| 1. |
- Agrell, Cecilia
(författare)
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Atmospheric transport of persistent organic pollutants to aquatic ecosystems
- 1999
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The load of persistent organic pollutants (POPs) is considered high in the Baltic ecosystem. The Baltic Sea spans over 12 latitudes and the regional differences in climate affect the behavior of POPs. Therefore spatial and temporal variability of the concentrations of POPs in air and precipitation within this area has been investgated at 16 (mostly rural) stations around the Baltic Sea between 1990-1993. In addition, the deposition of gaseous and particulate associated POPs to the Baltic Sea is estimated from empirical data. This atmospheric input of POPs is compared with the input from rivers. Additionally, data from Ross Island, Antarctica and Lake Kariba, Zimbabwe, Africa is presented, and all results are discussed and explained using the ”global fractionation hypothesis” as a framework. In the Baltic Sea, concentrations of individual POPs in air were found to be influenced by their physical-chemical properties, ambient air temperature and location. A latitudinal gradient, with higher levels in the south was found for PCBs and the gradient was more pronounced for the low volatility congeners. As a result, the high volatility congeners in air increased in relative importance with latitude. Generally, PCB concentrations increased with temperature, but slopes of the partial pressure in air versus reciprocal temperature were different between congeners and between stations. In general, the low volatility congeners were more temperature dependent than the high volatility PCB congeners. Steep slopes at a sampling location indicate that the concentration in air is largely determined by diffusive exchange with soils. Lack of a temperature dependence may be due to the influence of long-range transported air masses at remote sites and due to the episodic, or random nature of PCB sources at urban sites. The concentrations of individual congeners in precipitation were found to be influenced by atmospheric concentrations of PCBs, ambient temperature, precipitation volume and the compounds physical-chemical properties. Concentrations of PCBs in precipitation decreased with temperature, and the slopes of this relationship were the same for all stations but differed between congeners. High volatility congeners showed steeper slopes for the temperature relationship than did low volatility PCB congeners. Annual wash out ratios were calculated and found to decrease with congener volatility. Wash out ratios generally decreased with temperature. At snow scavenging events the wash out ratio of PCBs increased with a factor of 2. Latitudinal trends for PCB concentrations in precipitation and for deposition were not statistically significant, but tended to be higher in the south for low volatility congeners. For high volatility congeners the latitudinal trend was reversed. Deposition of PCB congeners varied seasonally, with a factor between 2.0-3.2, and was generally highest during fall. The calculated yearly deposition of PCBs to the Baltic Sea was 387 kg and 5-18 kg for individual congeners, with PCB-138 having the highest flux.
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| 2. |
- Agrell, Cecilia, et al.
(författare)
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Evidence of Latitudinal Fractionation of Polychlorinated Biphenyl Congeners along the Baltic Sea Region
- 1999
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Ingår i: Environmental Science & Technology. - : American Chemical Society (ACS). - 1520-5851 .- 0013-936X. ; 33:8, s. 1149-1156
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Tidskriftsartikel (refereegranskat)abstract
- Annual cycles of the atmospheric concentrations of PCBs were determined at 16 (mostly rural) stations around the Baltic Sea between 1990 and 1993. The concentration levels of individual congeners were found to be influenced by their physical-chemical properties, ambient temperature, and geographical location. Median levels of PCBs were similar at all stations except at one urban site near Riga. A latitudinal gradient with higher levels in the south was found for the sum of PCB as well as for individual congeners, and the gradient was more pronounced for the low volatility congeners. As a result, the high volatility congeners increased in relative importance with latitude. Generally, PCB concentrations increased with temperature, but slopes of the partial pressure in air versus reciprocal temperature were different between congeners and between stations. In general, the low volatility congeners were more temperature dependent than the high volatility PCB congeners. Steep slopes at a sampling location indicate that the concentration in air is largely determined by diffusive exchange with soils. Lack of a temperature dependence may be due to the influence of long-range transported air masses at remote sites and due to the episodic or random nature of PCB sources at urban sites.
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| 3. |
- Alatalo, Rauno V, et al.
(författare)
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Can Female Preference Explain Sexual Dichromatism In The Pied Flycatcher, Ficedula-Hypoleuca
- 1990
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Ingår i: Animal Behaviour. - 0003-3472 .- 1095-8282. ; 39, s. 244-252
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Tidskriftsartikel (refereegranskat)abstract
- How important female choice is for the evolution of male secondary sexual characteristics is controversial. Two field and one laboratory experiment, using the pied flycatcher, were performed to test the female choice aspect of sexual selection. In addition, non-manipulative data from 5 years are presented. The observational data suggest a slight preference for dark males by females but in field experiments in which males had territories at random sites (i.e. they did not choose a territory) or the colour of concurrently arriving males was altered, there was no preference for darker ones. Similarly, oestradiol-treated females did not prefer black or brown males in the laboratory. Thus, there is little support for the idea that female choice has been an important mechanism in the evolution of sexual dichromatism in the pied flycatcher.
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| 4. |
- Allander, Klas, et al.
(författare)
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Temporal variation and reliability of blood parasite levels in captive Yellowhammer males Emberiza citrinella
- 1997
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Ingår i: Journal of Avian Biology. - : JSTOR. - 0908-8857 .- 1600-048X. ; 28:4, s. 325-330
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Tidskriftsartikel (refereegranskat)abstract
- The temporal variation of blood parasites in captive Yellowhammer males was studied in order to investigate possible costs of parasites. Birds were caught in the wild in early April and kept in aviaries during the study period. Blood samples were taken, body mass measured, and moult was scored twelve times for the same individuals from April to October. Blood parasites were detectable in smears during the whole study period with an intensity peak coinciding with breeding in the wild. Young birds had more parasites and a consistently higher body mass than older birds. There was no relationship between parasite intensity and mass in older birds but possibly one in young birds. Parasites did not seem to affect moult in either age class. Repeatability of parasite counts of smears from the same individual was very high and smears are therefore a reliable method for estimating parasite intensity. We conclude that blood parasites are probably most severe during, but occur in their hosts long after, the breeding season. Possible costs of parasites outside the breeding season require further study.
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| 5. |
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| 6. |
- Anderbrant, O., et al.
(författare)
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Diprionyl esters attractive to males of the dailing pine sawfly Neodiprion dailingensis Xiao et Zhou (Hym., Diprionidae) in north-eastern China
- 1997
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Ingår i: Journal of Applied Entomology. - 0931-2048. ; 121:5, s. 281-283
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Tidskriftsartikel (refereegranskat)abstract
- The attraction of male Neodiprion dailingensis Xiao et Zhou to pheromone substances identified from other Neodiprion species was tested in plantations of Pinus tabulaeformis Carr. in Liaoning Province in north-eastern China. Both the acetate and propionate of (2S,3S,7S)-3,7-dimethyl-2-pentadecanol (diprionol) were highly attractive. An addition of 10% of the (2S,3R,7R)-isomer did not significantly reduce the catch to the acetate. The (2S,3R,7R)-isomer was not attractive by itself. This is the first pheromone study of a species belonging to the recently described East Asian group of Neodiprion. The response of N. dailingensis males is similar to that of N. sertifer males in eastern part of Asia.
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| 7. |
- Anderbrant, Olle, et al.
(författare)
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Field response of the pine sawfly Neodiprion sertifer to controlled release of diprionyl acetate, diprionyl propionate and trans-perillenal
- 1992
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Ingår i: Journal of Chemical Ecology. - 0098-0331. ; 18:10, s. 1707-1725
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Tidskriftsartikel (refereegranskat)abstract
- Two dispenser types for pine sawfly (Hymenoptera: Diprionidae) pheromones-glass capillaries and dental cotton rolls-are described, and release rates reported. Glass capillaries of different diameters were used in field tests to determine dose-response relationships of (2 S,3 S,7 S)-3,7-dimethylpentadecan-2-yl acetate (diprionyl acetate), diprionyl propionate, and trans-perillenal on the trap catch of male Neodiprion sertifer. A linear relationship between the logarithm of the capillary cross-sectional area and the logarithm of the release rate was found. However, capillaries of the same diameter could vary in the amount released by as much as a factor of 10. Both the acetate and propionate were attractive alone, but no synergistic effect was found. trans-Perillenal did not show any behavioral activity. Dental cotton rolls have been used extensively in diprionid pheromone research without knowledge about release rates. The release rate from rolls loaded with different amounts of diprionyl acetate was determined by extracting rolls after different times under constant temperature and wind conditions or after use in field tests. Quantification of diprionyl acetate was done on GC. The release rate was found to be proportional to the amount applied over several orders of magnitude, and persisted for several weeks. Capillaries and rolls with similar release rates caught similar numbers of sawflies.
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| 8. |
- Anderbrant, Olle, et al.
(författare)
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Field response of the pine sawfly Neodiprion sertifer to the pheromone (2S, 3S, 7S)‐diprionyl acetate and its stereoisomers
- 1992
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Ingår i: Entomologia Experimentalis et Applicata. - : Wiley. - 0013-8703. ; 62:2, s. 169-181
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Tidskriftsartikel (refereegranskat)abstract
- All eight optical isomers of 3,7‐dimethyl‐2‐pentadecanyl acetate (diprionyl acetate), of high optical purity (>97.4%), were tested for a behavioural activity on male pine sawflies, Neodiprion sertifer (Geoffr.) (Hymenoptera: Diprionidae), in northern Europe. Males were strongly attracted to (2S, 3S, 7S)‐diprionyl acetate. Addition of more than 0.1% of the (2S, 3R, 7R)‐isomer reduced the catch and above 2% the attraction was completely inhibited. Contrary to what has been reported for North American and Japanese populations, so significant synergistic effect of small amounts of the (2S, 3R, 7R)‐isomer could be demonstrated. The effects of addition of the other six optical isomers alone or in combinations, were also studied, but none was found to be a synergist. The (2S, 3R, 7S)‐isomer had a weak inhibitory effect, and completely inhibited the attraction to the (2S, 3S, 7S)‐isomer when applied in about equal amounts as the attractant. In some cases a reduction in catch was noted when other isomers were tested, but this could be attributed to the very small amounts of the inhibitory (2S, 3R, 7R)‐isomer present in these isomers. 1992 The Netherlands Entomological Society
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| 9. |
- Anderbrant, Olle
(författare)
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Gallery construction and oviposition of the bark beetle Ips typographus (Coleoptera : Scolytidae) at different breeding densities
- 1990
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Ingår i: Ecological Entomology. - : Wiley. - 0307-6946 .- 1365-2311. ; 15:1, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Abstract. 1. The bole of a Norway spruce, Picea abies(L.) Karst., was cut in 25 cm sections and infested in the laboratory with 2 or 8 females/dm2 of Ips typographus (L.) and an equal number of males. 2. One log of each beetle density was dissected every second day, beginning 2 days after female introduction. 3. The oviposition rate was highest at the beginning of the breeding period for both densities and then declined, especially at the high density. Residence time is a useful approximation for the number of laid eggs in the beginning of the oviposition period or when the density is low. 4. Final gallery length and egg number per gallery were on average significantly smaller at density 8 than at density 2. 5. Linear relationships between total gallery length and number of egg niches were found to be similar for the two densities. 6. An estimate of the egg to adult mortality at different densities was found by using data from a field study that related gallery length to breeding density in attacked living trees, together with published relationships between density and egg niches or emergence of new adults. 7. It was concluded that both decreased oviposition rate and earlier re‐emergence at higher densities contribute to a declining oviposition with increasing density. The final offspring production is futher reduced by lower survival due to larval competition as density increases.
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| 10. |
- Anderbrant, O.
(författare)
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Weather factors influencing catch of Neodiprion sertifer (Hymenoptera : Diprionidae) in pheromone traps
- 1993
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Ingår i: Environmental Entomology. - : Oxford University Press (OUP). - 0046-225X .- 1938-2936. ; 22:2, s. 445-452
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Tidskriftsartikel (refereegranskat)abstract
- Variation in number of European pine sawflies Neodiprion sertifer caught in pheromone traps during 11 d of the peak flight period was in part explained by weather. Daily average air temperature was the most important variable and explained 86% of the variation. A threshold for flight was c+11°C. Rain during most of the day inhibited flight, but occasional showers did not. -from Authors
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