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  • 201.
    Berger, Stella A.
    et al.
    Univ Munich, Dept Biol 2, Planegg Martinsried, Germany; Univ Georgia, Skidaway Inst Oceanog, Savannah, GA USA.
    Diehl, Sebastian
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Univ Munich, Dept Biol 2, Planegg Martinsried, Germany.
    Stibor, Herwig
    Univ Munich, Dept Biol 2, Planegg Martinsried, Germany.
    Sebastian, Patrizia
    Univ Munich, Dept Biol 2, Planegg Martinsried, Germany.
    Scherz, Antonia
    Univ Munich, Dept Biol 2, Planegg Martinsried, Germany.
    Separating effects of climatic drivers and biotic feedbacks on seasonal plankton dynamics: no sign of trophic mismatch2014In: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 59, no 10, p. 2204-2220Article in journal (Refereed)
    Abstract [en]

    Climate change may impact most strongly on temperate lake plankton communities in spring, when light availability and water temperature change rapidly due to thermal stratification. Effects of changing light and temperature on one food-web component transfer to other components, producing a complex interplay between physical drivers and biotic feedbacks. Understanding this interplay is important, because altered climate regimes could result in phenological mismatch between the phytoplankton spring bloom and the timing of maximum food requirements of grazers. To separate direct effects of light and temperature on spring plankton dynamics from effects mediated through micro- and mesograzer feedbacks, we manipulated water temperature, stratification depth and presence/absence of the mesograzer Daphnia in lake mesocosms. In early spring, stratification depth and water temperature directly influenced the light supply to phytoplankton and the growth rates of all plankton groups. Subsequently, indirect effects, including light-dependent food supply to grazers and temperature-dependent grazing pressure, became increasingly important. Phytoplankton and Daphnia peaked earlier in warmer treatments and reached higher peaks when stratification depth was shallower. Ciliates responded positively to increased food density and higher temperature and subsequently affected the taxonomic composition, but not the total biomass, of phytoplankton. In the absence of Daphnia, phytoplankton did not enter a distinct clear water phase. When present, Daphnia caused an extended clear water phase, maintaining phytoplankton and ciliates at low levels throughout early summer and suppressing all direct effects of physical drivers on these plankton groups. Our Daphnia treatments mimicked the high and low fish predation settings of the largely descriptive, recently revised Plankton Ecology Group (PEG) model of seasonal plankton succession and explored their responses to climate change scenarios. The results largely support the PEG model, but attribute greater importance to early season temperature effects and later season grazing effects of Daphnia. In warmer treatments, the timing of phytoplankton and zooplankton peaks tended to be more closely coupled, and temperature did not affect the height of zooplankton peaks. In line with other experiments, these results do not support the widely held concern that warming may create a trophic mismatch between phytoplankton and zooplankton and reduce spring zooplankton production.

  • 202. Berger, Stella A
    et al.
    Diehl, Sebastian
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Stibor, Herwig
    Trommer, Gabriele
    Ruhenstroth, Miriam
    Water temperature and stratification depth independently shift cardinal events during plankton spring succession2010In: Global Change Biology, ISSN 1354-1013, E-ISSN 1365-2486, Vol. 16, no 7, p. 1954-1965Article in journal (Refereed)
    Abstract [en]

    In deep temperate lakes, the beginning of the growing season is triggered by thermal stratification, which alleviates light limitation of planktonic producers in the surface layer and prevents heat loss to deeper strata. The sequence of subsequent phenological events (phytoplankton spring bloom, grazer peak, clearwater phase) results in part from coupled phytoplankton–grazer interactions. Disentangling the separate, direct effects of correlated climatic drivers (stratification-dependent underwater light climate vs. water temperature) from their indirect effects mediated through trophic feedbacks is impossible using observational field data, which challenges our understanding of global warming effects on seasonal plankton dynamics. We therefore manipulated water temperature and stratification depth independently in experimental field mesocosms containing ambient microplankton and inocula of the resident grazer Daphnia hyalina. Higher light availability in shallower surface layers accelerated primary production, warming accelerated consumption and growth of Daphnia, and both factors speeded up successional dynamics driven by trophic feedbacks. Specifically, phytoplankton peaked and decreased earlier and Daphnia populations increased and peaked earlier at both shallower stratification and higher temperature. The timing of ciliate dynamics was unrelated to both factors. Volumetric peak densities of phytoplankton, ciliates and Daphnia in the surface layer were also unaffected by temperature but declined with stratification depth in parallel with light availability. The latter relationship vanished, however, when population sizes were integrated over the entire water column. Overall our results suggest that, integrated over the entire water column of a deep lake, surface warming and shallower stratification independently speed up spring successional events, whereas the magnitudes of phytoplankton and zooplankton spring peaks are less sensitive to these factors. Therefore, accelerated dynamics under warming need not lead to a trophic mismatch (given similar grazer inocula at the time of stratification). We emphasize that entire water column dynamics must be studied to estimate global warming effects on lake ecosystems.

  • 203.
    Berggren, Andreas
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Ficedula hypoleuca hemoglobin levels in lead contaminated areas.: Is bird health affected by invertebrate community composition and abundance?2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Mining is a widespread industrial activity that in many cases, via mining wastes, leads to altered concentrations of metals in close vicinity to the mining activities. Metals in mining waste can have high toxicity and may persist in environments for long time periods. The presence of metals, such as lead (Pb), is known to contaminate and cause damage to nearby organisms and ecosystems. Birds are at risk of metal contamination and, since they are predators high up in the food chain, may face accumulation of metal in tissue over time, via consumption of contaminated prey. Small passerine species, such as the pied flycatcher (Ficedula hypoleuca), are suitable for studying metal contamination as they are ubiqutious, and high up in the food chain. Pied flycatchers feed exclusively on invertebrates, making the abundance, quality, and potential contamination of invertebrates interesting to study with regard to the health of the birds. Studies have shown that hemoglobin (Hb) levels in young pied flycatchers are reduced by high background levels of Pb.  This may be linked to prey availability and quality, as invertebrates are known to alter their composition, and contain higher Pb concentrations in Pb contaminated areas. Here, I investigated how invertebrate abundance and community composition, and pied flycatcher Hb concentrations (i.e. health), in reference and Pb contaminated areas, were related to each other. Invertebrate traps were set and sampled twice during the summer of 2018 to provide invertebrate data to the study. Bird Hb levels was acquired by taking blood samples from nearly fledged chicks in birdhouses placed in the different areas. I found a potential trend towards higher Hb levels in reference areas (p=0.110), suggesting that bird health is reduced by the presence of Pb, but this could not be explained by differences in invertebrate community composition or abundance (p>0.05). Hence, based on this study, high Pb concentrations in the soil does not directly, or indirectly via potential impacts on the prey community composition, influence the health of pied flycatchers.

  • 204.
    Berggren, Johanna
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Stoftnedfall från gruvindustrin: En utvärdering av analysdata och undersökning av provtagningspunkter kring Aitikgruvan, Gällivare2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this study was to investigate whether the sampling points for measuring airborne dust deposition in the Aitik copper mine - the largest, most effective opencast copper mining in Europe - are well located regarding efficiency to collect monitoring data. Issues that were addressed, among others, include background levels, weather impacts and possible external influence. The study was carried out by analyzing monitoring data covering a seven-year period (2010–2016). Dust-and copper levels, precipitation patterns, wind direction and wind speed were the parameters analyzed. A further look into the sampling points and their actual location in terrain was also made. The result of the study indicates, according to different aspects, on decreasing dust fall levels even though the production has increased. For instance, many of the 19 sampling points shows to have lower dust and copper levels according to a comparison of measurement data from 2010 to 2016. A correlation test showed that precipitation and wind does not have a strong connection to dust levels. On the other hand, wind speed showed to have a strong impact on dust fall levels under periods when the highest dust amounts were measured. Many of the sampling points also showed to have a strong connection to each other. The study concludes that a better dust control programme can be obtained if sampling points are reorganized along with a better method for calculating the dispersion of airborne dust.

  • 205. Berggren, M.
    et al.
    Bengtson, P.
    Soares, A. R. A.
    Karlsson, Jan
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Climate Impacts Research Centre (CIRC).
    Terrestrial support of zooplankton biomass in northern rivers2018In: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 63, no 6, p. 2479-2492Article in journal (Refereed)
    Abstract [en]

    The contribution of terrestrially derived carbon to micro-crustacean zooplankton biomass (i.e., allochthony) has been previously studied in lakes, reservoirs, and estuaries, but little is known about zooplankton allochthony in rivers. In lacustrine environments, allochthony is regulated by distinct selective feeding behavior of different taxa. However, we hypothesized that restricted possibility for selective grazing in turbulent environments such as rivers would decouple zooplankton from specific microbial and algal food resources, such that their allochthony would mirror the terrestrial contribution to the surrounding bulk particle pool. We tested this idea by analyzing allochthony in 13 widely distributed Swedish rivers, using a dual-isotope mixing model. Zooplankton biomasses were generally low, and allochthony in different micro-crustacean groups (Cladocera, Cyclopoida, Calanoida) varied from 2% to 77%. As predicted, there were no correlations between allochthony and variables indicating the supply of algal and microbial food resources, such as chlorophyll a and bacterial production. Instead, the allochthony was generally similar to the share allochthonous contribution in bulk particulate organic matter, with relationships close to the 1 : 1 line. The zooplankton community allochthony was strongly regulated by the ecosystem metabolic balance between production and respiration, which in turn was dependent upon the ratio between total autochthonous organic carbon concentrations and water color. Our study for the first time shows that micro-crustacean allochthony is regulated differently in rivers compared to in lacustrine systems, and points to inefficient support of zooplankton biomass by algal resources in turbulent waters.

  • 206.
    Berggren, Maja
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Bisfenol A i normalbefolkningen i Norr- & Västerbotten: Och en studie av om det finns samband mellan bisfenol A och rökning samt kolesterol2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 207.
    Berggren, Martin
    Umeå University, Faculty of Science and Technology, Ecology and Environmental Science.
    Bacterial use of allochthonous organic carbon for respiration and growth in boreal freshwater systems2009Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Aquatic systems worldwide receive large amounts of organic carbon from terrestrial sources. This ‘allochthonous’ organic carbon (AlloOC) affects critical physical and chemical properties of freshwater ecosystems, with consequences for food web structures and exchange of greenhouse gases with the atmosphere. In the boreal region, loadings of AlloOC are particularly high due to leaching from huge organic deposits in boreal forest, mire and tundra soils.

    A main process of AlloOC turnover in aquatic systems is its use by heterotrophic bacteria. Applying a bioassay approach, I measured the respiration and growth (production) of bacteria in northern Sweden, in streams and lakes almost totally dominated by AlloOC. The objective was to elucidate how variations in AlloOC source, age, composition and concentration impact on its use by aquatic bacteria, and how AlloOC properties, in turn, are regulated by landscape composition and by hydrology.

    The bacterial respiration (30-309 µg C L-1 d-1) was roughly proportional to the concentration of AlloOC (7-47 mg C L-1), but not significantly related to AlloOC source or character. Bacterial production (4-94 µg C L-1 d-1), on the other hand, was coupled to the AlloOC character, rather than concentration. A strong coupling to AlloOC character was also found for bacterial growth efficiency (0.06-0.51), i.e. production per unit of assimilated carbon. Bacterial production and growth efficiency increased with rising concentrations of low molecular weight AlloOC (carboxylic acids, free amino acids and simple carbohydrates). While the total AlloOC concentrations generally were the highest in mire-dominated catchments, low molecular weight AlloOC concentrations were much higher in forested catchments, compared to mire-dominated. These patterns were reflected in a strong landscape control of aquatic bacterial metabolism. Moreover, high flow episodes increased the export of organic carbon from forests, in relation to the export from mires, stimulating the bacterial production and growth efficiency in streams with mixed (forest and mire) catchments. The potential of AlloOC to support efficient bacterial growth decreased on time-scales of weeks to months, as the AlloOC was aged in laboratory or lake in situ conditions.

    To conclude, landscape, hydrology and conditions which determine AlloOC age have large influence on bacterial metabolism in boreal aquatic systems. Considering the role of bacteria in heterotrophic food chains, these factors can have spin-off effects on the structure and function of boreal aquatic ecosystems.

  • 208. Berggren, Martin
    et al.
    Bergström, Ann-Kristin
    Karlsson, Jan
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Intraspecific Autochthonous and Allochthonous Resource Use by Zooplankton in a Humic Lake during the Transitions between Winter, Summer and Fall2015In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 10, no 3, article id e0120575Article in journal (Refereed)
    Abstract [en]

    Seasonal patterns in assimilation of externally produced, allochthonous, organic matter into aquatic food webs are poorly understood, especially in brown-water lakes. We studied the allochthony (share biomass of terrestrial origin) in cladoceran, calanoid and cyclopoid micro-crustacean zooplankton from late winter to fall during two years in a small humic lake (Sweden). The use of allochthonous resources was important for sustaining a small population of calanoids in the water column during late winter. However, in summer the calanoids shifted to 100% herbivory, increasing their biomass several-fold by making efficient use of the pelagic primary production. In contrast, the cyclopoids and cladocerans remained at high levels of allochthony throughout the seasons, both groups showing the mean allochthony of 0.56 (range in mean 0.17-0.79 and 0.34-0.75, for the respective group, depending on model parameters). Our study shows that terrestrial organic matter can be an important resource for cyclopoids and cladocerans on an annual basis, forming a significant link between terrestrial organic matter and the higher trophic levels of the food web, but it can also be important for sustaining otherwise herbivorous calanoids during periods of low primary production in late winter.

  • 209. Berggren, Martin
    et al.
    Gudasz, Cristian
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Guillemette, Francois
    Hensgens, Geert
    Ye, Linlin
    Karlsson, Jan
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Systematic microbial production of optically active dissolved organic matter in subarctic lake water2019In: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590Article in journal (Refereed)
    Abstract [en]

    The ecology and biogeochemistry of lakes in the subarctic region are particularly sensitive to changes in the abundance and optical properties of dissolved organic matter (DOM). External input of colored DOM to these lakes is an extensively researched topic, but little is known about potential reciprocal feedbacks between the optical properties of DOM and internal microbial processes in the water. We performed 28-day dark laboratory incubation trials on water from 101 subarctic tundra lakes in northern Sweden, measuring the microbial decay of DOM and the resulting dynamics in colored (CDOM) and fluorescent (FDOM) DOM components. While losses in dissolved oxygen during the incubations corresponded to a 20% decrease in mean DOM, conversely the mean CDOM and total FDOM increased by 22% and 30%, respectively. However, the patterns in microbial transformation of the DOM were not the same in all lakes. Notably, along the gradient of increasing ambient CDOM (water brownness), the lakes showed decreased microbial production of protein-like fluorescence, lowered DOM turnover rates and decreasing bacterial growth per unit of DOM. These trends indicate that browning of subarctic lakes systematically change the way that bacteria interact with the ambient DOM pool. Our study underscores that there is no unidirectional causal link between microbial processes and DOM optical properties, but rather reciprocal dependence between the two.

  • 210.
    Berggren, Martin
    et al.
    Umeå University, Faculty of Science and Technology, Ecology and Environmental Science.
    Hjalmar, Laudon
    Umeå University, Faculty of Science and Technology, Ecology and Environmental Science.
    Jansson, Mats
    Umeå University, Faculty of Science and Technology, Ecology and Environmental Science.
    Aging of allochthonous organic carbon regulates bacterial production in unproductive boreal lakes2009In: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 54, no 4, p. 1333-1342Article in journal (Refereed)
    Abstract [en]

    We calculated average aquatic dissolved organic carbon (DOC) age (the time span from soil discharge to observation) in water from the inlets and outlets of two unproductive Swedish lakes at different times during an annual cycle. Bacterial production (BP) and bacterial growth efficiency (BGE) determined during 7-d bioassays decreased with increasing average aquatic DOC age. Parallel to the declines in BP and BGE there was a rise in specific ultraviolet absorbance at the wavelength of 254 nm (SUVA254), which indicates that decreasing BP and BGE were connected to a shift to a more aromatic and recalcitrant DOC pool. The relationships between bacterial metabolism and DOC age were stronger after a Q10 correction of the DOC age, showing that temperature affected rates of DOC quality changes over time and should be taken into account when relating lake bacterial growth to substrate aging in natural environments. We propose that hydrological variability in combination with lake size (water renewal time) have a large influence on pelagic BP in lakes with high input of terrigenous DOC.

  • 211. Berggren, Martin
    et al.
    Klaus, Marcus
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Selvam, Balathandayuthabani Panneer
    Ström, Lena
    Laudon, Hjalmar
    Jansson, Mats
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Karlsson, Jan
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Quality transformation of dissolved organic carbon during water transit through lakes: contrasting controls by photochemical and biological processes2018In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 15, no 2, p. 457-470Article in journal (Refereed)
    Abstract [en]

    Dissolved organic carbon (DOC) may be removed, transformed, or added during water transit through lakes, resulting in changes in DOC composition and pigmentation (color). However, the process-based understanding of these changes is incomplete, especially for headwater lakes. We hypothesized that because heterotrophic bacteria preferentially consume noncolored DOC, while photochemical processing removes colored fractions, the overall changes in DOC color upon water passage through a lake depend on the relative importance of these two processes, accordingly. To test this hypothesis we combined laboratory experiments with field studies in nine boreal lakes, assessing both the relative importance of different DOC decay processes (biological or photochemical) and the loss of color during water transit time (WTT) through the lakes. We found that influence from photo-decay dominated changes in DOC quality in the epilimnia of relatively clear headwater lakes, resulting in systematic and selective net losses of colored DOC. However, in highly pigmented brown-water lakes (absorbance at 420 nm > 7 m(-1)) biological processes dominated, and there was no systematic relationship between color loss and WTT. Moreover, in situ data and dark experiments supported our hypothesis on the selective microbial removal of nonpigmented DOC, mainly of low molecular weight, leading to persistent water color in these highly colored lakes. Our study shows that brown headwater lakes may not conform to the commonly reported pattern of the selective removal of colored constituents in freshwaters, as DOC can show a sustained degree of pigmentation upon transit through these lakes.

  • 212.
    Berggren, Martin
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Laudon, Hjalmar
    Skogens ekologi och skötsel, SLU, Umeå.
    Haei, Mahsa
    Skogens ekologi och skötsel, SLU, Umeå.
    Ström, Lena
    Naturgeografi och Ekosystemanalys, Lunds universitet, Lund.
    Jansson, Mats
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Efficient aquatic bacterial metabolism of dissolved low-molecular-weight compounds from terrestrial sources2010In: The ISME Journal, ISSN 1751-7362, Vol. 4, no 3, p. 408-416Article in journal (Refereed)
    Abstract [en]

    Carboxylic acids (CAs), amino acids (AAs) and carbohydrates (CHs) in dissolved free forms can be readily assimilated by aquatic bacteria and metabolized at high growth efficiencies. Previous studies have shown that these low-molecular-weight (LMW) substrates are released by phytoplankton but also that unidentified LMW compounds of terrestrial origin is a subsidy for bacterial metabolism in unproductive freshwater systems. We tested the hypothesis that different terrestrially derived CA, AA and CH compounds can offer substantial support for aquatic bacterial metabolism in fresh waters that are dominated by allochthonous dissolved organic matter (DOM). Drainage water from three catchments of different characters in the Krycklan experimental area in Northern Sweden were studied at the rising and falling limb of the spring flood, using a 2-week bioassay approach. A variety of CA, AA and CH compounds were significantly assimilated by bacteria, meeting 15–100% of the bacterial carbon demand and explaining most of the observed variation in bacterial growth efficiency (BGE; R2=0.66). Of the 29 chemical species that was detected, acetate was the most important, representing 45% of the total bacterial consumption of all LMW compounds. We suggest that LMW organic compounds in boreal spring flood drainage could potentially support all in situ bacterial production in receiving lake waters during periods of weeks to months after the spring flood.

  • 213.
    Berggren, Martin
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Laudon, Hjalmar
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Jansson, Mats
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Bacterial utilization of imported organic material in three small nested humic lakes2010In: INTERNATIONAL ASSOCIATION OF THEORETICAL AND APPLIED LIMNOLOGY, VOL 30, PT 9 / [ed] Jones J, Faaborg J, Stuttgart: E SCHWEIZERBART'SCHE VERLAGSBUCHHANDLUNG , 2010, Vol. 30, no 9, p. 1393-1396Conference paper (Refereed)
  • 214.
    Berggren, Martin
    et al.
    Umeå University, Faculty of Science and Technology, Ecology and Environmental Science.
    Laudon, Hjalmar
    Umeå University, Faculty of Science and Technology, Ecology and Environmental Science.
    Jansson, Mats
    Umeå University, Faculty of Science and Technology, Ecology and Environmental Science.
    Hydrological control of organic carbon support for bacterial growth in boreal headwater streams2009In: Microbial Ecology, ISSN 0095-3628, E-ISSN 1432-184X, Vol. 57, no 1, p. 170-178Article in journal (Refereed)
    Abstract [en]

    Terrestrial organic carbon is exported to freshwater systems where it serves as substrate for bacterial growth. Temporal variations in the terrigenous organic carbon support for aquatic bacteria are not well understood. In this paper, we demonstrate how the combined influence of landscape characteristics and hydrology can shape such variations. Using a 13-day bioassay approach, the production and respiration of bacteria were measured in water samples from six small Swedish streams (64° N, 19° E), draining coniferous forests, peat mires, and mixed catchments with typical boreal proportions between forest and mire coverage. Forest drainage supported higher bacterial production and higher bacterial growth efficiency than drainage from mires. The areal export of organic carbon was several times higher from mire than from forest at low runoff, while there was no difference at high flow. As a consequence, mixed streams (catchments including both mire and forest) were dominated by mire organic carbon with low support of bacterial production at low discharge situations but dominated by forest carbon supporting higher bacterial production at high flow. The stimulation of bacterial growth during high-flow episodes was a result of higher relative export of organic carbon via forest drainage rather than increased drainage of specific “high-quality” carbon pools in mire or forest soils.

  • 215.
    Berggren, Martin
    et al.
    Umeå University, Faculty of Science and Technology, Ecology and Environmental Science.
    Laudon, Hjalmar
    Umeå University, Faculty of Science and Technology, Ecology and Environmental Science.
    Jansson, Mats
    Umeå University, Faculty of Science and Technology, Ecology and Environmental Science.
    Landscape regulation of bacterial growth efficiency in boreal freshwaters2007In: Global Biogeochemical Cycles, ISSN 0886-6236, E-ISSN 1944-9224, Vol. 21Article in journal (Refereed)
    Abstract [en]

    Allochthonous organic carbon in aquatic systems is metabolized by heterotrophic bacteria, with significant consequences for the biostructure and energy pathways of freshwater ecosystems. The degree to which allochthonous substrates support growth of bacteria is largely dependent on bacterial growth efficiency (BGE), i.e., bacterial production (BP) per unit of assimilated carbon. Here we show how the spatial variability of BGE in the boreal region can be mediated by the distribution of the two dominating landscape elements forest and mires. Using an 11 days bioassay approach, the production and respiration of bacteria were measured in water samples from nine small Swedish streams (64°N 19°E), representing a gradient ranging from organic carbon supplied mainly from peat mires to carbon supplied mainly from coniferous forests. BP was positively correlated to forest coverage (%) of the catchment, while bacterial respiration was similar in all streams. Consequently, BGE showed a strong positive correlation with forest coverage. Partial least square regression showed that BGE was chiefly regulated by qualitative properties of the organic material, indicated by the absorbance ratio a254/a365 plus C/N and C/P ratios. The data suggest that a share of the organic carbon pool, drained mainly from forest soils, had a potential of being incorporated into bacterial biomass with great efficiency. Its potential for supporting growth was probably nutrient regulated as indicated by inorganic nutrient enrichment experiments.

  • 216.
    Berggren, Martin
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Laudon, Hjalmar
    Department of Forest Ecology and Management, SLU, Umeå.
    Jonsson, Anders
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Jansson, Mats
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Nutrient constraints on metabolism affect the temperature regulation of aquatic bacterial growth efficiency2010In: Microbial Ecology, ISSN 0095-3628, E-ISSN 1432-184X, Vol. 60, no 4, p. 894-902Article in journal (Refereed)
    Abstract [en]

    Inorganic nutrient availability and temperature are recognized as major regulators of organic carbon processing by aquatic bacteria, but little is known about how these two factors interact to control bacterial metabolic processes. We manipulated the temperature of boreal humic stream water samples within 0–25°C and measured bacterial production (BP) and respiration (BR) with and without inorganic nitrogen + phosphorus addition. Both BP and BR increased exponentially with temperature in all experiments, with Q 10 values varying between 1.2 and 2.4. The bacterial growth efficiency (BGE) showed strong negative relationships with temperature in nutrient-enriched samples and in natural stream water where community-level BP and BR were not limited by nutrients. However, there were no relationships between BGE and temperature in samples where BP and BR were significantly constrained by the inorganic nutrient availability. The results suggest that metabolic responses of aquatic bacterial communities to temperature variations can be strongly dependent on whether the bacterial metabolism is limited by inorganic nutrients or not. Such responses can have consequences for both the carbon flux through aquatic food webs and for the flux of CO2 from aquatic systems to the atmosphere.

  • 217. Berggren, Martin
    et al.
    Sponseller, Ryan A.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Soares, Ana R. Alves
    Bergström, Ann-Kristin
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Toward an ecologically meaningful view of resource stoichiometry in DOM-dominated aquatic systems2015In: Journal of Plankton Research, ISSN 0142-7873, E-ISSN 1464-3774, Vol. 37, no 3, p. 489-499Article in journal (Refereed)
    Abstract [en]

    Research on nutrient controls of planktonic productivity tends to focus on a few standard fractions of inorganic or total nitrogen (N) and phosphorus (P). However, there is a wide range in the degree to which land-derived dissolved organic nutrients can be assimilated by biota. Thus, in systems where such fractions form a majority of the macronutrient resource pool, including many boreal inland waters and estuaries, our understanding of bacterio-and phytoplankton production dynamics remains limited. To adequately predict aquatic productivity in a changing environment, improved standard methods are needed for determining the sizes of active (bioavailable) pools of N, P and organic carbon (C). A synthesis of current knowledge suggests that variation in the C:N:P stoichiometry of bioavailable resources is associated with diverse processes that differentially influence the individual elements across space and time. Due to a generally increasing organic nutrient bioavailability from C to N to P, we hypothesize that the C:N and N:P of bulk resources often vastly overestimates the corresponding ratios of bioavailable resources. It is further proposed that basal planktonic production is regulated by variation in the source, magnitude and timing of terrestrial runoff, through processes that have so far been poorly described.

  • 218.
    Berggren, Martin
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Ström, L
    Laudon, H
    Karlsson, Jan
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Jonsson, Anders
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Giesler, Reiner
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Bergström, Ann-Kristin
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Jansson, Mats
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Lake secondary production fueled by rapid transfer of low molecular weight organic carbon from terrestrial sources to aquatic consumers2010In: Ecology Letters, ISSN 1461-023X, E-ISSN 1461-0248, Vol. 13, no 7, p. 870-880Article in journal (Refereed)
    Abstract [en]

    Ecology Letters (2010) Abstract Carbon of terrestrial origin often makes up a significant share of consumer biomass in unproductive lake ecosystems. However, the mechanisms for terrestrial support of lake secondary production are largely unclear. By using a modelling approach, we show that terrestrial export of dissolved labile low molecular weight carbon (LMWC) compounds supported 80% (34-95%), 54% (19-90%) and 23% (7-45%) of the secondary production by bacteria, protozoa and metazoa, respectively, in a 7-km(2) boreal lake (conservative to liberal estimates in brackets). Bacterial growth on LMWC was of similar magnitude as that of primary production (PP), and grazing on bacteria effectively channelled the LMWC carbon to higher trophic levels. We suggest that rapid turnover of forest LMWC pools enables continuous export of fresh photosynthates and other labile metabolites to aquatic systems, and that substantial transfer of LMWC from terrestrial sources to lake consumers can occur within a few days. Sequestration of LMWC of terrestrial origin, thus, helps explain high shares of terrestrial carbon in lake organisms and implies that lake food webs can be closely dependent on recent terrestrial PP.

  • 219.
    Berggren, Åsa
    Umeå University, Faculty of Science and Technology, Ecology and Environmental Science.
    Hållbart skogsbruk i Robertsfors kommun - Är kontinuerligt skogsbruk en väg att gå?2006Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
  • 220.
    Bergknut, Magnus
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Wiberg, Karin
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Klaminder, Jonatan
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Vertical and lateral redistribution of POPs in soils developed along a hydrological gradient2011In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 45, no 24, p. 10378-10384Article in journal (Refereed)
    Abstract [en]

    Study of the dispersion of persistent organic pollutants (POPs) throughout the environment is necessitated by their toxicological properties and propensity to accumulate in biota. In this study, we use data from the analysis of three (210)Pb dated soil profiles collected along a 30-m hydrological gradient to demonstrate postdepositional mobility of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs). We found that (i) humus originating from litter exposed to surface fallout during the 1960-1970s contains the highest concentrations of PCDD/Fs and PCBs in the O-horizon of the soils; (ii) accumulation rates of PCDD/Fs and PCBs in the O-horizon (similar to 5.0 and similar to 210 mu g m(-2) yr(-1)) constituted only 9.1% and 3.5%, respectively, of the measured annual input, demonstrating that a minor fraction of the deposited material is retained within the O-horizon; (iii) POP inventories in the upper 0.5-0.9 m of the mineral soil constituted a considerable part (40-70%) of the total pool stored in the soil, implying significant vertical translocation of atmospheric derived POPs; and (iv) increasing downslope inventories of POPs suggest a lateral downward transport of POPs from uphill soils. The findings challenge the commonly accepted view that POPs fallout is effectively retained within O-horizons.

  • 221.
    Berglund, Bobby
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Länsstyrelsens arbete med anmälningsärenden inom djurskyddet: Kan andelen obefogade ärenden sänkas?2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The county administrative boards work with notification errands within animal welfare: Can the proportion of unjustified notifications be lowered?

  • 222. Berglund, H
    et al.
    Edman, M
    Umeå University, Faculty of Science and Technology, Ecology and Environmental Science.
    Ericson, L
    Umeå University, Faculty of Science and Technology, Ecology and Environmental Science.
    Temporal variation in wood-fungi diversity in boreal old-growth forests: implications for monitoring2005In: Ecological Applications, Vol. 15, p. 970-982Article in journal (Refereed)
  • 223. Berglund, Håkan
    et al.
    Jonsson, Bengt-Gunnar
    Umeå University, Faculty of Science and Technology, Ecology and Environmental Science.
    Erratum: Nested plant and fungal communities; the importance of area and habitat quality in maximizing species capture in boreal old-growth forests (Biological Conservation 112:3 (319-328) DOI: 10.1016/S0006-3207(02)00329-4)2004In: Biological Conservation, ISSN 0006-3207, E-ISSN 1873-2917, Vol. 117, no 5, p. 563-565Article in journal (Refereed)
  • 224.
    Berglund, Johan
    Umeå University, Faculty of Science and Technology, Ecology and Environmental Science.
    Omställning av Bredviksbergets avfallsanläggning i Piteå inför förbudet att deponera flytande avfall2004Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
  • 225.
    Berglund, Johnny
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Pelagic microorganisms in the northern Baltic Sea: Ecology, diversity and food web dynamics2005Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Heterotrophic microorganisms are important for the flow of carbon and nutrients in the sea. Bacteria, nanoflagellates and ciliates are relevant components of the pelagic food web. In order to be able to predict the outcome of e.g. eutrophication or climate change we need to know how the different components of the pelagic food web are regulated. With the focus on the northern Baltic Sea food web, this thesis deals with limitation and control of heterotrophic protists, the effect of resource heterogeneity on food web efficiency and diversity of nanoflagellates.

    In-situ microcosm experiments showed that the net growth of heterotrophic flagellates were resource limited throughout the year. Field data confirmed that the abundance of flagellates was bottom-up controlled. Furthermore, field data also showed that the annual average biomass of protists, flagellates and ciliates increased with primary productivity. On a smaller seasonal scale temperature and bacterial biomass were able to explain most of the variation in flagellate biovolume. The temporal variation in ciliate biovolume could not be explained by any bottom-up factors like bacterial biomass, flagellate biomass or chlorophyll a. This and an in-situ microcosm experiment implied that the seasonal dynamics of ciliates were more regulated by predators like mesozooplankton.

    The food web efficiency i.e. how much of production at the resource level is converted to production at the top trophic level, may be affected by specific size or type of resource. Indoor mesocosms revealed that the food web efficiency was 11 times lower when heterotrophic bacteria dominated basal production instead of nano- and micro-sized phytoplankton. This was due to a lengthening of the food web when pico-sized bacteria constituted the main resource.

    The PCR-DGGE molecular biological method was used to study the diversity of heterotrophic or mixotrophic chrysomonads. The focus was set on chrysomonads due to their relatively large contribution to the nanoflagellate community. Group-specific PCR primers were optimized for the target group. A field survey in the northern Baltic Sea showed that a handful of chrysomonad sequences were present throughout the year. Significantly more chrysomonads were recorded in the basin with higher primary productive and salinity. In total 15-16 different chrysomonad sequences were recorded. Most of them matched uncultured chrysomonad clones.

  • 226.
    Berglund, Johnny
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Jürgens, Klaus
    Bruchmüller, Iris
    Wedin, Mats
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Andersson, Agneta
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Use of group-specific PCR primers for identification of chrysophytes by denaturing gradient gel electrophoresis2005In: Aquatic Microbial Ecology, ISSN 0948-3055, E-ISSN 1616-1564, ISSN 0948-3055, Vol. 39, no 2, p. 171-182Article in journal (Refereed)
    Abstract [en]

    The chrysophytes Chrysophyceae and Synurophyceae are ecologically important groups of autotrophic, mixotrophic and heterotrophic flagellates. The smallest forms are difficult to identify by classical microscopy but have important functions both as primary producers and as consumers of bacteria in the aquatic food chain. Group-specific primers for amplification of the 18S small sub-unit rRNA gene were developed for analysis of chrysophyte diversity by denaturing gradient gel electrophoresis (DGGE). Two different primer pairs were tested. The first primer pair (EukC1-F–Chryso-R) primarily targeted Paraphysomonadaceae and Ochromonadales, which generally have heterotrophic or mixotrophic nutrition. The second primer pair (EukC2-F–Chryso-R) targeted both Chrysophyceae and Synurophyceae. The primer pairs were tested for PCR amplification of the 18S rRNA gene of 25 cultured chrysophyte species and 6 other closely related nanoplanktonic species. Both primer pairs performed well, since PCR products were obtained for the corresponding chrysophyte cultures. None of the non-chrysophyte species were amplified with these primers. PCR products of chrysophyte cultures could be separated by DGGE in a denaturing gradient from 40 to 60%. In order to test this PCR-DGGE system for natural planktonic systems, we used field samples from a brackish water area (Baltic Sea) and a freshwater lake. The most intense DGGE bands were excised, sequenced and compared to sequences in GenBank. All obtained sequences grouped within the chrysophytes. Thus, the method seems to be promising for examining chrysophyte diversity in planktonic systems.

  • 227.
    Berglund, Johnny
    et al.
    Umeå University, Faculty of Science and Technology, Ecology and Environmental Science.
    Müren, Umut
    Båmstedt, Ulf
    Andersson, Agneta
    Efficiency of a phytoplankton and bacterial-based food web in a pelagic marine ecosystemManuscript (Other academic)
  • 228.
    Berglund, Johnny
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Müren, Umut
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Båmstedt, Ulf
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Andersson, Agneta
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Efficiency of a phytoplankton-based and a bacterial-based food web in a pelagic marine system2007In: Limnology and Oceanography, Vol. 52, no 1, p. 121-131Article in journal (Refereed)
    Abstract [en]

    he food web efficiency in two contrasting food webs, one phytoplankton based and one bacteria based, was studied in a mesocosm experiment using seawater from the northern Baltic Sea. Organisms included in the experiment were bacteria, phytoplankton, protozoa, and mesozooplankton (copepods). A phytoplankton-based food web was generated by incubating at a high light level with the addition of nitrogen and phosphorus (NP). A bacteria-based food web was created by adding carbon, nitrogen, and phosphorus (CNP) and incubating at a lower light level. In the CNP treatment bacteria dominated the productivity (91%), while in the NP treatment phytoplankton were dominant producers (74%). The phytoplankton community in the NP treatment was dominated by autotrophic nanoflagellates. The food web efficiency, defined as mesozooplankton productivity per basal productivity (phytoplankton + bacteria), was 22% in the phytoplankton-based food web and 2% in the bacteria-based food web. This discrepancy could be explained by 1�xtra trophic levels in the bacteria-based food web where carbon passed through flagellates and ciliates before reaching mesozooplankton, while in the phytoplankton-based food web there was a direct pathway from phytoplankton to mesozooplankton. The results were supported by stable isotope analysis of mesozooplankton. We propose that climate change, with increased precipitation and river runoff in the Baltic Sea, might favor a bacteria-based food web and thereby reduce pelagic productivity at higher trophic levels.

  • 229.
    Berglund, Johnny
    et al.
    Umeå University, Faculty of Science and Technology, Ecology and Environmental Science.
    Samuelsson, Kristina
    Kruys, Åsa
    Andersson, Agneta
    Spatial and temporal variation of chrysomonads in the northern Baltic Sea estimated by DGGE and epifluorescence microscopyManuscript (Other academic)
  • 230.
    Berglund, Johnny
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Samuelsson, Kristina
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Kull, Tomas
    Muren, Umut
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Andersson, Agneta
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Relative strength of resource and predation limitation of heterotrophic nanoflagellates in a low-productive sea area2005In: Journal of Plankton Research, ISSN 0142-7873, E-ISSN 1464-3774, Vol. 27, no 9, p. 923-935Article in journal (Refereed)
    Abstract [en]

    The magnitude of resource and predation limitation of heterotrophic nanoflagellates (HNF) was studied in two short-term enclosure experiments performed in a low-productive sea area in the northern Baltic Sea in 2001. A cross-factorial design was used to simultaneously assess the relative importance of the two factors. Resource limitation was removed by adding bacteria, and predation limitation was eliminated by selective filtration. The first experiment was performed in June just after the spring bloom decline and the second in September at the end of the productive season. Resource limitation prevailed during both experiments, contributing to 60% of the net growth increase in June and 74% in September. Removal of predators had a significant effect only in June. Evidence for simultaneous resource and predation limitation was thus found only during the post-bloom situation. The results were applied to a model on resource and predation control of HNF abundances. To evaluate seasonal differences, field data on HNF and bacteria from a whole year study were applied to the model. Except for a few occasions during spring, the model indicated prevailing resource control of HNF at two locations with slightly different productivity.

  • 231.
    Berglund, Louise
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Riparian Vegetation Distribution along the Ume River: Predicted responses of riparian plants to environmental flow modifications in run-of-river impoundments2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    River environments are complex and dynamic ecosystems, and provide valuable ecosystem services such as clean water. The species rich riparian vegetation performs many important ecosystem functions such as reducing erosion and filter inputs from upland areas. Regulated flow regimes have decreased riparian plant species richness, cover and plant performance. To restore the integrity of riparian ecosystems, mitigation measures such as re-regulation of water-level regimes toward more natural seasonal fluctuations may be needed. The aim of this study was to assess potential responses of riparian plants to changes in water-level regulation in run-of-river impoundments to better match natural flow regimes. The elevational extent of plant species on riverbanks of two run-of-river impoundments in the Ume River were surveyed and their probability of occurrence along the gradient of inundation duration was modelled and compared to their distribution in the free-flowing Vindel River. Most species showed similar tolerance to flooding in the Ume and Vindel Rivers. Changes in elevational extent in response to three simulated environmental flow regimes were predicted by using the relationship between plant occurrence and inundation duration. A simulated spring flood and low water levels during the latter part of the growing season is predicted to result in the largest increase in elevational extent, with increases of 70-80% for several riparian species. However, only 47% of the riverbanks along run-of-river impoundments in the Ume River is deemed to be suitable for plant establishment, since many riverbanks are steep and devoid of fine-grained substrate as a result of erosion.

  • 232.
    Berglund, Louise
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Växtsamhällen på osorterade cirklar i Abisko: Hur förändrad kryogen aktivitet kan påverka sammansättning och artrikedom av kärlväxter2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Non-sorted circles are patterned ground features created by cryogenic activity in alpine and arctic areas. In these features, cryogenic activity controls vegetation communities by causing repeated disturbance and therefore provides habitat for species that are poor competitors but can tolerate disturbance. A recent study has shown that there is a trend where shrub vegetation overgrows the bare soil found within non-sorted circles. The aim of this study was to assess how the vascular plant communities on non-sorted circles have changed since 1985 and determine to what extent cryogenic activity affect vegetation communities. The study was conducted in Abisko and the point frame method was used to re-investigate how the plant species composition and richness have changed between 1985 and 2012, while a visual frame method was used to investigate how the plant communities change along a gradient of cryogenic activity. The results showed that the vascular plant communities on non-sorted circles in Abisko have changed since 1985 with a decrease in poorly competitive species, and an increase in competitive species. My results suggest that species richness is favoured by cryogenic activity, as the highest species richness was found on intermediately disturbed sites and on the transition zone between bare soil and fully developed vegetation cover. My findings indicate that poorly competitive species will lose habitat and become outcompeted by other species when cryogenic activity decreases, and therefore I conclude that there is a risk of local loss in vascular plant species richness in alpine areas.

  • 233.
    Berglund, Malin
    Umeå University, Faculty of Science and Technology, Ecology and Environmental Science.
    A Waste Management Plan for Recycling in Gwanda, Zimbabwe2004Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A waste management plan for recycling in Gwanda, Zimbabwe

    The city of Gwanda in Zimbabwe is facing problems such as insufficient, unreliable and improper waste management. The refuse collection is working inadequately, the town is experiencing a major problem regarding littering and the current refuse dump is not working satisfactorily. The main purpose of this study was to design a recycling model for Gwanda town. To achieve this, an inventory of the recycling market was performed, an investigation of what kinds of refuse Gwanda town generates was made, recycling companies able to collect specific categories of recyclables were identified and a recycling station was designed, where the material to be recycled could be gathered before collection. The study shows that paper and plastic are the most suitable waste categories to commence recycling in Gwanda. According to the proposed plan, a recycling depot will be established that is centrally situated in town, close to the sources of waste. The project will be community based and operated by youths, who will move around to stores and institutions within town collecting the recyclable material. Only the schools will be able to sell recyclables to the depot. Two recovering companies will purchase and collect the waste paper and plastic gathered at the depot. The project will benefit the youths by providing employment opportunities, the stakeholders (commerce, institutions) will benefit by reduced waste removal costs and the schools, through the profits they receive from selling recyclables to the depot. The local authority and the citizens will benefit immensely by enjoying streets free from litter and also reduced amount of waste disposed at the refuse dump. The lifetime of the refuse dump will be increased and the project will contribute to the preservation of natural resources and also to the development of a sustainable society.

  • 234.
    Berglund, Mattias
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Vad styr älgars betesmönster?: Hur älgbetesskador på tall påverkas av tallungskogars rumsliga fördelning och areal2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    One of the largest challenges humanity faces today is reducing CO₂-emissions to mitigate climate change. Part of the solution might be to increase the use of wood products. To do this, the efficiency of forestry has to be improved. In Sweden, a large obstacle for improving the efficiency of forestry is moose, or rather the damages its browsing causes on Scots pine. The aim of this study was to investigate how stand size and stand isolation affects the intensity of moose browsing damage on Scots pine. In addition, effects from tree density, stand age, and interactions between the different factors were investigated. This was done by using data from forest companies and field data collected from 29 Scots pine stands in central Sweden. The data were analysed in a multiple regression analysis, selecting the model that best explained variation in browsing damage. Results show that browsing damage was lower in more isolated stands. Stand size, however, did not have an effect on browsing damage. The factors stand age and Scots pine density had positive effects on the amount of browsing damage, but effects from stand age decreased with increasing pine density. In total, 77% of the variance in browsing damage was explained by the best model. In order to decrease browsing damage on Scots pine, I suggest that land owners take coordinated action to avoid creating large areas of young pine stands within the same area.

  • 235.
    Berglund, Åsa
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Responses to reduced industrial metal emissions: An ecotoxicological study on Pied Flycatcher (Ficedula hypoleuca, Aves)2010Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Metals have been used by humans for thousands of years, and this has resulted in increased concentrations in the biosphere. The environment around point-sources, such as mines and smelters, are of particular concern, as metals may accumulate to high concentrations, and potentially reach levels toxic to the local flora and fauna. This thesis focuses on the effects on pied flycatcher populations of two such point-sources, a lead mine and enrichment plant, and a sulfide ore smelter. Mining activities at the lead mine ceased in 2001 and pied flycatcher populations were assessed before and after the closure. At the sulfide ore smelter, pied flycatchers were studied during the 1980s. Since then, the metal emissions to air from the smelter (e.g. arsenic, cadmium, copper, mercury, lead and zinc) have been greatly reduced (by 93 – 99%).

    Pied flycatchers from these two contaminated environments differed in their responses to reduced atmospheric deposition. At the mine site, nestling responses reflected the reduced atmospheric deposition and less lead accumulated in their tissues. However, lead levels were still high enough to cause negative effects on blood status (δ-aminolevulinic acid dehydratase [ALAD], hemoglobin [Hb], hematocrit [ht], and mean cell hemoglobin concentration) and reproduction (reduced clutch size, increased mortality and reduced breeding success), as was observed when the mine was in operation. Along the pollution gradient away from the smelter, nestling concentrations reflected the metal load in the soil pool, accumulating over time, rather than the atmospheric deposition. This resulted in only a minor response to decreased metal deposition (slightly reduced liver lead concentrations at 3.5 – 90 km from the smelter). This suggests that in environments with highly polluted soils, decreased inputs of atmospheric metal deposition have only minor impacts, and recovery from contamination should not be expected within decades.

    The high metal concentrations in the vicinity of the smelter contributed to poorer blood status (ALAD, Hb and ht), induced oxidative damage and defenses, and decreased reproduction (increased mortality and reduced breeding success). There were only minor improvements in blood and reproductive variables at 3.5 km from the smelter.

  • 236.
    Berglund, Åsa
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Ingvarsson, Pär
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Danielsson, H
    IVL Swedish Environmental Research Institute Ltd., P.O. Box 5302, SE-400 14 Gothenburg, Sweden.
    Nyholm, Erik
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Lead exposure and biological effects in pied flycatchers (Ficedula hypoleuca) before and after the closure of a lead mine in northern Sweden.2010In: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 158, no 5, p. 1368-75Article in journal (Refereed)
    Abstract [en]

    Mining activities affect the surrounding environment by increasing exposure to metals. In this study, metal accumulation and its effects on reproduction and health of pied flycatcher (Ficedula hypoleuca) nestlings were monitored before and up to five years after a lead mine and enrichment plant closed down. The lead concentration in moss, nestling blood, liver and feces all indicated decreased lead exposure by at least 31% after closure, although only blood lead decreased significantly. Although the birds responded fairly well to the changed atmospheric deposition (based on moss samples), concentrations were still higher compared with birds in a reference area, and breeding was affected at the mine (smaller clutches and higher mortality). Surviving nestlings suffered from lower hemoglobin levels, mean cell hemoglobin concentrations and inhibited delta-aminolevulinic acid dehydratase activity. Lead poisoning contributed to poor health and adverse reproductive effects, but other factors (e.g. increased parasitic load) probably also affected the birds.

  • 237.
    Berglund, Åsa
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Klaminder, Jonatan
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Nyholm, Erik
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Effects of reduced lead deposition on Pied flycatcher (Ficedula hypoleuca): tracing exposure routes using stable lead Isotopes2009In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 43, no 1, p. 208-213Article in journal (Refereed)
    Abstract [en]

    To what extent the lead burden of birds living in strongly contaminated ecosystems is responding to decreased atmospheric lead deposition is not well known. In this study, we measured lead concentrations and stable lead isotope ratios (206Pb/207Pb and 208Pb/207Pb) in liver and feces from pied flycatcher nestlings (Ficedula hypoleuca) along a 90 km pollution gradient from the Rönnskär smelter in northern Sweden. Changes in lead concentration in the birds from 1984 to 2006 were used for assessing the recovery of the environment following reduced lead emissions at the smelter. The 206Pb/207Pb and 208Pb/207Pb ratios were used to identify lead sources to the birds. Lead concentrations in liver and feces have decreased since the 1980s, typically by 9−15% (liver) and 18−40% (feces) as a result of a 98% emission reduction. This relatively weak recovery is explained by a transfer of old lead contaminants accumulated in soil to the birds via their prey, which was evident by a 206Pb/207Pb ratio in liver tissue (1.15 ± 0.01) that overlapped with the ratio in ants (1.16 ± 0.01) and organic soil horizon (1.17 ± 0.01) rather than the current atmospheric lead pollution (1.11 ± 0.01). Our findings suggest that insectivorous birds living around smelters may remain contaminated decades after ceased emissions.

  • 238.
    Berglund, Åsa M. M.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Evaluating blood and excrement as bioindicators for metal accumulation in birds2018In: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 233, p. 1198-1206Article in journal (Refereed)
    Abstract [en]

    Birds are widely used to assess metal contamination in the environment and there are different approaches to determine the exposure level in individuals, some being destructive (collection of soft tissues) and some non-destructive (blood, feathers and excrement). The use of blood to detect internal concentrations of metals is an acknowledged method, but to what extent blood can predict the concentrations in soft tissues has been less well evaluated in wild terrestrial birds. The same is true for excrements. This study compares the non-destructive methods using blood and excrement with liver sampling, with respect to exposure and accumulation of the elements arsenic, cadmium, copper, lead and zinc in nestling pied flycatchers (Ficedula hypoleuca). Blood, liver and excrement reflected the environmental exposure of non-essential elements and were independent of nestling sex. There were asymptotic relationships between the concentration of arsenic, cadmium and lead in liver and blood, excrement and liver, and excrement and blood, but none for copper or zinc. Those relationships were generally stronger between liver and blood than between excrements and internal concentrations. Lead had the strongest associations for all matrixes. The conclusion is that blood is an appropriate tool to assess accumulation of arsenic, cadmium and especially lead, but that blood can underestimate the accumulation at highly contaminated sites. Excrement can also give an indication of metal accumulation, but may overestimate internal concentrations at high exposure, and individual variability makes direct comparisons between these matrices less appropriate.

  • 239.
    Berglund, Åsa M. M.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Koivula, Miia J.
    Eeva, Tapio
    Species- and age-related variation in metal exposure and accumulation of two passerine bird species2011In: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 159, no 10, p. 2368-2374Article in journal (Refereed)
    Abstract [en]

    We measured the concentration of several elements (arsenic [As], calcium [Ca], cadmium [Cd], copper [Cu], nickel [Ni], lead [Pb], selenium [Se] and zinc [Zn]) in adult and nestling pied flycatchers (Ficedula hypoleuca) and great tits (Parus major) at different distances to a Cu–Ni smelter in 2009. Feces of nestlings generally failed to correspond with internal element concentrations but reflected the pollution exposure, indicating an increased stress by removal of excess metals. The uptake of Cu and Ni were regulated, but As, Cd, Pb and Se accumulated in liver tissue. Pied flycatchers had generally higher element concentrations than great tits. The higher accumulation of As and Pb in pied flycatcher livers was explained by a more efficient absorption, whereas the higher Cd concentration was primarily due to different intake of food items. Age-related differences occurred between the two species, though both Cd and Se accumulated with age.

  • 240.
    Berglund, Åsa M. M.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Rainio, Miia J.
    Kanerva, Mirella
    Nikinmaa, Mikko
    Eeva, Tapio
    Antioxidant status in relation to age, condition, reproductive performance and pollution in three passerine species2014In: Journal of Avian Biology, ISSN 0908-8857, E-ISSN 1600-048X, Vol. 45, no 3, p. 235-246Article in journal (Refereed)
    Abstract [en]

    Oxidative stress has been suggested as a mediator in life-history trade-off. By spending more resources on for example reproduction an organism might sacrifice its antioxidant defence. So far, most conclusions on trade-offs between life-history traits and oxidative stress have been drawn from laboratory studies using a few model species and there is a need for studies conducted in natural settings. We investigated associations between markers for antioxidant status (antioxidant enzyme activities and antioxidant levels), body condition, age and reproduction in three species of wild-living passerines. The impact from an anthropogenic stressor (metal pollution) was also assessed. The three bird species showed interspecific variation in their SOD and CAT activities, indicating different pathways to eliminate radicals. The age of females affected both antioxidant status and the breeding performance, indicating the importance of age as a factor in life-history studies. Old birds had lower levels of antioxidants/antioxidant enzyme activities and they produced larger broods/more successful broods, though the latter might be confounded by surviving females having increased fitness. Metal exposure had a negative impact on breeding, and improved breeding outcome was also associated with increased antioxidant defence, but metal exposure was not directly related to the oxidative status of birds, emphasizing that additional stressors might independently affect the same traits. Our results highlight that caution has to be taken when generalizing and extrapolating results to even closely related species. The results support the idea that there is a cost of reproduction, in terms of increased resources spent on antioxidant defence, though this should be confirmed with experimental studies.

  • 241.
    Berglund, Åsa MM
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Rainio, Miia J
    Eeva, Tapio
    Temporal trends in metal pollution: using bird excrement as indicator2015In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 10, no 2, article id e0117071Article in journal (Refereed)
    Abstract [en]

    Past mining and smelting activities have resulted in metal polluted environments all over the world, but long-term monitoring data is often scarce, especially in higher trophic levels. In this study we used bird (Parus major and Ficedula hypoleuca) excrement to monitor metal pollution in the terrestrial environment following 16 years of continuously reduced emissions from a copper/nickel smelter in Finland. In the early 1990s, lead and cadmium concentrations dropped significantly in excrement, but the reduction did not directly reflect the changes in atmospheric emission from the smelter. This is likely due to a continuous contribution of metals also from the soil pool. We conclude that bird excrement can be used to assess changes in the environment as a whole but not specifically changes in atmospheric emission. Inter-annual variation in excrement concentration of especially copper and nickel demonstrates the importance of long-term monitoring to discern significant trends.

  • 242.
    Berglund, Åsa
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Nyholm, Erik
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Slow improvements of metal exposure, health- and breeding conditions of pied flycatchers (Ficedula hypoleuca) after decreased industrial heavy metal emissions2011In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 409, no 20, p. 4326-4334Article in journal (Refereed)
    Abstract [en]

    The environment around metal industries, such as smelters, is often highly contaminated due to continuous deposition of metals. We studied nest box breeding populations of pied flycatchers (Ficedula hypoleuca) in a well-studied pollution gradient from a sulfide ore smelter in Northern Sweden, after reduced aerial metal emissions (by 93-99%) from the smelter. The deposition of arsenic, cadmium, copper and zinc (based on moss samples) reflected the reduced emissions fairly well. However, nestling pied flycatchers had similar concentrations of these elements and mercury in tissues (bone, liver and blood) and feces in the 2000s, as in the 1980s, when the emissions were substantially higher. The exposure to high metal concentrations in the close vicinity of the smelter resulted in inhibited ALAD activities, depressed hemoglobin and hematocrit levels and increased mortality of nestlings. Our results indicate that in the highly contaminated environment around the smelter, nestlings reflected the slowly cycling soil pool, rather than the atmospheric deposition, and the concentration in soils plays an important role for the response of pied flycatchers to reduced atmospheric deposition.

  • 243.
    Berglund, Åsa
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Nyholm, Erik
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Slow improvements of metal exposure, health- and breeding conditions of pied flycatchers (Ficedula hypoleuca) after decreased industrial heavy metal emissionsManuscript (preprint) (Other academic)
    Abstract [en]

    The environment around metal industries, such as smelters, is often highly contaminated due to continuous deposition of metals. We studied nest box breeding populations of pied flycatchers (Ficedula hypoleuca) in a well-studied pollution gradient from a sulfide ore smelter in Northern Sweden, after reduced aerial metal emissions (by 93 – 99%) from the smelter. The deposition of As, Cd, Cu and Zn (based on moss samples) reflected the reduced emissions fairly well. However, nestling pied flycatchers had similar concentrations of these elements and Hg in tissue (bone, liver and blood) and feces in the 2000s, as in the 1980s, when the emissions were substantially higher. The slow improvement of metal accumulation in birds was explained by a food web transfer of metals mainly from the highly polluted soils, and it was concluded that nestlings reflected the slowly cycling soil pool, rather than the current atmospheric deposition. The exposure to high metal concentrations in the close vicinity of the smelter resulted in inhibited ALAD activities, depressed hemoglobin and hematocrit levels and increased mortality of nestlings. Our results indicate that in metal contaminated environments, the concentration in soils plays an important role for the response of pied flycatchers to reduced atmospheric deposition.

  • 244.
    Berglund, Åsa
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Sturve, J
    Department of Zoology, Göteborg University, Box 463, SE-405 30 Gothenburg, Sweden.
    Förlin, Lars
    Department of Zoology, Göteborg University, Box 463, SE-405 30 Gothenburg, Sweden.
    Nyholm, Erik
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Oxidative stress in pied flycatcher (Ficedula hypoleuca) nestlings from metal contaminated environments in northern Sweden2007In: Environmental Research, ISSN 0013-9351, E-ISSN 1096-0953, Vol. 105, no 3, p. 330-339Article in journal (Refereed)
    Abstract [en]

    Metals have been shown to induce oxidative stress in animals. One of the most metal polluted terrestrial environments in Sweden is the surroundings of a sulfide ore smelter plant located in the northern part of the country. Pied flycatcher nestlings (Ficedula hypoleuca) that grew up close to the industry had accumulated amounts of arsenic, cadmium, mercury, lead, iron and zinc in their liver tissue. The aim of this study was to investigate if pied flycatcher nestlings in the pollution gradient of the industry were affected by oxidative stress using antioxidant molecules and enzyme activities. The antioxidant assays were also evaluated in search for useful biomarkers in pied flycatchers. This study indicated that nestlings in metal contaminated areas showed signs of oxidative stress evidenced by up regulated hepatic antioxidant defense given as increased glutathione reductase (GR) and catalase (CAT) activities and slightly but not significantly elevated lipid peroxidation and glutathione-S-transferase (GST) activities. Stepwise linear regression indicated that lipid peroxidation and CAT activities were influenced mostly by iron, but iron and lead influenced the CAT activity to a higher degree. Positive relationships were found between GST and lead as well as GR activities and cadmium. We conclude that GR, CAT, GST activities and lipid peroxidation levels may function as useful biomarkers for oxidative stress in free-living pied flycatcher nestlings exposed to metal contaminated environments.

  • 245.
    Bergman, Tobias
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Resursen orrspel: En studie om kunskap och möjligheter för orrspelsguidning, generellt och specifikt vid turistanläggningen Granö beckasin2018Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aim of this report was to investigate how much people in general know about the bird black grouse and the possibilities for guiding on black grouse lek. I wanted to know how the possibilities where generally and specific at the tourist-facility Granö beckasin, which is situated in municipality of Vindeln in north of Sweden. I also wanted to get a better understanding about how the black grouse lek works and how the guiding would be best performed. Two different questionnaires were laid out, one with aim to reach a wide public and discover the knowledge and interest among people in general about black grouse lek. The aim with the second questionnaire was to reach people who is interested in bird- watching and get more quality answers about guiding on black grouse lek. While the questionnaires were collecting answers, market research about guiding and investigation of black grouse lekking spots possible for guiding around Granö was done. Most of the participants in the questionnaires showed a high level of awareness when it came to know what black grouse lek is, the majority also describe an active outdoorlife. The study showed a high level of black grouse lekking spots around Granö. Research and questionnaires showed that the target group for this type of guiding is small. The people in target for the type of guiding have big interest for birds and nature but doesn´t always have the time to research black grouse lekking spots themselves, therefore could a guide be helpful.  

  • 246.
    Bergmark, Paulina
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Jørgensen, Dolly
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Lophelia pertusa conservation in the North Sea using obsolete offshore structures as artificial reefs2014In: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 516, p. 275-280Article in journal (Refereed)
    Abstract [en]

    Deep-water coral reefs are classified as vulnerable marine ecosystems, with trawling identified as the primary cause of reef destruction. Lophelia pertusa is the main reef-building species in deep-water coral reefs. In addition to occurring on natural hard substrates, the species has been previously observed on standing offshore oil and gas structures in the North Sea. In this study, we review the available published information about Lophelia growth on standing offshore oil and gas industry structures in the North Sea. We discuss the potential uses of obsolete offshore structures repurposed as artificial reefs for targeted Lophelia habitat. Our survey of previous studies indicates that artificial reefs created from obsolete structures have a strong potential to form Lophelia reef communities similar to those found on natural substrates, although the absence of the polychaete worm Eunice norvegica poses some concerns about the completeness of the coral communities that develop on artificial reef structures.

  • 247.
    Bergroth, Simon
    Umeå University, Faculty of Science and Technology, Ecology and Environmental Science.
    Miljöledingssystem i offentlig förvaltning: - Modell för kartläggning och bedömning av Ålands landskapsregerings indirekta miljöaspekter2006Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
  • 248.
    Bergsjö, Mattias
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Sampling strategies for budgeting two Swedish lakes: Morphometry, seasons and other factors2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Two lakes in northern Sweden were sampled for carbon dioxide (CO2), dissolved inorganic carbon (DIC), total organic carbon (TOC), total nitrogen (TN), oxygen (O2) and temperature in April and in May 2016. This to calculate budgets for the lakes as well as make comparisons and find what makes them differ. Morphometry, seasons and trophic levels were explored and found to potentially have different degrees of effect on concentrations. Morphometry showed noticeable spatial variance within and between lakes, meaning that more complex lakes will have different concentration throughout the lake compared to a simple morphometry which will not show this spatial spread. Different seasons showed variance in total concentrations rather than spatial variance. Levels of humic substances showed a small potential variance in total concentrations between the two lakes.

    The variances found were then used to determine whether one of two sampling methods were more valid than another. One strategy entailed sampling the deepest point only and let it represent the whole lake. The other used points spread out over the lake’s area, taking the morphometry of the lake into account. Initial results pointed to the second strategy being more accurate because of morphometry etc. however when considering things such as time and cost, the reasonableness of this strategy may not be favorable depending on the aim of an eventual study.

  • 249. Bergsten, Johannes
    et al.
    Bilton, David T.
    Fujisawa, Tomochika
    Elliott, Miranda
    Monaghan, Michael T.
    Balke, Michael
    Hendrich, Lars
    Geijer, Joja
    Herrmann, Jan
    Foster, Garth N.
    Ribera, Ignacio
    Nilsson, Anders N.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Barraclough, Timothy G.
    Vogler, Alfried P.
    The Effect of Geographical Scale of Sampling on DNA Barcoding2012In: Systematic Biology, ISSN 1063-5157, E-ISSN 1076-836X, Vol. 61, no 5, p. 851-869Article in journal (Refereed)
    Abstract [en]

    Eight years after DNA barcoding was formally proposed on a large scale, CO1 sequences are rapidly accumulating from around the world. While studies to date have mostly targeted local or regional species assemblages, the recent launch of the global iBOL project (International Barcode of Life), highlights the need to understand the effects of geographical scale on Barcoding's goals. Sampling has been central in the debate on DNA Barcoding, but the effect of the geographical scale of sampling has not yet been thoroughly and explicitly tested with empirical data. Here, we present a CO1 data set of aquatic predaceous diving beetles of the tribe Agabini, sampled throughout Europe, and use it to investigate how the geographic scale of sampling affects 1) the estimated intraspecific variation of species, 2) the genetic distance to the most closely related heterospecific, 3) the ratio of intraspecific and interspecific variation, 4) the frequency of taxonomically recognized species found to be monophyletic, and 5) query identification performance based on 6 different species assignment methods. Intraspecific variation was significantly correlated with the geographical scale of sampling (R-square = 0.7), and more than half of the species with 10 or more sampled individuals (N = 29) showed higher intraspecific variation than 1%, sequence divergence. In contrast, the distance to the closest heterospecific showed a significant decrease with increasing geographical scale of sampling. The average genetic distance dropped from >7% for samples within 1 km, to <3.5% for samples up to >6000 km apart. Over a third of the species were not monophyletic, and the proportion increased through locally, nationally, regionally, and continentally restricted subsets of the data. The success of identifying queries decreased with increasing spatial scale of sampling; liberal methods declined from 100% to around 90%, whereas strict methods dropped to below 50% at continental scales. The proportion of query, identifications considered uncertain (more than one species <1% distance from query) escalated from zero at local, to 50% at continental scale. Finally, by resampling the most widely sampled species we show that even if samples are collected to maximize the geographical coverage, up to 70 individuals are required to sample 95%, of intraspecific variation. The results show that the geographical scale of sampling has a critical impact on the global application of DNA barcoding. Scale-effects result from the relative importance of different processes determining the composition of regional species assemblages (dispersal and ecological assembly) and global clades (demography, speciation, and extinction). The incorporation of geographical information, where available, will be required to obtain identification rates at global scales equivalent to those in regional barcoding studies. Our result hence provides an impetus for both smarter barcoding tools and sprouting national barcoding initiatives smaller geographical scales deliver higher accuracy.

  • 250. Bergsten, Johannes
    et al.
    Brilmyer, Gracen
    Crampton-Platt, Alex
    Nilsson, Anders N
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Sympatry and colour variation disguised well-differentiated sister species: Suphrodytes revised with integrative taxonomy including 5 kbp of housekeeping genes (Coleoptera: Dytiscidae)2012In: DNA Barcodes, ISSN 2299-1077, Vol. 1, no 1, p. 1-18Article in journal (Refereed)
    Abstract [en]

    The genus Suphrodytes, is currently regarded as a monobasic Palearctic genus with one colour-variable species, S. dorsalis. Here we show with >5 kbp of nuclear and mitochondrial genes and quantitative morphological characters that Suphrodytes consists of two well-defined species, albeit each with variable colour pattern. The primary barcode gene CO1, showed consistent signs of multiple copies, therefore a range of alternative housekeeping genes were screened for information. The two species were reciprocally monophyletic in genetrees from 12S, 16S, CO1, CO2, CytB, H3 and 18S. Explicit species delimitation tests based on the coalescent process model rejected the null hypothesis that the genealogies originated from a single panmictic species. The mitochondrial proteincoding genes were proportionally richest in information followed by 12S and Histone 3. Conservative nuclear 18S had a single fixed diagnostic character. The two species were significantly different in total bodylength, bodyshape, shape of the male aedeagus and parameres. We review the taxonomic literature of Suphrodytes and find S. dorsalis (Fabricius, 1787) and S. figuratus (Gyllenhal, 1826) to be the oldest available names for the respective species, and for which we designate lectotypes. Synonyms are established for both species which are broadly sympatric across the Palearctic and frequently even collected at the same locality.

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