| 1. |
- Hansson, Lars-Anders, et al.
(författare)
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Experimental evidence for a mismatch between insect emergence and waterfowl hatching under increased spring temperatures
- 2014
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Ingår i: Ecosphere. - : Ecological Society of America. - 2150-8925 .- 2150-8925. ; 5:9, s. 120-
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Tidskriftsartikel (refereegranskat)abstract
- By combining a large-scale experimental assessment on timing of insect emergence with longtermmonitoring of waterfowl hatching date, we here show that insect emergence is mainly driven bytemperature, whereas there is only a weak effect of increasing spring temperatures on inter-annualvariability in observations of waterfowl chicks. Hence, a change in timing of the mass-emergence of insectsfrom lakes and wetlands, which is the crucial food source for waterfowl chicks, will likely result in aconsumer/resource mismatch in a future climate change perspective. Specifically, we experimentally showthat a moderate increase in temperature of 38C above ambient, expected to occur within 25–75 years, leadsto a considerably (2 weeks) earlier, and more pronounced, peak in insect emergence (Chironomus sp).Moreover, by utilizing long-term Citizen Science databases, ranging over several decades, we also showthat common waterfowl species are unable to significantly adjust their reproduction to fit futuretemperature increase. Hence, based on our data we predict a future mismatch between insect emergenceand waterfowl species basing their reproduction on temperature. This will have a profound impact onreproductive success and population dynamics of many aquatic birds, as well as on freshwaterbiodiversity.
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| 2. |
- Erlandsson, Martin, et al.
(författare)
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PCR guide for construction products and works - Specifications to and evaluation of EN 15804
- 2013
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The main question handled in the project ‘Robust LCA’ is how to use LCA for a robust comparison of construction products or any construction works. The project is divided into two parts where the first part deals with a general introduction to methodology problems related to LCA and what we here call ‘choice of system perspective’. The latter aspect deals with the question when to use to use attributional or consequential LCA. An LCA typology is developed in this part of the project, where different ISO 14044 methodologies are classified. The typology also deals with what question these different methodologies address. The second part of the project, given in this report, deals with commonly methodology aspects that are important to find consensus about. These methodical aspects selected and handled here are based on a workshop result. Already existing standards is used as a baseline to describe the current best common practice. The main LCA methodology used as basis for this work is EN 15804, a so call ‘core PCR’, (product category rules) for all constructions products. However, since the common goal within an LCA case study is to use a harmonized method in the entirely study, such PCR are valid for all products and services used in the life cycle of any construction works. For instance, this implies that the impact from different energy wares is to be handled with the same methodology as used for the construction products. This PCR guide includes specifications to EN 15804, as well as the potential development for aspects that are not handled in this standard today. The outlined suggestions and recommendations are the result of a series of workshops, with delegates from different parties within the Swedish building material, construction and real estate sector, including civil engineering work. The PCR guides have been subject to an open consultation that was closed on the 20th of October 2013, where all parties have had the possibility to put forward their opinions. The final recommendation in this report is based on a common understanding within the project group and takes into account the submitted written contributions to the open consultation (version dated 2013-09-18). The recommendation therefore describes the current consensus in the Swedish group participating in this project. Moreover, the PCR Guide was also sent to some EPD program operators (EPD Norway, International EPD system, Institut Bauen und Umwelt (Germany)) and the working group behind EN 16485. This was done to create an opportunity to bring forward dissenting opinion to the specifications given here. Please note that this report shall not be regarded as a PCR, but as an inspiration for future development of such work.
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| 3. |
- Hansson, Lars-Anders, et al.
(författare)
-
Experimental evidence for a mismatch between insect emergence and waterfowl hatching under increased spring temperatures
- 2014
-
Ingår i: Ecosphere. - : Wiley-Blackwell. - 2150-8925. ; 5:9, s. 1-9
-
Tidskriftsartikel (refereegranskat)abstract
- By combining a large-scale experimental assessment on timing of insect emergence with long-term monitoring of waterfowl hatching date, we here show that insect emergence is mainly driven by temperature, whereas there is only a weak effect of increasing spring temperatures on inter-annual variability in observations of waterfowl chicks. Hence, a change in timing of the mass-emergence of insects from lakes and wetlands, which is the crucial food source for waterfowl chicks, will likely result in a consumer/resource mismatch in a future climate change perspective. Specifically, we experimentally show that a moderate increase in temperature of 3 degrees C above ambient, expected to occur within 25-75 years, leads to a considerably (2 weeks) earlier, and more pronounced, peak in insect emergence (Chironomus sp). Moreover, by utilizing long-term Citizen Science databases, ranging over several decades, we also show that common waterfowl species are unable to significantly adjust their reproduction to fit future temperature increase. Hence, based on our data we predict a future mismatch between insect emergence and waterfowl species basing their reproduction on temperature. This will have a profound impact on reproductive success and population dynamics of many aquatic birds, as well as on freshwater biodiversity.
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| 4. |
- Bianco, Giuseppe, et al.
(författare)
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Plankton 3D tracking: the importance of camera calibration in stereo computer vision systems
- 2013
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Ingår i: Limnology and Oceanography: Methods. - : Wiley. - 1541-5856. ; 11, s. 278-286
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Tidskriftsartikel (refereegranskat)abstract
- Computer vision applications are very useful to study animal movements, but due to their intrinsic complexity they are challenging to design, implement, and use properly. We here describe a calibration procedure for a laboratory stereo vision system for tracking zooplankton in three dimensions (3D). We demonstrate the crucial importance of using a correct calibration for proper interpretation of animal swimming tracks. We also address the effect of the air-water shift phase in the calibration procedure. Actually, not performing a proper calibration caused an average positional error of more than 25 body-lengths in the investigated animal Daphnia magna. Furthermore, we evaluate the different outcomes of using 2D and 3D tracks obtained with a calibrated stereo vision system and show that although 2D tracking might be sufficient in some cases, the method was in our study unable to give information of swimming path geometry and underestimated the speed by 25%. Finally, we discuss consequences for biologically relevant questions when an incorrect methodology is used and strongly recommend that future studies provide detailed descriptions of the framework used for calibration to allow for comparisons between different studies.
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| 5. |
- Ekvall, Mattias, et al.
(författare)
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Differences in recruitment and life-history strategy alter zooplankton spring dynamics under climate-change conditions.
- 2012
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:9
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Tidskriftsartikel (refereegranskat)abstract
- In recent decades temperature elevation has been the focus of many studies on climate change, including effects on planktonic communities, but few studies have examined the effects of increased water color ("brownification"). Since these changes are likely to occur simultaneously, it is important to investigate their potential interactive effects. Accordingly, we performed a mesocosm experiment where we combined a 3°C increase in temperature with a doubling in water color to study how these factors affect zooplankton. In particular, we looked at recruitment of cladocerans and copepods from the sediment in spring, as well as their establishment in the water column. Our results show that an elevated temperature will have considerable effects on recruitment as well as on pelagic abundances of both cladocerans and copepods, whereas increases in water color will have less effects on the recruitment and pelagic establishment. But more importantly, the proportion of cladocerans in the water column, relative to copepods, increased at higher temperature, suggesting that cladocerans benefit more from elevated temperatures than copepods do. Overall, these results likely stem from the combined effect of changes in recruitment and differences in life history between copepods and cladocerans. Taking a wider outlook, this suggests that future climate warming will change the dominance pattern of zooplankton communities in spring, and, in accordance with the experimental data, we here show that cladocerans are more abundant than copepods in natural lake ecosystems during warmer rather than cooler years.
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| 6. |
- Ekvall, Mattias, et al.
(författare)
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Linking cascading effects of fish predation and zooplankton grazing to reduced cyanobacterial biomass and toxin levels following biomanipulation.
- 2014
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:11
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Tidskriftsartikel (refereegranskat)abstract
- Eutrophication has been one of the largest environmental problems in aquatic ecosystems during the past decades, leading to dense, and often toxic, cyanobacterial blooms. In a way to counteract these problems many lakes have been subject to restoration through biomanipulation. Here we combine 13 years of monitoring data with experimental assessment of grazing efficiency of a naturally occurring zooplankton community and a, from a human perspective, desired community of large Daphnia to assess the effects of an altered trophic cascade associated with biomanipulation. Lake monitoring data show that the relative proportion of Daphnia spp. grazers in June has increased following years of biomanipulation and that this increase coincides with a drop in cyanobacterial biomass and lowered microcystin concentrations compared to before the biomanipulation. In June, the proportion of Daphnia spp. (on a biomass basis) went from around 3% in 2005 (the first year of biomanipulation) up to around 58% in 2012. During months when the proportion of Daphnia spp. remained unchanged (July and August) no effect on lower trophic levels was observed. Our field grazing experiment revealed that Daphnia were more efficient in controlling the standing biomass of cyanobacteria, as grazing by the natural zooplankton community never even compensated for the algal growth during the experiment and sometimes even promoted cyanobacterial growth. Furthermore, although the total cyanobacterial toxin levels remained unaffected by both grazer communities in the experimental study, the Daphnia dominated community promoted the transfer of toxins to the extracellular, dissolved phase, likely through feeding on cyanobacteria. Our results show that biomanipulation by fish removal is a useful tool for lake management, leading to a top-down mediated trophic cascade, through alterations in the grazer community, to reduced cyanobacterial biomass and lowered cyanobacterial toxin levels. This improved water quality enhances both the ecological and societal value of lakes as units for ecosystem services.
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| 7. |
- Ekvall, Mattias, et al.
(författare)
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Synergistic and species-specific effects of climate change and water colour on cyanobacterial toxicity and bloom formation
- 2013
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Ingår i: Freshwater Biology. - : Wiley. - 0046-5070. ; 58:11, s. 2414-2422
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Tidskriftsartikel (refereegranskat)abstract
- Cyanobacterial blooms are a worldwide phenomenon in both marine and freshwater ecosystems and are predicted to occur more frequently due to global climate change. However, our future water resources may also simultaneously suffer from other environmental threats such as elevated amounts of humic content and consequent increased water colour, a phenomenon called brownification'. In order to investigate the effects of temperature and water colour in combination, we performed a mesocosm experiment combining a 3 degrees C increase in temperature and a doubling in water colour. With this, we created a projected future scenario for our water resources, and we specifically focused on how these changes would affect cyanobacterial bloom formation and toxicity. We showed that despite total cyanobacterial biomass remaining unaffected, the abundance of one individual cyanobacterial species, Microcystis botrys, increased in response to the combination of elevated temperature and increased water colour. Furthermore, population fluctuations in M.botrys explained the majority of the variations in microcystin concentrations, suggesting that this species was responsible for the more than 300% higher microcystin concentrations in the future scenario treatment compared to the ambient scenario. Hence, it was not a change in cyanobacterial biomass, but rather a species-specific response that had the most profound impact on bloom toxicity. We argue that understanding such species-specific responses to multiple stressors is crucial for proper management decisions because toxic blooms can significantly affect both biodiversity and ecosystem functioning, as well as ecosystem services such as drinking water supply and recreation.
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| 8. |
- Ekvall, Mikael, et al.
(författare)
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Three-dimensional tracking of small aquatic organisms using fluorescent nanoparticles.
- 2013
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:11
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Tidskriftsartikel (refereegranskat)abstract
- Tracking techniques are vital for the understanding of the biology and ecology of organisms. While such techniques have provided important information on the movement and migration of large animals, such as mammals and birds, scientific advances in understanding the individual behaviour and interactions of small (mm-scale) organisms have been hampered by constraints, such as the sizes of existing tracking devices, in existing tracking methods. By combining biology, chemistry and physics we here present a method that allows three-dimensional (3D) tracking of individual mm-sized aquatic organisms. The method is based on in-vivo labelling of the organisms with fluorescent nanoparticles, so-called quantum dots, and tracking of the organisms in 3D via the quantum-dot fluorescence using a synchronized multiple camera system. It allows for the efficient and simultaneous study of the behaviour of one as well as multiple individuals in large volumes of observation, thus enabling the study of behavioural interactions at the community scale. The method is non-perturbing - we demonstrate that the labelling is not affecting the behavioural response of the organisms - and is applicable over a wide range of taxa, including cladocerans as well as insects, suggesting that our methodological concept opens up for new research fields on individual behaviour of small animals. Hence, this offers opportunities to focus on important biological, ecological and behavioural questions never before possible to address.
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| 9. |
- Ekvall, Sara, et al.
(författare)
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Co-Occurring SHOC2 and PTPN11 Mutations in a Patient With Severe/Complex Noonan Syndrome-Like Phenotype
- 2011
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Ingår i: American Journal of Medical Genetics Part A. - : Wiley. - 1552-4825 .- 1552-4833. ; 155:6, s. 1217-1224
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Tidskriftsartikel (refereegranskat)abstract
- Noonan syndrome (NS) is a heterogeneous disorder caused by activating mutations in the RAS-MAPK signaling pathway. It is associated with variable clinical expression including short stature, congenital heart defect, unusual pectus deformity, and typical facial features and the inheritance is autosomal dominant. Here, we present a clinical and molecular characterization of a patient with Noonan-like syndrome with loose anagen hair phenotype and additional features including mild psychomotor developmental delay, osteoporosis, gingival hyperplasia, spinal neuroblastoma, intrathoracic extramedullary hematopoiesis, and liver hemangioma. Mutation analysis of PTPN11, SOS1, RAF1, KRAS, BRAF, MEK1, MEK2, NRAS, and SHOC2 was conducted, revealing a co-occurrence of two heterozygous previously identified mutations in the index patient. The mutation SHOC2 c.4A> G; p.Ser2Gly represents a de novo mutation, whereas, PTPN11 c. 1226G>C; p.Gly409Ala was inherited from the mother and also identified in the brother. The mother and the brother present with some NS manifestations, such as short stature, delayed puberty, keratosis pilaris, cafe-au-lait spots, refraction error (mother), and undescended testis (brother), but no NS facial features, supporting the notion that the PTPN11 p. Gly409Ala mutation leads to a relatively mild phenotype. We propose that, the atypical phenotype of the young woman with NS reported here is an additive effect, where the PTPN11 mutation acts as a modifier. Interestingly, co-occurrence of RAS-MAPK mutations has been previously identified in a few patients with variable NS or neurofibromatosis-NS phenotypes. Taken together, the results suggest that co-occurrence of mutations or modifying loci in the RAS-MAPK pathway may contribute to the clinical variability observed among NS patients.
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| 10. |
- Erlandsson, Martin, et al.
(författare)
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Robust LCA: Typologi över LCA-metodik - två kompletterande systemsyner
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Användningen av livscykelanalys (LCA) kan delas in i utvärderingar av enskilda produkter och utvärderingar av sammansatta system med flera produkter. I det första fallet talar vi i detta projekt om en bokförings-LCA och i det andra fallet om en konsekvens-LCA . I båda fallen tillämpas ett livscykeltänkande. I en bokförings-LCA ingår bara direkta effekter inom den studerade produktens livscykel, medan en konsekvens-LCA även inkluderar effekter på angränsande produkter. Systemperspektiven kompletterar med andra ord varandra. Notera att i en LCA används begreppet produkt för alla nyttigheter som en process genererar oavsett om det är en tjänst, ett enskilt material, eller en komplex produkt såsom ett byggnadsverk. En bokförings-LCA kännetecknas av ambitionen att den beräknade miljöbelastningen för alla världens produkter ska kunna summeras och stämmer då med de globala utsläppen, det vill säga den så kallade 100%-regeln. I en konsekvens-LCA gäller inte detta utan här ges en beskrivning av vad som händer vid en förändring och vilka konsekvenser detta har på ett bredare, mer sammansatt system och dess miljöbelastning. I projektet och tidigare vetenskapliga studier konstateras det att dessa två systemsyner svarar på olika frågor och därmed kan existera parallellt, givet att det är tydligt vilken systemsyn som använts. Följande rekommendationer om användningen av de två systemsynerna, baseras på det arbete som gjorts i projektetet Robust LCA, och kan sammanfattas enligt nedan: Bokförings-LCA lämpar sig för att utvärdera och jämföra produkter där det är viktigt att entydiga svar erhålls och att miljöbelastning som beskrivs stämmer med de utsläpp som beslutsfattarna kan relatera till. Konsekvens-LCA inkluderar indirekta effekter och lämpar sig för att ge beslutsfattare insikt i hur deras beslut kan påverka samhällets miljöbelastning. I den LCA-typologi som tagits fram delas bokförings-LCA in i tillämpningsfall som här benämns Produkter respektive Material . På motsvarande sätt delas konsekvens-LCA delas in i Undvikna emissioner och Korg av funktioner . Sedan kan dessa varianter, beroende på vilken typ av konsekvenser som analyseras, utföras med en Antagen marginal , Driftsmarginal , Utbyggnadsmarginal eller Komplex marginal .
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