The European Alps are undergoing rapid climatic and environmental changes that are strongly affecting regional carbon and nutrient dynamics across a wide range of ecosystems, including peatlands, wetlands, forests, grasslands and glacier forelands. Carbon stocks and fluxes, as well as nutrient cycling, are highly heterogeneous, shaped by steep climatic gradients, complex topography, land-use history, and hydrological controls. For instance, recent findings highlight that alpine peatlands are more widespread than previously assumed and represent important long-term carbon reservoirs, while alpine wetlands may function as dynamic and transitional systems. However, how differing Alpine ecosystems will respond to warming, altered precipitation regimes, cryospheric change, and land-use pressures, remains insufficiently understood.
This session brings together experts working on all facets of carbon and nutrient dynamics in Alpine soils, including both high and low elevation sites. We welcome contributions presenting new estimates of carbon stocks in vegetation and soils, measurements of greenhouse gas fluxes (e.g. CO₂ , CH₄ or N2O), emergent remote-sensing approaches, studies focused on below-ground hydrology, soil biogeochemistry, microbiology or vegetation dynamics. We also encourage submissions presenting monitoring networks, and modelling frameworks aimed at upscaling observations, quantifying uncertainties, and projecting future trajectories under changing climate and land-use scenarios. By integrating observational, experimental, and modelling perspectives, the session aims to foster interdisciplinary exchange and improve understanding of the current and future soil dynamics of the Alpine Region.
Registered Abstracts
The “from–to” times per abstract indicate the full presentation slot (if available: including an optional bracketed Q&A duration at the end)
Peatland Stratigraphy and Hydrogeology in Formerly Glaciated Alpine Regions
Mattiazzi, M.
Hopfinger, M.; Salcher, B.; Otto, J.-C.; Flores-Orozco, A.; Hilberg, S.; Tribsch, A.; Watson-Cook, E.; and Wimmer, X.
Abstract/Description
Peatlands are ecosystems that comprise the largest terrestrial carbon store on Earth. They play a critical role in climate change mitigation, while also supporting unique biodiversity, regulating water flow and serving as palaeoecological archives. Understanding the history of peatland formation is essential for predicting their future development. The influence of glaciations on postglacial peat-forming processes has received limited attention, even though glaciers exert a first-order control on peatland development in both mountain environments and lowlands.
Glaciers can provide suitable conditions for peatland formation by the ability to i) form local depressions and ii) deliver abundant fine sediments to induce ponding. However, the efficiency of glacial erosion strongly depends on geological factors like rock erodibility or basal topography. Other factors may in turn impede postglacial peat accumulation despite apparently suitable geological and climatic conditions. These include e.g. a high flood frequency, fluvial erosion in alluvial valleys, or, in mountainous environments, high landslide frequency.
We apply a combination of geophysical methods, including ground penetrating radar and electrical resistivity tomography, and core drilling to investigate peatland stratigraphy and hydrogeology. We present characteristic peatland environments in central and perialpine settings and discuss how i) glacial depositional and ii) glacial erosional processes control their formation. In addition, we examine the onset of peat growth and rates of peat accumulation in formerly glaciated regions of the Eastern Alps.
These insights contribute to the understanding of present-day peatland ecosystem functioning, and the interactions between subsurface stratigraphy, hydrological characteristics and vegetation patterns. Such knowledge is essential for predicting their response to future climate change.
CO2 fluxes at high-altitude mountain ecosystems: a comparative study of two grasslands in the Aosta valley
Vivaldo, G.
Ferraris, D.; Baneschi, I.; Baronetti, A.; Giamberini, M. S.; Provenzale, A.; Brunella, R.; and Galvagno, M.
Abstract/Description
Mountain ecosystems are highly sensitive to the impacts of climate change. Nevertheless, our knowledge of critical biogeochemical processes—key to understanding how these ecosystems cope to shifting environmental conditions—remains limited.
This study investigates and compares turbulent carbon dioxide (CO₂) fluxes measured using the eddy covariance (EC) technique at two high‑elevation Italian sites: Torgnon and Nivolet in the Western Alps. These locations belong to the ICOS (Integrated Carbon Observatory System) network as Associated stations IT‑Tor (Torgnon) and IT‑Niv (Nivolet). Both are unmanaged subalpine grasslands situated at 2050 m and 2750 m a.s.l., respectively, and host distinct plant community compositions. Snow typically persists from late October to late May at IT‑Tor, and until June at IT‑Niv, resulting in a growing season of roughly four to five months. Continuous EC measurements of CO₂ fluxes have been collected at IT‑Tor since June 2017 and at IT‑Niv since June 2019.
This work compares CO₂ fluxes from the two sites under similar meteorological conditions to highlight ecophysiological differences between the two grassland canopies. Furthermore, phenological dynamics are examined to assess how each ecosystem responds to extreme weather events, including the 2022 summer drought, the most intense episode recorded over the past 17 years.
Our findings highlight how vulnerable mountain ecosystems are to climate change, stressing the importance of sustained monitoring efforts to improve their understanding and management. Differences in ecophysiological responses between the two sites will be explored in connection with their elevation, species composition, and past management practices.
Ongoing research, combining long-term data with advanced modeling approaches will be crucial for developing a more comprehensive understanding of how climate extremes affect mountain ecosystems across Europe.
Declining SOC storage in Swiss mountain grasslands as an effect of declining effective storage capacity?
Volk, M.
Uvere, F.; and Huguenin-Elie, O.
Abstract/Description
In an earlier experiment above the Engadine valley (2200 m a.s.l., Canton Grisons) we demonstrated the climate sensitivity of subalpine pasture carbon (C) stocks, resulting in a negative net ecosystem C balance of ca. 10 t C ha-1 in five years with + 3°C warming, despite unaffected plant productivity. A follow-up study, using a long-term (32 yrs.) grassland mineral fertilisation experiment above the Albula valley (1200 m a.s.l., Canton Grisons), indicated that under strongly limiting nitrogen (N) supply, the uniformly low N-availability set allometric limitations for microbial decomposition, leading to uniformly declining soil organic C (SOC) stocks.
In the study presented here, we analysed another long-term grassland fertilisation experiment in the Swiss Jura mountains (920 m a.s.l., Canton Solothurn), providing 22 years of climate, yield and SOC stock data. We attempted to isolate the effects of plant yield gradients (2.8 – 8.3 t dry matter ha-1 yr-1) and N-availability (0 – 150 kg N ha-1 yr-1) in driving SOC stock change.
We hypothesised that N-fertilisation driven plant productivity affects both organic matter availability for SOC storage and interacts with N availability driven C use efficiency levels to generate different, steady-state SOC stocks. But if SOC stocks would not differ between treatment combinations, we assumed that the climate factor, consisting of a distinct pattern of temperature and precipitation, would act evenly on effective SOC storage capacity and would result in the same SOC stocks in all treatment combinations.
We found that while plant productivity was highly responsive to different mineral fertilisation levels, SOC stocks were not responsive to either plant productivity or N input, even though they usually constitute limiting factors for soil C storage. This led us to assume that we observed, on a decadal scale, the decline from an earlier effective SOC storage capacity to a new, lower effective storage capacity. We deduce that the SOC stock decline is driven by increased temperatures, that have increased OM decomposition rates. This implies, that under the given edaphic conditions and including a wide range of agricultural management options, the warming climate constitutes an increasingly limiting factor for SOC storage.
Tracing Carbon Flux Dynamics and Ecosystem Functioning Along a Land-Use Gradient: Long-Term Eddy Covariance Observations in the western Italian Alps
Ferraris, D.
Galvagno, M.; Oddi, L.; Filippa, G.; Cremonese, E.; Pogliotti, P.; Grosso, F.; Morra di Cella, U.; Koliopoulos, S.; Guarnieri, C.; Wohlfahrt, G.; Leitinger, G.; Migliavacca, M.; Hammerle, A.; and Papale, D.
Abstract/Description
This study reports a comparative investigation of two alpine research sites situated in the Aosta Valley (Italian Alps), representing distinct neighbouring ecosystems: a high-altitude grassland and a mature larch forest. Eddy covariance flux measurements have been operational since 2008 at the grassland site (2168 m a.s.l.) and since 2012 at the larch forest site (2100 m a.s.l.). Each station is fully instrumented for flux and meteorological observations using identical instrumentation. The straight-line distance between the two sites is approximately 2.7 km and they experience comparable climatic conditions, thereby enabling direct inter-site comparisons. The primary aim of this study is to quantify and interpret differences in the carbon dioxide exchange between these ecosystems, with particular attention to the peculiarities of the years showing extreme meteorological conditions. The two sites represent contrasting stages along a land‑use transition gradient, where the abandoned grasslands — no longer subject to livestock grazing since 2008, when the area was fenced and permanently excluded from grazing — exhibit a progressive encroachment by woody
species, ultimately evolving into mature larch stands. This is a widely documented process in the Alpine region: the abandonment of traditional grazing practices and the subsequent natural recolonization of former grasslands by forest species. To complement this analysis, preliminary results from a third eddy covariance station, installed in 2024 within a transitional ecotone characterized by scattered small larch saplings and shrub
species, will also be presented. Overall, this study demonstrates how multi-year eddy covariance measurements can reveal differences in ecosystem functioning under the same climatic conditions but across distinct vegetation types and successional stages, offering new insights into carbon flux dynamics along alpine land-use gradients.
Eddy-covariance CO₂ flux measurements at an alpine forest site
Platter, A.
Hammerle, A.; and Wohlfahrt, G.
Abstract/Description
We present eddy-covariance measurements of CO₂ exchange (net ecosystem exchange, NEE) from 2022–2025 from the Forest-Atmosphere-Interaction-Research (FAIR) site on the Mieminger Plateau, Tyrol, Austria, in a Scots pine (Pinus sylvestris) forest. Using observations from a measurement tower above the canopy, we quantify seasonal and interannual variability in ecosystem carbon budgets. Over the study period, the forest acted as a net CO₂ sink with annual NEE on the order of -100 g C m–2. Uptake typically peaks in spring, while frequent warm, dry spells in summer shift the system toward net carbon release, indicating that the timing of extremes is more consequential than mean climatic conditions and helps explain interannual variability.
To identify the dominant drivers of NEE dynamics, we fit Generalized Additive Models (GAMs) using air temperature, relative humidity, soil moisture, and shortwave radiation as predictors. Partial effects reveal a temperature optimum for gross primary production (GPP) around 17–20 °C. Simple scenario analyses based on the fitted GAMs suggest that, considering GPP alone, moderate warming could enhance photosynthetic uptake. However, accounting for ecosystem respiration, which is strongly temperature-sensitive, reduces sink strength and can shift the net balance towards a carbon source under warmer climates.
We further illustrate the role of event timing with simple extreme-event scenarios: a spring heatwave can increase net uptake under high light and favorable water status, whereas a comparable event in summer substantially reduces uptake or induces net release. These results emphasize how seasonal context and the timing of extreme events control alpine forest carbon dynamics.
Submitted Abstracts
If you are not yet logged-in, please log in to your My#Conf environment
Click “Submissions” and select the session you want to review (you need to be chair or co-chair to see the session and the submissions to the session) by clicking on the “external link” symbol:
On the selected session page, scroll down to get to the section “Submitted abstracts”.
-> this list shows all abstracts submitted to your session.
-> each line shows one abstract
To get to the review section, please click on the “eye” symbol: of the abstract.
-> the abstract expands and new sections (First author, Co-author(s) and description) appear.
-> additional, the abstract review area appears below the abstract content.
The review area gives you now a new panel to adjust: FOR CO-CHAIRS
-> dropdown menu to set a review recommendation (you can overwrite this recommendation as often as you want)
-> optional: comments to share with your chair-colleagues and the organizing committee (max. 50 characters, not visible for the authors of the abstract) INFO: You can change your review (incl. comments) for an abstract as often as you want until the chair makes the final decision. Changes are overwritten and not archived.
FOR CHAIRS
-> checkbox to set your final review (when activated, you confirm your final choice and will close the review process of this abstract)
-> optional: comments to share with your co-chair(s) and the organizing committee (max. 50 characters, not visible for the authors of the abstract) INFO: You can leave comments without making your final review as often as you want. Changes are overwritten and not archived. When activating the checkbox, you make your final review and close the review process for this abstract. In case of an erroneous review, you can of course contact us via contact form (please provide the abstract number). You can do the review no matter if your co-chair(s) have already submitted a review recommendation or not.
Details of the used icons/symbols
Once the review of the abstract is completed by the chair, this icon appears.
If at least one review/comment has been provided by the co-chair, this icon appears.
If at least one comment has been provided by the (co-)chair(s), this icon appears.
IMPORTANT: The review result (of the chair) is a general recommendation to the organizing committee, which finally decides on the review. In most cases, we will follow your decisions and in case changes are needed due to organizational issues (e.g. not enough contributions for an individual session), we would contact you. The authors of the abstracts will not be informed immediately after you completed the review but after the end of the review phase.
Abstracts are only visible to (co-)chairs at the moment. Please log in with your account to see this list.
If you are not yet logged-in, please log in to your My#Conf environment
Click “Submissions” and select the session you want to review (you need to be chair or co-chair to see the session and the submissions to the session) by clicking on the “external link” symbol:
On the selected session page, scroll down to get to the section “Submitted abstracts”.
-> this list shows all abstracts submitted to your session.
-> each line shows one abstract
To get to the review section, please click on the “eye” symbol: of the abstract.
-> the abstract expands and new sections (First author, Co-author(s) and description) appear.
-> additional, the abstract review area appears below the abstract content.
The review area gives you now a new panel to adjust: FOR CO-CHAIRS
-> dropdown menu to set a review recommendation (you can overwrite this recommendation as often as you want)
-> optional: comments to share with your chair-colleagues and the organizing committee (max. 50 characters, not visible for the authors of the abstract) INFO: You can change your review (incl. comments) for an abstract as often as you want until the chair makes the final decision. Changes are overwritten and not archived.
FOR CHAIRS
-> checkbox to set your final review (when activated, you confirm your final choice and will close the review process of this abstract)
-> optional: comments to share with your co-chair(s) and the organizing committee (max. 50 characters, not visible for the authors of the abstract) INFO: You can leave comments without making your final review as often as you want. Changes are overwritten and not archived. When activating the checkbox, you make your final review and close the review process for this abstract. In case of an erroneous review, you can of course contact us via contact form (please provide the abstract number). You can do the review no matter if your co-chair(s) have already submitted a review recommendation or not.
Details of the used icons/symbols
Once the review of the abstract is completed by the chair, this icon appears.
If at least one review/comment has been provided by the co-chair, this icon appears.
If at least one comment has been provided by the (co-)chair(s), this icon appears.
IMPORTANT: The review result (of the chair) is a general recommendation to the organizing committee, which finally decides on the review. In most cases, we will follow your decisions and in case changes are needed due to organizational issues (e.g. not enough contributions for an individual session), we would contact you. The authors of the abstracts will not be informed immediately after you completed the review but after the end of the review phase.
We are processing your request…Just a few seconds — thanks for your patience…Almost done — preparing everything for you…Huuuh… this seems to be a difficult thing 🤔I’m not sure if I can manage this right now…
Please refresh the page — I think something went wrong.
If this happens again, please get in touch with us.
