T. Lauridsen | Aarhus University (original) (raw)

Papers by T. Lauridsen

Research paper thumbnail of Appendix E. Detailed results of the principal-components analyses performed on the centered and standardized richness matrices of each geographic region

Detailed results of the principal-components analyses performed on the centered and standardized ... more Detailed results of the principal-components analyses performed on the centered and standardized richness matrices of each geographic region.

Research paper thumbnail of Artificial Vegetation Module (AVM) system; A new technique for fish sampling and experimental designing

Research paper thumbnail of Lake and catchment management in Denmark

The Ecological Bases for Lake and Reservoir Management, 1999

Page 1. Hydrobiologia 395/396: 419–432, 1999. DM Harper, B. Brierley, AJD Ferguson & G. Phill... more Page 1. Hydrobiologia 395/396: 419–432, 1999. DM Harper, B. Brierley, AJD Ferguson & G. Phillips (eds), The Ecological Bases for Lake and Reservoir Management. © 1999 Kluwer Academic Publishers. Printed in the Netherlands. 419 ...

Research paper thumbnail of NuukBasic - Climate effects monitoring in low arctic Greenland

The climate effects research program in Zackenberg in high arctic Greenland got a counterpart in ... more The climate effects research program in Zackenberg in high arctic Greenland got a counterpart in Nuuk in low arctic West Greenland in 2007. The programme NuukBasic is described and, for the first time, results will presented from several of the monitoring components (Table 1). In particular, we focus on changes in plant phenology, vegetation greenness, graded effects of UVB radiation

Research paper thumbnail of Water Framework Directive Intercalibration: Central-Baltic Lake Fish fauna ecological assessment methods. Part B: Development of the intercalibration common metric; Part C: Intercalibration

HAL (Le Centre pour la Communication Scientifique Directe), 2017

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Research paper thumbnail of Appendix D. Additional information on the gradients realized through the lake-selection procedure

Additional information on the gradients realized through the lake-selection procedure.

Research paper thumbnail of Horizontal distribution of cladocerans in arctic Greenland lakes – impact of macrophytes and fish

... inside the macrophyte beds (R. Burks, pers. comm.). Another factor behind the more even distr... more ... inside the macrophyte beds (R. Burks, pers. comm.). Another factor behind the more even distribution in oligo-/mesotrophic lakes is the pres-ence of fish within the less dense macrophyte beds where they constitute a potential threat to zooplankton (Venugopal & Winfield, 1993 ...

Research paper thumbnail of Fish and crustaceans in northeast Greenland lakes with special emphasis on interactions between Arctic charr (Salvelinus alpinus), Lepidurus arcticus and benthic chydorids

Hydrobiologia, 2001

We studied the trophic structure in the pelagial and crustacean remains in the surface 1 cm of th... more We studied the trophic structure in the pelagial and crustacean remains in the surface 1 cm of the sediment of 13 shallow, high arctic lakes in northeast Greenland (74° N). Seven lakes were fishless, while the remaining six hosted a dwarf form of Arctic charr (Salvelinus alpinus). In fishless lakes, Daphnia pulex was abundant, while no daphnids were found in

Research paper thumbnail of Ferske vandomrâder

Research paper thumbnail of Impacts of climate warming on the long-term dynamics of key fish species in 24 European lakes

Hydrobiologia, 2012

Fish playa key role in the trophic dynamics of lakes. With climate wanning, complex changes in fi... more Fish playa key role in the trophic dynamics of lakes. With climate wanning, complex changes in fish assemblage structure may be expected owing to direct effects of temperature and indirect effects operating through eutrophication, water level changes, stratification and salinisation. We reviewed published and new long-term (10 100 years) fish data series from 24 We dedicate this paper to the late Prof. JUrgen Benndorf, a true pioneer and mentor in lake and reservoir management oriented research, who inspired a number of us to initiate long term comprehensive experimental ecological studies on lakes and reservoirs. Handling editor: P. Noges E. Jeppesen «(gJ). M. S0ndergaard .

Research paper thumbnail of Trophic structure, species richness and biodiversity in Danish lakes: changes along a phosphorus gradient

Research paper thumbnail of Fish diversity in European lakes: geographical factors dominate over anthropogenic pressures

Freshwater Biology, 2013

The NERC and CEH trademarks and logos ('the Trademarks') are registered trademarks of NERC in the... more The NERC and CEH trademarks and logos ('the Trademarks') are registered trademarks of NERC in the UK and other countries, and may not be used without the prior written consent of the Trademark owner.

Research paper thumbnail of Lake responses to reduced nutrient loading - an analysis of contemporary long-term data from 35 case studies

Freshwater Biology, 2005

1. This synthesis examines 35 long-term (5-35 years, mean: 16 years) lake re-oligotrophication st... more 1. This synthesis examines 35 long-term (5-35 years, mean: 16 years) lake re-oligotrophication studies. It covers lakes ranging from shallow (mean depth <5 m and/or polymictic) to deep (mean depth up to 177 m), oligotrophic to hypertrophic (summer mean total phosphorus concentration from 7.5 to 3500 lg L)1 before loading reduction), subtropical to temperate (latitude: 28-65°), and lowland to upland (altitude: 0-481 m). Shallow northtemperate lakes were most abundant. 2. Reduction of external total phosphorus (TP) loading resulted in lower in-lake TP concentration, lower chlorophyll a (chl a) concentration and higher Secchi depth in most lakes. Internal loading delayed the recovery, but in most lakes a new equilibrium for TP

Research paper thumbnail of Effekt af pesticider i vandmiljøet og på randområder: Måling af afdrift ved brug af biokemiske plantebiomarkører

Research paper thumbnail of Appendix A. A detailed account of the aim and methodology of lake selection and of the sampling procedures and sample analyses

A detailed account of the aim and methodology of lake selection and of the sampling procedures an... more A detailed account of the aim and methodology of lake selection and of the sampling procedures and sample analyses.

Research paper thumbnail of Appendix B. A detailed protocol on the application of DGGE for bacteria and eukaryotes

A detailed protocol on the application of DGGE for bacteria and eukaryotes.

Research paper thumbnail of Appendix F. Scatter plots showing the associations between taxon richness values of the organism groups and gradients of submerged vegetation cover, total phosphorus content, and lake area

Scatter plots showing the associations between taxon richness values of the organism groups and g... more Scatter plots showing the associations between taxon richness values of the organism groups and gradients of submerged vegetation cover, total phosphorus content, and lake area.

Research paper thumbnail of The importance of environmental variables for submerged macrophyte community assemblage and coverage in shallow lakes: differences between northern and southern Europe

Much information is available on community composition and abundance of submerged macrophytes in ... more Much information is available on community composition and abundance of submerged macrophytes in North temperate lakes, including their response to variation in environmental variables. Less is known about macrophytes in other climate regions. We studied 98 shallow lakes distributed in three different European latitudinal regions. The lakes were selected along mutually independent gradients of macrophyte coverage and total phosphorus and were sampled monthly from May to October for water chemistry and physical variables. We tested for changes in the impact of selected environmental variables on the macrophyte assemblage, coverage and richness in the three regions. Coverage was measured along transects during July/August and June in the northern/central and southern European lakes, respectively. Correspondence Discriminant Analysis was used to detect for differences in macrophyte composition among different regions, and univariate regression trees were used to detect relationships between environmental variables and macrophyte coverage and richness. In the northern lakes, the coverage was mainly related to chlorophyll a followed by pH, and richness was related to Secchi depth and chlorophyll a. In the southern lakes, pH was the key environmental variable for both coverage and richness. North-south differences may be of relevance for determining management strategies related to global climate change.

Research paper thumbnail of Climate change impacts on lakes: an integrated ecological perspective based on a multi-faceted approach, with special focus on shallow lakes

Journal of Limnology, 2014

Freshwater ecosystems and their biodiversity are presently seriously threatened by global develop... more Freshwater ecosystems and their biodiversity are presently seriously threatened by global development and population growth, leading to increases in nutrient inputs and intensification of eutrophication-induced problems in receiving fresh waters, particularly in lakes. Climate change constitutes another threat exacerbating the symptoms of eutrophication and species migration and loss. Unequivocal evidence of climate change impacts is still highly fragmented despite the intensive research, in part due to the variety and uncertainty of climate models and underlying emission scenarios but also due to the different approaches applied to study its effects. We first describe the strengths and weaknesses of the multi-faceted approaches that are presently available for elucidating the effects of climate change in lakes, including space-for-time substitution, time series, experiments, palaeoecology and modelling. Reviewing combined results from studies based on the various approaches, we describe the likely effects of climate changes on biological communities, trophic dynamics and the ecological state of lakes. We further discuss potential mitigation and adaptation measures to counteract the effects of climate change on lakes and, finally, we highlight some of the future challenges that we face to improve our capacity for successful prediction.

Research paper thumbnail of Fish diversity in European lakes: geographical factors dominate over anthropogenic pressures

Freshwater Biology, Jun 1, 2013

1. We aimed to distinguish the relative contributions of natural and anthropogenic local factors ... more 1. We aimed to distinguish the relative contributions of natural and anthropogenic local factors on patterns of fish diversity in European lakes at different geographical scales. 2. We compiled data from standardised fish monitoring using multimesh benthic gill nets, information on lake morphometry and on geographical, climatic and anthropogenic pressure variables from 1632 lakes in 11 European countries. By means of regression trees, we determined those natural and anthropogenic factors and their thresholds that best predicted local fish diversity, density and mean size. Generalised linear models were used to assess the influence of anthropogenic factors at smaller geographical and morphometric scales. 3. Local fish species richness and diversity were related mainly to morphometric and (bio)geographical/climatic variables. Larger and deeper lakes in warm areas tended to be the most species rich and diverse. Fish density was related mainly to anthropogenically driven productivity bu...

Research paper thumbnail of Appendix E. Detailed results of the principal-components analyses performed on the centered and standardized richness matrices of each geographic region

Detailed results of the principal-components analyses performed on the centered and standardized ... more Detailed results of the principal-components analyses performed on the centered and standardized richness matrices of each geographic region.

Research paper thumbnail of Artificial Vegetation Module (AVM) system; A new technique for fish sampling and experimental designing

Research paper thumbnail of Lake and catchment management in Denmark

The Ecological Bases for Lake and Reservoir Management, 1999

Page 1. Hydrobiologia 395/396: 419–432, 1999. DM Harper, B. Brierley, AJD Ferguson & G. Phill... more Page 1. Hydrobiologia 395/396: 419–432, 1999. DM Harper, B. Brierley, AJD Ferguson & G. Phillips (eds), The Ecological Bases for Lake and Reservoir Management. © 1999 Kluwer Academic Publishers. Printed in the Netherlands. 419 ...

Research paper thumbnail of NuukBasic - Climate effects monitoring in low arctic Greenland

The climate effects research program in Zackenberg in high arctic Greenland got a counterpart in ... more The climate effects research program in Zackenberg in high arctic Greenland got a counterpart in Nuuk in low arctic West Greenland in 2007. The programme NuukBasic is described and, for the first time, results will presented from several of the monitoring components (Table 1). In particular, we focus on changes in plant phenology, vegetation greenness, graded effects of UVB radiation

Research paper thumbnail of Water Framework Directive Intercalibration: Central-Baltic Lake Fish fauna ecological assessment methods. Part B: Development of the intercalibration common metric; Part C: Intercalibration

HAL (Le Centre pour la Communication Scientifique Directe), 2017

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Research paper thumbnail of Appendix D. Additional information on the gradients realized through the lake-selection procedure

Additional information on the gradients realized through the lake-selection procedure.

Research paper thumbnail of Horizontal distribution of cladocerans in arctic Greenland lakes – impact of macrophytes and fish

... inside the macrophyte beds (R. Burks, pers. comm.). Another factor behind the more even distr... more ... inside the macrophyte beds (R. Burks, pers. comm.). Another factor behind the more even distribution in oligo-/mesotrophic lakes is the pres-ence of fish within the less dense macrophyte beds where they constitute a potential threat to zooplankton (Venugopal &amp;amp;amp;amp; Winfield, 1993 ...

Research paper thumbnail of Fish and crustaceans in northeast Greenland lakes with special emphasis on interactions between Arctic charr (Salvelinus alpinus), Lepidurus arcticus and benthic chydorids

Hydrobiologia, 2001

We studied the trophic structure in the pelagial and crustacean remains in the surface 1 cm of th... more We studied the trophic structure in the pelagial and crustacean remains in the surface 1 cm of the sediment of 13 shallow, high arctic lakes in northeast Greenland (74° N). Seven lakes were fishless, while the remaining six hosted a dwarf form of Arctic charr (Salvelinus alpinus). In fishless lakes, Daphnia pulex was abundant, while no daphnids were found in

Research paper thumbnail of Ferske vandomrâder

Research paper thumbnail of Impacts of climate warming on the long-term dynamics of key fish species in 24 European lakes

Hydrobiologia, 2012

Fish playa key role in the trophic dynamics of lakes. With climate wanning, complex changes in fi... more Fish playa key role in the trophic dynamics of lakes. With climate wanning, complex changes in fish assemblage structure may be expected owing to direct effects of temperature and indirect effects operating through eutrophication, water level changes, stratification and salinisation. We reviewed published and new long-term (10 100 years) fish data series from 24 We dedicate this paper to the late Prof. JUrgen Benndorf, a true pioneer and mentor in lake and reservoir management oriented research, who inspired a number of us to initiate long term comprehensive experimental ecological studies on lakes and reservoirs. Handling editor: P. Noges E. Jeppesen «(gJ). M. S0ndergaard .

Research paper thumbnail of Trophic structure, species richness and biodiversity in Danish lakes: changes along a phosphorus gradient

Research paper thumbnail of Fish diversity in European lakes: geographical factors dominate over anthropogenic pressures

Freshwater Biology, 2013

The NERC and CEH trademarks and logos ('the Trademarks') are registered trademarks of NERC in the... more The NERC and CEH trademarks and logos ('the Trademarks') are registered trademarks of NERC in the UK and other countries, and may not be used without the prior written consent of the Trademark owner.

Research paper thumbnail of Lake responses to reduced nutrient loading - an analysis of contemporary long-term data from 35 case studies

Freshwater Biology, 2005

1. This synthesis examines 35 long-term (5-35 years, mean: 16 years) lake re-oligotrophication st... more 1. This synthesis examines 35 long-term (5-35 years, mean: 16 years) lake re-oligotrophication studies. It covers lakes ranging from shallow (mean depth <5 m and/or polymictic) to deep (mean depth up to 177 m), oligotrophic to hypertrophic (summer mean total phosphorus concentration from 7.5 to 3500 lg L)1 before loading reduction), subtropical to temperate (latitude: 28-65°), and lowland to upland (altitude: 0-481 m). Shallow northtemperate lakes were most abundant. 2. Reduction of external total phosphorus (TP) loading resulted in lower in-lake TP concentration, lower chlorophyll a (chl a) concentration and higher Secchi depth in most lakes. Internal loading delayed the recovery, but in most lakes a new equilibrium for TP

Research paper thumbnail of Effekt af pesticider i vandmiljøet og på randområder: Måling af afdrift ved brug af biokemiske plantebiomarkører

Research paper thumbnail of Appendix A. A detailed account of the aim and methodology of lake selection and of the sampling procedures and sample analyses

A detailed account of the aim and methodology of lake selection and of the sampling procedures an... more A detailed account of the aim and methodology of lake selection and of the sampling procedures and sample analyses.

Research paper thumbnail of Appendix B. A detailed protocol on the application of DGGE for bacteria and eukaryotes

A detailed protocol on the application of DGGE for bacteria and eukaryotes.

Research paper thumbnail of Appendix F. Scatter plots showing the associations between taxon richness values of the organism groups and gradients of submerged vegetation cover, total phosphorus content, and lake area

Scatter plots showing the associations between taxon richness values of the organism groups and g... more Scatter plots showing the associations between taxon richness values of the organism groups and gradients of submerged vegetation cover, total phosphorus content, and lake area.

Research paper thumbnail of The importance of environmental variables for submerged macrophyte community assemblage and coverage in shallow lakes: differences between northern and southern Europe

Much information is available on community composition and abundance of submerged macrophytes in ... more Much information is available on community composition and abundance of submerged macrophytes in North temperate lakes, including their response to variation in environmental variables. Less is known about macrophytes in other climate regions. We studied 98 shallow lakes distributed in three different European latitudinal regions. The lakes were selected along mutually independent gradients of macrophyte coverage and total phosphorus and were sampled monthly from May to October for water chemistry and physical variables. We tested for changes in the impact of selected environmental variables on the macrophyte assemblage, coverage and richness in the three regions. Coverage was measured along transects during July/August and June in the northern/central and southern European lakes, respectively. Correspondence Discriminant Analysis was used to detect for differences in macrophyte composition among different regions, and univariate regression trees were used to detect relationships between environmental variables and macrophyte coverage and richness. In the northern lakes, the coverage was mainly related to chlorophyll a followed by pH, and richness was related to Secchi depth and chlorophyll a. In the southern lakes, pH was the key environmental variable for both coverage and richness. North-south differences may be of relevance for determining management strategies related to global climate change.

Research paper thumbnail of Climate change impacts on lakes: an integrated ecological perspective based on a multi-faceted approach, with special focus on shallow lakes

Journal of Limnology, 2014

Freshwater ecosystems and their biodiversity are presently seriously threatened by global develop... more Freshwater ecosystems and their biodiversity are presently seriously threatened by global development and population growth, leading to increases in nutrient inputs and intensification of eutrophication-induced problems in receiving fresh waters, particularly in lakes. Climate change constitutes another threat exacerbating the symptoms of eutrophication and species migration and loss. Unequivocal evidence of climate change impacts is still highly fragmented despite the intensive research, in part due to the variety and uncertainty of climate models and underlying emission scenarios but also due to the different approaches applied to study its effects. We first describe the strengths and weaknesses of the multi-faceted approaches that are presently available for elucidating the effects of climate change in lakes, including space-for-time substitution, time series, experiments, palaeoecology and modelling. Reviewing combined results from studies based on the various approaches, we describe the likely effects of climate changes on biological communities, trophic dynamics and the ecological state of lakes. We further discuss potential mitigation and adaptation measures to counteract the effects of climate change on lakes and, finally, we highlight some of the future challenges that we face to improve our capacity for successful prediction.

Research paper thumbnail of Fish diversity in European lakes: geographical factors dominate over anthropogenic pressures

Freshwater Biology, Jun 1, 2013

1. We aimed to distinguish the relative contributions of natural and anthropogenic local factors ... more 1. We aimed to distinguish the relative contributions of natural and anthropogenic local factors on patterns of fish diversity in European lakes at different geographical scales. 2. We compiled data from standardised fish monitoring using multimesh benthic gill nets, information on lake morphometry and on geographical, climatic and anthropogenic pressure variables from 1632 lakes in 11 European countries. By means of regression trees, we determined those natural and anthropogenic factors and their thresholds that best predicted local fish diversity, density and mean size. Generalised linear models were used to assess the influence of anthropogenic factors at smaller geographical and morphometric scales. 3. Local fish species richness and diversity were related mainly to morphometric and (bio)geographical/climatic variables. Larger and deeper lakes in warm areas tended to be the most species rich and diverse. Fish density was related mainly to anthropogenically driven productivity bu...