Jörg Löffler

• Professor
• Professor at University of Bonn

Considering the recent widespread greening and browning trends associated with shrubs in arctic–alpine ecosystems, further understanding of how these shrubs respond in a rapidly changing environment is of crucial importance. We here monitor shrub growth, using high-precision dendrometers to produce fine-scale intra-annual growth patterns from hourl...

Under climate change, cold-adapted alpine ecosystems are turning into hotspots of warming. However, the complexity of driving forces of growth, associated biomass gain and carbon storage of alpine shrubs is poorly understood. We monitored alpine growth mechanisms of six common shrub species across contrasting biomes, Mediterranean and tundra, using...

Alpine plants are particularly sensitive to climate change, and in the Mediterranean more fre-quently interrupted winter cold and prolonged summer drought are expected to shift species´ growth patterns, altering their range and strategies to cope with these dual climatic stressors. However, adaptive strategies to drought and frost and their impact...

Mediterranean‐alpine plants are exposed to harsh conditions, forcing them to perform with well‐adapted physiological strategies to withstand the dual stressors that arise from winter cold and summer drought. Such growth strategies are not yet fully understood, although they gain importance with regard to the resilience of species in the face of ong...

The Mediterranean alpine is one of the most vulnerable ecosystems under future environmental change. Yet, patterns, timing and environmental controls of plant growth are poorly investigated. We aimed at an improved understanding of growth processes, as well as stem swelling and shrinking patterns, by examining two common coexisting green‐stemmed sh...

Here we present a Data Paper with microscopically measured data on ring widths of the arctic-alpine dwarf shrub species Betula nana L. from Central Norway. We intend to continuously update the dataset in the future with further ring width measurements of this widespread shrub species.

All ecosystems face ecological challenges in this century. Therefore, it is becoming increasingly important to understand the ecology and degree of local adaptation of functionally important Arctic-alpine biomes by looking at the most diverse taxon of metazoans: the Arthropoda. This is the first study to utilize metabarcoding in the Alpine tundra,...

The Mediterranean alpine is one of the most vulnerable ecosystems under future environmental change. Yet, patterns, timing and environmental controls of plant growth are poorly investigated. We aimed at an improved understanding of growth processes, as well as stem swelling and shrinking patterns, by examining two common coexisting green-stemmed sh...

Here, we present a datapaper containing observational air quality and meteorological data related to our long-term air quality monitoring program at the UNESCO Natural World Heritage Site Geirangerfjord, Western Norway. The dataset will be updated with future data.

This is a datapaper including microscopically measured data of annual ring widths from the Mediterranean-alpine shrub species Cytisus galianoi (Sierra Nevada, Spain). The dataset will be updated with future measurements.

Here, we present a datapaper containing microscopically measured data of annual ring widths in the arctic-alpine dwarf-shrub species Salix herbacea (central Norway). The dataset will be updated with future measurements.

To predict species' responses to a rapidly changing environment, it is necessary to detect current clines of life-history traits and understand their drivers. We studied body size variation, a key trait in evolutionary biology, of two arctic-alpine lycosid spiders and underlying mechanisms controlling this variation. We used long time-series data o...

To predict species’ responses to a rapidly changing environment, it is necessary to detect current clines of life-history traits and understand their drivers. We studied body size variation, a key trait in evolutionary biology, of two arctic–alpine lycosid spiders and underlying mechanisms controlling this variation. We used long time-series data o...

Arctic-alpine ecosystems are considered hot-spots of environmental change, with rapidly warming conditions causing massive alterations in vegetational structure. These changes and their environmental controls are highly complex and variable across spatial and temporal scales. Yet, despite their numerous implications for the global climate system, t...

Boulder-dominated landforms of periglacial, paraglacial and related origin constitute a valuable, but often unexplored source of palaeoclimatic and morphodynamic information. The timing of landform development initiation and its subsequent stabilization can be linked to past climatic conditions offering the potential to reconstruct cold climatic pe...

Here, we present measurement data of stem diameter variability of three common woody plants, monitored in the Mediterranean-alpine biome for six consecutive years (2015–2020). These focal species (Astragalus granatensis, Cytisus galianoi, and Genista versicolor) are abundant across the Sierra Nevada mountain chain (Southern Spain) and will potentia...

Mountain glaciers currently experience significant mass losses and frontal retreat at the global scale. Because mountain glaciers generally respond sensitively to climate and are differently affected by climate variations at the regional scale, they may significantly and specifically impact their natural and human environment. Norway has the larges...

Arctic and alpine ecosystems are strongly affected by rapidly changing environmental conditions, resulting in profound vegetation shifts, which are highly heterogeneous and hard to predict, yet have strong global impacts. Shrubs have been identified as a key driver of these shifts. In this study, we aim to improve the understanding of how such broa...

Broad‐scale changes in arctic‐alpine vegetation and their global effects have long been recognized and labeled one of the clearest examples of the terrestrial impacts of climate change. Arctic‐alpine dwarf shrubs are a key factor in those processes, responding to accelerated warming in complex and still poorly understood ways. Here, we look closely...

Litter decomposition is a key process for carbon and nutrient cycling in terrestrial ecosystems and is mainly controlled by environmental conditions, substrate quantity and quality as well as microbial community abundance and composition. In particular, the effects of climate and atmospheric nitrogen (N) deposition on litter decomposition and its t...

Litter decomposition is a key process for carbon and nutrient cycling in terrestrial ecosystems and is mainly controlled by environmental conditions, substrate quantity, and quality as well as microbial community abundance and composition. In particular, the effects of climate and atmospheric nitrogen (N) deposition on litter decomposition and its...

Here, we present fine-scale measurements of stem diameter variation from three common arctic-alpine dwarf-shrub species monitored in two mountain regions of Central Norway. All three species (Betula nana, Empetrum nigrum ssp. hermaphroditum, and Phyllodoce caerulea) are abundant within the studied regions and highly important contributors to potent...

Considering the recent widespread greening associated with dwarf shrubs in arctic and alpine ecosystems, further understanding of how these shrubs respond to environmental conditions is of crucial importance. Here we present novel insights and propose a new method to monitor shrub growth, using high-precision point dendrometers. We analyzed intra-...

Eurasian lynx (Lynx lynx) once inhabited almost the whole of the European continent. After facing nearly complete extinction about a century ago, they now form a more or less connected metapopulation with eleven broad-scale populations and numerous isolated habitat patches throughout Europe. Increasing public interest and a favourable legislative s...

Woody encroachment is increasingly threatening savanna ecosystems, but it remains unclear how this is driven by different land tenures and management systems. In South Africa, communal land is mainly managed under continuous grazing, while commercial land is under rotational grazing. We hypothesize that woody encroachment has increased since the en...

Effects of climate change on shrub growth in high mountains: With the rapid warming of the alpine zone shrub growth has increased and shrubs have expanded. Satellite proxies for vegetation biomass have shown greening trends in recent decades over large parts of the tundra biome, which have been linked to shrub growth chronologies, and summer temper...

The Arctic is projected to be severely impacted by changes in temperature and precipitation. Species react to these changes by shifts in ranges, phenology, and body size. In ectotherms, the patterns of body size clines and their underlying mechanisms are often hard to untangle. Mountains provide a space-for-time substitute to study these shifts alo...

The investigation of periglacial and related landforms in South Norway is of high interest for exploring timings of deglaciation and to assess their geomorphological connectivity to palaeoclimatic changes during the Late Quaternary and the Holocene. The ice margins of the Scandinavian Ice Sheet during the Last Glacial Maximum (LGM) are fairly well...

Within the context of species distribution models, scrutiny arises from the choice of meaningful environmental predictors. Thermal conditions are not the sole driver, but are the most widely acknowledged abiotic driver of plant life within alpine ecosystems. We linked long‐term measurements of direct, plant‐relevant, near‐surface temperatures to pl...

Assessing biodiversity in arctic-alpine ecosystems is a costly task. We test in the current study whether we can map the spatial patterns of spider alpha and beta diversity using remotely-sensed surface reflectance and topography in a heterogeneous alpine environment in Central Norway. This proof-of-concept study may provide a tool for an assessmen...

Body size is one of the most important individual traits, determining various other life-history traits, including fitness. Both evolutionary and ecological factors shape the body size in arthropods, but the relative contribution of abiotic drivers acting at different spatial scales has been little investigated. We aimed to identify the importance...

We present new 10Be surface exposure ages from two selected locations in southern Norway. A total of five 10Be samples allow a first assessment of local deglaciation dynamics of the Scandinavian Ice Sheet at Dalsnibba (1476 m a.s.l.) in southwestern Norway. The bedrock ages from the summit of Dalsnibba range from 13.3±0.6 to 12.7±0.5 ka and probabl...

The transition from net deforestation to net reforestation in China has received much scientific attention, in the hope that, by understanding the underlying drivers and processes, it might be reproduced in other regions of the world. The scientific literature has suggested that this process was driven by the creation of off-farm opportunities and...

An improved knowledge of long‐term climatic variations over the Altai‐Dzungarian region will increase our understanding of the current climate and help to predict the effects of global warming on future water availability in this region. We sampled 77 Larix sibirica Ledeb. trees at upper and lower treelines in the southern Mongolian Altai mountains...

Microbial communities in arctic–alpine soils show biogeographic patterns related to elevation, but the effect of fine-scale heterogeneity and possibly related temperature and soil moisture regimes remains unclear. We collected soil samples from different micro-topographic positions and elevational levels in two mountain regions of the Scandes, Cent...

Growth and decay of Quaternary glaciers and ice sheets had fundamental implications for environmental changes worldwide. The chronology of the last deglaciation following the Last Glacial Maximum (LGM, 26.5-20 ka) and its ice marginal positions in Norway are generally perceived as being well constrained. The detailed vertical extent in Norway remai...

Schmidt-hammer exposure-age dating (SHD) was applied to a variety of boulder-dominated periglacial landforms in an attempt to establish a local mid-/late-Holocene chronology for the Geirangerfjellet in South Norway. Landform ages were obtained by application of a local calibration curve for Schmidt hammer R-values based on young and old control poi...

The effect of environmental conditions on reproductive traits in spiders is not completely understood. We studied the trade-off between the egg number and egg size of a common spider species along an elevational gradient in Norway. Life history theory predicts that egg size should decrease and clutch size increase as temperatures rise. In 2006, 201...

Through litter decomposition enormous amounts of carbon is emitted to the atmosphere. Numerous large-scale decomposition experiments have been conducted focusing on this fundamental soil process in order to understand the controls on the terrestrial carbon transfer to the atmosphere. However, previous studies were mostly based on site-specific litt...

Warming may lead to a cover increase of tundra shrubs and a north-and upward shift of tree-lines. The latter may be inhibited by a densification of shrub stands. However, the climatic drivers of near-treeline shrub growth are relatively unexplored, especially that of shrub species from different functional groups growing intertwined, in competition...

Schmidt-hammer exposure-age dating (SHD) was performed on blockfields and related landforms on Blåhø, Southern Norway. By developing a linear high-precision age-calibration curve through young and old control points of known age from terrestrial cosmogenic nuclide dating, it was possible to gain landform age estimates based on Schmidt hammer R-valu...

Schmidt-hammer exposure-age dating (SHD) was carried out on various talus derived periglacial and paraglacial landforms around Dalsnibba (1476 m a.s.l.) in proximity to the Geiranger fjord in Opplendskedalen. The investigated landforms comprise amongst others rock-slope failures and pronival ramparts. The ages of landforms are critical in terms of...

The Arctic and alpine biome is rapidly warming, which might be causing an encroachment of relatively tall woody shrub vegetation into tundra ecosystems, which will probably result in an overall positive feedback to climate warming. This encroachment is, however, believed to remain limited to the relatively warm parts of the biome, where taller shru...

Our study tries to close gaps in knowledge regarding Carabidae distribution and activity in response to microclimate following two steps. We aimed to characterize the spatio-temporal distribution of Carabidae species along multiple gradients and explain the activity-abundance of assemblages and their indicator species using microclimatic measuremen...

The arctic-alpine biome is warming rapidly, resulting in a gradual replacement of low statured species by taller woody species in many tundra ecosystems. In northwest North America, the remotely sensed normalized difference vegetation index (NDVI), suggests an increase in productivity of the arctic and alpine tundra and a decrease in productivity o...

Through litter decomposition enormous amount of carbon is emitted to the atmosphere. Numerous large-scale decomposition experiments have been conducted focusing on this fundamental soil process in order to understand the controls on the terrestrial carbon transfer to the atmosphere. However, previous studies were mostly based on site-specific litte...

Through litter decomposition enormous amounts of carbon is emitted to the atmosphere. Numerous large-scale decomposition experiments have been conducted focusing on this fundamental soil process in order to under-stand the controls on the terrestrial carbon transfer to the atmosphere. However, previous studies were mostly based on site-specific litt...

Monitoring lichen-rich vegetation types in central and northern Norway during the last decades has revealed a significant decrease of lichen cover over space and time. The possible reason for such a sharp decline could be the simultaneously increasing populations of reindeer. Despite this ongoing development, little knowledge exists about the exten...

Blockfields in high latitude mountain areas are a wide spread proxy for glaciation history. Their origin is debated since decades, especially in south-central Norway, where glaciation had a major global climate implication. Some authors explain old blockfield features by protection of cold-based ice, others claim they persisted as nunataks during t...

Schmidt-hammer exposure-age dating (SHD) was performed on various talus derived landforms on Blåhø in south-central Norway. By developing a linear high-precision age-calibration curve through young and old control points of known age from the same lithology, it was possible to determine landform age estimations. The application of Schmidt-hammer ex...

Rapid climate warming has resulted in shrub expansion, mainly of erect deciduous shrubs in the Low Arctic, but the more extreme, sparsely vegetated, cold and dry High Arctic, is generally considered to remain resistant to such shrub expansion in the next decades. Dwarf shrub dendrochronology may reveal climatological causes of past changes in growt...

How to assess the spatio-temporal variability of reindeer pastures? What about the actual utilization of pasture resources by reindeer? These topics are addressed as one example of recent landscape ecological research in the new edition of the textbook "landscape ecology" of H. Leser and J. Löffler.

Umweltprobleme nehmen kontinuierlich zu und werden komplexer! Die Landschaftsökologie beleuchtet die vielschichtige Problematik und zeigt Lösungen auf. Der integrative Ansatz in der Landschaftsökologie gewinnt vor dem Hintergrund zahlreicher und komplexer Umweltprobleme immer mehr an Bedeutung. Dieses Lehrbuch liefert einen umfassenden Überblick üb...

The current greening of arctic-alpine landscapes poses the question about its underlying ecological mechanisms. Given its importance across various contexts and scales, it is vital to understand the drivers of contemporary patterns in phytomass and primary productivity to improve predictions under altered environmental conditions. Here, we analysed...

Due to increasing anthropogenic habitat alteration, fragmentation, and loss, the analysis of how, when, and why animals select particular habitats has become a central issue in ecology and biogeography. Animals adapt to spatiotemporal variability in resources either by tracking these resources or by plasticity in behavior to cover their needs, lead...

Today’s overall challenges of reindeer pastoralism, i.e., pasture degradation, climate change, conflicting land use, and predation as well as the underlying meshwork of ecology, socio-economy, culture, and politics requires further research. Overutilization of pastures, reinforced by their general loss has led to a decrease in body weight of reinde...

There is an obvious need for a better understanding of the drivers of local spatial heterogeneity in alpine phytomass. Facing challenges in scaling relations with data available either at biome-scale or at plot-scale we wanted to disentangle the driving forces behind spatial patterns of phytomass, productivity, and energy content in alpine reindeer...

Climate-driven variability of habitat selection of large herbivores has not yet been explicitly analyzed. To this end, we aimed to better understand the climate-ecological mechanisms behind geographic patterns of reindeer (Rangifer tarandus tarandus) habitat utilization. Our study area comprised of the ranges of Filefjell Reinlag, southern Norway (...

Nitrogen (N) deposition has been increasing in alpine ecosystems, but its fate in soils and plants remains unclear. We assumed that the increased N load will be efficiently retained in alpine ecosystems but that the degree of N use efficiency changes with elevation. Thus, we performed a 3–year 15N tracer experiment, in which we added 1 g m−2 of eit...

Differentiations in reproductive traits along climatic gradients can be substantial for a species to spread along a wide spatial range. We compared the reproductive effort allocated to first egg sacs of five species of the genus Pardosa: P. palustris (Linnaeus 1758), P. amentata (Clerck 1757), P. lugubris (Walckenaer 1802), P. hyperborea (Thorell 1...

While striving for “global” species models of habitat selection, spatiotemporal variation in utilization patterns within a particular habitat and intraspecies variation in space use are still poorly understood. We addressed these challenges by exploring habitat use of domesticated reindeer (Rangifer tarandus tarandus), focusing on factors that unde...

Both the ‘cascade model’ of ecosystem service provision and the Driver-Pressure-State-Impact-Response framework individually contribute to the understanding of human–nature interactions in social–ecological systems (SES). Yet, as several points of criticism show, they are limited analytical tools when it comes to reproducing complex cause–effect re...

Deeper winter snow is hypothesized to favor shrub growth and may partly explain the shrub expansion observed in many parts of the arctic during the last decades, potentially triggering biophysical feedbacks including regional warming and permafrost thawing. We experimentally tested the effects of winter snow depth on shrub growth and ecophysiology...

This study addresses the spatial distribution of spiders (Araneae) in relation to their environment along multiple ecological and biogeographical gradients. Two study regions representing considerable variation in the alpine climate were sampled for epigeal spiders using pitfall traps: one in the oceanic region and one in the continental region of...

Our research addresses questions about how micro-climate affects activity abundance of a common and widespread harvestman in an alpine ecosystem. Activity patterns of the Harvestman Mitopus morio (Fabricius, 1779) were studied along different alpine gradients in the central Norwegian Scandes. Within a nested design, we surveyed 18 alpine habitats w...

Arctic and alpine ecosystems are among the most sensitive ecosystems regarding climate change, as the species which make up these ecosystems are adapted to the specific and harsh climatic conditions at high latitudes and altitudes. Increasing growing season temperatures may lead to a general northward and upward shift of arctic and alpine ecozones....

In recent years, increased focus has been put on the study of alpine ecosystems in high latitudes. Still there is an immense lack of knowledge regarding their faunistic characteristics. The present study analyses diversity patterns of ground beetles (Carabidae) across an elevational transect in the continental area of central Norway and aims to des...

Precipitation and topsoil samples from a climate transect over the Scandinavian Mountains, Norway, were analyzed for bulk and compound-specific delta O-18 values. The natural abundance of O-18 in the plant-derived hemicellulose biomarkers arabinose and xylose correlates positively with delta O-18 of bulk soil, but not with delta O-18 of precipitati...

The soil living oribatid Provertex kuehnelti Mihelcic, 1959 was sampled for the first time in Fennoscandia in the western part of Norway at Dalsnibba (More og Romsdal). We found seven individuals in pit fall traps during the snow free period of 2009. The specimens were sampled on a ridge 1332.2m.a.s.l. Between 15 July and 12 August 2009 three adult...

A number of new records of Chionea araneoides Dalman, 1816 from the county of Nordland (NSI and NSY) are presented. The total knowledge today indicates a distribution over the whole country. A single individual of Chionea crassipes Boheman, 1846 collected in Rana (NSI) contradicts an earlier assumption of a bicentric distribution in Norway. While C...

Climate change impact assessment studies (CCIAS) are a common approach and many publications on hydrological responses to climate change have been published. Nonetheless, CCIAS focusing on soil moisture are widely missing especially at the catchment scale where adaptation strategies are readily viable. The wide neglect of soil moisture in CCIAS con...

Climate change is expected to profoundly influence the hydrosphere of mountain ecosystems. The focus of current process-based research is centered on the reaction of glaciers and runoff to climate change; spatially explicit impacts on soil moisture remain widely neglected. We spatio-temporally analyzed the impact of the climate on soil moisture in...

Reindeer grazing has been entitled as ecological keystone in arctic-alpine landscapes. In addition, reindeer husbandry is tightly connected to the identity of the indigenous Sámi people in northern Europe. Nowadays, reindeer husbandry is challenged in several ways, of which pasture degradation, climate change, conflicting land uses and predation ar...

Mountain ecosystems are commonly regarded as being highly sensitive to global change. Due to the system complexity and multifaceted interacting drivers, however, understanding current responses and predicting future changes in these ecosystems is extremely difficult. We aim to discuss potential effects of global change on mountain ecosystems and gi...

Soil moisture is a highly dynamic ecological variable. This dynamic is especially distinct in high mountains areas, where topography, snow cover, micro-climate, vegetation, soil properties and land cover vary across short distances. For such areas, soil moisture modelling on a fine scale is therefore particularly challenging. We evaluated the distr...

Tree-ring widths and stable carbon and oxygen isotopes of five European larch trees from Lötschental, Switzerland were investigated for the period 1900–2004. The objective was to test the suitability of each of these parameters for high-frequency climate reconstructions. This is of special interest with regard to the problem of cyclic larch budmoth...