Jürgen Böhner

Hamburg University | UHH · Center for Earth System Research and Sustainability (CEN) , Institute of Geography, Section Physical Geography

The Anthropocene presents challenges for preserving and restoring ecosystems in human-altered landscapes. Policy development and landscape planning must consider long-term developments to maintain and restore functional ecosystems, ideally by using wildlife umbrella species as proxies. Forest and Landscape Restoration (FLR) aims to support both env...

Link to the open access data: https://www.fdr.uni-hamburg.de/record/16239 Description: Valid and unbiased species occurrence data are scarce, making their availability a challenge for ecological modelling approaches. Remote sensing is a promising approach for increasing the availability of species occurrence data, but it requires ground truthin...

The availability of valid, non-biased species occurrence data has always been a major challenge for biodiversity research and modelling studies. Data from open-source databases or remote sensing are promising approaches to increase the availability of species occurrence data. However, these data may contain spatial, temporal, and taxonomic biases o...

The impacts of the Anthropocene on climate and biodiversity pose societal and ecological problems that may only be solved by ecosystem restoration. Local to regional actions are required, which need to consider the prevailing present and future conditions of a certain landscape extent. Modeling approaches can be of help to support management effort...

As elevational limits caused by heat deficiency climatic treelines in the world's high mountains will shift upslope in the course of climate change, at least in the long term, unless not prevented by non-thermal site factors. Most empirical studies in mountains of the world found treelines to be advancing, but quite a few assessed a distinct persis...

Irrigation is a crucial land use practice to adapt agriculture to unsuitable climate and soil conditions. Aiming to improve the growth of plants, irrigation modifies the soil condition, which causes atmospheric effects and feedbacks through land–atmosphere interaction. These effects can be quantified with numerical climate models, as has been done...

Amid a heated debate on what are possible and what are plausible climate futures, ascertaining evident changes that are attributable to historical climate change can provide a clear understanding of how warmer climates will shape our future habitability. Hence, we detect changes in the streamflow simulated using three different datasets for the his...

Forstlicher Forschungsbericht München, Band 224; The project partners achieved the goal to describe the water balance within their respective site information mapping systems as realistically as possible, spatially highly resolved and dynamically in relation to climate change using deterministic water balance models. For this purpose, a universal p...

Anthropogenic land use and land cover change (LULCC) is a major driver of environmental changes. The biophysical impacts of these changes on the regional climate in Europe are currently being extensively investigated within the World Climate Research Program (WCRP) Coordinated Downscaling Experiment (CORDEX) Flagship Pilot Study (FPS) Land Use and...

Irrigation is a crucial land use practice to adapt agriculture to unsuitable climate and soil conditions. Aiming for improving the growth of plants, irrigation modifies the soil condition, which causes atmospheric effects and feedbacks through land-atmosphere interaction. These effects can be quantified with numerical climate models, as has been do...

Humans play an interconnecting role in social-ecological systems (SES), they are part of these systems and act as agents of their destruction and regulation. This study aims to provide an analytical framework, which combines the concept of SES with the concept of tipping dynamics. As a result, we propose an analytical framework describing relevant...

The identification of the biogeophysical effects due to land-use, land-cover, and land- management changes (LULCC) is yet to be clearly understood. A range of factors, such as the inclusion of an interactive ocean model component, representation of land management, transient LULCC, and accountability for atmospheric feedback, potentially shifts how...

Zusammenfassung Digitale Informationstechniken gewinnen zunehmend an Bedeutung für Optimierungsstrategien in der landwirtschaftlichen Produktion, wobei einer Gewinnmaximierung die Minimierung kritischer Umweltwirkungen z. B. durch Oberflächenabfluss und Bodenerosion gegenübersteht. Mit dem hier vorgestellten Simulationsmodell lassen sich die an den...

Using a landscape approach, the sensitivity, and response of a treeline ecotone to climate warming were addressed in a multiyear study in Rolwaling Himal, Nepal. The Rolwaling treeline ecotone still has a vegetation zonation unaffected by human land use, providing ideal conditions for capturing a climate signal. Along the elevational gradient, uppe...

Anthropogenic land-use and land cover change (LULCC) is a major driver of environmental changes. The biophysical impacts of these changes on the regional climate in Europe are currently extensively investigated within the WCRP CORDEX Flagship Pilot Study (FPS) LUCAS - "Land Use and Climate Across Scales" using an ensemble of different Regional Clim...

Due to the link between air pollutants and human health, reliable model estimates of hourly pollutant concentrations are of particular interest. Artificial neural networks (ANNs) are powerful modeling tools capable of reproducing the observed variations in pollutants with high accuracy. We present a simple ANN for the city of Hamburg that estimated...

Der Klimawandel führt zu steigenden Temperaturen und dem häufigeren Auftreten von Trockenperioden, Starkregenereignissen und Stürmen. Die Wälder Deutschlands sind dadurch direkt oder indirekt (z. B. durch Schädlingsbefall) stark betroffen. Die sich ändernden Klimabedingungen betreffen insbesondere den bisher meist als konstant angesehenen Standortf...

The concept of plant functional types (PFTs) is shown to be beneficial in representing the complexity of plant characteristics in land use and climate change studies using regional climate models (RCMs). By representing land use and land cover (LULC) as functional traits, responses and effects of specific plant communities can be directly coupled t...

The sensitivity and response of climatic treelines in the Himalayas to climate change is still being debated. Regeneration of tree species in the treeline ecotone is considered a sensitivity indicator and thus of great scientific interest. The aim of this study is to detect predictor variables for regeneration densities of the major tree species in...

Climate warming is expected to facilitate alpine treeline advance to higher elevations. However, empirical studies in diverse mountain ranges give evidence of both advancing alpine treelines and rather insignificant responses. In this context, we aim at analysing environmental drivers of species composition and tree species density in the near-natu...

Anthropogenic land-use and land cover change (LULCC) is a major driver of environmental changes. The biophysical impacts of these changes on the regional climate in Europe are currently extensively investigated within the WCRP CORDEX Flagship Pilot Study (FPS) LUCAS – "Land Use and Climate Across Scales" using an ensemble of different Regional Clim...

The concept of plant functional types (PFTs) is shown to be beneficial in representing the complexity of plant characteristics in land use and climate change studies using regional climate models (RCMs). By representing land use and land cover (LULC) as functional traits, responses and effects of specific plant communities can be directly coupled t...

The lithology, ostracods, palynomorphs and black carbon of a sediment core from a saline wetland in the southern Tibetan highlands (29°14′33.40″N/87°13′09.10″E, 4480 m a.s.l., A.R. Xizang, China) is analyzed and climate modelling applied with respect to core questions in Quaternary research: (1) Do meso-climatic effects of regional landscape struct...

Im Rahmen des IpsPro-Verbundvorhabens wurde ein webbasiertes Werkzeug für eine räumlich explizite Prognose des Befallsrisikos für fichtendominierte Waldbestände durch Borkenkäfer, insbesondere den Buchdrucker, entwickelt. Das sogenannte Borkenkäfer-Frühwarnsystem IpsRisk stellt das "Front End" einer komplexen Modellkette dar, in der das tagesaktuel...

High-quality land use and land cover (LULC) information is of crucial importance for the performance of regional climate models (RCMs), in particular at high spatial resolutions down to convection permitting scales below 4 km. Several satellite-based high-resolution products are currently available for implementation into RCMs. One of the most rece...

Hochgebirge beeinflussen Zirkulationsprozesse in der Atmosphäre als Strömungshindernisse wie auch durch ihre unterschiedlichen Temperaturen. Die Strömung verändernde Prozesse im Einflussbereich von Hochgebirgen sind abhängig von der Stabilität der Temperaturschichtung der Atmosphäre und sie führen zu regional veränderten Bewölkungs- und Niederschla...

At a global scale, heat deficits during the growing season result in growth limitations, which determine the elevation of natural alpine treelines. Thus, the expected response to global warming is a treeline advance to higher elevations. However, empirical studies of diverse mountain ranges have yielded evidence of both advancing alpine treelines a...

Various environmental processes are strongly controlled by spatio-temporal variations of surface air temperature (hereafter temperature) in complex terrain. However, the usually scarce network of observations in high mountain regions does not allow for an investigation of the relevant micro-meteorological processes that result in complex temperatur...

Owing to unique topographic and ecological diversity, central Himalayan state of Nepal is exposed to adverse impacts of climate change and associated disasters. However, countrywide historical assessment of mean and extreme temperature changes, a prerequisite for devising adequate adaptation strategies, is still lacking. Here, we present a comprehe...

Highly seasonal water supplies from the Himalayan watersheds of Jhelum, Kabul and upper Indus basin (UIB) are critical for managing the world's largest contiguous irrigation system of the Indus basin and its dependent agrarian economy of Pakistan. Here, we assess changes in the contrasting hydrological regimes of these Himalayan watersheds, and sub...

To respond to the emerging challenge of climate change, feasible strategies need to be formulated towards sustainable development and energy security on a national and international level. Lacking a dynamic sustainability assessment of technologies for electricity planning, this paper fills the gap with a multi-criteria and multi-stakeholder evalua...

Climate change affects the productivity (e.g., Boisvenue and Running 2006) and carbon sequestration of forests (cf. Hui et al. 2017). To model potential future site-specific forest productivity, high quality data for both forest stands and climate are required. So far, the available climate data meet the requirements for forestry scientific questio...

Characterizing prevailing precipitation regimes from a comprehensive database of 11 observational data sets, this chapter first analyzes the fidelity of 36 state-of-the-art global climate model experiments from the Coupled Model Intercomparison Project Phase 5, and then presents changes in the surface water budgets from moderate-to-high fidelity ex...

Assessment of future water availability from the Himalayan watersheds of Indus Basin (Jhelum, Kabul and upper Indus basin—UIB) is a growing concern for safeguarding the sustainable socioeconomic wellbeing downstream. This requires, before all, robust climate change information from the present-day state-of-the-art climate models. However, the robus...

The model depicts the change in the priorities of different stakeholders towards the allocation of investments and the installation of electricity generation technologies in different locations in Egypt. These priorities are used later on in investigating conditions, scenarios and strategies for future planning of energy in Egypt, with an emphasis...

The World Urban Database and Access Portal Tools (WUDAPT) project has grown out of the need for better information on the form and function of cities globally. Cities are described using Local Climate Zones (LCZ), which are associated with a range of key urban climate model parameters and thus can serve as inputs to high resolution urban climate mo...

Floods and landslides represent a major risk for the Himalayan region of Nepal and the increasing frequency of intense precipitation events during recent decades leads to an escalating exposure to hazards. A better understanding of the dynamics causing extreme rainfall events is crucial in order to improve their prediction and to minimize the assoc...

Snow cover modelling is primarily focused on snow depletion in context of hydrological research. Degree-day or temperature index models (TIM) as well as energy balance models (EBM) are conventional to quantify catchment runoff. Whereas the former exploit relationships between snow (and/or ice) melt and air temperatures, the latter rest upon quantif...

Modelling ecological niches across vast distribution ranges in remote, high mountain regions like the Himalayas faces several data limitations, in particular nonavailability of species occurrence data and fine-scale environmental information of sufficiently high quality. Remotely sensed data provide key advantages such as frequent, complete, and lo...

Himalayan treelines are exposed to above average climate change impact, resulting in complex tree growth-climate relationships for Himalayan Silver Fir (Abies spectabilis (D. Don) Spach) at central Himalayan treelines. The majority of recent studies detected current tree growth sensitivity to dry conditions during pre-monsoon seasons. The aim of th...

Future electricity planning necessitates a thorough multi-faceted analysis of the available technologies in order to secure the energy supply for coming generations. To cope with worldwide concerns over sustainable development and meet the growing demands of electricity we assess the future potential technologies in Egypt through covering their tec...

We propose the implementation of the Soil and Landscape Evolution Model (SaLEM) for the spatiotemporal investigation of soil parent material evolution following a lithologically differentiated approach. Relevant parts of the established Geomorphic/Orogenic Landscape Evolution Model (GOLEM) have been adapted for an operational Geographical Informati...

Seedling establishment is a crucial factor for spatial dynamics of treelines. However, safe sites for successful tree regeneration which is a basic prerequisite for a supposed treeline advance in response to climate warming have not been fully characterised, especially in the Himalayas. In this study, we aim at analysing safe sites of the tree spec...

This article describes the design of a new model-based assessment framework to identify and analyse possible future trajectories of agricultural development and their environmental consequences within the states of Mato Grosso and Pará in Southern Amazonia, Brazil. The objective is to provide a tool for improving the information basis for scientist...

“GIS in Climatology and Meteorology” introduces basic sources of ground-based and remotely sensed climate and weather observations and provides an overview of principles, methods and techniques for the GIS-based analysis, estimation and spatial modeling of continuous climate surfaces from point source data. The chapter covers the main concepts of d...

We propose the implementation of a soil and landscape evolution model (SaLEM) for the spatiotemporal investigation of soil parent material evolution following a lithologically differentiated approach. Relevant parts of the established model GOLEM have been adapted for an operational GIS tool within the open source software framework SAGA, thus taki...

High-resolution information on climatic conditions is essential to many applications in environmental and ecological sciences. Here we present the CHELSA (Climatologies at high resolution for the earth's land surface areas) data of downscaled model output temperature and precipitation estimates of the ERA-Interim climatic reanalysis to a high resol...

Abstract Questions: Species composition and ecology of treeline vegetation types in the Rolwaling Valley is largely unknown to date. The aim of this study is to differentiate plant communities along the elevational gradient in the treeline ecotone, and to identify site factors which cause the differentiation of the treeline ecotone vegetation. Stud...

Mesoscale dynamical refinements of global climate models or atmospheric reanalysis have shown their potential to resolve intricate atmospheric processes, their land surface interactions, and subsequently, realistic distribution of climatic fields in complex terrains. Given that such potential is yet to be explored within the central Himalayan regio...

The target of our project is the development of a realtime digital decision system to optimise farming with regard to an increase of crop yield and minimal damage to the environment. Basis for this decision system is SAGA, which is an open-source geographic information system. During our development we add new SAGA tools, which analyse local circum...

Timely meteorological data of high accuracy and spatiotemporal resolution can contribute to sustainable urban planning and management in terms of human thermal comfort, heat wave warning, air pollution prediction, as well as building and transport management among others. Today, the scientific knowledge about the specific urban climate is not fully...

Largely depending on the meltwater from the Hindukush–Karakoram–Himalaya, withdrawals from the upper Indus Basin (UIB) contribute half of the surface water availability in Pakistan, indispensable for agricultural production systems, industrial and domestic use, and hydropower generation. Despite such importance, a comprehensive assessment of prevai...

At a global scale, tree growth in alpine treeline ecotones is limited by low temperatures. At a local scale, however, tree growth at its upper limit depends on multiple interactions of influencing factors and mechanisms. The aim of our research was to understand local scale effects of soil properties and nutrient cycling on tree growth limitation,...

Questions: Species composition and ecology of treeline vegetation types in the Rolwaling Valley is largely unknown to date. The aim of this study is to differentiate plant communities along the elevational gradient in the treeline ecotone, and to identify site factors which cause the differentiation of the treeline ecotone vegetation. Study area: R...