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Pettersson, Kurt
Publikasjoner (10 av 29) Visa alla publikasjoner
Yang, Y., Pettersson, K. & Padisák, J. (2016). Repetitive baselines of phytoplankton succession in an unstably stratified temperate lake (Lake Erken, Sweden): a long-term analysis. Hydrobiologia, 764(1), 211-227
Åpne denne publikasjonen i ny fane eller vindu >>Repetitive baselines of phytoplankton succession in an unstably stratified temperate lake (Lake Erken, Sweden): a long-term analysis
2016 (engelsk)Inngår i: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 764, nr 1, s. 211-227Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

The seasonal development of phytoplankton is a sequence of consecutive events with waxes and wanes of biomass and compositional shifts. This study analyzed 16 years data in Lake Erken, Sweden and revealed four baselines of phytoplankton succession with their underlying drivers. Results showed that there were two diatom-dominated phases annually. The vernal community was dominated by centric diatoms larger than 15 A mu m (functional groups B and C) which were fast-growing diatoms being highly efficient in the use of nutrients. The autumn community was comprised mainly meroplanktonic mixing-dependent Aulacoseira granulata and Fragilaria sp. (MP and P) or/and large centric diatoms (B). Between the two mixing-phases with diatoms, a Gloeotrichia echinulata (H 2) bloom occurred due to its preference for a stratified water column with elevated water temperatures and high light availability. The summer stratification in Lake Erken was weak and short, thus, favoring meroplanktonic diatoms to peak once the lake turned over in early autumn. Lake Erken represents an intermediate case between a highly mixed polymictic lake and a lake with strong summer stratification, where the observed stratification patterns allowed the development of an autumn diatom phase similar, by extent, to the vernal one and mainly dominated by meroplanktonic diatoms.

HSV kategori
Identifikatorer
urn:nbn:se:uu:diva-262459 (URN)10.1007/s10750-015-2314-1 (DOI)000365727500017 ()
Tilgjengelig fra: 2015-09-15 Laget: 2015-09-15 Sist oppdatert: 2017-12-04bibliografisk kontrollert
Yang, Y., Colom-Montero, W., Pierson, D. & Pettersson, K. (2016). Water column stability and summer phytoplankton dynamics in a temperate lake (Lake Erken, Sweden). Inland Waters, 6(4), 499-508
Åpne denne publikasjonen i ny fane eller vindu >>Water column stability and summer phytoplankton dynamics in a temperate lake (Lake Erken, Sweden)
2016 (engelsk)Inngår i: Inland Waters, ISSN 2044-2041, E-ISSN 2044-205X, Vol. 6, nr 4, s. 499-508Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Phytoplankton development in aquatic ecosystems is caused by interactions among multiple environmental factors. Physical processes, particularly development of thermal stratification, have been proposed to be important factors for regulating phytoplankton composition and abundance during summer. This study examined the temporal pattern of thermal stratification during summer in Lake Erken, Sweden, based on 21 years of historical data spanning 23 years and investigated the role played by water stability on phytoplankton development. Water column stability indexes were calculated from high frequency measurements during periods of summer thermal stratification. Clustering and ordination analyzed the dissimilarities between communities during different periods and extracted the significant environmental gradients controlling phytoplankton succession. Wind introduced the major external disturbance to Lake Erken during summer and played an important role for the progression of thermocline depth. Species-specific thermal stability preference or tolerance determined the response of individual species to the stratification and constitutes a mechanism of species selection in phytoplankton dynamics. Lake Erken is an unstably stratified lake during summer, caused by wind-induced turbulence and internal seiches. Adaptation to these unstable conditions is the major determinant of phytoplankton dynamics. Hydrodynamic variability, characterized by different stability indexes in early, mid, and late summer, was the key factor regulating phytoplankton dynamics, directly by changing phytoplankton distribution and indirectly by altering both the light and nutrient availability in the epilimnion.

Emneord
Gloeotrichia echinulata, hydrodynamics, Lake Analyzer, phytoplankton dynamics, succession, thermal stratification and mixing
HSV kategori
Identifikatorer
urn:nbn:se:uu:diva-262451 (URN)10.5268/IW-6.4.874 (DOI)000388608700003 ()
Tilgjengelig fra: 2015-09-15 Laget: 2015-09-15 Sist oppdatert: 2024-01-04bibliografisk kontrollert
Schroeder, F., Traunspurger, W., Pettersson, K. & Peters, L. (2012). Temporal changes in periphytic meiofauna in lakes of different trophic states. Journal of limnology, 71(1), 216-227
Åpne denne publikasjonen i ny fane eller vindu >>Temporal changes in periphytic meiofauna in lakes of different trophic states
2012 (engelsk)Inngår i: Journal of limnology, ISSN 1129-5767, E-ISSN 1723-8633, Vol. 71, nr 1, s. 216-227Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Meiofaunal organisms in the periphyton of stony hard-substrates (epilithon) were studied in three Swedish lakes with different trophic states (oligo-, meso- and eutrophic) with respect to seasonal successions in abundance, biomass, and production. Over a period of 2 years, the meiofaunal population of all three lakes fluctuated greatly, with densities varying up to nine-fold within a season. In the oligotrophic lake, a significant decrease in meiofauna in winter was striking, whereas in the other two lakes, richer in nutrients, there was a pronounced peak in early summer Although the lakes, on average, did not differ in epilithic organic and inorganic material, the differences in meiofaunal abundance, biomass, and production were significant. Correlation analysis revealed that altogether the meiofaunal biomass was positively related to the lakes trophic state (total phosphorus), while the meiofaunal abundance and production along the trophic spectrum displayed a humped-shape distribution, with maximum values measured in the mesotrophic Lake Erken (1324 ind cm(-2) and 2249 mu g DW cm(-2) y(-1)). Nematodes were the dominant meiofaunal group in the epilithon of all three lakes, accounting for up to 58% in abundance, 33% in biomass and 55% in production of the whole meiofaunal community. However their relative importance tended to decrease with increasing trophic state. Beside nematodes, rotifers, oligochaetes, copepods and tardigrades were also found in large numbers in the epilithon. Overall, the results demonstrated that, due to their high abundance, biomass, and production, meiofaunal organisms play an important role in epilithic communities.

Emneord
nematodes, meiofaunal production, epilithon, seasonal succession, Lake Erken
HSV kategori
Identifikatorer
urn:nbn:se:uu:diva-175871 (URN)10.4081/jlimnol.2012.e23 (DOI)000303943400023 ()
Tilgjengelig fra: 2012-06-13 Laget: 2012-06-13 Sist oppdatert: 2017-12-07bibliografisk kontrollert
Pierson, D. C., Weyhenmeyer, G. A., Arvola, L., Benson, B., Blenckner, T., Kratz, T., . . . Weathers, K. (2011). An automated method to monitor lake ice phenology. Limnology and Oceanography: Methods, 9, 74-83
Åpne denne publikasjonen i ny fane eller vindu >>An automated method to monitor lake ice phenology
Vise andre…
2011 (engelsk)Inngår i: Limnology and Oceanography: Methods, E-ISSN 1541-5856, Vol. 9, s. 74-83Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

A simple method to automatically measure the date of ice-on, the date of ice-off, and the duration of lake ice cover is described. The presence of ice cover is detected by recording water temperature just below the ice/water interface and just above the lake bottom using moored temperature sensors. The occurrence of ice-on rapidly leads to detectible levels of inverse stratification, defined as existing when the upper sensor records a temperature at least 0.1 degrees C below that of the bottom sensor, whereas the occurrence of ice-off leads to the return of isothermal mixing. Based on data from 10 lakes over a total of 43 winter seasons, we found that the timing and duration of inverse stratification monitored by recording temperature sensors compares well with ice cover statistics based on human observation. The root mean square difference between the observer-based and temperature-based estimates was 7.1 d for ice-on, 6.4 d for ice-off, and 10.0 d for the duration of ice cover. The coefficient of determination between the two types of estimates was 0.93, 0.86, and 0.91, respectively. The availability of inexpensive self-contained temperature loggers should allow expanded monitoring of ice cover in a large and diverse array of lakes. Such monitoring is needed to improve our ability to monitor the progression of global climate change, and to improve our understanding of the relationship between climate and ice cover over a wide range of temporal and spatial scales.

HSV kategori
Identifikatorer
urn:nbn:se:uu:diva-154537 (URN)10.4319/lom.2011.9.74 (DOI)000290678500004 ()
Tilgjengelig fra: 2011-06-07 Laget: 2011-06-07 Sist oppdatert: 2023-02-03bibliografisk kontrollert
Naddafi, R., Blenckner, T., Eklöv, P. & Pettersson, K. (2011). Physical and chemical properties determine zebra mussel invasion success in lakes. Hydrobiologia, 669(1), 227-236
Åpne denne publikasjonen i ny fane eller vindu >>Physical and chemical properties determine zebra mussel invasion success in lakes
2011 (engelsk)Inngår i: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 669, nr 1, s. 227-236Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

To address the question whether the abundance of an invasive species can be explained by physical and chemical properties of the invaded ecosystems, we gathered density data of invasive zebra mussels and the physical and chemical data of ecosystems they invaded. We assembled published data from 55 European and 13 North American lakes and developed a model for zebra mussel density using a generalized additive model (GAM) approach. Our model revealed that the joint effect of surface area, total phosphorus and calcium concentrations explained 62% of the variation in Dreissena density. Our study indicates that large and less productive North American lakes can support larger local populations of zebra mussels. Our results suggest that the proliferation of an exotic species in an area can partially be explained by physical and chemical properties of the recipient environment.

Emneord
Invasion success, Zebra mussel, Density, Generalized additive model, Physical and chemical properties, North American and European lakes
HSV kategori
Identifikatorer
urn:nbn:se:uu:diva-154605 (URN)10.1007/s10750-011-0689-1 (DOI)000290678600016 ()
Tilgjengelig fra: 2011-06-09 Laget: 2011-06-08 Sist oppdatert: 2017-12-11bibliografisk kontrollert
Blenckner, T., Adrian, R., Arvola, L., Järvinen, M., Nõges, P., Nõges, T., . . . Weyhenmeyer, G. A. (2010). The impact of climate change on lakes in northern Europe. In: D.G. George (Ed.), The impact of climate change on European lakes (pp. 339-358). Springer
Åpne denne publikasjonen i ny fane eller vindu >>The impact of climate change on lakes in northern Europe
Vise andre…
2010 (engelsk)Inngår i: The impact of climate change on European lakes / [ed] D.G. George, Springer , 2010, s. 339-358Kapittel i bok, del av antologi (Annet vitenskapelig)
sted, utgiver, år, opplag, sider
Springer, 2010
Serie
Aquatic Ecology Series, ISSN 1573-4595 ; 4
HSV kategori
Identifikatorer
urn:nbn:se:uu:diva-146044 (URN)10.1007/978-90-481-2945-4 (DOI)978-90-481-2944-7 (ISBN)978-90-481-2945-4 (ISBN)
Tilgjengelig fra: 2011-02-14 Laget: 2011-02-14 Sist oppdatert: 2014-01-16
Naddafi, R., Eklöv, P. & Pettersson, K. (2009). Stoichiometric constraints do not limit successful invaders: zebra mussels in Swedish lakes. PLOS ONE, 4(4), e5345
Åpne denne publikasjonen i ny fane eller vindu >>Stoichiometric constraints do not limit successful invaders: zebra mussels in Swedish lakes
2009 (engelsk)Inngår i: PLOS ONE, E-ISSN 1932-6203, Vol. 4, nr 4, s. e5345-Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Background: Elemental imbalances of carbon (C): nitrogen (N): phosphorus (P) ratios in food resources can constrain the growth of grazers owning to tight coupling between growth rate, RNA allocation and biomass P content in animals. Testing for stoichiometric constraints among invasive species is a novel challenge in invasion ecology to unravel how a successful invader tackles ecological barriers in novel ecosystems.Methodology/Principal Findings: We examined the C:P and N:P ratios and the condition factor of a successful invader in lakes, the zebra mussel (Dreissena polymorpha), collected from two Swedish lakes. Concurrently, we analyzed the elemental composition of the food (seston) and tissue of the mussels in which nutrient composition of food and mussels varied over time. Zebra mussel condition factor was weakly related to the their own tissue N:P and C:P ratios, although the relation with the later ratio was not significant. Smaller mussels had relatively lower tissue N:P ratio and higher condition factor. There was no difference in C:P and N:P ratios between seston and mussels' tissues. Our results indicated that the variation in nutrient stoichiometry of zebra mussels can be explained by food quality and quantity. Conclusions/Significance: Our study suggests that fitness of invasive zebra mussels is not constrained by nutrient stoichiometry which is likely to be important for their proliferation in novel ecosystems. The lack of imbalance in C:P and N:P ratios between seston and mussels along with high tissue C:P ratio of the mussel allow them to tolerate potential P limitation and maintain high growth rate. Moreover, zebra mussels are able to change their tissue C:P and N:P ratios in response to the variation in elemental composition of their food. This can also help them to bypass potential nutrient stoichiometric constraints. Our finding is an important step towards understanding the mechanisms contributing to the success of exotic species from stoichiometric principles.

Emneord
Invasion success, Zebra mussel, Ecological stoichiometry
HSV kategori
Forskningsprogram
Limnologi
Identifikatorer
urn:nbn:se:uu:diva-103253 (URN)10.1371/journal.pone.0005345 (DOI)000265601100006 ()
Tilgjengelig fra: 2009-05-15 Laget: 2009-05-15 Sist oppdatert: 2022-01-28bibliografisk kontrollert
Naddafi, R., Pettersson, K. & Eklöv, P. (2008). Effects of the zebra mussel, an exotic freshwater species, on seston stoichiometry. Limnology and Oceanography, 53(5), 1973-1987
Åpne denne publikasjonen i ny fane eller vindu >>Effects of the zebra mussel, an exotic freshwater species, on seston stoichiometry
2008 (engelsk)Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 53, nr 5, s. 1973-1987Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

We examined the effect of the zebra mussel, Dreissena polymorpha, an exotic species, on seston stoichiometry by conducting laboratory experiments in which we varied nutrient composition of seston and mussels over time. Zebra mussels altered the stoichiometry of seston through removal of particulate organic nutrients and changed the stoichiometry of the dissolved nutrient pool through nutrient excretion. Grazers had stronger effects on carbon : phosphorus (C : P) and nitrogen (N) : P ratios than on the C:N ratio of seston. Elemental residence time in tissue and high mass-specific nutrient excretion by small mussels caused small mussels to be more efficient nutrient recyclers than larger mussels. Zebra mussels reduced P availability through enhancing C: P and N: P molar ratios of seston during the period extending from June to August, when P was limited in the lake, and increased the C:N molar ratio of seston in June, when N was at the minimum level in the lake. C: P and N: P molar ratios for zebra mussel tissue were higher in August and somewhat in September than in all other months. N was retained more efficiently than P in Dreissena tissue. Nutrient mass-specific uptake rate was higher than excretion rate by zebra mussels.

sted, utgiver, år, opplag, sider
American Society of Limnology and Oceanography, 2008
HSV kategori
Identifikatorer
urn:nbn:se:uu:diva-96408 (URN)10.4319/lo.2008.53.5.1973 (DOI)000259356000024 ()
Tilgjengelig fra: 2007-11-14 Laget: 2007-11-14 Sist oppdatert: 2024-04-25bibliografisk kontrollert
Naddafi, R., Eklöv, P. & Pettersson, K. (2007). Non-lethal predator effects on the feeding rate and prey selection of the exotic zebra mussel (Dreissena polymorpha). Oikos, 116(8), 1289-1298
Åpne denne publikasjonen i ny fane eller vindu >>Non-lethal predator effects on the feeding rate and prey selection of the exotic zebra mussel (Dreissena polymorpha)
2007 (engelsk)Inngår i: Oikos, ISSN 0030-1299, E-ISSN 1600-0706, Vol. 116, nr 8, s. 1289-1298Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Predators may induce changes in prey feeding that indirectly influence both the impact of prey on resource abundances and their interactions with other species in their community. We evaluated whether clearance and excretion (faeces plus pseudofaeces) of phytoplankton by zebra mussels were affected by the presence of predatory cues from roach (Rutilus rutilus) and signal crayfish (Pasifastacus leniusculus). We found that non-lethal effects of predators can alter zebra mussel clearance rate and thus the impact of zebra mussels on phytoplankton. Risk cues released by both predators had similar negative effects on clearance rate of zebra mussels and cascading positive indirect effects on phytoplankton resources. Predation risk had a stronger effect on zebra mussels' clearance rate of cyanobacteria and diatoms than cryptophytes and chrysophytes. The presence of predators did not significantly affect the rate at which zebra mussels expelled and excreted phytoplankton, although there was a tendency for more chlorophyll to be expelled and excreted in the presence of predators. Our results contribute to the growing evidence that predators indirectly affect resource dynamics and food web structure through their non-lethal effects on consumers. Our results suggest that exotic species such as zebra mussels can show behavioural responses to both native (e.g., roach) and exotic (e.g., crayfish) predators.

Emneord
Non-lethal effect of predator, Invasive species, Zebra mussel, Feeding rate, Prey selection, Trait-mediated indirect interaction, Phytoplankton community structure, Ecosystem function
HSV kategori
Identifikatorer
urn:nbn:se:uu:diva-96407 (URN)10.1111/j.2007.0030-1299.15695.x (DOI)000248681100004 ()
Tilgjengelig fra: 2007-11-14 Laget: 2007-11-14 Sist oppdatert: 2022-01-28
Naddafi, R., Pettersson, K. & Eklöv, P. (2007). The effect of seasonal variation in selective feeding by zebra mussels (Dreissena polymorpha) on phytoplankton community composition. Freshwater Biology, 52(5), 823-842
Åpne denne publikasjonen i ny fane eller vindu >>The effect of seasonal variation in selective feeding by zebra mussels (Dreissena polymorpha) on phytoplankton community composition
2007 (engelsk)Inngår i: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 52, nr 5, s. 823-842Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

To investigate the impact of zebra mussels (Dreissena polymorpha) on phytoplankton community composition, temporal variability in selective feeding by the mussels was determined from April to November 2005 in a natural lake using Delayed Fluorescence (DF) excitation spectroscopy. Selective grazing by zebra mussels varied in relation to seasonal phytoplankton dynamics; mussels showed a consistent preference for cryptophytes and avoidance of chlorophytes and cyanobacteria. Diatoms, chrysophytes and dinoflagellates responded differentially to zebra mussel grazing depending on their size. Analysis of excreted products of the zebra mussels revealed that in addition to chlorophytes and cyanobacteria, phytoplankton >50 μm and very small phytoplankton (≤7 μm) were largely expelled in pseudofaeces. The zebra mussel is a selective filter-feeder that alters its feeding behaviour in relation to phytoplankton composition to capture and ingest high quality phytoplankton, especially when phytoplankton occur in preferred size ranges. Flexibility of zebra mussel feeding behaviour and variation in susceptibility among phytoplankton groups to mussel ingestion indicate that invading zebra mussels could alter phytoplankton community composition of lakes and have important ecosystem consequences.

Emneord
Delayed Fluorescence, Lake Erken, phytoplankton dynamics, selective feeding, Zebra mussel
HSV kategori
Identifikatorer
urn:nbn:se:uu:diva-96406 (URN)10.1111/j.1365-2427.2007.01732.x (DOI)000245987200005 ()
Tilgjengelig fra: 2007-11-14 Laget: 2007-11-14 Sist oppdatert: 2017-12-14bibliografisk kontrollert
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