| 51. |
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| 52. |
- Cousins, Sara, et al.
(författare)
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I nattviolens hage
- 2008
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Ingår i: Olsson, R. (red), Mångfaldsmarker. - Uppsala : Centrum för biologisk mångfald. - 9789189232297 ; , s. 9-28
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- I en svensk naturbetesmark kan man hitta över 40 växtarter inom en enda kvadratmeter. Det är världsrekord. En stor del av de arter som finns i betesmarkerna förekommer inte i andra naturtyper. Idag återstår inte mer än en tiondel av den areal naturbetesmarker som fanns i Sverige för drygt 100 år sedan. Igenväxningen hotar inte bara en lång rad arter. Också stora kulturhistoriska värden och vårt vackra, variationsrika odlingslandskap står på spel. Fortsatt hävd förutsätter att det finns en levande landsbygd med bärkraftiga jordbruksföretag.
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| 53. |
- Davranche, Aurélie, et al.
(författare)
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Space based tools to monitor the habitats of migratory waterbirds
- 2010
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Ingår i: The abstract book. ; , s. 44-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Natural fluctuations in the availability of suitable habitat coupled with anthropogenic activities (hunting, agriculture, tourism, urbanism) and anticipated modifications due to climate change confront migratory waterbirds with a formidable challenge. Among them, dabbling ducks, greatly rely on local exogenous resources to fulfil their energy requirements. Habitat suitability along their flyway is of primary importance as any change might induce dramatic effects on individual survival and breeding success. Although, the monitoring of such sensitive flooded areas that are wetlands stopover sites is usually complex, space based techniques, with an exhaustive and systematic covering of the territory and a periodical data acquisition, can explore cost-efficiently the ecological conditions for migratory species in these environments. Hence, multiseason reflectance data from radiometrically and geometrically corrected multispectral SPOT-5 scenes, combined with thorough field campaigns and land cover digitizing using data mining, can provide robust tools for habitat monitoring and help the conservation of wetlands for migrants.
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| 54. |
- Dessborn, Lisa, 1976-, et al.
(författare)
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Hatching in dabbling ducks and emergence in chironomids : a case of predator-prey synchrony?
- 2009
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Ingår i: Hydrobiologia. - : Springer Verlag (Germany). - 0018-8158 .- 1573-5117. - 0018-8158 ; 636:1, s. 319-329
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Tidskriftsartikel (refereegranskat)abstract
- It has been hypothesized that dabbling ducks (Anas spp.) time breeding to coincide with annual regional peaks in emerging dipterans, especially Chironomidae, which are important prey for newly hatched ducklings. However, this hypothesis has never been evaluated in a replicated lake-level study, including year effects in emergence patterns. We collected duck and invertebrate data from 12 lakes during the nesting seasons 1989-1994 in a watershed in southern Finland. The oligotrophic study lakes are typical of the boreal Holarctic, as are the three focal duck species: mallard Anas platyrhynchos L., widgeon Anas penelope L and teal Anas crecca L. Hatching of ducklings showed a clear peak in relation to ambient phenology (annual ice-out date of lakes), whereas chironomid emergence was more erratic and showed no clear peak at the lake level, although total watershed-level emergence was somewhat higher before and long after the duck hatching peak. Thus, we find no evidence that ducklings hatch in synchrony with abundance peaks of emerging chironomids. There was large within-year temporal variation in chironomid emergence among lakes, but this was not correlated with ambient temperature. The rank of individual lakes with respect to the abundance of emerging chironomids was consistent among as well as within years, a predictability that ought to make adaptive lake choice by ducks possible. On the lake level, there was a positive correlation between the total amount of emerging chironomids and brood use. We argue that emergence patterns of chironomids on typical boreal lakes are neither compressed nor predictable enough to be a major selective force on the timing of egg-laying and hatching in dabbling ducks. Despite spatial (among-lake) patterns of abundance of emerging chironomids being predictable within and among years, the observed pattern of brood use suggests that other factors, e.g. habitat structure, also affect lake choice.
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| 55. |
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| 56. |
- Edenius, Lars, et al.
(författare)
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Landscape level effects of modern forestry on bird communities in North Swedish boreal forests
- 1996
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Ingår i: Landscape Ecology. - 0921-2973 .- 1572-9761. - 0921-2973 ; 11:6, s. 325-338
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Tidskriftsartikel (refereegranskat)abstract
- We address effects of large-scale forestry on landscape structure and the structure and composition of boreal bird communities in North Sweden. Specifically, we ask: after controlling for the effect of patch size, forest age and tree species composition, is there any residual effect attributable to the reduction in area of old forest? Pairs of landscape blocks (25 by 25 km) were selected to maximize area difference in human-induced disturbance, clear-cut as opposed to semi-natural old forest. Median distance to natural edge (wetlands, open water) from randomly selected points in forest was 250 and 200 m in high and low impact landscapes, respectively, indicating a high degree of 'natural' fragmentation of the pristine boreal landscape in the area. By contrast, median distance to clear-cut in uncut forest was 750 and 100 m, respectively. Clear-cuts in high impact landscapes were disproportionally more common in areas with contiguous forest land than in areas with spatially disjunct forest, implicating that forestry increases natural fragmentation of the landscape by subdividing larger forest tracts. Point counts along forestry roads showed that species richness and relative abundance of forest birds were higher in landscapes with low forestry impact. These differences can partly be explained by differences in age composition of forest and composition of tree species. After controlling for patch size, forest age and tree species composition, a significant effect of forestry impact remained for Sibirian species and the Tree pipit Anthus trivialis. Our results thus imply that this group of species and the Tree pipit may be sensitive to forest fragmentation. In contrast to previous Finnish studies, we found relatively small negative effects on relative abundance of species hypothesized to be negatively affected by large-scale clear-cutting forestry. However, our picture of the present does not contradict results from Finnish long-term population studies. Five factors may account for this: 1) clear-cut areas are not permanently transformed into other land use types, 2) planted forests are not completely inhabitable for species preferring older forest, 3) the majority of species in the regional pool are habitat generalists, 4) the region studied is still extensively covered with semi-natural forest, and 5) our study area is relatively close to contiguous boreal forest in Russia, a potential source area for taiga species.
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| 57. |
- Ehn Börjesson, Stina-Mina, 1964-, et al.
(författare)
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Enterococcus spp in wastewater and in mallards (Anas platyrhynchos) exposed to wastewater wetland
- 2013
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Ingår i: International Journal of Environmental Protection. - 2226-6437. ; 3:10, s. 1-12
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Tidskriftsartikel (refereegranskat)abstract
- In this study, twelve Mallards living in an artificial wastewater wetland were exposed to treated wastewater containing 1 x 103- 4 x 103 enterococci 100 ml-1 for a period of 55 days. Faecal samples were collected before, during and after exposure and analysed for Enterococcus spp. The isolates were phenotyped using the PhenePlateTM system. 270 Enterococcus spp. of Mallard origin were analysed, together with 116 Enterococcus spp. isolates from treated wastewater and from incoming raw wastewater. In general, the Mallard and wastewater enterococci isolates belonged to different phenotypes, although several sharing identical phenotypic profiles were found. One E. faecalis phenotype was found in Mallards before, during and after exposure to treated wastewater, as well as in raw and treated wastewater. Our results indicate that there is a common source of enterococci for Mallards and humans. We propose an increased focus on emissions of human bacteria and on systems that mediate their transfer to wild animals.
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| 58. |
- Ehn Börjesson, Stina-Mina, 1964-
(författare)
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Perspectives on urban wastewater as a source of microbial pollution
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Wastewater treatment plants are important links for dissemination of intestinal bacteria into surface waters. In this study, twelve mallards were exposed to treated wastewater for a period of 55 days. Faecal samples were collected and analysed for Enterococcus spp. and C. jejuni. In general, the mallard and wastewater enterococci isolates belonged to different phenotypes, although some strains were identical. Phenotypical characteristics of C. jejuni, including antibiotic resistance, and genetical (PFGE and MLST) patterns were compared. All STs have previously been found in both humans and wild birds. The phenotypical expression of resistance against ampicillin and cefazolin, and ability to assimilate malate and succinate, changed during the mallards exposure to wastewater. Edible clams were collected in Maputo Bay during both the dry and rainy seasons, and number of viable counts of V. parahaemolyticus peaked during the rainy season. A high percentage showed haemolytic capacity but did not carry the standard set of virulence genes. The persistence of E. faecium and E. faecalis strains in sterilized treated wastewater at 10°C and 20°C was evaluated, including if ciprofloxacin had any effect. We could conclude that E. faecalis had a lower DC10 (92 and 43 days) than E. faecium (333 and 68 days) at 10°C and 20°C, respectively. Most of the strains were unaffected of ciprofloxacin was, but there were exceptions. All strains remained culturable the whole studied period (108 days).
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| 59. |
- Elmberg, Johan, 1960-, et al.
(författare)
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Abundance-distribution relationships on interacting trophic levels : the case of lake-nesting waterfowl and dytiscid water beetles
- 2000
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Ingår i: Journal of Biogeography. - 0305-0270 .- 1365-2699. - 0305-0270 ; 27:4, s. 821-827
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Tidskriftsartikel (refereegranskat)abstract
- Aim To compare patterns in local abundance, regional distribution and body size in waterfowl and dytiscid beetles sampled from the same lakes. Location Thirty Swedish lakes, 56-63 degrees N. Methods Birds were censused repeatedly, at which time submerged activity traps were placed on the littoral to catch invertebrates. Avian patterns were analysed separately for four different selections of species, each motivated on functional or phylogenetical grounds. Patterns in dytiscid beetles have been described earlier in Nilsson, Elmberg & Sjoberg (1994). Results Although there were large differences between individual lakes, there was no significant latitudinal gradient at the lake level in either species richness or abundance in any of the bird groupings. Lakes which were rich in species and numbers of dytiscid beetles were also rich in species and numbers of all four waterfowl groups. Three of the four bird groups conform with the general pattern of widely distributed species being more abundant locally, as do dytiscid beetles in the same lakes. Body mass and local abundance were correlated in one of the four birds groups only, i.e. dabbling ducks, (Anas spp.). Main conclusions We find evidence for a similar and positive local abundance-distribution relationship in dytiscid beetles and waterfowl breeding in the same lakes, but no common general pattern in local abundance vs. body size.
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