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Using a dendrochronological approach, we determined the resistance, recovery and resilience of the radial stem increment towards episodes of growth decline, and the accompanying variation of 13C discrimination against atmospheric CO2 (Δ13C) in tree rings of two palaeotropical pine species. These species co-occur in the mountain ranges of south–central Vietnam (1500–1600 m a.s.l.), but differ largely in their areas of distribution (Pinus kesiya from northeast India to the Philippines; P. dalatensis only in south and central Vietnam and in some isolated populations in Laos). For P. dalatensis, a robust growth chronology covering the past 290 years could be set up for the first time in the study region. For P. kesiya, the 140-year chronology constructed was the longest that could be established to date in that region for this species. In the first 40 years of the trees’ lives, the stem diameter increment was significantly larger in P. kesiya, but levelled off and even decreased after 100 years, whereas P. dalatensis exhibited a continuous growth up to an age of almost 300 years. Tree-ring growth of P. kesiya was negatively related to temperature in the wet months and season of the current year and in October (humid transition period) of the preceding year and to precipitation in August (monsoon season), but positively to precipitation in December (dry season) of the current year. The P. dalatensis chronologies exhibited no significant correlation with temperature or precipitation. Negative correlations between BAI and Δ13C indicate a lack of growth impairment by drought in both species. Regression analyses revealed a lower resilience of P. dalatensis upon episodes of growth decline compared to P. kesiya, but, contrary to our hypothesis, mean values of the three sensitivity parameters did not differ significantly between these species. Nevertheless, the vigorous growth of P. kesiya, which does not fall behind that of P. dalatensis even at the margin of its distribution area under below-optimum edaphic conditions, is indicative of a relatively high plasticity of this species towards environmental factors compared to P. dalatensis, which, in tendency, is less resilient upon environmental stress even in the “core” region of its occurrence.
Detection of Preferential Water Flow by Electrical Resistivity Tomography and Self-Potential Method
(2021)
This study explores the hydrogeological conditions of a landslide-prone hillslope in the Upper Mosel valley, Luxembourg. The investigation program included the monitoring of piezometer wells, hydrogeological field tests, analysis of drillcore records, and geophysical surveys. Monitoring and field testing in some of the observation wells indicated very pronounced preferential flow. Electrical resistivity tomography (ERT) and self-potential geophysical methods were employed in the study area for exploration of the morphology of preferential flowpaths. Possible signals associated with flowing groundwater in the subsurface were detected; however, they were diffusively spread over a relatively large zone, which did not allow for the determination of an exact morphology of the conduit. Analysis of drillcore records indicated that flowpaths are caused by the dissolution of thin gypsum interlayers in marls. For better understanding of the site’s hydrogeological settings, a 3D hydrogeological model was compiled. By applying different subsurface flow mechanisms, a hydrogeological model with thin, laterally extending flowpaths embedded in a porous media matrix showed the best correspondence with field observations. Simulated groundwater heads in a preferential flow conduit exactly corresponded with the observed heads in the piezometer wells. This study illustrates how hydrogeological monitoring and geophysical surveys in conjunction with the newest hydrogeological models allow for better conceptualization and parametrization of preferential flow.
Perennial energy crops (PECs) are increasingly used as feedstock to produce energy in an environmental friendly way. Compared to traditional conversion strategies like thermal use, sophisticated technologies such as biomethanation defined different re-quirements of the feedstock. Whereas the first concept relies on dry, woody mate-rial, biomethanation requires a moist feedstock. Thus, over time, the spectrum of species used as PECs has widened. Moreover, harvest dates were adjusted to pro-vide the feedstock at suitable moisture contents. It is well known that perennial, lignocellulose- based energy crops, compared to annual, sugar- and starch- based ones, offer ecological advantages such as, inter alia, improving biodiversity in landscape, protecting soil against erosion, and protecting groundwater from nutrient inputs. However, one of the main arguments for PEC cultivation was their undemanding nature concerning external inputs. With respect to the broader spectrum of PEC spe-cies and changed harvest dates, the question arises whether the concept of PECs being low- input energy crops is still valid. This also implies the question of suitable grow-ing conditions and sustainable management. The aims of this opinion paper were to classify different PECs according to their life- form strategy, compare nutrient exports when harvested in different maturation stages, and to discuss the results in the context of sustainable PEC cultivation on marginal land. This study revealed that nutrient exports with yield biomass of PECs harvested in green state are in the same range than those of annual energy crops and therewith several times higher than those of PECs harvested in brown state or of woody short rotation coppices. Thus, PECs can-not universally be claimed as low- input energy crops. These results also imply the consequences of cultivation of PECs on marginal land. Finally, the question has to be raised whether the term PECs should prospectively be better specified in written and spoken words.
The endemic argan tree (Argania spinosa) populations in southern Morocco are highly degraded due to overbrowsing, illegal firewood extraction and the expansion of intensive agriculture. Bare areas between the isolated trees increase due to limited regrowth; however, it is unknown if the trees influence the soil of the intertree areas. Hypothetically, spatial differences in soil parameters of the intertree area should result from the translocation of litter or soil particles (by runoff and erosion or wind drift) from canopy-covered areas to the intertree areas. In total, 385 soil samples were taken around the tree from the trunk along the tree drip line (within and outside the tree area) and the intertree area between two trees in four directions (upslope, downslope and in both directions parallel to the slope) up to 50 m distance from the tree. They were analysed for gravimetric soil water content, pH, electrical conductivity, percolation stability, total nitrogen content (TN), content of soil organic carbon (SOC) and C/N ratio. A total of 74 tension disc infiltrometer experiments were performed near the tree drip line, within and outside the tree area, to measure the unsaturated hydraulic conductivity. We found that the tree influence on its surrounding intertree area is limited, with, e.g., SOC and TN content decreasing significantly from tree trunk (4.4 % SOC and 0.3 % TN) to tree drip line (2.0 % SOC and 0.2 % TN). However, intertree areas near the tree drip line (1.3 % SOC and 0.2 % TN) differed significantly from intertree areas between two trees (1.0 % SOC and 0.1 % TN) yet only with a small effect. Trends for spatial patterns could be found in eastern and downslope directions due to wind drift and slope wash. Soil water content was highest in the north due to shade from the midday sun; the influence extended to the intertree areas. The unsaturated hydraulic conductivity also showed significant differences between areas within and outside the tree area near the tree drip line. This was the case on sites under different land usages (silvopastoral and agricultural), slope gradients or tree densities. Although only limited influence of the tree on its intertree area was found, the spatial pattern around the tree suggests that reforestation measures should be aimed around tree shelters in northern or eastern directions with higher soil water content or TN or SOC content to ensure seedling survival, along with measures to prevent overgrazing.
In der vorliegenden Arbeit wurden die Einsatzmöglichkeiten von Carbon Footprints in Großküchen untersucht. Dabei wurden sowohl methodische Aspekte und Herausforderungen ihrer Erhebung untersucht als auch mögliche Kennzeichnungsformate (Label) evaluiert.
Zunächst wurde am Beispiel Hochschulgastronomie eine vollständige Carbon Footprint Studie nach DIN 14067 für sechs exemplarische Gerichte (PCF) sowie angelehnt an DIN 14064 für den Mensabetrieb (CCF) durchgeführt. Es zeigte sich, dass die gewichteten durchschnittlichen Emissionen pro Teller, unter Einbezug der verwendeten Rohstoffe und des Energiebedarfs, 1,8 kg CO2eq pro Teller betragen (Mgew=1,78 kg CO2eq; [0,22-3,36]). Zur Vereinfachung des Erhebungsprozesses wurden anknüpfend an diese Ergebnisse Pauschalisierungsansätze zur vereinfachten Emissionsallokation im Gastrosektor evaluiert und in Form eines appgestützten Berechnungstools umgesetzt. Es konnte verifiziert werden, dass der Energiebedarf und die daraus resultierenden Emissionen unabhängig von der Beschaffenheit der Gerichte auf die Anzahl produzierter Gerichte alloziert werden können und die Ausgabewerte dennoch hinreichend belastbar sind (Abweichung <10 %).
In dieser Studie konnte gezeigt werden, dass am untersuchten Standort Skaleneffekte hinsichtlich der Anzahl produzierter Gerichte und Strombedarf pro Gericht auftreten. Beide Faktoren korrelieren stark negativ miteinander (r=-.78; p<.05). Zur Verifikation der Ergebnisse wurde eine Datenabfrage unter allen deutschen Studierendenwerken (N=57) hinsichtlich des Energiebedarfs und der Produktionsmengen in Hochschulmensen durchgeführt. Aus den Daten von 42 Standorten konnten für das Jahr 2018 prognostizierte Gesamtemissionen in Höhe von 174.275 Tonnen CO2eq, verursacht durch etwa 98 Millionen verkaufte Gerichte, ermittelt werden. Im Gegensatz zur durchgeführten Standort-Studie konnten die Skaleneffekte, d.h. sinkender Strombedarf pro Teller bei steigender Produktionszahl, bei der deutschlandweiten Datenerhebung statistisch nicht nachgewiesen werden
(r=-.29; p=.074).
Im Anschluss wurden mögliche Label-Formate für Carbon Footprints evaluiert, indem vier vorbereitete Label unterschiedlicher Beschaffenheit (absolute Zahlen, einordnend, vergleichend und wertend) in sechs Fokusgruppen mit insgesamt 17 Teilnehmer:innen im Alter zwischen 20 und 31 Jahren (M=25,12; SD=3,31) diskutiert wurden. Im Ergebnis zeigte sich, dass bei den Teilnehmer:innen ein breiter Wunsch nach der Ausweisung absoluter Zahlen bestand. Zur besseren Einordnung sollte ein Label zudem einordnende Elemente enthalten. Wertende Label in Form von Ampelsymbolen oder Smileys mit unterschiedlichen Emotionen wurden überwiegend abgelehnt. Ableitend aus den Erkenntnissen konnten zwei synthetisierende Label-Vorschläge entwickelt werden.
The nonhydrostatic regional climate model CCLM was used for a long-term hindcast run (2002–2016) for the Weddell Sea region with resolutions of 15 and 5 km and two different turbulence parametrizations. CCLM was nested in ERA-Interim data and used in forecast mode (suite of consecutive 30 h long simulations with 6 h spin-up). We prescribed the sea ice concentration from satellite data and used a thermodynamic sea ice model. The performance of the model was evaluated in terms of temperature and wind using data from Antarctic stations, automatic weather stations (AWSs), an operational forecast model and reanalyses data, and lidar wind profiles. For the reference run we found a warm bias for the near-surface temperature over the Antarctic Plateau. This bias was removed in the second run by adjusting the turbulence parametrization, which results in a more realistic representation of the surface inversion over the plateau but resulted in a negative bias for some coastal regions. A comparison with measurements over the sea ice of the Weddell Sea by three AWS buoys for 1 year showed small biases for temperature around ±1 K and for wind speed of 1 m s−1. Comparisons of radio soundings showed a model bias around 0 and a RMSE of 1–2 K for temperature and 3–4 m s−1 for wind speed. The comparison of CCLM simulations at resolutions down to 1 km with wind data from Doppler lidar measurements during December 2015 and January 2016 yielded almost no bias in wind speed and a RMSE of ca. 2 m s−1. Overall CCLM shows a good representation of temperature and wind for the Weddell Sea region. Based on these encouraging results, CCLM at high resolution will be used for the investigation of the regional climate in the Antarctic and atmosphere–ice–ocean interactions processes in a forthcoming study.
Grundlage der Arbeit stellten zwei Arbeitshypothesen dar, die es zu überprüfen galt. Die beiden Arbeitshypothesen wurden aufgrund einer Beobachtung eines Phänomens im Freiland formuliert, da bei scheinbar unterschiedlich starkem Reblausbesatzes im Boden kein direkter Zusammenhang zu einer schädigenden Wirkung dieses Stressphänomens (Reblausbefall) hergestellt werden konnte. Im Gegenteil traten die schädigenden Wirkungen des Reblausbefalls in Form von Rückgangserscheinungen eher in Rebflächen auf, die einer mangelhaften Bewirtschaftung oder Bestandsführung unterlagen. Zur Klärung dieses Phänomens wurden daher die beiden (A., B.) folgenden Hypothesen aufgestellt, die es zu überprüfen galt:
A.: Die in mit Unterlagsrebsorten der Kreuzung V. berlandieri x V. riparia zu beobachtenden Rückgangserscheinungen in Rebanlagen mit Reblausvorkommen werden nicht allein durch die Saugtätigkeit der Reblaus an den Rebwurzeln verursacht; eine direkte Korrelation zwischen Reblausdichte und Ausmaß der Rückgangserscheinungen an infizierten Reben besteht nicht. B.: Das Ausmaß möglicher Rückgangserscheinungen ist abhängig von der Bewirtschaftung des Rebbestands, wobei der Bodenbewirtschaftung eine maßgebliche Rolle zukommt.
Um diese Hypothesen zu überprüfen wurde ableitend von den Zielen der Arbeit ein Reblausbonitursystem zur Erfassung der Reblausabudanz im Freiland im Boden erarbeitet. Die besonderen Schwierigkeiten bei der Erfassung des Reblausbefalls im Boden aufgrund des stark variierenden Wurzelsystems der Rebe und dem ebenfalls stark schwankenden Reblausbefalls an der Wurzel der Rebe wurde mit dem Reblausbonitursystem (Grabungen) Rechnung getragen, sodass ein valides System zur Beurteilung des Reblausbefalls auch im jahreszeitlichen Verlauf erstellt worden konnte. Damit wurde ein Reblausbonitursystem geschaffen, das auch in praktischer Anwendung durchführbar ist und somit mit seiner höheren möglichen Replikationsrate bei der Probenentnahme dem stark variierenden Charakter des Reblausbefalls im Boden Rechnung trägt.
Um Rückgangserscheinungen in einem Weinberg nachhaltig analysieren zu können, wurde ein Wuchsbonitursystem evaluiert. Dieses System beurteilt alle Reben einer Rebfläche innerhalb eines einfachen für den Menschen kognitiv sehr gut verarbeitenden Bewertungssystem zum Wuchs der Reben. Damit ist eine Erfassung einer sehr großen Datenmenge zur Beurteilung des Wuchses auf einem Rebfeld möglich. Die Korrelation des mit dem System ermittelten Wuchses zu vielen Leistungsparametern der Rebe und den Gegebenheiten auf den Versuchsflächen zeigt die hohe Validität des Wuchsbonitursystems auf. Auch konnten Wuchsunterschiede in sehr differierenden Versuchsfeldern mit dieser Methode deutlich belegt werden. Damit wurde deutlich, dass mit dieser Wuchsboniturmethode die Rückgangserscheinungen in einer Rebfläche erkannt und analysiert werden konnten. Somit konnten mit den beiden Instrumenten der Wuchs- und Reblausbonitur die beiden Arbeitshypothesen dahingehend belegt werden, dass unter Verwendung der Unterlagensorten der Kreuzungskombination V. berlandieri x V. riparia kein Zusammenhang zwischen der Reblausdichte im Boden und Rückgangserscheinungen der Rebe vorliegen. Darüber hinaus konnte belegt werden, dass in Erweiterung dieser Erkenntnis das Ausmaß der Rückganserscheinungen bei Reben maßgeblich von der Art der Bewirtschaftung abhängt und somit deutlich abzutrennen ist vom Einfluss des Reblausbefalls. Vor allem konnte durch die vorliegende Arbeit unter Einbeziehung des Wuchsbonitursystems eine Methode erarbeitet werden, die in Zukunft bei der Beurteilung von Fernerkundungsdaten ein nützliches Instrument darstellt, um die wirklichen Gegebenheiten hinsichtlich des Wuchses der Reben auf Weinbergsflächen mit den berechneten Werten zu Wuchsindizes zu korrelieren.
Aufgrund oftmals erhöhter Arsen- und Schwermetallgehalte in den Oberböden von Auen ist eine Verwertung von Auenböden, zum Beispiel im Rahmen von Renaturierungsmaßnahmen, oftmals schwierig, da keine auenspezifische Bewertungsgrundlage für dieser Stoffgehalte vorliegt.
Am Beispiel der Lippeaue erfolgte auf Grundlage abgeleiteter Haupteinflussfaktoren für die Konzentration von Arsen- und Schwermetallen in den Oberböden die Ableitung von Hintergrundgehalten. Die Metall- und Schwermetallgehalte in den Oberböden der Lippeaue lagen i. d. R. erwartungsgemäß oberhalb der in der Praxis verwendeten Einstufungswerte (z. B. Vorsorgewerte der BBodSchV, Hintergrundwerte von NRW), die sich allerdings auf Standorte außerhalb der Aue beziehen.
Anhand von gewonnen Daten aus Projektarbeiten im Zuge der Umsetzung der EU-Wasserrahmenrichtlinie (z. B. bodenkundliche und ingenieurgeologische Profilaufnahme, bodenmechanische Laborversuche) und ergänzend durchgeführter Untersuchungen, wie z. B. Bodentypenkartierung und mineralogische Untersuchungen, erfolgte eine detaillierte Standortcharakterisierung der Böden in der Lippeaue.
Auf Basis der abgeleiteten Hintergrundgehalte wurden unter Berücksichtigung der ermittelten Bodenkennwerte und Einflussgrößen auenspezifische Einbauregeln abgeleitet. Mit dem Ziel einer praktikablen Anwendbarkeit wurde eine auf die wesentlichen Kenngrößen reduzierte Bewertungsmatrix erarbeitet. Bei geplanten baulichen Eingriffen in den Boden kann nun mit den lippeauenspezifischen Einbauwerten für Arsen und Schwermetalle anhand konventioneller Parameter für jeden Standort ermittelt werden, ob besonders günstige oder ungünstige Bedingungen für einen potenziellen Wiedereinbau vorliegen. Die abgeleiteten Hintergrundgehalte und Einbauwerte verstehen sich dabei als – auf Basis der aktuellen Datenlage abgeleitete – Handlungsempfehlung und Orientierung zur Bewertung von Böden im Hinblick auf einen gebietsübergreifenden Wiedereinbau in der Lippeaue.
Finding behavioral parameterization for a 1-D water balance model by multi-criteria evaluation
(2019)
Evapotranspiration is often estimated by numerical simulation. However, to produce accurate simulations, these models usually require on-site measurements for parameterization or calibration. We have to make sure that the model realistically reproduces both, the temporal patterns of soil moisture and evapotranspiration. In this study, we combine three sources of information: (i) measurements of sap velocities; (ii) soil moisture; and (iii) expert knowledge on local runoff generation and water balance to define constraints for a “behavioral” forest stand water balance model. Aiming for a behavioral model, we adjusted soil moisture at saturation, bulk resistance parameters and the parameters of the water retention curve (WRC). We found that the shape of the WRC influences substantially the behavior of the simulation model. Here, only one model realization could be referred to as “behavioral”. All other realizations failed for a least one of our evaluation criteria: Not only transpiration and soil moisture are simulated consistently with our observations, but also total water balance and runoff generation processes. The introduction of a multi-criteria evaluation scheme for the detection of unrealistic outputs made it possible to identify a well performing parameter set. Our findings indicate that measurement of different fluxes and state variables instead of just one and expert knowledge concerning runoff generation facilitate the parameterization of a hydrological model.
Background: Increasing exposure to engineered inorganic nanoparticles takes actually place in both terrestric and aquatic ecosystems worldwide. Although we already know harmful effects of AgNP on the soil bacterial community, information about the impact of the factors functionalization, concentration, exposure time, and soil texture on the AgNP effect expression are still rare. Hence, in this study, three soils of different grain size were exposed for up to 90 days to bare and functionalized AgNP in concentrations ranging from 0.01 to 1.00 mg/kg soil dry weight. Effects on soil microbial community were quantified by various biological parameters, including 16S rRNA gene, photometric, and fluorescence analyses.
Results: Multivariate data analysis revealed significant effects of AgNP exposure for all factors and factor combinations investigated. Analysis of individual factors (silver species, concentration, exposure time, soil texture) in the unifactorial ANOVA explained the largest part of the variance compared to the error variance. In depth analysis of factor combinations revealed even better explanation of variance. For the biological parameters assessed in this study, the matching of soil texture and silver species, and the matching of soil texture and exposure time were the two most relevant factor combinations. The factor AgNP concentration contributed to a lower extent to the effect expression compared to silver species, exposure time and physico–chemical composition of soil.
Conclusions: The factors functionalization, concentration, exposure time, and soil texture significantly impacted the effect expression of AgNP on the soil microbial community. Especially long-term exposure scenarios are strongly needed for the reliable environmental impact assessment of AgNP exposure in various soil types.
Because EU water quality policy can result in infrastructure creation or adaptation at the local level across member states, compliance cases are worth examining critically from a sustainable spatial planning perspective. In this study, the 2000 EU Water Framework Directive’s (WFD) reach to local implementation efforts in average towns and cities is shown through the case study of nonconforming household wastewater infrastructure in the German state of Rhineland Palatinate. Seeing wastewater as a socio-technical infrastructure, we ask how the WFD implementation can be understood in the context of local infrastructure development, sustainability, and spatial planning concepts. In particular, this study examines what compliance meant for the centralization or decentralization of local wastewater infrastructure systems—and the sustainability implications for cities
from those choices.
Understanding the mechanisms that shape access to the fisheries ecosystem service in Tsokomey, Accra
(2019)
Questions of access to ecosystem services remain largely unaddressed. Yet, in the coming decades, addressing access to services and securing them for livelihoods and well-being of people will likely gain importance, especially to guide according policies at the local scale. Through a qualitative approach, this paper addresses the mechanisms that shape access to the fisheries eco- system service in Accra, Ghana. The analysis uses a framework that focuses on access to land, tools and technology, knowledge and information, capital and credit, as well as labor. This research reveals how access is organized across the different categories of this framework and how people’s well-being is shaped. Moreover, it helps to further our understanding of what regulates the access to ecosystem services and how to address future shocks and capacity in terms of production of ecosystem services.
In the present study a non-motion-stabilized scanning Doppler lidar was operated on board of RV Polarstern in the Arctic (June 2014) and Antarctic (December 2015– January 2016). This is the first time that such a system measured on an icebreaker in the Antarctic. A method for a motion correction of the data in the post-processing is presented.
The wind calculation is based on vertical azimuth display (VAD) scans with eight directions that pass a quality control. Additionally a method for an empirical signal-tonoise ratio (SNR) threshold is presented, which can be calculated for individual measurement set-ups. Lidar wind profiles are compared to total of about 120 radiosonde profiles and also to wind measurements of the ship.
The performance of the lidar measurements in comparison with radio soundings generally shows small root mean square deviation (bias) for wind speed of around 1ms-1(0.1ms-1) and for wind direction of around 10 (1). The post-processing of the non-motion-stabilized data shows comparably high quality to studies with motion-stabilized systems.
Two case studies show that a flexible change in SNR threshold can be beneficial for special situations. Further the studies reveal that short-lived low-level jets in the atmospheric boundary layer can be captured by lidar measurements with a high temporal resolution in contrast to routine radio soundings. The present study shows that a non-motionstabilized Doppler lidar can be operated successfully on an
icebreaker. It presents a processing chain including quality control tests and error quantification, which is useful for further measurement campaigns.
Reptiles belong to a taxonomic group characterized by increasing worldwide population declines. However, it has not been until comparatively recent years that public interest in these taxa has increased, and conservation measures are starting to show results. While many factors contribute to these declines, environmental pollution, especially in form of pesticides, has seen a strong increase in the last few decades, and is nowadays considered a main driver for reptile diversity loss. In light of the above, and given that reptiles are extremely underrepresented in ecotoxicological studies regarding the effects of plant protection products, this thesis aims at studying the impacts of pesticide exposure in reptiles, by using the Common wall lizard (Podarcis muralis) as model species. In a first approach, I evaluated the risk of pesticide exposure for reptile species within the European Union, as a means to detect species with above average exposure probabilities and to detect especially sensitive reptile orders. While helpful to detect species at risk, a risk evaluation is only the first step towards addressing this problem. It is thus indispensable to identify effects of pesticide exposure in wildlife. For this, the use of enzymatic biomarkers has become a popular method to study sub-individual responses, and gain information regarding the mode of action of chemicals. However, current methodologies are very invasive. Thus, in a second step, I explored the use of buccal swabs as a minimally invasive method to detect changes in enzymatic biomarker activity in reptiles, as an indicator for pesticide uptake and effects at the sub-individual level. Finally, the last part of this thesis focuses on field data regarding pesticide exposure and its effects on reptile wildlife. Here, a method to determine pesticide residues in food items of the Common wall lizard was established, as a means to generate data for future dietary risk assessments. Subsequently, a field study was conducted with the aim to describe actual effects of pesticide exposure on reptile populations at different levels.
The changing views on the evolutionary relationships of extant Salamandridae (Amphibia: Urodela)
(2018)
The phylogenetic relationships among members of the family Salamandridae have been repeatedly investigated over the last 90 years, with changing character and taxon sampling. We review the changing composition and the phylogenetic position of salamandrid genera and species groups and add a new phylogeny based exclusively on sequences of nuclear genes. Salamandrina often changed its position depending on the characters used. It was included several times in a clade together with the primitive newts (Echinotriton, Pleurodeles, Tylototriton) due to their seemingly ancestral morphology. The latter were often inferred as a monophyletic clade. Respective monophyly was almost consistently established in all molecular studies for true salamanders (Chioglossa, Lyciasalamandra, Mertensiella, Salamandra), modern Asian newts (Cynops, Laotriton, Pachytriton, Paramesotriton) and modern New World newts (Notophthalmus, Taricha). Reciprocal non-monophyly has been established through molecular studies for the European mountain newts (Calotriton, Euproctus) and the modern European newts (Ichthyosaura, Lissotriton, Neurergus, Ommatotriton, Triturus) since Calotriton was identified as the sister lineage of Triturus. In pre-molecular studies, their respective monophyly had almost always been assumed, mainly because a complex courtship behaviour shared by their respective members. Our nuclear tree is nearly identical to a mito-genomic tree, with all but one node being highly supported. The major difference concerns the position of Calotriton, which is no longer nested within the modern European newts. This has implications for the evolution of courtship behaviour of European newts. Within modern European newts, Ichthyosaura and Lissotriton changed their position compared to the mito-genomic tree. Previous molecular trees based on seemingly large nuclear data sets, but analysed together with mitochondrial data, did not reveal monophyly of modern European newts since taxon sampling and nuclear gene coverage was too poor to obtain conclusive results. We therefore conclude that mitochondrial and nuclear data should be analysed on their own.
Species can show strong variation of local abundance across their ranges. Recent analyses suggested that variation in abundance can be related to environmental suitability, as the highest abundances are often observed in populations living in the most suitable areas. However, there is limited information on the mechanisms through which variation in environmental suitability determines abundance. We analysed populations of the microendemic salamander Hydromantes flavus, and tested several hypotheses on potential relationships linking environmental suitability to population parameters. For multiple populations across the whole species range, we assessed suitability using species distribution models, and measured density, activity level, food intake and body condition index. In high-suitability sites, the density of salamanders was up to 30-times higher than in the least suitable ones. Variation in activity levels and population performance can explain such variation of abundance. In high-suitability sites, salamanders were active close to the surface, and showed a low frequency of empty stomachs. Furthermore, when taking into account seasonal variation, body condition was better in the most suitable sites. Our results show that the strong relationship between environmental suitability and population abundance can be mediated by the variation of parameters strongly linked to individual performance and fitness.
The main socio-ecological pressures in five wetlands in the Greater Accra Region were first identified and then summarized by reviewing the relevant literature. As a second step, fieldwork in the region was carried out in 2016 to further examine the pressures identified in the literature. Most research on the wetlands in Ghana was published around the year 2000. Yet, similar socio-ecological pressures persist today. Based on both, fieldwork observations and the literature review, these pressures were ranked using the IUCN pressures system analysis framework. It is suggested that further research needs to proceed with uncovering how trade-offs between ecosystem and quality of life can be defined.
Der vorliegende Artikel beschreibt die klimatische Situation des Naturparks Saar-Hunsrück. Neben der Einordnung der Region in die großskalige klimatische Zirkulation werden die wesentlichen Klimaelemente beschrieben. Da sich die Klimaelemente mit zunehmender Höhe verändern, bestimmt im unteren Saartal, im Saar-Nahe-Bergland und Hunsrück mit Osburger Hochwald, Schwarzwälder Hochwald und Idarwald die Höhenlage entscheidend die räumliche Struktur der einzelnen Klimaelemente. Die Niederschlagsverteilung zeigt deutlich den Luveffekt in den westlichen Teilen des Naturparks und die Abnahme der Niederschlagshöhen in nordöstlicher Richtung. Die räumlichen Muster der mittleren und maximalen Lufttemperatur folgen der Topographie, während Minimalwerte der Temperatur ein weniger differenziertes Bild zeigen. In den tiefer gelegenen Regionen des Naturparks treten 4-7 Hitzetage in langjährigen Mittel auf, in den Hochlagen des Hunsrücks werden nur noch 1-3 Tage / Jahr beobachtet. Oberhalb der 600 m-Höhenlinie ergeben sich im Mittel 110-130 Frosttage im Jahr, im südwestlichen Teil des Naturparks geht die Zahl auf 50 Tage / Jahr zurück. Die mittlere Anzahl der Tage mit Schneedecke liegt, bezogen auf das Areal des Naturparks, insgesamt zwischen 10 und 90 Tagen pro Jahr. Ihre Veränderung infolge des regionalen Klimawandels zeigt eine Abnahme zwischen 3-15 Tagen pro Jahr zwischen den Zeiträumen 1961-1990 und 1981-2010. Die aktuelle Sonnenscheindauer beträgt im westlichen Teil des Naturparks im Mittel 1500-1600 Sonnenscheinstunden pro Jahr, im südöstlichen Teil werden bis 1600 Stunden pro Jahr erreicht.
As in many other cities of the Global South, in Accra and its Greater Metropolitan Area (GAMA) water provision for drinking, domestic and productive uses is coproduced by multiple provisioning and delivery modalities. This paper contributes to the overall understanding of sociospatial conditions of urban water (in)security in GAMA. By looking at the geography of infrastructure and inequalities in water access, it seeks to identify patterns of uneven access to water. The first part provides an overview of urban water supply in GAMA, focusing on water infrastructure and the perspective of water providers. In the second part, households’ access strategies are discussed by combining both quantitative and qualitative perspectives. The paper brings together literature research and empirical material collected during fieldwork in the Ghanaian capital city.
GIS – what can and what can’t it say about social relations in adaptation to urban flood risk?
(2017)
Urban flooding cannot be avoided entirely and in all areas, particularly in coastal cities. Therefore adaptation to the growing risk is necessary. Geographical Information Systems (GIS) based knowledge on risk informs location-based approach to adaptation to climate risk. It allows managing city- wide coordination of adaptation measures, reducing adverse impacts of local strategies on neighbouring areas to the minimum. Quantitative assessments dominate GIS applications in flood risk management, for instance to demonstrate the distribution of people and assets in a flood prone area. Qualitative, participatory approaches to GIS are on the rise but have not been applied in the context of flooding yet. The overarching research question of this working paper is: what can GIS, and what can it not say about relationships / social relations in adaptation to urban flood risk? The use of GIS in risk mapping has exposed environmental injustices. Applications of GIS further allow model- ling future flood risk in function of demographic and land use changes, and combining it with decision support systems (DSS). While such GIS applications provide invaluable information for urban planners steering adaptation they however fall short on revealing the social relations that shape individual and household adaptation decisions. The relevance of networked social relations in adaptation to flood risk has been demonstrated in case studies, and extensively in the literature on organizational learning and adaptation to change. The purpose of this literature review is to identify the type of social relations that shape adaptive capacities towards urban flood risk which can- not be identified in a conventional GIS application.