| 1. |
- Householder, John Ethan, et al.
(författare)
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One sixth of Amazonian tree diversity is dependent on river floodplains
- 2024
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Ingår i: NATURE ECOLOGY & EVOLUTION. - 2397-334X. ; 8, s. 901-911
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Tidskriftsartikel (refereegranskat)abstract
- Amazonia's floodplain system is the largest and most biodiverse on Earth. Although forests are crucial to the ecological integrity of floodplains, our understanding of their species composition and how this may differ from surrounding forest types is still far too limited, particularly as changing inundation regimes begin to reshape floodplain tree communities and the critical ecosystem functions they underpin. Here we address this gap by taking a spatially explicit look at Amazonia-wide patterns of tree-species turnover and ecological specialization of the region's floodplain forests. We show that the majority of Amazonian tree species can inhabit floodplains, and about a sixth of Amazonian tree diversity is ecologically specialized on floodplains. The degree of specialization in floodplain communities is driven by regional flood patterns, with the most compositionally differentiated floodplain forests located centrally within the fluvial network and contingent on the most extraordinary flood magnitudes regionally. Our results provide a spatially explicit view of ecological specialization of floodplain forest communities and expose the need for whole-basin hydrological integrity to protect the Amazon's tree diversity and its function.
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| 2. |
- Luize, Bruno Garcia, et al.
(författare)
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Geography and ecology shape the phylogenetic composition of Amazonian tree communities
- 2024
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Ingår i: JOURNAL OF BIOGEOGRAPHY. - 0305-0270 .- 1365-2699. ; 51:7, s. 1163-1184
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Tidskriftsartikel (refereegranskat)abstract
- Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types. Location: Amazonia. Taxon: Angiosperms (Magnoliids; Monocots; Eudicots). Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran's eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny. Results: In the terra firme and v & aacute;rzea forest types, the phylogenetic composition varies by geographic region, but the igap & oacute; and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R-2 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R-2 = 28%). A greater number of lineages were significant indicators of geographic regions than forest types. Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions.
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| 3. |
- ter Steege, Hans, et al.
(författare)
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Mapping density, diversity and species-richness of the Amazon tree flora
- 2023
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Ingår i: COMMUNICATIONS BIOLOGY. - 2399-3642. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution. A study mapping the tree species richness in Amazonian forests shows that soil type exerts a strong effect on species richness, probably caused by the areas of these forest types. Cumulative water deficit, tree density and temperature seasonality affect species richness at a regional scale.
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| 4. |
- Martin, Tina, et al.
(författare)
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Comparison of hydrogeological properties based on DCIP, surface NMR and hydraulic tests
- 2023
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Ingår i: NSG2023 2nd Conference on Hydrogeophysics. ; 2023
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Konferensbidrag (refereegranskat)abstract
- The success and the costs of infrastructure projects depends to a large extent on a reliable characterisation of the subsurface. Information about the groundwater is crucial to protect groundwater resources and to avoid stability problems. Usually, drillings followed by hydraulic tests are conducted which are reliable but expensive and only give punctual information. The use of the geophysical methods Induced Polarisation (IP) and Nuclear Magnetic Resonance (NMR) can help to optimise drillings since they can give information about the hydraulic conductivity (K), the water content and the pore space characteristics. The combined methods were tested at three Swedish sites to investigate how reliably the hydrogeological properties of the underground can be characterised on a field scale. At the test site shown as example, it was accompanied by slug tests and the hydraulic profiling tool (HPT), where we could identify layers with different intrinsic permeabilities based on the IP data. Furthermore, we found that the water content is decreasing with depth. The comparison of the geophysical results with HPT and slug tests shows a correlation but more improvements regarding the K estimation from the IP data needs to be made.
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| 5. |
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| 6. |
- Martin, Tina, et al.
(författare)
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Geophysical mapping of groundwater properties for transport infrastructure construction planning - Final report
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The success and costs of infrastructure projects largely depend on reliable characterization of the subsoil, where information on groundwater is essential to protect groundwater resources and to avoid stability problems. To determine the hydrogeological characteristics, drilling is carried out followed by hydraulic tests which are reliable but expensive and provide limited information which, in some cases, may not be representative of the entire area that may be affected. The use of geophysical methods can overcome this problem and by providing continuous information that can be used to optimize well placement and execution. The esults of the drilling and hydraulic tests can then in turn be fed back to improve the interpretation of the geophysical results. It is thereby possible to get more comprehensive and relevant results that reduce the risk of problems in the construction phase, thus saving resources, time and costs. The geoelectrical method DCIP (Direct Current resistivity and time-domain Induced Polarization) can provide information on the intrinsic permeability. In addition, MRS (Magnetic Resonance Sounding) can provide information on the water content and properties of the pore spaces, and thus also information related to the hydraulic conductivity. By combining both methods and using them in a two- or three-dimensional layout, a more comprehensive description of the subsoil is possible. The purpose of the project is to find out how both methods can contribute to a reliable characterisation of the subsoil's hydrogeological properties. The methods were tested alongside conventional tests of the hydraulic conductivity using boreholes, slug tests and HPT (hydraulic profiling tool) to investigate three different test sites. The test sites were chosen to reflect different hydrogeological conditions and to provide access to reference data. Furthermore, their electromagnetic noise level was a crucial factor as it can affect the geophysical results. Measured data were processed, interpreted and compared, to evaluate the geophysical results with regard to hydrogeological information value, as well as robustness in measurement environments with different signal interference conditions. The results show that DCIP tomography provided inverted depth sections with hydraulic conductivity along the survey lines that mostly agree with the reference data from conventional methods at all three test locations. They also show that DCIP is robust enough to give good results along all test lines performed. However, it is not a guarantee that the method works everywhere due to the presence of noise/disturbances, for example in urban environments. It should also be mentioned that the algorithms that have been used for the interpretation of the hydraulic properties are part of research software, and that there is great potential for further development but also a need to adapt the user interface for a wider use. The results also show that MRS can provide information on water content and hydraulic properties that are mainly consistent with the reference data from other methods, thereby providing valuable complementary information. However, MRS measured from the ground surface, as tested here, is significantly more sensitive to electromagnetic interference, which was manifested in the fact that the method only worked fully at one of the test sites while giving limited or no useful results at the other test sites, due to the presence of noise generated by adjacent infrastructure.
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| 7. |
- Mendoza, Alfredo
(författare)
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Groundwater occurrence and risk of pollution in a mountain watershed of Nicaragua
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Hydrogeological and geophysical methods were applied in the Río Artiguas watershed, a mountain basin located in central Nicaragua. This area is under environmental stress from anthropogenic activities like gold mining using mercury and waste disposal into the streams. The aim of this work was to characterise the hydrogeological conditions in the basin with emphasis on understanding the possible connections between streams and groundwater. It was also important to evaluate the vulnerability and risk of groundwater pollution. Hydrogeological mapping, resistivity imaging, hydrological measurements and hydrochemical surveys were combined to meet the aims of the work. The hydrogeological characterisation permitted identification of a) recharge areas, b) geological units that contribute to the formation of the groundwater system and c) a mechanism of discharge through springs and streams. The geophysical surveys allowed mapping the extension of weathering and tectonic features with hydrogeological significance, e.g. faults, dykes and fractures. A total of 99 perennial springs were documented and classified according to their mechanism of formation. Isotopic data indicate that the recharge occurs very close to the sites where the springs are formed. This is also supported by the relatively low ion concentrations found in the water of the springs. The weathering layers together with fractures and dykes form shallow aquifers that commonly discharge in a spring or along the streams. The high precipitation regime is an immediate source of water to the system, and in conjunction with the geology and steep topography it generates a constant and rapid circulation of water from recharge areas to discharge zones. The natural implication of this hydrogeological framework is that the formation of large or regional flows is not evident at the current state of knowledge. The same factors that influence groundwater occurrence are to some extent responsible for the degree of groundwater vulnerability to pollution. The vulnerable areas are situated along the steep valleys of the basin, where the interactions between subsurface and surface water can facilitate the spreading of pollutants. Since the pollution sources are located near the streams the risk of groundwater pollution is concentrated there. The pollutants disposed into the streams are rapidly removed by the river flow, which has a high contribution from precipitation. The pollutants are then transported far away from the sources. The urgent need to end the pollution of Río Artiguas is obvious. The tools to prevent further deterioration are not only to be found in the hydro geosciences and mining technology sphere, but they are also located in the socio?political arena. In this respect, the research presented in this thesis will gain importance as it reaches and informs local decision makers about the vulnerability and risks of pollution that the current anthropogenic activities represent for the groundwater resources.
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| 8. |
- Mendoza, Alfredo, et al.
(författare)
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Tidsserieanalys och grundvattenbildning längs Alnarpsdalen, Skåne.
- 2022
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Ingår i: ; , s. 1-1
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Konferensbidrag (refereegranskat)abstract
- Akvifären Alnarpsdalen är 6 - 10 km bred och sträcker sig från Skivarp i sydost till Löddeköpinge i nordväst och vidare ut i Öresund. Trots att flertalet kommuner i Skåne numera försörjs med vatten från Vombsjön eller Bolmen finns det kommuner, industrier och jordbrukare som använder vatten från Alnarpsdalen.Det finns ett antal frågor som kan ställas gällande Alnarpsdalen, till exempel hur mycket vatten som infiltreras eller hur stora uttag som kan göras, utan att riskera en ohållbar minskning av grundvattennivåer. Ett antal undersökningar har genomfört sedan 60-talet med syfte att svara på dessa frågor. Dessa undersökningar har gett viktig, men översiktlig information. För att få ökad förståelse finns behov av att genomföra mer detaljerade undersökningar.Med traditionella undersökningar beräknas hydrauliska parametrar genom provpumpningar. Denna metod fungerar bra, men är resurskrävande och resultaten gäller vanligtvis ett begränsat område. Användandet av tidsserieanalys kan vara en alternativ metod för att beräkna hydrauliska parametrar genom att observera naturliga grundvattennivåer. Tidsserieanalyser är ett relativt nytt forskningsområde inom hydrogeologi, vilket veterligen inte använts i södra Sverige. Trots att metoden under lång tid tillämpats inom t.ex. hydrologi, började användandet av tidsserieanalys inom hydrogeologi så sent som på 1990-talet. Detta projekts syfte var att studera sambanden mellan grundvattenbildning och grundvattennivåer längs Alnarpsdalen, vilket är ett av de viktigaste grundvattenmagasinen som finns i Skåne. Resultaten bidrar ny kunskap om cirkulationen under mark för vårt viktigaste livsmedel. Analysen utgår från användning av klassiska beräkningsmetoder anpassade till serier av grundvattennivåer, vilka har registrerats kontinuerligt i ett antal brunnar.Utgångsanalysen baserades på den så kallade Water-table fluctuation method, där variationer i grundvattennivåer med tid anses härröra från några faktorer. Dessa faktorer är nederbörd (infiltration), uttag, tidvatten, mm (Healy och Cook, 2002). Ett viktigt moment i analysen var att särskilja dessa olika faktorer i nivådata.Resultaten ger relevanta kunskaper om grundvattnet för framtida vattenförsörjningsplaner och skyddsåtgärder. Resultaten kan också vara viktiga för stadsplanering, eftersom kunskap om grundvattenbildning behövs för planering av ytor tillgängliga för urbanisering.
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| 9. |
- Mendoza, Jose Alfredo, et al.
(författare)
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Aquifer interactions with a polluted mountain river of Nicaragua
- 2008
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Ingår i: Hydrological Processes. - : Wiley. - 1099-1085 .- 0885-6087. ; 22:13, s. 2264-2273
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Tidskriftsartikel (refereegranskat)abstract
- The interactions between a stream and nearby shallow aquifers were investigated in a mountain basin being polluted by mercury released during mining in central Nicaragua. Hourly data series of water levels and temperatures were analysed using cross-correlation. Resistivity imaging was used to map the subsurface and to complement the hydrological data interpretation. The results show the complex hydrogeological conditions that characterize the region, with weathering and fractured rock as main contributors to groundwater transport. The resistivity images suggest the presence of two vertical dykes perpendicular to the stream, and zones rich in clay. The data series indicate a rapid response from the aquifers to recharge events, followed by immediate discharge on a yearly basis. Furthermore, alternating periods of stream infiltration and aquifer discharge were identified. This work demonstrates that surface water pollution is a threat to groundwater quality in the area.
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| 10. |
- Persson, Peter, et al.
(författare)
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Lessons of Feedback in Higher Education in Sweden
- 2018
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Ingår i: 10:e Pedagogiska Inspirationskonferensen 2018. - 2003-3761 .- 2003-377X. ; 10
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Lessons learned in the feedback process are atwo-sided coin that ultimately guide the PhD candidatetowards becoming an independent researcher as well aseducating “reader/docents” in their role as supervisor.Building on a brief literature review, observations from 14interviewed PhD candidates were reflected upon and these arethe suggested lessons learned. The study’s preliminary findingssuggest that feedback is most productive when it is organized,systematic, and tends to offer guidance rather than directinstruction. Perhaps of greatest significance is the need to haveconsistent dialogue about the feedback’s form and contentbetween student and supervisor(s).
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| 11. |
- Picado, Francisco, et al.
(författare)
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Ecological, Groundwater, and Human Health Risk Assessment in a Mining Region of Nicaragua
- 2010
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Ingår i: Risk Analysis: an official publication of the Society for Risk Analysis. - : Wiley. - 1539-6924. ; 30:6, s. 916-933
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Tidskriftsartikel (refereegranskat)abstract
- Macroinvertebrates and fish in the contaminated river are faced with a higher risk to suffer from exposure to Hg than humans eating contaminated fish and bacteria living in the groundwater. The river sediment is the most hazardous source for the macroinvertebrates, and macroinvertebrates make up the highest risk for fish. The distribution of body concentrations of Hg in fish in the mining areas of the basin may exceed the distribution of endpoint values with close to 100% probability. Similarly, the Hg concentration in cord blood of humans feeding on fish from the river was predicted to exceed the BMDLs(0.1) with about 10% probability. Most of the risk to the groundwater quality is confined to the vicinity of the gold refining plants and along the river, with a probability of about 20% to exceed the guideline value.
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| 12. |
- Valenti, Emanuele, et al.
(författare)
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Informal coercion in psychiatry : a focus group study of attitudes and experiences of mental health professionals in ten countries
- 2015
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Ingår i: Social Psychiatry and Psychiatric Epidemiology. - : Springer Science and Business Media LLC. - 0933-7954 .- 1433-9285. ; 50:8, s. 1297-1308
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Tidskriftsartikel (refereegranskat)abstract
- Whilst formal coercion in psychiatry is regulated by legislation, other interventions that are often referred to as informal coercion are less regulated. It remains unclear to what extent these interventions are, and how they are used, in mental healthcare. This paper aims to identify the attitudes and experiences of mental health professionals towards the use of informal coercion across countries with differing sociocultural contexts.Focus groups with mental health professionals were conducted in ten countries with different sociocultural contexts (Canada, Chile, Croatia, Germany, Italy, Mexico, Norway, Spain, Sweden, United Kingdom).Five common themes were identified: (a) a belief that informal coercion is effective; (b) an often uncomfortable feeling using it; (c) an explicit as well as (d) implicit dissonance between attitudes and practice-with wider use of informal coercion than is thought right in theory; (e) a link to principles of paternalism and responsibility versus respect for the patient's autonomy.A disapproval of informal coercion in theory is often overridden in practice. This dissonance occurs across different sociocultural contexts, tends to make professionals feel uneasy, and requires more debate and guidance.
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