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Forschergruppe (FOR) 1501: Resilience, Collapse and Reorganisation in Social-Ecological Systems of East- and South Africa's Savannahs, Vulnerability and Resilience of Rangeland Vegetation as Affected by Livestock Management, Soils and Climate

The vegetation of East and South African savannahs has been shaped by the complex interaction of geo-biophysical processes and human impact. For both regions a controversial discussion is pertinent, as to whether massive degradation threatens the sustainability of livelihoods in these regions. Rangeland vegetation is mainly affected by environmental conditions (soil and climate) and by livestock management. Extent and interaction of these drivers are not well understood but have profound impacts on the resilience and vulnerability of these systems to be shifted toward unfavourable degraded or bush encroached states. The project aims to analyse and model rangeland vegetation in response to range management including livestock, soil quality and climatic conditions and to assess the impacts of changes in these conditions on the resilience and vulnerability of rangeland systems. Field measurements, remote sensing of vegetation patterns and dynamics and simulation modelling will be used to understand the dynamics of rangeland vegetation. We will use the 'fast' or 'state' variables potential of pastures to produce palatable biomass, the variability of this production, and the system's potential to recover from disturbance impact as indicators of resilience. 'slow' variables that control (or drive) the 'fast' variables such as management, climate and soil variables are recorded in cooperation with other subprojects as with A1 for soil variables. Results of the project will show which management activities are most favourable for individual regions to sustain plant production in the long term.

The iron-snow regime in Fe-FeS cores: a numerical and experimental approach

In the Earth, the dynamo action is strongly linked to core freezing. There is a solid inner core, the growth of which provides a buoyancy flux that drives the dynamo. The buoyancy in this case derives from a difference in composition between the solid inner core and the fluid outer core. In planetary bodies smaller than the Earth, however, this core differentiation process may differ - Fe may precipitate at the core-mantle boundary (CMB) rather than in the center and may fall as iron snow and initially remelt with greater depth. A chemical stable sedimentation zone develops that comprises with time the entire core - at that time a solid inner core starts to grow. The dynamics of this system is not well understood and also whether it can generate a magnetic field or not. The Jovian moon Ganymede, which shows a present-day magnetic dipole field, is a candidate for which such a scenario has been suggested. We plan to study this Fe-snow regime with both a numerical and experimental approach. In the numerical study, we use a 2D/3D thermo-chemical convection model that considers crystallization and sinking of iron crystals together with the dynamics of the liquid core phase (for the 3D case the influence of the rotation of the Fe snow process is further studied).The numerical calculations will be complemented by two series of experiments: (1) investigations in metal alloys by means of X-ray radioscopy, and (2) measurements in transparent analogues by optical techniques. The experiments will examine typical features of the iron snow regime. On the one hand they will serve as a tool to validate the numerical approach and on the other hand they will yield important insight into sub-processes of the iron snow regime, which cannot be accessed within the numerical approach due to their complexity.

Waldbrand - Nadelwald / Nadelholz

Der Dienst (WMS-Dienst) stellt die Waldbrandeinsatzkarte des Saarlandes im Geoportal dar.:Nadelwald aus dem ATKIS Basis-DLM

Water use characteristics of bamboo (South China)

Bamboos (Poaceae) are widespread in tropical and subtropical forests. Particularly in Asia, bamboos are cultivated by smallholders and increasingly in large plantations. In contrast to trees, reliable assessments of water use characteristics for bamboo are very scarce. Recently we tested a set of methods for assessing bamboo water use and obtained first results. Objectives of the proposed project are (1) to further test and develop the methods, (2) to compare the water use of different bamboo species, (3) to analyze the water use to bamboo size relationship across species, and (4) to assess effects of bamboo culm density on the stand-level transpiration. The study shall be conducted in South China where bamboos are very abundant. It is planned to work in a common garden (method testing), a botanical garden (species comparison, water use to size relationship), and on-farm (effects of culm density). Method testing will include a variety of approaches (thermal dissipation probes, stem heat balance, deuterium tracing and gravimetry), whereas subsequent steps will be based on thermal methods. The results may contribute to an improved understanding of bamboo water use characteristics and a more appropriate management of bamboo with respect to water resources.

Indonesian Throughflow variability on sub-orbital timescales during Marine Isotopes Stages (MIS) 2 and 3

This project will provide quantitative estimates of the flow of low-salinity warm water through the Indonesian Gateway on suborbital timescales during MIS 2 and 3 (focusing on Dansgaard Oeschger (D-O) oscillations) and will assess the Indonesian Throughflow (ITF) s impact on the hydrography of the eastern Indian Ocean and global thermohaline circulation during this critical interval of high climate variability. ITF fluctuations, associated with sea level change, temperature and salinity variations in the West Pacific Warm Pool (WPWP) strongly influence precipitation over Australia, the strength of the southeast-Asian summer monsoon, and the intensity of warm meridional currents in the Indian Ocean. We will test the hypothesis that increased ITF is associated with warm interstadials of MIS 3, whereas a strong reduction in ITF occurred during stadials. We will use as main proxies planktonic and benthic foraminiferal isotopes in conjunction with Mg/Ca temperature estimates and radiogenic isotopes (mainly Nd) as tracers of Pacific water masses along depth transects in the Timor Passage and the eastern Indian Ocean. This project will provide the paleoceanographic framework that will be crucial to validate and refine circulation models of D-O events and high-frequency climate variability on a global scale.

Waldbrand - Waldbrandeinsatzkarte

Der Dienst (WMS-Dienst) stellt die Waldbrandeinsatzkarte des Saarlandes im Geoportal dar.:Der Dienst stellt die Waldbrandeinsatzkarte des Saarlandes im Geoportal dar.

Waldbrand - Waldbesitzarten

Der Dienst (WMS-Dienst) stellt die Waldbrandeinsatzkarte des Saarlandes im Geoportal dar.:Darstellung der Staats-, Kommunal- und Privatwälder im Saarland.

Waldbrand - Reviergrenzen

Der Dienst (WMS-Dienst) stellt die Waldbrandeinsatzkarte des Saarlandes im Geoportal dar.:Die gesamte Landesfläche des Saarlandes wird lückenlos in Forstreviere unterteilt. Innerhalb dieser Flächen ist die Leiterin / der Leiter des Forstrevieres für die Bewirtschaftung des Staatswaldes und des vertraglich betreuten Kommunal- und Privatwaldes zuständig. Darüber hinaus gibt es kommunale und private Waldbesitzer, die ihren Wald in Eigenregie bewirtschaften. Auf deren Flächen nehmen Mitarbeiter des SaarForst Landesbetriebes nur in begrenztem Umfang zumeist hoheitliche Aufgaben wahr. Die Grenzen der Forstreviere wurden auf Basis der TK25 digitalisiert und decken sich daher nicht in allen Fällen mit den Grenzen der Waldbestände.

Waldbrand - Rettungspunkte

Der Dienst (WMS-Dienst) stellt die Waldbrandeinsatzkarte des Saarlandes im Geoportal dar.:Bei Unfällen im Wald und in der freien Landschaft kommt dem Herbeiführen von Rettungskräften eine besondere Bedeutung zu. Die sonst üblichen Bezeichnungn von Straßen und Hausnummern sind hier nicht zu finden, Flurnamen oder betriebliche Bezeichnungen von Waldstücken oder Standorten werden oft nicht verstanden und daher fehlerhaft interpretiert. Aus dieser Situation heraus wurde länderübergreifend ein System geschaffen, bei dem Rettungskräfte zu einem eindeutig bezeichneten Rendezvous Punkt bestellt werden. Diese Punkte liegen so in der Landschaft, dass sie eindeutig beschreibbar, und auch von potenziellen Unfallstandorten in Wald und Landschaft möglichst kurz erreichbar sind.

Waldbrand - Forstwegenetz

Der Dienst (WMS-Dienst) stellt die Waldbrandeinsatzkarte des Saarlandes im Geoportal dar.:Dieser Datensatz enthält Hauptwege und beschränkt befahrbare Wege für Lösch- und Rettungsfahrzeuge im saarländischen Wald.

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