Albin Hammerle

Albin Hammerle
University of Innsbruck | UIBK · Institute of Ecology

Dr.

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82
Publications
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Publications

Publications (82)
Article
Full-text available
Lakes receive and transform significant amounts of terrestrial carbon and are often considered a source of atmospheric carbon dioxide (CO2). Yet, continuous direct measurements of lake‐atmosphere CO2 exchange with high temporal resolution are sparse. In this study, we measured the CO2 exchange of a mountain lake in the eastern Austrian Alps continu...
Article
Full-text available
Hydropower emits less carbon dioxide than fossil fuels but the lower albedo of hydropower reservoirs compared to terrestrial landscapes results in a positive radiative forcing, offsetting some of the negative radiative forcing of hydroelectricity generat ion. The cumulative effect of this lower albedo has not been quantified. Here we show, by quant...
Preprint
Full-text available
Research in environmental science relies heavily on global climatic grids derived from estimates of air temperature at around 2 meter above ground1-3. These climatic grids however fail to reflect conditions near and below the soil surface, where critical ecosystem functions such as soil carbon storage are controlled and most biodiversity resides4-8...
Article
Full-text available
p>The following authors were omitted from the original version of this Data Descriptor: Markus Reichstein and Nicolas Vuichard. Both contributed to the code development and N. Vuichard contributed to the processing of the ERA-Interim data downscaling. Furthermore, the contribution of the co-author Frank Tiedemann was re-evaluated relative to the co...
Article
Full-text available
Gross primary productivity (GPP), the CO2 uptake by means of photosynthesis, cannot be measured directly on the ecosystem scale but has to be inferred from proxies or models. One newly emerged proxy is the trace gas carbonyl sulfide (COS). COS diffuses into plant leaves in a fashion very similar to CO2 but is generally not emitted by plants. Labora...
Article
Full-text available
The FLUXNET2015 dataset provides ecosystem-scale data on CO2, water, and energy exchange between the biosphere and the atmosphere, and other meteorological and biological measurements, from 212 sites around the globe (over 1500 site-years, up to and including year 2014). These sites, independently managed and operated, voluntarily contributed their...
Article
Full-text available
The FLUXNET2015 dataset provides ecosystem-scale data on CO2, water, and energy exchange between the biosphere and the atmosphere, and other meteorological and biological measurements, from 212 sites around the globe (over 1500 site-years, up to and including year 2014). These sites, independently managed and operated, voluntarily contributed their...
Article
Full-text available
The potential of carbonyl sulfide (COS) flux measurements as an additional constraint for estimating the gross primary production depends, among other preconditions, on our understanding of the soil COS exchange and its contribution to the overall net ecosystem COS flux. We conducted soil chamber measurements of COS, with transparent chambers, in t...
Preprint
Full-text available
Gross primary productivity (GPP), the CO2 uptake by means of photosynthesis, cannot be measured directly on ecosystem scale, but has to be inferred from proxies or models. One newly emerged proxy is the trace gas carbonyl sulfide (COS). COS diffuses into plant leaves in a fashion very similar to CO2, but is generally not emitted by plants. Laborato...
Article
The Innsbruck Atmospheric Observatory (IAO) aims to investigate atmospheric chemistry, micrometeorology, and mountain meteorology in a synergistic fashion within an urban setting. A new measurement supersite has been established in order to study processes affecting the exchange of momentum, energy, trace gases, and aerosols in an Alpine urban envi...
Article
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The modification of the surface radiation and energy balance in urban areas causes the temperatures in these areas to exceed those of the surrounding countryside. It has thus been suggested that urban environments may serve as field laboratories for studying the effects of a warming climate on biota in a space-for-time substitution. Here we investi...
Article
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Plain Language Summary Plants are Earth's biggest contributor for cleaning the atmosphere of carbon dioxide and remove around one quarter of the carbon dioxide emitted by humans each year. However, this contribution cannot be measured directly and has to be inferred or modelled on the basis of related parameters. This introduces large uncertainties...
Article
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The viability of carbonyl sulfide (COS) measurements for partitioning ecosystem-scale net carbon dioxide (CO 2 ) fluxes into photosynthesis and respiration critically depends on our knowledge of non-leaf sinks and sources of COS in ecosystems. We combined soil gas exchange measurements of COS and CO 2 with next-generation sequencing technology (NGS...
Article
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Automated transparent chambers have gained increasing popularity in recent years to continuously measure net CO2 fluxes between low-statured canopies and the atmosphere. In this study, we carried out four field campaigns with chamber measurements in a variety of mountainous grasslands. A mathematic stationary point (or critical point, a point at wh...
Article
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Abstract Remote sensing of sun-induced chlorophyll fluorescence (SIF) has been suggested as a promising approach for probing changes in global terrestrial gross primary productivity (GPP). To date, however, most studies were conducted in situations when/where changes in both SIF and GPP were driven by large changes in the absorbed photosyntheticall...
Article
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Alpine ecosystems are, similar to arctic ecosystems, characterized by a very long snow season. Previous studies investigating arctic or alpine ecosystems have shown that winter CO2 effluxes can dominate the annual balance and that the timing and duration of the snow cover plays a crucial role for plant growth and phenology and might also influence...
Article
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This work aims to assess a diagnostic approach which links evapotranspiration (ET) to land surface temperature (LST) measured by thermal remote sensing in the Alps. We estimated gridded ET, from field (30 m) to regional (1 km) scales, and we performed a specific study on grassland ecosystems in the Alps in South Tyrol (Italy), to evaluate the model...
Presentation
Full-text available
Gross primary productivity (GPP) is the proximal driver of the terrestrial land sink, which presently removes around one quarter of the anthropogenic carbon dioxide (CO 2) emissions from the atmosphere each year and thus contributes towards slowing down anthropogenic climate change. Beyond the scale of single leaves, however, GPP cannot be measured...
Article
Central European grasslands are characterized by a wide range of different management practices in close geographical proximity. Site-specific management strategies strongly affect the biosphere-atmosphere exchange of the three greenhouse gases (GHG) carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4). The evaluation of environmental impact...
Article
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Atmospheric chemistry is fueled by a large annual influx of nonmethane volatile organic compounds (NMVOC). These compounds influence ozone formation, lead to secondary organic aerosol production, and play a significant role for the oxidizing capacity of the atmosphere. The anthropogenic NMVOC budget is considerably uncertain due to the diversity of...
Article
Full-text available
The trace gas carbonyl sulfide (COS) has lately received growing interest from the eddy covariance (EC) community due to its potential to serve as an independent approach for constraining gross primary production and canopy stomatal conductance. Thanks to recent developments of fast-response high-precision trace gas analysers (e.g. quantum cascade...
Article
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Nitrogen oxide (NOx) pollution is emerging as a primary environmental concern across Europe. While some large European metropolitan areas are already in breach of EU safety limits for NO2, this phenomenon does not seem to be only restricted to large industrialized areas anymore. Many smaller scale populated agglomerations including their surroundin...
Article
Full-text available
During recent years, carbonyl sulfide (COS), a trace gas with a similar diffusion pathway into leaves as carbon dioxide (CO2), but with no known “respiration-like” leaf source, has been discussed as a promising new approach for partitioning net ecosystem-scale CO2 fluxes into photosynthesis and respiration. The utility of COS for flux partitioning...
Conference Paper
Full-text available
The trace gas carbonyl sulfide (COS) has been proposed as a tracer for canopy gross primary production (GPP), canopy transpiration and stomatal conductance of plant canopies in the last few years. COS enters the plant leaf through the stomata and diffuses through the intercellular space, the cell wall, the plasma membrane and the cytosol like carbo...
Conference Paper
Full-text available
With an average mole fraction of 100 ppb carbon monoxide (CO) plays a critical role in atmospheric chemistry and has an indirect global warming potential. While sources/sinks of CO on land at least partially cancel out each other and their magnitude is very likely lower compared to other sinks and sources, the magnitude of CO sources and sinks is h...
Article
Full-text available
The trace gas carbonyl sulphide (COS) has lately received growing interest in the eddy covariance (EC) community due to its potential to serve as an independent approach for constraining gross primary production and canopy stomatal conductance. Thanks to recent developments of fast-response high-precision trace gas analysers (e.g. quantum cascade l...
Article
Full-text available
In complex, sloping terrain, horizontal measurements of net radiation are not reflective of the radiative energy available for the conductive and convective heat exchange of the underlying surface. Using data from a grassland site on a mountain slope characterised by spatial heterogeneity in inclination and aspect, we tested the hypothesis that a c...
Article
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Thermal infrared (TIR) cameras perfectly bridge the gap between (i) on-site measurements of land surface temperature (LST) providing high temporal resolution at the cost of low spatial coverage and (ii) remotely sensed data from satellites that provide high spatial coverage at relatively low spatio-temporal resolution. While LST data from satellite...
Article
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We evaluated the size effect on stem water status and growth in Norway spruce (Picea abies (L.) Karst.) occurring at the edge of its natural range in a dry inner Alpine environment (750 m asl, Tyrol, Austria). Intra-annual dynamics of stem water deficit (W), maximum daily shrinkage (MDS), and radial growth (RG) were compared among saplings (stem di...
Article
Full-text available
Plant phenological development is orchestrated through subtle changes in photoperiod, temperature, soil moisture and nutrient availability. Presently, the exact timing of plant development stages and their response to climate and management practices are crudely represented in land surface models. As visual observations of phenology are laborious,...
Article
Full-text available
In this paper we explore the skill of hyperspectral reflectance measurements and vegetation indices (VIs) derived from these in estimating carbon dioxide (CO2) fluxes of grasslands. Hyperspectral reflectance data, CO2 fluxes and biophysical parameters were measured at three grassland sites located in European mountain regions using standardized pro...
Article
Full-text available
Plant phenological development is orchestrated through subtle changes in photoperiod, temperature, soil moisture and nutrient availability. Presently, the exact timing of plant development stages and their response to climate and management practices are crudely represented in land surface models. As visual observations of phenology are laborious,...
Article
Full-text available
Pre-rain-event soil moisture (preSM) plays a crucial role when evaluating runoff formation during heavy rainfall. Using sprinkling experiments and numerical modeling, this study investigates the impact of preSM on runoff formation at the small hillslope scale (≤ 100 m 2). Sprinkling experiments were conducted on three sites in the Austrian Alps and...
Article
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This study analyzes the impact of droughts, compared with average climatic conditions, on the supporting ecosystem service water provision in sub-watersheds in managed alpine grasslands in two climatically different regions of the Alps, Lautaret (French Alps) and Stubai (Austrian Alps). Soil moisture was modeled in the range of 0-0.3 m. At both sit...
Article
Urban areas are known to have a local climate different from that of surrounding rural landscapes and the temperature difference constitutes an urban heat island (UHI). Despite being described as ‘heating islands’, cities are not isolated from their environment. But only few studies respect the UHI as a relative measure and consider both the driver...
Article
Pre-rain-event soil moisture (preSM) plays a crucial role when evaluating runoff formation during heavy rainfall. Using sprinkling experiments and numerical modeling, this study investigates the impact of preSMon runoff formation at the small hillslope scale (≤100m2). Sprinkling experiments were conducted on three sites in the Austrian Alps and obs...
Article
Full-text available
Above- and belowground processes in plants are tightly coupled via carbon and water fluxes through the soil–plant–atmosphere system. The oxygen isotopic composition of atmospheric CO2 and water vapour (H2Ov) provides a valuable tool for investigating the transport and cycling of carbon and water within this system. However, detailed studies on the...
Article
Full-text available
In this paper we explore the use of hyperspectral reflectance measurements and vegetation indices (VIs) derived therefrom in estimating carbon dioxide (CO2) fluxes (net ecosystem exchange – NEE; gross primary production – GPP), and some key ecophysiological variables related to NEE and GPP (light use efficiency – ε; initial quantum yield – α; and G...
Article
Full-text available
On-line measurements of photosynthetic carbon isotope discrimination (13Δ) under field conditions are sparse. Hence, experimental verification of the natural variability of instantaneous 13Δ is scarce, although 13Δ is, explicitly and implicitly, used from leaf to global scales for inferring photosynthetic characteristics. This work presents the fir...
Article
Field measurements of photosynthetic carbon isotope discrimination ((13) Δ) of Fagus sylvatica, conducted with branch bags and laser spectrometry, revealed a high variability of (13) Δ, both on diurnal and day-to-day timescales. We tested the prediction capability of three versions of a commonly-used model for (13) Δ [called here comprehensive ((13...
Article
Full-text available
It is well established that warming leads to longer growing seasons in seasonally cold ecosystems. Whether this goes along with an increase in the net ecosystem carbon dioxide (CO2) uptake is much more controversial. We studied the effects of warming on the start of the carbon uptake period (CUP) of three mountain grasslands situated along an eleva...
Article
Full-text available
Above- and belowground processes in plants are tightly coupled via carbon and water flows through the atmosphere-plant-soil system. While recent studies elucidated the influence of drought on the carbon flow through plant and soil using 13C, much less is known about the propagation of 18O. Therefore, this study aimed to examine the timing and inten...
Article
Cities and urban areas are known to have a local climate different from that of surrounding rural landscapes. The so-called 'urban heat island' phenomenon results from the replacement of natural with impervious, non-evaporative surfaces such as concrete and asphalt. Urban areas usually have higher solar radiation absorption and a greater thermal co...
Article
Available soil water is a major constraint for numerous ecosystem functions and is likely to be considerably affected by projected shifts in temperature and precipitation. Quantifying likely future changes in soil water content is therefore essential for assessing impacts of climate change on ecosystem functions. Here we present a modeling study ad...
Conference Paper
Full-text available
There has been much discussion about whether earlier vegetation greenup associated with global warming will allow for an earlier starts of the net carbon dioxide (CO2) uptake period (CUP) by vegetation and thus possibly increase the terrestrial carbon sink. One aspect of this discussion that has received little attention so far is that earlier vege...
Conference Paper
Background/Question/Methods In Central Europe, temperate grasslands are agroecosystems of high agricultural, ecological and economic importance. Growth, distribution and yield of this vegetation type depend strongly on the sufficiency of water supply in late spring/early summer. Until now, water has never been considered as a limiting factor. Howe...
Article
It is well established that warming leads to an earlier onset and delayed termination of seasonal plant activity in the Northern hemisphere. Whether this goes along with an increase or decrease in the carbon dioxide (CO2) sink strength of terrestrial ecosystems, however, is much more controversial. We used a simple model that considers temperature...
Article
The stable isotope 18O in water and carbon dioxide is a powerful tracer to investigate ecological processes, such as the coupled carbon-water cycle and can provide a constraint on the contribution of terrestrial ecosystems to the global carbon and water cycles. Recently, laser spectroscopic techniques for isotope measurements have been developed wh...
Article
The research project "Cooling Town" will investigate the thermal properties of landscapes and landscape elements and assess the thermal connectivity between urban areas and surrounding landscape components in South Tyrol (Italy). Surface temperature regimes will be analysed for selected municipalities and evaluated in regard to their relations to u...
Article
Biogeochemical models are often difficult to calibrate due to their complex structure and/or their large number of parameters. To provide reliable results as well as defensible estimations of uncertainty any data-fusion approach has to account for and quantify all errors consisting of input, model structural and parameter errors. Here we present a...
Article
Climate change is expected to affect the Alps by increasing the frequency and intensity of summer drought events with negative impacts on ecosystem water resources. The response of CO2 and H2O exchange of a mountain grassland to natural fluctuations of soil water content was evaluated during 2001-2009. In addition, the physiological performance of...
Article
Recent (13) CO(2) canopy pulse chase labeling studies revealed that photosynthesis influences the carbon isotopic composition of soil respired CO(2) (δ(13) C(SR)) even on a diel timescale. However, the driving mechanisms underlying these short-term responses remain unclear, in particular under drought conditions. The gas exchange of CO(2) isotopes...
Conference Paper
Background/Question/Methods A 13CO2 canopy pulse labeling experiment was conducted in order to investigate the impact of drought on (i) the time-lag between assimilation and (soil) respiration (ii) the role of leaf mobile and immobile carbon pools for soil respiration on a diurnal time-scale, and (iii) plant carbon allocation. The study was condu...
Article
When using the eddy covariance (EC) method for measuring the ecosystem–atmosphere exchange of sensible and latent heat, it is not uncommon to find that these two energy fluxes fall short of the available energy by 20 to 30%. As the causes for the energy imbalance are still under discussion, it is currently not clear how the energy balance should be...