristics of the strips. Flower abundance, seed mixture, vegetation structure, management, age and landscape have been identified as factors influencing insect abundance and diversity. 7. Future work should address under-represented comparisons, such as with pollen- and nectar-rich seed mixes, and neglected groups, in particular parasitoids. Nevertheless, sown wildflower strips can already be seen as a beneficial measure to enhance insect diversity. This is especially the case, where schemes for sown strips vary within a region to favour different species groups
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| 3. |
- Stenbacka, Fredrik, et al.
(author)
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Saproxylic parasitoid (Hymenoptera, Ichneumonoidea) communities in managed boreal forest landscapes
- 2010
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In: Insect Conservation and Diversity. - : Wiley. - 1752-458X .- 1752-4598. ; 3, s. 114-123
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Journal article (peer-reviewed)abstract
- 4. The general distribution pattern revealed no significant differences in species richness among stand types, but parasitoid assemblages were affected by forest successional stage. Idiobionts, dominated by Ontsira antica and Bracon obscurator, preferred clear-cuts over forested sites, while koinobionts, especially Cosmophorus regius, were more common in mature forests and reserves. We conclude that the stand types studied were complementary in assemblage composition, but that none held a complete assemblage of saproxylic parasitoids and we suggest that a range of successional stages be retained to help conserve the entire parasitoid community.
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| 4. |
- Brunet, Jörg
(author)
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Implications from large-scale spatial diversity patterns of saproxylic beetles for the conservation of European Beech forests
- 2013
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In: Insect Conservation and Diversity. - : Wiley. - 1752-458X .- 1752-4598. ; 6, s. 162-169
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Journal article (peer-reviewed)abstract
- . 1.European Beech (Fagus sylvatica) is the natural dominant tree species in many forests across Europe. Despite Europe's global responsibility for these forests, the correct conservation strategies are still a matter of debate. In particular, it remains controversial whether high conservation efforts should be directed towards beech forests, owing to the small number of insects that are Fagus specialists, and at what spatial scale conservation should take place. 2.To provide evidence for this discussion, we compiled saproxylic beetle data from 1115 flight-interception traps in eight countries and addressed two main questions: (i) what percentage of central European species can be expected in beech-dominated forests? and (ii) which are the important spatial scales for the conservation of biodiversity in beech-dominated forests?3.We included six spatial scales in our analysis: among traps, forest stands, forest sites, low/high elevations, oligo/eutrophic soils, and European bioregions. 4.By extrapolating species numbers, we showed that 70% of the central European saproxylic beetle species can be expected in beech-dominated forests. Multiplicative -diversity partitioning revealed the forest site level as the most important diversity scale for species richness, particularly for red-listed and rare species, followed by elevation and bioregion. 5.We conclude that beech-dominated forests form a useful umbrella for the high species diversity of central European saproxylic beetles. Conservation activities, such as protecting areas or increasing dead wood, should be undertaken in as many forest sites as possible, at different elevations, and in different bioregions. For this, the Natura 2000 net may provide the most useful template.
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| 5. |
- Johansson, Therese, et al.
(author)
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Short-term responses of beetle assemblages to wildfire in a region with more than 100 years of fire suppression
- 2011
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In: Insect Conservation and Diversity. - : Wiley. - 1752-458X .- 1752-4598. ; 4:2, s. 142-151
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Journal article (peer-reviewed)abstract
- 1. Suppression of wildfires in boreal landscapes has become widespread and has seriously affected many fire favoured species. However, little is known about the response of organism assemblages to large wildfires in regions with a long history of effective fire suppression, such as Scandinavia.2. We studied the short-term effects of a >1600 ha wildfire on beetle assemblages in northern Sweden. The first summer after fire, beetles were sampled in 12 sites using 36 large window traps, half in old pine forest stands in the burned area and half in similar, but unburned control stands. The entire beetle assemblage and eight subgroups were analysed: saproxylics, non-saproxylics, moderately fire favoured, strongly fire favoured, fungivores, predators, cambium consumers and red-listed species.3. Species composition differed markedly between burned and unburned forests in all nine groups. Furthermore, beetle abundance was higher in the burned area for the entire assemblage and for saproxylics, both groups of fire favoured species, predators and cambium consumers. Species number was higher only for non-saproxylics, strongly fire favoured species and cambium consumers.4. Our results show that wildfire has rapid and strong effects on a wide range of beetles. However, we only trapped two individuals of fire-dependent beetles, which may suggest a lack of such species in the region, possibly due to >100 years of fire suppression. At the regional scale, the studied wildfire may potentially increase the abundance of these beetles after a longer period of reproduction in the burned area.
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| 6. |
- Marini, Lorenzo, et al.
(author)
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High mobility reduces beta-diversity among orthopteran communities - implications for conservation
- 2012
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In: Insect Conservation and Diversity. - : Wiley. - 1752-458X .- 1752-4598. ; 5, s. 37-45
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Journal article (peer-reviewed)abstract
- 5. Measures currently included in most agri-environment schemes have only focused on the extensive management at the field scale. Our results imply that orthopteran diversity would benefit from maintaining extensively managed meadows scattered throughout the whole region, as the loss of species-rich isolated grassland patches due to abandonment or eutrophication might cause severe reductions of the regional species pool. Increasing connectivity might be also considered as a complementary measure to increase species occupancy and population persistence, particularly for sedentary species.
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| 7. |
- Ranius, Thomas
(author)
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Dispersal patterns of a saproxylic beetle, Osmoderma eremita, in Mediterranean woodlands
- 2013
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In: Insect Conservation and Diversity. - : Wiley. - 1752-458X .- 1752-4598. ; 6, s. 309-318
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Journal article (peer-reviewed)abstract
- Dispersal patterns of a beetle inhabiting tree hollows, Osmoderma eremita (Scopoli, 1763) (Coleoptera: Cetoniidae), were studied in a cork oak (Quercus suber) woodland in central Italy, the southernmost part of its distribution range. During 2years, we used radio telemetry to monitor dispersal of 39 free-ranging individuals (16 males, 23 females). Telemetered beetles spent their lifetime not only inside hollow trees but also in other habitats, such as above or under the ground surface. Beetles were more active at the beginning of the season. Eighty-one per cent of the males and 69% of the females conducted dispersals during their lifetime. The dispersal distance over individuals' lifetime did not differ between sexes. The longest dispersal was conducted by a female that moved 1504m. Thirty-nine per cent of dispersing individuals reached distances farther than 250m. Both dispersal rate and range are higher than what has been found in Northern Europe. The population size per tree is low, most of the adults leave their natal tree, and a high predation rate (at least 28%) was observed among dispersing beetles. Therefore, to balance the local extinction risk from single trees, a high density of hollow trees is probably required. It is desirable that suitable trees are concentrated at a spatial scale of a few hundred metres.
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| 8. |
- Sarin, Camilla, et al.
(author)
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Habitat utilisation of burnet moths (Zygaena spp.) in southern Sweden: a multi-scale and multi-stage perspective
- 2010
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In: INSECT CONSERVATION AND DIVERSITY. - : Blackwell Publishing Ltd. - 1752-458X .- 1752-4598. ; 3:3, s. 180-193
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Journal article (peer-reviewed)abstract
- 1. Habitat requirements and occurrence patterns of three species of burnet moths (Zygaena filipendulae, Zygaena lonicerae and Zygaena viciae) were studied at different life stages and different scales on the Baltic island of Oland, Sweden. 2. Larvae of all three species were more likely to occur in small-scale patches (i.e. 1 m2) with a greater cover of their most important host plants, Lotus corniculatus, Trifolium medium/pratense, or Vicia spp., than were pupae or adults, and were also observed on significantly larger than random plants. Pupation of Z. filipendulae took place in taller vegetation than preferred by feeding larvae and adults. 3. Adults of all species preferred different nectar plants of Asteraceae and Dipsacaceae, growing in sunny conditions. 4. A large-scale analysis of occupancy patterns was made, evaluating the relationship between burnet occurrence and the area of meadows and pastures within 10 x 10 km grid cells in Sweden. All three species showed a significant positive relationship with the area of semi-natural grassland. The area required for a 50% probability of burnet occurrence was 454 ha for Z. filipendulae, 925 ha for Z. lonicerae and 2055 ha for Z. viciae. 5. Conservation work should aim at preserving and restoring open areas rich in the respective host plants and nectar sources, with light grazing or mowing late in the season. At the landscape scale, burnet moths were favoured by a high density of semi-natural grassland and management priorities should be directed to these regions.
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| 9. |
- Berg, Åke, et al.
(author)
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Butterflies in semi-natural pastures and power-line corridors - effects of flower richness, management, and structural vegetation characteristics
- 2013
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In: Insect Conservation and Diversity. - : Wiley. - 1752-458X .- 1752-4598. ; 6, s. 639-657
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Journal article (peer-reviewed)abstract
- The aim of this study was to compare the butterfly assemblages in semi-natural pastures and power-line corridors and to analyse the effects of vegetation height, occurrence of trees and shrubs and different flowering vascular plant groups on butterfly diversity and abundance. Twelve of 26 analysed butterfly species were more abundant in power-line corridors than in semi-natural pastures. Only one species preferred semi-natural pastures. In semi-natural pastures butterflies were most common in segments with tall vegetation, whereas butterflies in power-line corridors were most common in segments with vegetation of short or intermediate height. Short vegetation was sparser in power-line corridors (mean cover 4%) than in semi-natural pastures (33%), whereas tall vegetation was more common in power-line corridors (59%) than in semi-natural pastures (35%). The amount of flowers was the factor that affected the abundance of most species. Twenty-one of the 26 species showed positive associations with numbers of flowers of different families. Flowers of the plant families Apiaceae, Caryophyllaceae, Primulaceae, Rubiaceae, Scrophulariaceae, and Violaceae showed positive associations with the abundance of several butterfly species. Vegetation height seems to be a limiting factor in semi-natural pastures, and less intensive management (division of pastures into grazing pens, late season grazing, grazing every second year, or reduced grazing pressure) would benefit butterflies. In power-line corridors (dominated by tall vegetation) the opposite would be beneficial for butterflies, for example more frequent clearing of vegetation along the power-line trails combined with mowing of selected areas.
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| 10. |
- Birkhofer, Klaus, et al.
(author)
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Grassy margins along organically managed cereal fields foster trait diversity and taxonomic distinctness of arthropod communities
- 2014
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In: Insect Conservation and Diversity. - : Wiley. - 1752-4598 .- 1752-458X. ; 7:3, s. 274-287
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Journal article (peer-reviewed)abstract
- It is not known if grassy margins contribute to the conservation of biodiversity if situated along organically managed cereal fields as the contrast in environmental conditions between fields and margins may be too small in absence of pesticide applications. Communities of spiders, ground beetles, true bugs and aphids were sampled in 2years along transects from the centre of organically managed cereal fields into adjacent grassy margins. Based on species richness, abundances, ecological and body size traits of species and taxonomic distinctness between species, communities were compared between organically managed cereal fields and their grassy margins. The species richness, abundance and variation in taxonomic distinctness of true bugs were significantly higher in grassy margins. For spiders and ground beetles, these metrics were either higher in cereal fields or did not differ significantly. At the species level, spiders living under stones or in soil crevices, as well as phytophagous ground beetles and true bugs that overwinter as eggs benefited from grassy margins. True bug communities in cereal fields were dominated by a few abundant species, whereas communities in margins were rather dominated by a few large species. Our comprehensive analyses highlight the importance of accounting for species identities and biology in biodiversity studies. The traits that characterised arthropod species that benefited from margins are not characteristic for pest species. Grassy margins along organic fields therefore represent an important agri-environmental scheme for the conservation of several arthropod taxa and margins should not be removed to increase the crop production area in organically managed cereal fields.
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