API src

Found 43 results.

Forest management in the Earth system

The majority of the worlds forests has undergone some form of management, such as clear-cut or thinning. This management has direct relevance for global climate: Studies estimate that forest management emissions add a third to those from deforestation, while enhanced productivity in managed forests increases the capacity of the terrestrial biosphere to act as a sink for carbon dioxide emissions. However, uncertainties in the assessment of these fluxes are large. Moreover, forests influence climate also by altering the energy and water balance of the land surface. In many regions of historical deforestation, such biogeophysical effects have substantially counteracted warming due to carbon dioxide emissions. However, the effect of management on biogeophysical effects is largely unknown beyond local case studies. While the effects of climate on forest productivity is well established in forestry models, the effects of forest management on climate is less understood. Closing this feedback cycle is crucial to understand the driving forces behind past climate changes to be able to predict future climate responses and thus the required effort to adapt to it or avert it. To investigate the role of forest management in the climate system I propose to integrate a forest management module into a comprehensive Earth system model. The resulting model will be able to simultaneously address both directions of the interactions between climate and the managed land surface. My proposed work includes model development and implementation for key forest management processes, determining the growth and stock of living biomass, soil carbon cycle, and biophysical land surface properties. With this unique tool I will be able to improve estimates of terrestrial carbon source and sink terms and to assess the susceptibility of past and future climate to combined carbon cycle and biophysical effects of forest management. Furthermore, representing feedbacks between forest management and climate in a global climate model could advance efforts to combat climate change. Changes in forest management are inevitable to adapt to future climate change. In this process, is it possible to identify win-win strategies for which local management changes do not only help adaptation, but at the same time mitigate global warming by presenting favorable effects on climate? The proposed work opens a range of long-term research paths, with the aim of strengthening the climate perspective in the economic considerations of forest management and helping to improve local decisionmaking with respect to adaptation and mitigation.

Pollen and environmental reconstruction, Holocene dynamics of tropical rainforest, climate, fire, human impact and land use in Sulawesi and Sumatra, Indonesia

The present-day configuration of Indonesia and SE Asia is the results of a long history of tectonic movements, volcanisms and global eustatic sea-level changes. Not indifferent to these dynamics, fauna and flora have been evolving and dispersing following a complicate pattern of continent-sea changes to form what are today defined as Sundaland and Wallacea biogeographical regions. The modern intraannual climate of Indonesia is generally described as tropical, seasonally wet with seasonal reversals of prevailing low-level winds (Asian-Australian monsoon). However at the interannual scale a range of influences operating over varying time scales affect the local climate in respect of temporal and spatial distribution of rainfall. Vegetation generally reflects climate and to simplify it is possible to distinguish three main ecological elements in the flora of Malaysia: everwet tropical, seasonally dry tropical (monsoon) and montane. Within those major ecological groups, a wide range of specific local conditions caused a complex biogeography which has and still attract the attention of botanists and biogeographers worldwide. Being one of the richest regions in the Worlds in terms of species endemism and biodiversity, Indonesia has recently gone through intensive transformation of previously rural/natural lands for intensive agriculture (oil palm, rubber, cocoa plantations and rice fields). Climate change represents an additional stress. Projected climate changes in the region include strengthening of monsoon circulation and increase in the frequency and magnitude of extreme rainfall and drought events. The ecological consequences of these scenarios are hard to predict. Within the context of sustainable management of conservation areas and agro-landscapes, Holocene palaeoecological and palynological studies provide a valuable contribution by showing how the natural vegetation present at the location has changed as a consequence of climate variability in the long-term (e.g. the Mid-Holocene moisture maximum, the modern ENSO onset, Little Ice Age etc.). The final aim of my PhD research is to compare the Holocene history of Jambi province and Central Sulawesi. In particular: - Reconstructing past vegetation, plant diversity and climate dynamics in the two study areas Jambi (Sumatra) and Lore Lindu National Park (Sulawesi) - Comparing the ecological responses of lowland monsoon swampy rainforest (Sumatra) and everwet montane rainforests (Sulawesi) to environmental variability (vulnerability/resilience) - Investigating the history of human impact on the landscape (shifting cultivation, slash and burn, crop cultivation, rubber and palm oil plantation) - Assessing the impact and role of droughts (El Niño) and fires - Adding a historical perspective to the evaluation of current and future changes.

Schwerpunktprogramm (SPP) 1488: Planetary Magnetism (PlanetMag), Evolution of geomagnetic dipole moment and South Atlantic Anomaly

The geomagnetic field shields our habitat against solar wind and radiation from space. Due to the geometry of the field, the shielding in general is weakest at high latitudes. It is also anomalously weak in a region around the south Atlantic known as South Atlantic Anomaly (SAA), and the global dipole moment has been decreasing by nearly 10 percent since direct measurements of field intensity became possible in 1832. Due to our limited understanding of the geodynamo processes in Earths core, it is impossible to reliably predict the future evolution of both dipole moment and SAA over the coming decades. However, lack of magnetic field shielding as would be a consequence of further weakening of dipole moment and SAA region field intensity would cause increasing problems for modern technology, in particular satellites, which are vulnerable to radiation damage. A better understanding of the underlying processes is required to estimate the future development of magnetic field characteristics. The study of the past evolution of such characteristics based on historical, archeo- and paleomagnetic data, on time-scales of centuries to millennia, is essential to detect any recurrences and periodicities and provide new insights in dynamo processes in comparison to or in combination with numerical dynamo simulations. We propose to develop two new global spherical harmonic geomagnetic field models, spanning 1 and 10 kyrs, respectively, and designed in particular to study how long the uninterrupted decay of the dipole moment has been going on prior to 1832, and if the SAA is a recurring structure of the field.We will combine for the first time all available historical and archeomagnetic data, both directions and intensities, in a spherical harmonic model spanning the past 1000 years. Existing modelling methods will be adapted accordingly, and existing data bases will be complemented with newly published data. We will further acquire some new archeomagnetic data from the Cape Verde islands from historical times to better constrain the early evolution of the present-day SAA. In order to study the long-term field evolution and possible recurrences of similar weak field structures in this region, we will produce new paleomagnetic records from available marine sediment cores off the coasts of West Africa, Brazil and Chile. This region is weakly constrained in previous millennial scale models. Apart from our main aim to gain better insights into the previous evolution of dipole moment and SAA, the models will be used to study relations between dipole and non-dipole field contributions, hemispheric symmetries and large-scale flux patterns at the core-mantle boundary. These observational findings will provide new insights into geodynamo processes when compared with numerical dynamo simulation results.Moreover, the models can be used to estimate past geomagnetic shielding above Earths surface against solar wind and for nuclide production from galactic cosmic rays.

Screening-Studie zu gefährlichen Stoffen in Meeressäugern der Ostsee

Wie die HELCOM-Expertengruppe für Meeressäugetiere (EG MAMA; portal.helcom.fi, 2021) feststellt, liegen nur begrenzte Informationen über das Vorkommen, die (Öko-)Toxizität und die potenziellen gesundheitlichen Auswirkungen von Neuen Schadstoffen bei Meeressäugern vor. Neue Schadstoffe werden durch verschiedene anthropogene Aktivitäten in die Umwelt eingebracht, und einige dieser Stoffe haben das Potenzial, in Meeres-, Süßwasser- und/oder terrestrische Nahrungsnetze zu gelangen, wo sie sich anreichern können. Gegenwärtig fehlen häufig Informationen über die Exposition, und es besteht ein dringender Bedarf an ausreichenden Daten zum Vorkommen und die Auswirkungen, um CEC bewerten und gegebenenfalls Maßnahmen zur Risikominderung einleiten zu können. Ziel des Projekts war das Screening auf potenziell gefährliche Neue Schadstoffe in Meeressäugetieren aus der Ostsee unter Verwendung modernster analytischer Methoden für ein weitreichendes Ziel- und Verdachtsscreening. Zu diesem Zweck wurden 11 gepoolte Leber- und eine nicht gepoolte Muskelprobe von 11 Meeressäugern (Schweinswal (Phocoena phocoena), Gewöhnlicher Delphin (Delphinus delphis), Kegelrobbe (Halichoerus grypus), Seehund (Phoca vitulina)) von HELCOM-Vertragsparteien aus Deutschland, Schweden, Dänemark und Polen zur Verfügung gestellt. Die interessierenden Verunreinigungen wurden aus den gefriergetrockneten Matrizes mit Hilfe allgemeiner Extraktionsmethoden extrahiert, und die endgültigen Extrakte wurden sowohl mit Flüssig- als auch mit Gaschromatographie in Verbindung mit hochauflösender Massenspektrometrie (HRMS; LC-ESI-QToF und GC-APCI-QToF) analysiert. Die Proben wurden quantitativ auf das Vorhandensein von mehr als 2,500 organischen Schadstoffen untersucht, darunter Verbindungen verschiedener Klassen wie Arzneimittel, Kosmetika, Biozide, Pflanzenschutzmittel, illegale Drogen, Stimulanzien, Süßstoffe und Industriechemikalien (z. B. Per- und Polyfluoralkylsubstanzen (PFAS), Flammschutzmittel, Korrosionsinhibitoren, Weichmacher, Tenside) sowie deren Umwandlungsprodukte (TPs). Darüber hinaus wurde eine Methode zur Analyse von 23 Verbindungen entwickelt, die in Sprengstoffen enthalten sind, die in der Vergangenheit in die Ostsee verklappt wurden, wobei ein anderes Verfahren zur Probenvorbereitung verwendet wurde. Eine spezifische Ziel-Screeningmethode, die dieselbe Probenvorbereitung verwendet, wurde auch für 13 neue phosphororganische Flammschutzmittel (OPFR) und zwei Dechloran-plus-Verbindungen angewandt.Das Verdachtsscreening von 65.690 umweltrelevanten Substanzen aus der NORMAN-Stoffdatenbank wurde an allen HRMSRohchromatogrammen durchgeführt. Die Chromatogramme wurden auch in die NORMAN Digital Sample Freezing Platform (DSFP) hochgeladen und stehen somit für das retrospektive Screening von noch mehr Verbindungen zur Verfügung, sobald die Informationen für deren Screening verfügbar sind...

Eco-evolutionary responses and feedbacks of a key herbivore to lake oligotrophication

The project will use analysis of long-term data, resurrection ecology and modeling to investigate the ecological and evolutionary response of an aquatic key herbivore, Daphnia, to environmental change. In addition, the results obtained will enable to estimate the consequences of the evolutionary response of Daphnia for its population dynamics, persistence and consequently, overall ecosystem dynamics. The project will analyze in detail the response of Daphnia, its food, competitors and predators to oligo-trophication in a model ecosystem, i.e., Lake Constance and additionally variability in Daphnia population dynamics in several of the best studied lakes of the world. Historical field samples from Lake Constance will be re-analyzed to study the phenotypic life history and morphological responses of Daphnia to oligo-trophication. Using resurrection ecology we will analyze the evolutionary response of Daphnia galeata life history parameters to oligo-trophication - with special emphasis on its investment into sexual reproduction/production of resting eggs as well as life history plasticity in response to invertebrate predators and declining food levels. These analyses (in combination with model simulations) will provide key data for understanding the role of Daphnia life cycle strategy (overwintering in the plankton or in resting eggs) for Daphnia persistence in permanent lakes, for the interpretation of Daphnia resting egg banks, and the evolution of the genetic variances and co-variances of life history parameters.

TOP-Energy - Toolkit for Optimization of Industrial Energy Systems

Rational energy use in industry decreases costs, environmental pollution and the depletion of resources. Since energy costs are often of the same magnitude as the profit, reduced energy use considerably affects the company results. Yet, systematic, profound analysis and optimization of energetic processes are seldom conducted. In order to reduce the effort and increase the quality of energy system analysis, a computer aided method is being developed in a research project called TOP-Energy (Toolkit for Optimisation of Industrial Energy Systems). The main aim of TOP-Energy is to support energy consultants in analysing and optimising industrial energy supply systems by providing modules for documentation, simulation and evaluation of energy systems with respect to energetic, economic and environmental aspects. To ensure an integrated workflow, TOP-Energy reflects a business process model derived from the German guideline, VDI 3922. TOP-Energy consists of two major parts, a unifying framework and a set of modules: The former supplies the services of a modern GUI-application such as module-sensitive dialogs and presentations, flow sheet editing and report generation. It includes a sophisticated, abstract data model and operates as a software bus for modules allowing them to integrate their own XML-based data. The latter are technical modules, addressing particular aspects of energy system analysis such as economic analysis or system simulation. An outstanding feature of TOP-Energy is the supply system simulator, called eSim, which can be tailored to the end users needs. It evaluates energy supply concepts by means of historical demand data. In contrast to other simulator packages, eSim supersedes the costly modelling of control systems at an early stage of concept development by automatic optimisation of component deployment.

Forschergruppe (FOR) 1246: Kilimanjaro ecosystems under global change: Linking biodiversity, biotic interactions and biogeochemical ecosystem processes, Effects of climate and land use on functional diversity of birds and bats and on their mutualistic interaction networks - KiLi-SP 6

Birds and bats deliver crucial ecosystem services, i.e. seed dispersal and predation on arthropods. As they are rarely considered together in ecosystem studies linking biodiversity and ecosystem functioning, we will test 1. for functional redundancy within and among the two groups, 2. differential reactions towards altitude and land use, and 3. potential influence of climate change and further intensification of land use on composition and functionality. Bird and bat assemblages will be assessed by sampling at the same sites along an elevational and land use gradient. The functional role of birds and bats as seed dispersers will be assessed by feeding experiments and measuring seed rain. Exclosure experiments will be conducted jointly (SP 7) to determine their role as predators of arthropods. Path analysis will be used to quantify relationships between climatic factors (SP 1-3), habitat structure (SP 4, 5), food availability (SP 7, 8), structure of bird and bat assemblages and associated ecosystem services. The path coefficients can be applied to predict changes based on various scenarios of climate and land use change. We will also analyse temporal changes in forest bird communities in relation to climate and land use change using historical monitoring data.

Kohlenstoffspeicherung in einem ungenutzten Kalkbuchenwald des Nationalparks Hainich

Differenzierung der Quellen- und Senkenfunktion des Bodens unter Berücksichtigung der Nutzungsgeschichte. Im Rahmen des CARBOEUROFLUX-Projekts wurden im Hainich (Thüringen) Kohlenstoff (C)- Speicherungsraten festgestellt, die der Vorstellung der Kohlendioxid-Neutralität von alten Wäldern widersprechen und die Frage nach deren Kyoto-Relevanz aufwerfen. Im Rahmen europäischer Projekte lässt sich allerdings nicht klären, wie diese hohen Speicherraten entstehen und wo C im System verbleibt. Wir vermuten, dass durch historischen C-Export, z.B. infolge von Streunutzung, die Böden im Hainich verarmten und die entleerten Speicher jetzt wieder aufgefüllt werden. Um das Ausmaß des nutzungsbedingten C-Exports abschätzen zu können, werden aus Schriftquellen Art und Umfang der Biomassenutzung in ihrer zeitlichen und örtlichen Entwicklung rekonstruiert. Zudem untersuchen wir, welche Anteile des C-Eintrages veratmet, gespeichert und über den Wasserpfad exportiert werden. Hierzu werden 13C und 14C- Isotopenverhältnisse an Bodengasen sowie gelöstem und festem Boden- C bestimmt. Unsere Untersuchungen zielen auf ein grundlegendes Verständnis der C-Speicherung im Jahresverlauf ab. Die Zusammenarbeit mit dem Kompetenzzentrum 'Dynamik Komplexer Geosysteme' und dem europäischen CARBOEUROPE Cluster wird die Doppelerhebung von Daten verhindern und deren gegenseitige Verfügbarkeit sicherstellen. Ziel der Arbeit ist es, den historischen Kohlenstoffexport insbesondere unter Berücksichtigung der forstlichen Nebennutzung abzuschätzen. Hierzu soll anhand von Literaturdaten einerseits die Vegetationsgeschichte geklärt werden. Andererseits soll der im Untersuchungsgebiet im Zuge der forstlichen und landwirtschaftlichen Nutzungen erfolgte Biomasseentzug nach Art und Umfang dokumentiert werden. Diese Arbeiten sind notwendig, um den Einfluss der Nutzungsgeschichte auf die Kohlenstoffspeicherung im Untersuchungsstandort abzuschätzen. Im Rahmen des Gesamtprojektes sollen zunächst Daten zur Entwicklung der Biomasse im Untersuchungsgebiet zusammengestellt werden. Eine weitere Aufgabe besteht darin, auf der Basis von Literaturstudien einen möglichen Vergleichsstandort mit unterschiedlicher Nutzungsgeschichte zu identifizieren.

Schwerpunktprogramm (SPP) 1158: Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas; Bereich Infrastruktur - Antarktisforschung mit vergleichenden Untersuchungen in arktischen Eisgebieten, Diversity and evolution of Antarctic gastropods explored by a genomic approach

The Antarctic irwertebrate fauna appears highiy diverse, but is only localiy and sporadically explored - and already threatened by global climate change. Gastropods are abundant, species rieh, ecologically and economically irnportant, count with a rieh fossil record and are wellestablished äs model organisms for many scientific disciplines. Most of the roughly 600 Antarctic gastropod species are regarded valid at the mornent based on shell features of often just a few or single specimens. Intraspecific morphological variability, soft pari anatomy, biology' and ecology are usually unknown, and many synonyms have been proposed. Wolecular data are limited to CÖI barcode sequences of few individuals of the more common species: Phylogenetic analyses of single genes suggest complexes of cryptic species or deep lineages, which may show distinct geographic distributions and special ecological niches. Rarity of species or samples prohibits general population genetics approaches. The prirnary goal of our herein proposed project is revealing the species diversity of Antarctic gastropods comprehensively and reliably. In addition to mltochondrial CÖI, we will use next generation sequencing (NGS) and newly established methods (double digest Restriction Associated DMA sequencing, ddRADseq) to efficiently generate a multitude of independent nuclear genomic sequence markers. We will include all species and subsamples from rnore than 2000 Southern Öcean gastropod samples available at the ZSM Mollusca collection suitable for genetic studies, plus further material to be collected at expeditions or from other museums. We will perform phylogenetic analyses (ML, Bayes, in subgroups BEST) and combined, up to-date molecular species delimitation approaches (ABGD, GMYCS BP&P), An integrative taxonomic approach reiying on congruence will be applied to revea! conservative and reliable evolutionary species units, which will be used for diversity analyses, We will also explore genomic evolutionary archives of seiected gastropod lineages performing fossil-calibrated BEAST chronograms. The dynamics of diversification will be analyzed via recent Birth-Death-Shift models, and historical biogeography will be reconstructed using recent Software (e.g, RASP). With our massif genomic data from many subtaxa we will test current paradigms on biogeography and evolution, such äs glacial cycles causing an 'Antarctic speciation pump', and evaluate competing hypotheses on glacial refuges and migration scenarios. The herein proposed combination of ddRADseqs with up to date multi-iocus analyses is novel, extremely cost and time effective, and can include thousands instead of few specimens' without any a priori selectron. It is expected to be very powerful to delimitate newty collected, unrecognized, or cryptic species, even jf badly sampled or just represented by singletons...

FP6-SUSTDEV, Toward the European Distributed Institute of Taxonomy (EDIT)

The overall objective of EDIT is to integrate European taxonomic effort within the ERA and to build a world leading capacity. EDIT will create a European virtual centre of excellence, which will increase both the scientific basis and capacity for biodiversity conservation. The operational and structural objectives of EDIT are: (1) To reduce fragmentation and to transform taxonomy into an integrated science, (2) To strengthen the scientific, technological and information capacities needed for Europe to understand how biodiversity is modified through Global change, (3) To progress toward a transnational entity by encouraging durable integration of the most important European taxonomic institutions, forming the nucleus of excellence around and from which institutions and taxonomists can integrate their activities, (4) To promote the undertaking of collaborative research developing, improving and utilising the bio-informatics technologies needed, (5) To create a forum for stakeholders and end-users for taxonomy in biodiversity and ecosystem research, (6) To promote the spreading of excellence to fulfil the needs of biodiversity and ecosystem research for taxonomy based information. EDIT will address significant information and management of knowledge problems in a rapidly changing field. The issues to be addressed are scientific but also structural: about governance and management; about providing a suitable IT environment; about the development of new tools; and about getting taxonomists to work as one across European (and other) institutions. EDIT will bring together the leading taxonomic institutions in Europe that for historical reasons have developed independently. The association with leading North American and Russian partners will make it a worldwide leading network: the consortium so constituted unites the premier natural history collections-based institutions, to progress toward EDIT's structural and scientific objectives. Prime Contractor: Caisse des Depots et Consignations; Paris; France.

1 2 3 4 5