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How a society relates to nature is shaped by the Dominant Social Paradigm (DSP): a society's collective view on social, economic, political and environmental issues. The characteristics of the DSP have important consequences for natural systems and their conservation. Based on a synthesis of academic literature, this paper provides a new gradient of twelve types of human-nature relationships synthesized from scientific literature, and an analysis of where the DSP of industrialized, and more specifically, neoliberal societies fit on that gradient. We aim to answer how the industrialized DSP relates to nature, i.e. what types of human-nature relationships this DSP incorporates, and what the consequences of these relationships are for nature conservation and a sustainable future. The gradient of human-nature relationships is based on three defining characteristics 1) a nature-culture divide, 2) core values, and 3) being anthropocentric or ecocentric. We argue that the industrialized DSP includes elements of the anthropocentric relationships of mastery, utilization, detachment and stewardship. It therefore regards nature and culture as separate, is mainly driven by instrumental values, and drives detachment from and commodification of nature. Consequently, most 'green' initiatives and policies driven by an industrialized and neoliberal DSP are based on economic incentives and economic growth, without recognition of the needs and limits of natural systems. This leads to environmental degradation and social inequality, obstructing the path to a truly sustainable society. To reach a more ecocentric DSP, systemic changes, in addition to individual changes, in the political and economic structures of the industrialized DSP are needed, along with a change in values and approach towards nature, long term sustainability, and conservation.

Quantum dots (QDs) are colloidal fluorescent semiconductor nanocrystals with exceptional optical properties. Their widespread use, particularly in light-emitting diodes (LEDs), displays, and photovoltaics, is questioning their potential toxicity. The most widely used QDs are CdSe and CdTe QDs, but due to the toxicity of cadmium (Cd), their use in electrical and electronic equipment is now restricted in the European Union through the Restriction of hazardous substances in electrical and electronic equipment (RoHS) directive. This has prompted the development of safer alternatives to Cd-based QDs; among them, InP QDs are the most promising ones. We recently developed RoHS-compliant QDs with an alloyed core composed of InZnP coated with a Zn(Se,S) gradient shell, which was further coated with an additional ZnS shell to protect the QDs from oxidative surface degradation. In this study, the toxicity of single-shelled InZnP/Zn(Se,S) core/gradient shell and of double-shelled InZnP/Zn(Se,S)/ZnS core/shell/shell QDs was evaluated both in their pristine form and after aging in a climatic chamber, mimicking a realistic environmental weathering. We show that both pristine and aged QDs, whatever their composition, accumulate in the cytoplasm of human primary keratinocytes where they form agglomerates at the vicinity of the nucleus. Pristine QDs do not show overt toxicity to cells, while aged QDs show cytotoxicity and genotoxicity and significantly modulate the mRNA expression of proteins involved in zinc homeostasis, cell redox response, and inflammation. While the three aged QDs show similar toxicity, the toxicity of pristine gradient-shell QD is higher than that of pristine double-shell QD, confirming that adding a second shell is a promising safer-by-design strategy. Taken together, these results suggest that end-of-life degradation products from InP-based QDs are detrimental to skin cells in case of accidental exposure and that the mechanisms driving this effect are oxidative stress, inflammation, and disturbance of cell ...

International audience ; Quantum dots (QDs) are colloidal fluorescent semiconductor nanocrystals with exceptional optical properties. Their widespread use, particularly in light-emitting diodes (LEDs), displays, and photovoltaics, is questioning their potential toxicity. The most widely used QDs are CdSe and CdTe QDs, but due to the toxicity of cadmium (Cd), their use in electrical and electronic equipment is now restricted in the European Union through the Restriction of hazardous substances in electrical and electronic equipment (RoHS) directive. This has prompted the development of safer alternatives to Cd-based QDs; among them, InP QDs are the most promising ones. We recently developed RoHS-compliant QDs with an alloyed core composed of InZnP coated with a Zn(Se,S) gradient shell, which was further coated with an additional ZnS shell to protect the QDs from oxidative surface degradation. In this study, the toxicity of single-shelled InZnP/Zn(Se,S) core/gradient shell and of double-shelled InZnP/Zn(Se,S)/ZnS core/shell/shell QDs was evaluated both in their pristine form and after aging in a climatic chamber, mimicking a realistic environmental weathering. We show that both pristine and aged QDs, whatever their composition, accumulate in the cytoplasm of human primary keratinocytes where they form agglomerates at the vicinity of the nucleus. Pristine QDs do not show overt toxicity to cells, while aged QDs show cytotoxicity and genotoxicity and significantly modulate the mRNA expression of proteins involved in zinc homeostasis, cell redox response, and inflammation. While the three aged QDs show similar toxicity, the toxicity of pristine gradient-shell QD is higher than that of pristine double-shell QD, confirming that adding a second shell is a promising safer-by-design strategy. Taken together, these results suggest that end-of-life degradation products from InP-based QDs are detrimental to skin cells in case of accidental exposure and that the mechanisms driving this effect are oxidative stress, ...

International audience ; Quantum dots (QDs) are colloidal fluorescent semiconductor nanocrystals with exceptional optical properties. Their widespread use, particularly in light-emitting diodes (LEDs), displays, and photovoltaics, is questioning their potential toxicity. The most widely used QDs are CdSe and CdTe QDs, but due to the toxicity of cadmium (Cd), their use in electrical and electronic equipment is now restricted in the European Union through the Restriction of hazardous substances in electrical and electronic equipment (RoHS) directive. This has prompted the development of safer alternatives to Cd-based QDs; among them, InP QDs are the most promising ones. We recently developed RoHS-compliant QDs with an alloyed core composed of InZnP coated with a Zn(Se,S) gradient shell, which was further coated with an additional ZnS shell to protect the QDs from oxidative surface degradation. In this study, the toxicity of single-shelled InZnP/Zn(Se,S) core/gradient shell and of double-shelled InZnP/Zn(Se,S)/ZnS core/shell/shell QDs was evaluated both in their pristine form and after aging in a climatic chamber, mimicking a realistic environmental weathering. We show that both pristine and aged QDs, whatever their composition, accumulate in the cytoplasm of human primary keratinocytes where they form agglomerates at the vicinity of the nucleus. Pristine QDs do not show overt toxicity to cells, while aged QDs show cytotoxicity and genotoxicity and significantly modulate the mRNA expression of proteins involved in zinc homeostasis, cell redox response, and inflammation. While the three aged QDs show similar toxicity, the toxicity of pristine gradient-shell QD is higher than that of pristine double-shell QD, confirming that adding a second shell is a promising safer-by-design strategy. Taken together, these results suggest that end-of-life degradation products from InP-based QDs are detrimental to skin cells in case of accidental exposure and that the mechanisms driving this effect are oxidative stress, ...

International audience ; Quantum dots (QDs) are colloidal fluorescent semiconductor nanocrystals with exceptional optical properties. Their widespread use, particularly in light-emitting diodes (LEDs), displays, and photovoltaics, is questioning their potential toxicity. The most widely used QDs are CdSe and CdTe QDs, but due to the toxicity of cadmium (Cd), their use in electrical and electronic equipment is now restricted in the European Union through the Restriction of hazardous substances in electrical and electronic equipment (RoHS) directive. This has prompted the development of safer alternatives to Cd-based QDs; among them, InP QDs are the most promising ones. We recently developed RoHS-compliant QDs with an alloyed core composed of InZnP coated with a Zn(Se,S) gradient shell, which was further coated with an additional ZnS shell to protect the QDs from oxidative surface degradation. In this study, the toxicity of single-shelled InZnP/Zn(Se,S) core/gradient shell and of double-shelled InZnP/Zn(Se,S)/ZnS core/shell/shell QDs was evaluated both in their pristine form and after aging in a climatic chamber, mimicking a realistic environmental weathering. We show that both pristine and aged QDs, whatever their composition, accumulate in the cytoplasm of human primary keratinocytes where they form agglomerates at the vicinity of the nucleus. Pristine QDs do not show overt toxicity to cells, while aged QDs show cytotoxicity and genotoxicity and significantly modulate the mRNA expression of proteins involved in zinc homeostasis, cell redox response, and inflammation. While the three aged QDs show similar toxicity, the toxicity of pristine gradient-shell QD is higher than that of pristine double-shell QD, confirming that adding a second shell is a promising safer-by-design strategy. Taken together, these results suggest that end-of-life degradation products from InP-based QDs are detrimental to skin cells in case of accidental exposure and that the mechanisms driving this effect are oxidative stress, ...

Die naturräumliche Lage Guatemalas hat dazu geführt, dass sich hier im Hinblick auf die Artenvielfalt ein hotspot mit besonders hoher Schutzpriorität entwickelt hat. Aufgrund der hohen Abholzungsrate in Guatemala sind vor allem die guatemaltekischen Bergnebelwälder in den vergangenen Jahrzehnten sehr stark unter Druck anthropogener Einflüsse geraten. Die jährliche Abholzungsrate von 1,7% auf nationaler Ebene verdeutlicht die Gefährdung.Zudem sind mit der traditionellen Landnutzung der Maya-Q'eqchi-Bevölkerung in den Bergnebelwaldgebieten Guatemalas prägnante pedoökologische Veränderungen verbunden, die Auswirkungen auf verschiedene Bodenfunktionen nach sich ziehen. Im Hinblick auf eine nachhaltige Bodennutzung und die Erhaltung der Biodiversität ist der Schutz von Bodenfunktionen dringend erforderlich. In diesem Kontext liefert die Implementierung der Ressource Boden in die Biodiversitätsstrategie Guatemalas eine gute Möglichkeit, durch die gesetzliche Verankerung eine langfristige Verbesserung zu gewährleisten. Im Rahmen dieser Arbeit sind zum einen die Prozesse der Waldkonversion, Zunahme der Fragmentierung sowie die Quantifizierung der Landschaftsveränderung dokumentiert worden. Zum anderen ist das Landnutzungspotential in den unterschiedlichen Landnutzungssystemen anhand der Bodenfruchtbarkeit bestimmt worden. Die Erkenntnisse dieser Untersuchung zur Waldkonversion und Bodendegradation in den Bergnebelwäldern Guatemalas geben Aufschluss über die realen und potenziellen Folgeerscheinungen auf die Biodiversität. Der Umfang und die Komplexität dieser Arbeit tragen zur Vervollkommnung der Kenntnisse über das Ökosystem der Bergnebelwälder bei und erlauben Rückschlüsse auf ähnliche Naturräume Zentralamerikas. Folgende Fragestellungen und Zielsetzungen lagen dem Forschungsprojekt zugrunde:Eingebunden in die umfangreichen Untersuchungen zur Wertschätzung und Erhaltung von Biodiversität sind u.a. über die Auswertung einer falschen Zeitreihe die Auswirkungen des traditionellen Anbaus auf die Bodenfunktionen untersucht worden. Die Veränderungen der bodenchemischen, -physikalischen sowie -biologischen Parameter werden aufgrund folgender Analysen determiniert: Ct, Corg, Nt, pH (H2O, KCl und CaCl2), Elektrische Leitfähigkeit, Pt und Pverf., effektive Austauschkapazität (KAKeff.: Na, K, Mg, Ca, Mn, Fe, Al, H+), Totalgehalte (Na, K, Ca, Al, Cu, Mg, Mn, Zn und Fe), Korngrößenverteilung, Lagerungsdichte, Wassergehalt, Zelluloseabbau im Boden. Die Ermittlung der Waldflächenverteilung erfolgt durch Auswertung zweier Landsat-TM und -ETM-Szenen vom 14.04.1986 und 23.01.2000 mit Hilfe der Software ENVI 3.2 mittels geeigneter Klassifizierungsfunktionen. Der Einfluss von NGO's und staatlichen Schutzprojekten in den letzten Jahren führte im Untersuchungsgebiet partiell zu einer verbesserten Bodennutzung und damit Verringerung des Rodungsdruckes auf die Nebelwaldrestbestände. Im Zeitraum von 1986 bis 2000 ist eine geringe Zunahme der Waldfläche zu verzeichnen. Kritisch gesehen ist diese Änderung jedoch z.T. mit unumgänglichen methodischen Fehlerquellen zu erklären. Die Zahlen verdeutlichen allerdings grundsätzlich, dass die aktuelle Abholzung in der Region nur minimal ist. In den Randzonen der Waldflächen ist zwar ein geringes Fortschreiten der Waldrodung zu identifizieren, die Abholzungsraten liegen jedoch weit unterhalb des nationalen Durchschnitts von Guatemala in Höhe von 1,7%. Das Bodenpotenzial in den untersuchten Bergnebelwaldregionen ist als sehr hoch einzustufen. Die Bodenfunktionen sind durch die intensive traditionelle Landnutzung der Q'eqchi-Bevölkerung dennoch stark beeinträchtigt. Vor allem der Verlust von organischer Substanz und damit von N und P stellt ein gravierendes Problem dar. Es zeichnet sich ein deutlicher Gradient hinsichtlich der bodenchemischen Fruchtbarkeit in den unterschiedlichen Habitaten ab: Primärwald > Sekundärwald > milpa-System (15 Jahre > 25 Jahre > 60 Jahre). Auch anhand der effektiven Kationenaustauschkapazität (KAKeff.) sind starke Veränderung der bodenchemischen Parameter aufgrund des traditionellen Maisanbaus erkennbar. Die höchsten Werte sind unter Primärwald sowie Sekundärbusch (Guamil) gegeben, eine deutliche Verringerung zeigt sich hingegen auf den traditionellen Maisflächen (milpa-System). Bracheflächen nach lang anhaltender Bewirtschaftung weisen zunächst keine signifikante Verbesserung der Kationenaustauschkapazitäten auf. Mit ausschlaggebend für die Veränderung der Bodenparameter ist die erhöhte Erosionsanfälligkeit auf den landwirtschaftlichen Nutzflächen.Die Auswirkungen des anthropogenen Eingriffes in die Ökosysteme werden anhand der gesteigerten biologischen Aktivität auf den gestörten Flächen erkennbar. Aufgrund des feuchteren Milieus und der geringeren (Boden-)Temperaturen im Primärwald, bedingt durch ein geschlossenes Kronendach, sind hier geringere mikrobielle Aktivitäten nachweisbar. Mit der Zunahme der biologischen Aktivität auf genutzten Flächen geht eine Verringerung des Kohlenstoffgehalts einher, die wiederum zu einer fortschreitenden Verringerung der Nährstoffbindung und damit Verarmung des Bodens mit seinen pedoökologischen Funktionen führt.Die Studie zeigt, welche Folgen die Abholzung auf den Boden und das Mikroklima hat. Die Bodendegradation führt zur potenziellen Abnahme der Artenvielfalt. Die niedrigen Flächenerträge aufgrund zunehmender Bodendegradation erhöhen den Flächenbedarf. Dieser erhöhte Flächenbedarf führt zur Ausweitung landwirtschaftlich genutzter Flächen und zur Verringerung der Waldressourcen. Eine sachgemäße Bewirtschaftung der landwirtschaftlichen Flächen stellt daher einen bedeutenden Beitrag zur Erhaltung und Bewahrung der Biodiversität dar. Die Bodendegradation als wohl gravierendstes globales Umweltproblem ist bereits in der AGENDA 21 integriert, genauso wie auch im Aktionsprogramm 2015 der Bundesregierung als Beitrag zur weltweiten Halbierung extremer Armut. Eine Implementierung in die nationale Biodiversitätsstrategie der einzelnen betroffenen Länder, wie in diesem Falle Guatemala (ENB 1999b), würde zudem auf regionaler sowie lokaler Ebene Handlungsrichtlinien geben, um somit der Bodendegradation und gleichzeitig der damit einhergehenden Verringerung der Biodiversität entgegenzuwirken. Diesbezüglich wurden in diesem Teilprojekt Handlungsempfehlungen für den Ressourcenschutz erarbeitet. ; Due to their number of ecological functions and endemic flora and fauna, the tropical montane cloud forests of Guatemala need to be protected. They were classified by the World Bank as vulnerable and biogeographically unique. Therefore they obtained a high conservation priority. To guarantee the sustainable development of the tropical montane cloud forests in Guatemala it is necessary to identify sustainable land use systems. The integration of the protection of natural resources and sustainable land use in the surrounding is a passable way to protect the forests and to assure the alimentation of the population.A complete land use potential and landscape structure evaluation is carried out, under special consideration of the resource "forest" and "soil", in order to recommend protected areas in the montane cloud forests in the Department Alta Verapaz. Processes regarding the forest conversion will be researched as well as studies with respect to the soil resources potential. The main objectives are the quantification of the changes in landscape structure and the satellite supported analysis of the land use dynamics, as well as the determination of the usage potential within the context of the degradation processes, soil evaluation and soil hazards. This allows to take into account the following goals: ability to prioritise for the selection of protected areas; formulation of consequences in order to avoid future soil degradation; spatial evaluation of the landscape ecology in the tropics under consideration of protected area selection; evaluation of the influence of colonisation, deforestation and land use as well as the analysis and valuation of conservation strategies such as segregation and integration. The inclusion of the partially investigated soil quality and soil differentiation within the nutrient turnover in the tropical mountainous cloud forests can be used as a basis for the selection of biological protected areas as well as for recommendations for forestry cultivation.Forest distribution and spatiotemporal changes are determinated by studying and evaluating satellite images (LANDSAT-TM 5 and -ETM 7) dated 14.04.1986 and 23.01.2000, as well as aerial views from 23.01.1964, 14.02.1991 and 20.01.2000. The changes of the chemical, physical and biological soil parameters through deforestation and intensive land use will be determinated on the basis of the following analyses: Ct, Corg, Nt, pH (H2O, KCl und CaCl2), conductivity, P, effective cation exchange capacity (CECeff.: Na, K, Mg, Ca, Mn, Fe, Al, H), total nutrient contents (Na, K, Ca, Al, Cu, Mg, Mn, Zn, Fe, Cr, Co, Ni, P, S, Mo, Cd, Tl, Pb), grain size distribution, bulk density, water content etc.The microclimate is an important factor for the description of changes in land use in Alta Verapaz. Consequently we have installed three climate stations to collect primary data to determine the differences between habitats in terms of the habitat climate (primary forest, secondary forest, milpa- system [corn-bean-cultivation]). The study area is located in the Sierra Yalijux in Alta Verapaz, Guatemala (15°22,432'N / 90°04,266'W).Both the convention on biological diversity and the AGENDA 21 claim the determination and monitoring of ecosystems and habitats. The Agenda 21 demands furthermore the implementation of a monitoring system for the continuously control of the soil degradation with the objective to improve the living conditions in the adjacent areas. At the investigation site in Guatemala a lot of changes took place concerning forest conversion, soil quality and microclimate. The soil quality declines through increasing of land use intensity respectively length of time of land use. The soil degradation as a result of agricultural use is high. The contents of carbon and nitrogen for example reduce strongly: primary forest > milpa 15 years > milpa 25 years > milpa 60 years > secondary scrub > fallow land. A marked increase of soil temperature is identified after logging with effects on the composition of soil organisms. The high relief leads to extreme strong slopes, where in spite of natural and anthropogenic hazards no one gives up the land use.The forest area changed in a conspicuous and dramatic way between 1950 and 2000 in Guatemala. The loss of primary forest due deforestation is obvious when taking the forest cover change into account: in 1950 65 % of the total land area of Guatemala was forested and decreased in 2000 to 26 %. This requires proactive decisions in order to stop a further decline of forested land. The resource 'soil' is of major importance especially regarding the discussions about biodiversity. However, world-wide this has not been paid sufficient attention. Forest conversion and soil degradation have significant effects on the biodiversity of flora and fauna. Forest conversion is leading to loss, changing and fragmentation of habitats. Soil degradation will lead to changes of the soil functions, reduction of biological diversity and lower yields and consequently to an expanded demand of agricultural areas (=forest conversion). Taking these effects into account it is necessary to implement the resource 'soil' into the national biodiversity strategy of Guatemala.

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) ; Empresa Brasileira de Pesquisa Agropecuaria - Embrapa ; UK Government Darwin Initiative ; Nature Conservancy ; UK Natural Environment Research Council (NERC) ; H2020-MSCA-RISE-2015 ; CNPq: 574008/2008-0 ; Empresa Brasileira de Pesquisa Agropecuaria - Embrapa: SEG: 02.08.06.005.00 ; UK Government Darwin Initiative: 17-023 ; UK Natural Environment Research Council (NERC): NE/ F01614X/1 ; UK Natural Environment Research Council (NERC): NE/G000816/1 ; UK Natural Environment Research Council (NERC): NE/K016431/1 ; UK Natural Environment Research Council (NERC): NE/P004512/1 ; H2020-MSCA-RISE-2015: 691053-ODYSSEA ; CNPq: PELD-RAS 441659/2016-0 ; CNPq: 458022/2013-6 ; CNPq: 305054/ 2016-3 ; Wildfires produce substantial CO2 emissions in the humid tropics during El Nino-mediated extreme droughts, and these emissions are expected to increase in coming decades. Immediate carbon emissions from uncontrolled wildfires in human-modified tropical forests can be considerable owing to high necromass fuel loads. Yet, data on necromass combustion duringwildfires are severely lacking. Here, we evaluated necromass carbon stocks before and after the 2015-2016 El Nino in Amazonian forests distributed along a gradient of prior human disturbance. We then used Landsat-derived burn scars to extrapolate regional immediate wildfire CO2 emissions during the 20152016 El Nino. Before the El Nino, necromass stocks varied significantly with respect to prior disturbance and were largest in undisturbed primary forests (30.2 +/- 2.1 Mg ha(-1), mean +/- s. e.) and smallest in secondary forests (15.6 +/- 3.0 Mg ha(-1)). However, neither prior disturbance nor our proxy of fire intensity (median char height) explained necromass losses due towildfires. In our 6.5 million hectare (6.5 Mha) study region, almost 1 Mha of primary (disturbed and undisturbed) and 20 000 ha of secondary forest burned during the 2015-2016 ElNino. Covering less than 0.2% of Brazilian Amazonia, thesewildfires resulted in expected immediate CO2 emissions of approximately 30 Tg, three to four times greater than comparable estimates fromglobal fire emissions databases. Uncontrolled understoreywildfires in humid tropical forests during extreme droughts are a large and poorly quantified source of CO2 emissions. This article is part of a discussion meeting issue 'The impact of the 2015/2016 El Nino on the terrestrial tropical carbon cycle: patterns, mechanisms and implications'.

Environmental degradation related to uncontrolled development resulted in the passage of the United States Clean Water Act (CWA) in 1972, with the stated purpose "to restore and maintain the integrity of the nation's waters". Implementation of the CWA leads to increased research to develop multimetric indicators to better measure and understand the complex patterns of ecological responses to stress occurring across levels of biological, spatial, and temporal organization. One area of research is the use of integrated indices of chemical risk, ecotoxicological risk, and ecological risk to assess the impact of human activity across disturbance gradients of urbanization. Selecting relevant metrics for constructing a multimetric index requires identifying bioindicator organisms with capacities to detect signals from anthropogenic disturbances. This study explored the potential efficacy of a suite of higher plant ecotoxicological assays for use as bioindicators in ecological risk assessment along a gradient of urbanization in a wetland ecosystem. The study was conducted in the Pike River watershed (Racine, Wisconsin, USA) in six wetlands selected across a gradient of dominant land-use types (agricultural, commercial, residential, undeveloped, and industrial). MicroBioTest PhytotoxkitTM ecotoxicological assays, based on growth inhibition of three plants (Sinapis, Sorghum, and Lepidium) were used to assess sediment toxicity. The relationships between Phytotoxkit™ responses and predicted pollutant loadings calculated from surrounding land use provided clear signals of stress from watershed pollutants draining into the wetland sites. The potential for these ecotoxicological indicators to serve as biological response signatures is strong, and further research and calibration in field and microcosms studies will assist in calibrating responses for use in integrated monitoring efforts.

Soil-erosion-induced land degradation is a great challenge in the Ethiopian highlands. Consequently, the government has invested in soil and water conservation (SWC) measures, mainly farmland terracing and exclosure of degraded lands. This study analyzed the effectiveness of those measures to tackle land degradation in the North and South Wello zones of the Amhara region (Ethiopia). The study analyzed land use/cover (LULC) and inter-annual normalized difference vegetation index (NDVI) changes based on moderate resolution imaging spectrometer (MODIS) image and NDVI data composited at 8-day and 2-monthly intervals, respectively. The analysis was based on data from 2000 to 2010 covering 300,000 km². The LULC showed remarkable changes, where large decrease in degraded woody vegetation and increases in grassland/woody grassland. Similarly, NDVI showed considerable changes over time where the area covered by NDVI values >0.4 and 0.3 to 0.4 increased by 12.5%, and 2.3%, respectively, which indicate vegetation restoration. Areas along highways, showed a positive NDVI trend, which indicates restoration, while the other parts were identified as degradation hotspots, which could be due to differences in SWC policy implementation. The study also assessed farmland terrace soil fertility and crop yield as well as soil fertility change in exclosures at micro-watershed scale. Soil fertility change in exclosure was analyzed using soil samples from three age categories (open sites, 10- and 27-year-old exclosures), two agro-ecological zones ( Weyna- Dega /mild and Dega /cool) and three terrain positions (lower, middle and upper). The samples were analyzed for selected physico-chemical properties, and statistically tested with analysis of variance (ANOVA). The results reveal that the exclosure soils showed significantly higher organic carbon (9 g/kg) and total nitrogen (1.2 g/kg) content than those on open sites. However, differences between the 10- and 27-year-old exclosures were non-significant, indicating a decline in fertility restoration rate with age. Exclosures in the Weyna-Dega zone showed significantly better soil fertility restoration than those in the Dega zone. This might be due to the effect of micro-climate on biomass production, vegetation types and organic matter mineralization. The soil physico-chemical properties neither had significant differences nor followed a regular trend across the terrain of the exclosure, which could be due to mechanical SWC measures. Therefore, exclosure planning should consider soil fertility restoration variation with age, agro-ecology and management. The farmland terrace soil fertility analysis used composite topsoil (0-20 cm) samples collected from plots representing 4 terrain slope ranges (3-5%, 5-8%, 8-15% and 15-30%) at 3 positions within a terrace and compared with 1983 survey data. The samples were analyzed for selected soil physico-chemical properties and statistically tested using ANOVA. Yield data (grain and biomass) of selected crops monitored between 1995 and 2009 from 40 fixed plots on three terrace positions (low-, mid- and up) were statistically tested by a mixed linear model in SAS. The analysis revealed that farmland terracing helped to maintain soil fertility and crop yield. Crop yields and most soil properties except pH, exchangeable bases and clay content did not show significant differences across the terrain. Unlike in other studies, all topsoil properties except bulk density showed insignificant differences within a terrace, while yields of most crops significantly decreased from low- towards up- terrace position. Gradual bench terrace formation might reduce topsoil fertility gradients within a terrace, but this does not avoid soil depth and crop yield gradients. Soil fertility and crop yield also showed only slight changes (stable yield) across terrace age which indicates that terracing reduced soil and nutrient loss due to water erosion. However, terracing alone does not improve soil fertility and thereby crop productivity. Thus, terracing should be supplemented by soil fertility amendments by considering sitespecific conditions. Although SWC measures have limitations, generally they played a significant role in maintaining and/or restoring soil fertility, maintaining agricultural production, restoring vegetation cover, and mitigating anthropogenic land degradation. ; Die Wirksamkeit von Boden-und Wasserschutzmaßnahmen bei der Rekultivierung von degradiertem Land am Beispiel des äthiopischen Wello-Hochlands Erosionsbedingte Bodendegradation im äthiopischen Hochland stellt eine große Herausforderung an das Landmangement dar. Daher hat die Regierung in Boden- und Wasserschutzmaßnahmen (SWC) investiert, insbesondere in Terrassierung landwirtschaftlicher Flächen und Nutzungsausschluss (Exclosures) von degradiertem Land. Jedoch gibt es keine Studien, die die Auswirkungen dieser Maßnahmen umfassend bewerten. Die vorliegende Studie konzentrierte sich daher auf die Untersuchung der Effektivität der oben genannten Maßnahmen bei der Bekämpfung der Bodendegradation in den North und South Wello Zonen der Amhara Region (Äthiopien). Analysiert wurden Veränderungen der Landnutzung/Landbedeckung (LULC) und inter-annuell Veränderungen des normalisierten differenzierten Vegetationsindex (NDVI) anhand von mittelaufgelösten MODIS-Daten sowie NDVI-Daten, in 8 Tages- und 2 Monatsintervallen zusammengefasst. Die Daten decken den Zeitraum 2000 bis 2010 und eine Fläche von ca. 30.000 km² ab. Die LULC- Werte zeigten große Abnahme der Bedeckung in der Landbedeckung, vor allem in degradierter Gehölz-/Strauchvegetation und Zunahme in Grasland/Strauchvegetation. Auch die NDVI-Werte deuten auf eine zeitliche Vegetationsveränderung hin; Flächen mit einem NDVI >0.4 und 0.3-0.4 nahmen um 12.5% bzw 2.3% zu. Flächen entlang der Straßen zeigten einen positiven NDVI Trend, was auf eine Wiederherstellung der Vegetation hindeutet, während andere Bereiche degradierten. Dies könnte die Folge unterschiedlicher Umsetzung der SWC Maßnahmen sein. Desweitern wurden Bodenfruchtbarkeit und Fruchterträge auf terassierten Flächen sowie Bodenfruchtbarkeitsveränderung in den von Landnutzung ausgeschlossenen Gebieten untersucht. In den Exclosures wurden Bodenproben aus drei Alterskategorien (offene Flächen, 10 and 27 Jahre alte Exclosures), aus zwei agro-ökologischen Zonen ( Weyna-Dega /mild, Dega /kühl) sowie aus drei Hangpositionen (untere, mittlere, obere) physikalisch und chemisch untersucht und anhand von Varianzanalysen (ANOVA) statistisch analysiert. Die Ergebnisse zeigten einen signifikant höheren Anteil an organischem Kohlenstoff (9 g/kg) und Gesamtstickstoff (1.2 g/kg) in den Böden der Exclosures als auf offenen Flächen. Die Unterschiede zwischen den 10 bzw. 27 Jahre alten Exclosures waren jedoch nicht signifikant; dies zeigt, dass die Bodenfruchtbarkeit sich mit dem Alter der Exclosures stabilisierte. Die Böden der Exclosures in der Weyna-Dega -Zone zeigten eine signifikant bessere Regeneration als die in der Dega -Zone, möglicherweise die Wirkung von Mikroklima auf Biomasseproduktion, Vegetationstyp und Mineralisierung des organischen Materials. Es konnten weder signifikante Unterschiede noch bestimmte Trends in Bodeneigenschaften über die Fläche der Exclosures festgestellt werden, vermutlich eine Folge der mechanischen SWC-Maßnahmen. Bei der Planung von Exclosures sollte daher die Variation in der Bodenfruchtbarkeitswiederherstellung über Alter, Agroökologie sowie Management berücksichtigt werden. Für die Bodenfruchtbarkeitsanalyse der Terrassen wurden Mischproben (0-20 cm) von Flächen mit vier verschiedenen Hangneigungen (3-5%, 5-8%, 8-15% und 15-30%) von drei Positionen innerhalb einer Terrasse mit Daten aus dem Jahr 1983 verglichen. Der Boden wurde auf ausgewählte bodenphysikalisch-chemische Eigenschaften analysiert und statistisch mit ANOVA überprüft. Ertragsdaten (Körner und Biomasse) aus dem Zeitraum von 1995 bis 2009 von 40 permanenten Versuchsflächen lokalisiert auf den drei o.g. Hangpositionen wurden mit einem gemischten linearen Regressionsmodell in SAS getestet. Die Ergebnisse zeigten, dass Terassierung zu einer Stabilisierung der Bodenfruchtbarkeit und Erträge führt. Weder die Erträge noch die Bodeneigenschaften, ausser Boden-pH, austauschbare Basen und Lehmgehalt, zeigten signifikante Unterschiede. Im Gegensatz zu anderen Studien zeigten die Bodeneigenschaften, außer Bodendichte, keine signifikanten Unterschiede innerhalb einer Terrasse, während die Erträge der meisten Kulturen von den unteren Terassenstufen zu den oberen signifikant abnahmen. Die allmähliche Bildung von Stufenterrassen könnte demzufolge die Fruchtbarkeitsgradienten des Oberbodens innerhalb einer Terrasse reduzieren, sie vermeidet jedoch nicht Gradienten in der Bodentiefe und in Fruchterträgen. Bodenfruchtbarkeit und Erträge zeigten sehr geringe Unterschiede. Dies deutet daraufhin, dass Terrasierung zu einer Abnahme der Bodenerosion sowie Nährstoffverlagerung über die Fläche führt. Trotzdem reicht Terrassierung als alleinige Maßnahme nicht zur Verbesserung von Bodenfruchtbarkeit und damit von Erträgen aus. Zusätzlich sollten standortspezifische Bodenverbesserungsmaßnahmen durchgeführt werden. Trotz der aufgezeigten Einschränkungen spielen SWC-Maßnahmen eine signifikante Rolle bei der Erhaltung und/oder Wiederherstellung der Bodenfruchtbarkeit, Verbesserung der landwirtschaftlichen Produktivität, Wiederherstellung der Vegetationsbedeckung sowie Verminderung der anthropogenen Landdegradation.

The northern Tibetan Plateau is the most traditional and important semi- nomadic region in Tibet. The alpine vegetation is sensitive and vulnerable to climate change and human activities, and is also important as an ecological security in protecting the headwaters of major rivers in Asia. Therefore, the Tibetan alpine grasslands have fundamental significance to both Mainland China and South Asia. The pasture degradation, however, likely threatens the livelihood of residents and the habitats of wildlife on this plateau. Since 2004, the government has launched a series of ecological restoration projects and economic compensatory payment polices. Many fences were additionally built on degraded pastures to prevent new degradation, to promote functionality recovery, and to balance the stocking rate with forage productivity. The grazed vs. fenced paired pastures across different zonal grassland communities along evident environmental gradients provide us with a natural comparative experiment platform to test the relative contributions of natural and anthropogenic factors. This study critically reviews the background, significance of and debates on short-term grazing exclusion with fences in this region. We also aim to figure out scientific and standardized workflows for assessing the effectiveness of grazing exclusion and compensatory payments in the future. View Full-Text

Our society is undergoing a progressive change about the life style and habits. The world population is continuously increasing with 7.6 billion of human beings in 2018, resulting in an increasingly demand of resources in terms of food, water and energy. The exploitation of the planet resources since the first Industrial Revolution, results today in an unsustainable condition, which requires fundamental changes. In particular, in the energy sector the adoption of fossil fuels as the main energy source for human beings' activities resulted in a strong impact on our planet, leading to climate changes and environmental pollution. Nowadays these aspects have induced society to a substantial challenge to find new sustainable energy sources for the future of human civilization. Low-grade thermal energy, derived from industrial or geothermal sources, represents an interesting resource for energy production. Indeed, huge amounts of low-grade thermal energy are available. Considering the industrial sector an amount ranging between 20-50% of the energetic input of industrial plants, are lost every day, in the form of hot gasses and liquid streams. However, the recovery and re-use of low-grade thermal energy or waste heat is limited due to the lack of efficient technologies for converting low-temperature heat sources into electrical power. Recently, Salinity Gradient Power Heat Engines (SGP-HEs) have been proposed as a viable process for the recovery of low-grade heat. In particular, this PhD thesis focuses on the analysis of Reverse Electrodialysis Heat Engines (RED-HEs), contributing to the activities of the European project "RED-Heat-to-Power" funded by the European Union's Horizon 2020 Research and Innovation Programme (www.red-heat-to-power.eu). The aim of the project is to study and develop the first prototypes for the conversion of low-grade heat into electricity through a reverse electrodialysis (RED) unit. A reverse electrodialysis heat engine consists of two main units: (i) a power generation unit based on the reverse electrodialysis process, where the salinity gradient between two salt solutions is exploited to produce electricity, and (ii) a regeneration unit where low-grade heat is used to restore the salinity gradient of the reverse electrodialysis solutions exiting from the power generation unit. The restoring of the two solutions can be achieved by means of different strategies, e.g. solvent extraction and salt extraction, as summarized in the following. (a) In solvent extraction, the salt exchanged within the reverse electrodialysis unit is integrated by adding a part of the exhausted dilute stream to the exhausted concentrate stream, then, the resulting solution is fed to the regenerative unit where solvent is recovered by a thermal separation process (e.g. multi-effect distillation, membrane distillation) and transferred to the dilute solution. (b) In salt extraction, the exhausted dilute solution is fed to the regenerative unit where the salt is recovered by using low-grade heat as an energy source and transferred again to the concentrate solution. Rebalancing of the solvent is eventually carried-out to restore the solvent amount in the two streams. The main objective of this thesis is to provide a proof of the ground-breaking concept of a reverse electrodialysis heat engine, demonstrating the technological readiness level of such technology at a lab-scale prototype level. To this aim, both configuration, solvent and salt extraction reverse electrodialysis heat engines were investigated. The first part of this PhD thesis was dedicated to the development of a mathematical model for the RED process, based on a multi-scale modelling approach, considering two different scales of description: (i) a lower-scale model, describing the main phenomena involved in a single repeating unit (cell pair) and (ii) a higher-scale model related to the whole system, including all cell pairs and the relevant interconnections. The mathematical model was validated against experimental results and integrated with exergy analysis tools useful to evaluate the main causes and location of irreversibility sources. Ad hoc experimental campaigns were carried out in order to characterize the behaviour of different salt-water solutions, membrane properties and the operability of lab-scale units. In particular, a purposely-developed test rig was built in order to evaluate the osmotic and activity coefficients of salt-solutions from vapour pressure measurements, then used to determine novel data for caesium and potassium acetate salt solutions. This activity was performed at the University of Edinburgh, during a period abroad of six months. Furthermore, several experimental results on lab-scale reverse electrodialysis unit were carried out in order to provide membrane properties and experimental results for the mathematical model validation. In the case of solvent extraction strategies, validated mathematical models were developed for a reverse electrodialysis heat engine implementing either membrane distillation or multi-effect distillation as regeneration unit. These activities were performed in collaboration with the "Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT)" of Almeria. Finally, an exergy analysis at component level was performed for the integrated RED-MED HE, analysing the impact of the main operating conditions and membranes properties on the exergy efficiency of the system and identifing the main irreversibility sources. In the case of salt extraction strategies, thermolytic salts were selected and studied as working solutions of the RED-HE. Solutions of thermolytic salts have the peculiarity that their ions dissolved in water undergo a degradation process into gaseous species when the temperature is increased over a certain limit. Then, the dissolved thermolytic salt can be removed nearly completely from the solution by means of a thermal desorption process. The stripped gaseous species can be dissolved again in the aqueous solutions through an absorption step, resulting in an aqueous solution consisting of the very same ions of the thermolytic salt. Experimental test-rigs were designed, built and tested to investigate the stripping process of thermolytic salts. Mathematical models were developed in ASPEN Plus® and validated by comparison with experimental results. The model was also used to perform a sensitivity analysis and investigate the performance of the whole regeneration unit, including also the absorption process. Then, a mathematical model of a RED-HE fed by thermolytic salts was developed by coupling the ASPEN Plus® process model for the regeneration unit to the RED process model and used to perform sensitivity analyses. Finally, all the knowledge gained by theoretical and experimental works have made possible the design, construction and operation of the first world prototype of the thermolytic RED HE, demonstrating for the first time the feasibility of the process. The present thesis has been organised in order to cover the main aspects of the RED process and describe the aforementioned objectives. Chapter 1 introduces the concept of salinity gradient power (SGP) and related SGP-HEs, describing the SGP-HE concept and analysing the state of the art of the technology. Section I - Reverse Electrodialysis process Chapter 2 presents an overview of the reverse electrodialysis process, describing the technological fundamentals, experimental tests and modelling. Chapter 3 reports an original exergy analysis of the RED unit and the potential applications of the process in real environments. Chapter 4 presents the analysis on the influence of salt-solution properties on the RED-HE performance, reporting novel osmotic and activity coefficients for potassium acetate and caesium acetate water solutions. Section II - Solvent Extraction: RED with evaporative regeneration unit Chapter 5 and Chapter 6 are dedicated to the solvent extraction reverse electrodialysis heat engine. In particular, Chapter 5 reports the simplified mathematical models used to evaluate preliminary performances of (i) theoretical SGP unit fed by different salt solutions, (ii) RED-MED HE and (iii) RED-MD HE fed by NaCl solutions. Chapter 6 describes the advanced RED-MED-HE model developed to perform exergy analysis on the integrated system. Section III - Salt Extraction: Thermolytic salts Chapter 7 and Chapter 8 reports the analysis on thermolytic salts. In particular, Chapter 7 is focused on the regeneration unit of thermolytic salts presenting mathematical models and experimental assessments. Chapter 8 presents the first operating thermolytic RED heat engine (t-RED HE) and a perspective analysis based a validated process model for the t-RED HE.

Human activities seriously threaten biodiversity. In terms of global changes, overexploitation of populations and habitat destruction/degradation are at the top of the list of factors responsible for biodiversity loss. Climate change is increasing in magnitude and adding additional pressure on species. In response to the increase in global temperatures, communities are changing as a result of the shift in the geographical distribution of species towards the poles. But the accumulation of anthropogenic pressures is likely to produce interaction effects that limit community adjustment to global warming. In this critical context, conservation biology aims to reconcile human activities with biodiversity conservation. In this thesis I have investigate how the accumulation of anthropogenic pressures can limit the adjustment of communities to global warming and to identify solutions that could be put in place to facilitate their adaptation to this warming. I have used the wintering waterbird species in the countries of the Mediterranean basin as a model for my study. These iconic species benefit from an international census to monitor their populations in response to hunting and the degradation of the wetlands on which they depend. The Mediterranean is a highly anthropized region where the use of natural resources exerts significant pressures on wetlands and their biodiversity. In response, countries have different strategies to protect these ecosystems, making this region an interesting experimental plan to measure the impact in global changes on species assemblage based on conservation measures implemented. By studying the response of communities to global warming under a gradient of habitat loss/degradation, I show that community adjustment is reduced or even prevented by wetland degradation. The Ramsar Convention aims to protect wetlands and their biodiversity by maintaining a rational use of natural resources. In assessing the effect of this convention, I show that its effectiveness in conserving bird populations ...

Human activities seriously threaten biodiversity. In terms of global changes, overexploitation of populations and habitat destruction/degradation are at the top of the list of factors responsible for biodiversity loss. Climate change is increasing in magnitude and adding additional pressure on species. In response to the increase in global temperatures, communities are changing as a result of the shift in the geographical distribution of species towards the poles. But the accumulation of anthropogenic pressures is likely to produce interaction effects that limit community adjustment to global warming. In this critical context, conservation biology aims to reconcile human activities with biodiversity conservation. In this thesis I have investigate how the accumulation of anthropogenic pressures can limit the adjustment of communities to global warming and to identify solutions that could be put in place to facilitate their adaptation to this warming. I have used the wintering waterbird species in the countries of the Mediterranean basin as a model for my study. These iconic species benefit from an international census to monitor their populations in response to hunting and the degradation of the wetlands on which they depend. The Mediterranean is a highly anthropized region where the use of natural resources exerts significant pressures on wetlands and their biodiversity. In response, countries have different strategies to protect these ecosystems, making this region an interesting experimental plan to measure the impact in global changes on species assemblage based on conservation measures implemented. By studying the response of communities to global warming under a gradient of habitat loss/degradation, I show that community adjustment is reduced or even prevented by wetland degradation. The Ramsar Convention aims to protect wetlands and their biodiversity by maintaining a rational use of natural resources. In assessing the effect of this convention, I show that its effectiveness in conserving bird populations ...

Human activities seriously threaten biodiversity. In terms of global changes, overexploitation of populations and habitat destruction/degradation are at the top of the list of factors responsible for biodiversity loss. Climate change is increasing in magnitude and adding additional pressure on species. In response to the increase in global temperatures, communities are changing as a result of the shift in the geographical distribution of species towards the poles. But the accumulation of anthropogenic pressures is likely to produce interaction effects that limit community adjustment to global warming. In this critical context, conservation biology aims to reconcile human activities with biodiversity conservation. In this thesis I have investigate how the accumulation of anthropogenic pressures can limit the adjustment of communities to global warming and to identify solutions that could be put in place to facilitate their adaptation to this warming. I have used the wintering waterbird species in the countries of the Mediterranean basin as a model for my study. These iconic species benefit from an international census to monitor their populations in response to hunting and the degradation of the wetlands on which they depend. The Mediterranean is a highly anthropized region where the use of natural resources exerts significant pressures on wetlands and their biodiversity. In response, countries have different strategies to protect these ecosystems, making this region an interesting experimental plan to measure the impact in global changes on species assemblage based on conservation measures implemented. By studying the response of communities to global warming under a gradient of habitat loss/degradation, I show that community adjustment is reduced or even prevented by wetland degradation. The Ramsar Convention aims to protect wetlands and their biodiversity by maintaining a rational use of natural resources. In assessing the effect of this convention, I show that its effectiveness in conserving bird populations ...

Human activities seriously threaten biodiversity. In terms of global changes, overexploitation of populations and habitat destruction/degradation are at the top of the list of factors responsible for biodiversity loss. Climate change is increasing in magnitude and adding additional pressure on species. In response to the increase in global temperatures, communities are changing as a result of the shift in the geographical distribution of species towards the poles. But the accumulation of anthropogenic pressures is likely to produce interaction effects that limit community adjustment to global warming. In this critical context, conservation biology aims to reconcile human activities with biodiversity conservation. In this thesis I have investigate how the accumulation of anthropogenic pressures can limit the adjustment of communities to global warming and to identify solutions that could be put in place to facilitate their adaptation to this warming. I have used the wintering waterbird species in the countries of the Mediterranean basin as a model for my study. These iconic species benefit from an international census to monitor their populations in response to hunting and the degradation of the wetlands on which they depend. The Mediterranean is a highly anthropized region where the use of natural resources exerts significant pressures on wetlands and their biodiversity. In response, countries have different strategies to protect these ecosystems, making this region an interesting experimental plan to measure the impact in global changes on species assemblage based on conservation measures implemented. By studying the response of communities to global warming under a gradient of habitat loss/degradation, I show that community adjustment is reduced or even prevented by wetland degradation. The Ramsar Convention aims to protect wetlands and their biodiversity by maintaining a rational use of natural resources. In assessing the effect of this convention, I show that its effectiveness in conserving bird populations ...