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The development and functions of ecosystems and their responses to environmental drivers are inherently long-term processes that need to be studied along gradients in time and space. Global anthropogenic drivers of change interact with natural processes, causing uncertainties, tipping points and potential crises in system behaviour. Further, most ecosystem services are strongly interlinked and require a multi- and transdisciplinary approach that allows for the simultaneous analysis of multiple processes and feedbacks. The environmental drivers affecting one domain are also easily reflected in other domains. Considering the current extensive land use changes and climate change, integrated studies where aquatic and terrestrial ecosystems are studied in combination are urgently required. The sites and platforms of the long-term ecosystem, critical zone and socio-ecological research networks and research infrastructures (ILTER, eLTER) distributed around the globe offer a unique tool for this, while coupled ecosystem-scale experimentation (AQUACOSM) can further strengthen the hypothesis testing.

This session focuses on research performed at sites and platforms implementing a whole system approach, also cross the terrestrial and aquatic domains. Emphasis will be on results presenting long-term changes and responses of ecosystem and socio-ecological processes to environmental drivers, as well as ecosystem-scale experiments (mesocosms) and observations scaling up from sites to larger regions up to the continental level.

We welcome studies linking biodiversity loss, climate change, and other anthropogenic pressures to ecosystems. We encourage contributions using interdisciplinary and multidisciplinary approaches, addressing relationships among different ecosystem compartments (vegetation, soils, waters etc.) or between ecological and social systems, as well as transdisciplinary studies that incorporate diverse forms of knowledge beyond the scientific community.

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Co-sponsored by eLTER and ILTER
Convener: Michael Mirtl | Co-conveners: Jaana Bäck, Giorgio Matteucci, Daniel Orenstein
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| Attendance Fri, 08 May, 10:45–12:30 (CEST)

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Chat time: Friday, 8 May 2020, 10:45–12:30

Chairperson: Mirtl, Bäck
D367 |
EGU2020-2651
| Highlight
Antonello Provenzale, Carl Beierkuhnlein, Silvia Giamberini, Simona Imperio, Carmela Marangi, and Ramona Viterbi

The EU H2020 ECOPOTENTIAL project was devoted to make best use of Earth observations to improve ecosystem benefits and support conservation strategies. The project followed a whole-ecosystem approach, with special attention to geosphere-biosphere interactions. The project, started in 2015 and ended in 2019, focused its activities on a set of more than 20 protected areas of international relevance in Europe and beyond, many of which are also eLTER and ILTER sites, covering a wide array of biogeographic regions and ecosystems (www.ecopotential-project.eu). The site/sites – specific research activities have been developed within a comprehensive framework (called the project’s “Storylines”) where real-life issues of broad conservation relevance for Protected Areas are linked with research questions. The Storylines specify the needs for remote sensing and in-situ data for ecosystem modelling, ecosystem service assessment, cross-scale interaction estimates, demands for future protections, policy and capacity building. Each storyline has been focused within at least one protected area and has sets the basis for further operational work in the field, adding specifics, defining a work plan and assigning tasks. Storylines have been conceived as iterative processes whose flow of activity and practical implementation evolved with the increase of knowledge and the demands by the users of the scientific findings. After a general introduction to the Storyline approach, here we focus on the case of the Gran Paradiso National Park, considering population dynamics of wild ungulates, biodiversity assessments and Critical Zone exploration. The Storyline concept is now left as a legacy of the ECOPOTENTIAL project to eLTER RI and to the GEO ECO community activities.

How to cite: Provenzale, A., Beierkuhnlein, C., Giamberini, S., Imperio, S., Marangi, C., and Viterbi, R.: ECOPOTENTIAL Storylines: a whole system approach to Protected Area ecosystems, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-2651, https://doi.org/10.5194/egusphere-egu2020-2651, 2020

D368 |
EGU2020-21461
Angela Lausch, Peter Dietrich, and Jan Bumberger

Ecosystems fulfil a whole host of ecosystem functions that are essential for life on our planet. However, an unprecedented level of anthropogenic influences is reducing the resilience and stability of our ecosystems as well as their ecosystem functions. The relationships between drivers, stress and ecosystem functions in ecosystems are complex, multi-facetted and often non-linear and yet environmental managers, decision makers and politicians need to be able to make rapid decisions that are data-driven and based on short- and long-term monitoring information, complex modeling and analysis approaches. A huge number of long-standing and standardized ecosystem health and monitoring approaches of bio-and geodiversity exist and are increasingly integrating remote-sensing based monitoring approaches. Unfortunately, these approaches in monitoring, data storage, analysis, prognosis and assessment still do not satisfy the future requirements of information and digital knowledge processing of the 21st century. This presentation presents new concepts of monitoring of bio-and geodiversity and discusses the requirements for using Data Science as a bridge between complex and multidimensional Big Data in environmental health.

It became apparent that no existing monitoring approach, technique, model or platform is sufficient on its own to monitor, model, forecast or assess forest health and its resilience. In order to advance the development of a multi-source ecosystem health monitoring network, we argue that in order to gain a better understanding of ecosystem health in our complex world it would be conducive to implement the concepts of Data Science with the components: (i) digitalization, (ii) standardization with metadata management after the FAIR (Findability, Accessibility, Interoperability, and Reusability) principles, (iii) Semantic Web, (iv) proof, trust and uncertainties, (v) tools for Data Science analysis and (vi) easy tools for scientists, data managers and stakeholders for decision-making support (Lausch et al., 2019, 2018, 2016).

 

Lausch, A., et al., 2019. Linking Remote Sensing and Geodiversity and Their Traits Relevant to Biodiversity—Part I: Soil Characteristics. Remote Sens. 11, 2356. https://doi.org/10.3390/rs11202356

Lausch, A., 2016. Linking Earth Observation and taxonomic, structural and functional biodiversity: Local to ecosystem perspectives. Ecol. Indic. 70, 317–339. https://doi.org/10.1016/j.ecolind.2016.06.022

Lausch, A., 2018. Understanding Forest Health with Remote Sensing, Part III: Requirements for a Scalable Multi-Source Forest Health Monitoring Network Based on Data Science Approaches. Remote Sens. 10, 1120. https://doi.org/10.3390/rs10071120

How to cite: Lausch, A., Dietrich, P., and Bumberger, J.: Monitoring bio- geodiversity and ecosystem health by traits, remote sensing and data science approaches, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-21461, https://doi.org/10.5194/egusphere-egu2020-21461, 2020

D369 |
EGU2020-19266
Ludovica Oddi, Marta Galvagno, Edoardo Cremonese, Gianluca Filippa, Mirco Migliavacca, Mauro Bassignana, Umberto Morra di Cella, and Consolata Siniscalco

Climate and land-use changes have major impacts on global biodiversity and carbon cycle of ecosystems. Severe heat waves and droughts, already experienced by the European Alps, e.g. in 2015 and 2018, are expected to further increase in the near future.

In the last decades, land-use changes have led to the abandonment of several mountain grasslands and pastures, so that in Europe a net conversion of grasslands to forest is currently occurring. However, the consequences of alpine grassland abandonment on the ecosystem responses to climate extremes are still largely unknown. Understanding climate change impacts and feedbacks of alpine and subalpine grasslands is essential, because they are ecologically sensitive ecosystems, and they constitute an important C sink and hotspots of biodiversity.

In this work we aim at understanding the effects of heat waves and drought on the relative productivity of grasses and forbs and consequently on ecosystem functioning in an abandoned subalpine grassland located in the Western Italian Alps (Aosta Valley) at 2100 m asl. We took advantage of a 10-years natural experiment in which we analysed biomass production, LAI and Net Ecosystem CO2 Exchange. Vegetation of the study area is characterized by a dominance of the grass Nardus stricta, and by Arnica montana, Trifolium alpinum, Geum montanum and several other forb species typical of alpine and subalpine grasslands.

In the period 2009-2019, primary production as represented by biomass and leaf area index (LAI) gradually decreased with important drops in 2015 and 2018, which were characterised by extreme climatic conditions.

Considering the functional type response to extremes, the LAI peak of grasses, which appeared always the dominant portion of the total LAI, showed significantly lower values in 2015 and 2018 compared to long-term. On the other hand, LAI peak values of forbs showed higher variability among plots and years. The clear decrease of the LAI of grasses (mainly represented by Nardus stricta) contributed significantly to the decrease of the total biomass production and to the NEE reduction. The response of Nardus stricta to heat waves and drought is very clear and influences ecosystem functioning and consequently vegetation dynamics, modifying the relative productivity of grasses and forbs. As an example, in the years 2015 and 2018 an evident phenological response was observed in Arnica montana, with an exceptional number of inflorescences.

In conclusion, we found that heat waves and droughts have the potential to influence the natural vegetation dynamics following abandonment and contribute to the reduction of plant biomass production with consequences on the net ecosystem C exchange and species competition in mountain grasslands.

How to cite: Oddi, L., Galvagno, M., Cremonese, E., Filippa, G., Migliavacca, M., Bassignana, M., Morra di Cella, U., and Siniscalco, C.: Heat waves and droughts strongly impact productivity and ecosystem functioning in an abandoned subalpine grassland, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-19266, https://doi.org/10.5194/egusphere-egu2020-19266, 2020

D370 |
EGU2020-22096
| Highlight
Christiane Hasemann, Ingo Schewe, and Thomas Soltwedel

The past decades have seen remarkable changes in key arctic variables, including a decrease in sea-ice extent and sea-ice thickness, changes in temperature and salinity of arctic waters, and associated shifts in nutrient distributions. To detect and track the impact of large-scale environmental changes in the transition zone between the northern North Atlantic and the central Arctic Ocean, the Alfred Wegener Institute for Polar and Marine Research (AWI) established in 1999 about 150 km west of Svalbard the deep-sea long-term observatory HAUSGARTEN, which constitutes the first, and until now only open-ocean long-term station in a polar region. 21 permanent sampling sites along a depth transect between 1000 – 5500 m, and along a latitudinal transect following the 2500 m water depth isobath are revisited yearly. The central HAUSGARTEN station serves as an experimental area for biological short- and long-term experiments at the deep seafloor, simulating various scenarios in changing environmental settings. Multidisciplinary research activities at HAUSGARTEN comprise biochemical analyses to estimate the input of organic matter from phytodetritus sedimentation and activities and biomasses of the small sediment-inhabiting biota as well as assessments of distribution patterns of benthic organisms (covering size classes from bacteria to meiofauna as well as megafauna).The past decades have seen remarkable changes in key arctic variables, including a decrease in sea-ice extent and sea-ice thickness, changes in temperature and salinity of arctic waters, and associated shifts in nutrient distributions. To detect and track the impact of large-scale environmental changes in the transition zone between the northern North Atlantic and the central Arctic Ocean, the Alfred Wegener Institute for Polar and Marine Research (AWI) established in 1999 about 150 km west of Svalbard the deep-sea long-term observatory HAUSGARTEN, which constitutes the first, and until now only open-ocean long-term station in a polar region. 21 permanent sampling sites along a depth transect between 1000 – 5500 m, and along a latitudinal transect following the 2500 m water depth isobath are revisited yearly. The central HAUSGARTEN station serves as an experimental area for biological short- and long-term experiments at the deep seafloor, simulating various scenarios in changing environmental settings. Multidisciplinary research activities at HAUSGARTEN comprise biochemical analyses to estimate the input of organic matter from phytodetritus sedimentation and activities and biomasses of the small sediment-inhabiting biota as well as assessments of distribution patterns of benthic organisms (covering size classes from bacteria to meiofauna as well as megafauna).

How to cite: Hasemann, C., Schewe, I., and Soltwedel, T.: Benthic investigations at the Arctic long-term deep-sea observatory HAUSGARTEN, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-22096, https://doi.org/10.5194/egusphere-egu2020-22096, 2020

D371 |
EGU2020-4901
Simon Haberstroh, Maria C. Caldeira, Raquel Lobo-do-Vale, Joana Martins, Maren Dubbert, Joaquim G. Pinto, Matthias Cuntz, Miguel N. Bugalho, and Christiane Werner

Mediterranean type ecosystems such as cork oak (Quercus suber) woodlands are currently threatened by extreme drought events and shrub encroachment in the Iberian Peninsula. Recently, the frequency of extreme droughts has increased with negative effects on many ecosystems. Decreasing soil water availability reduces growth and fitness of trees, and may eventually induce tree mortality. Shrub encroachment may further increase the competition for soil water, impacting tree vulnerability and resilience negatively. Yet, the synergistic effects of extreme droughts and shrub encroachment on ecosystems have rarely been investigated.

We established a precipitation manipulation and shrub encroachment experiment in a cork oak stand to study the combined effects of the two environmental pressures. The cork oak woodland is located in Southeast Portugal and partially invaded by the native shrub gum rockrose (Cistus ladanifer). In December 2017, we installed rainout shelters (30 to 45% of precipitation reduction) in replicated cork oak stands invaded and uninvaded by gum rockrose, complemented by control plots with natural precipitation. In each treatment, the trees (n = 9) and shrubs (n = 9) were measured for water and carbon fluxes to reveal species-specific responses and competition effects under recurrent extreme drought.

The hydrological year 2018 was characterised by above-average precipitation mainly caused by large spring rainfall events. Probably due to sufficient water supply, no clear treatment effects were evident. For example, minimum leaf water potentials (ΨPD) of the cork oak trees did not drop below −1.5 ± 0.1 MPa and maximum sap flux density was 2.1 ± 0.2 m3 m−2 day1. Minimum ΨPD of the shrubs was three times lower (−3.5 ± 0.1 MPa) and maximum sap flux density over four-fold higher (8.8 ± 0.8 m3 m−2 day1) than those of the trees, suggesting distinct species-specific behaviour. Reduced winter and spring precipitation, combined with a late onset of autumn rainfalls in 2019, led to a decrease in water input down to 66% (control) and 44% (drought) compared to the long-term average of 585 mm. In this dry year, negative synergistic effects of drought and shrub encroachment were expressed during the dry-down and drought period by a lower minimum ΨPD and an average sap flux density reduced by 50% (0.4 ± 0.1 m3 m−2 day1) of invaded trees exposed to the experimental drought, compared to control trees (0.8 ± 0.1 m3 m−2 day1). In sum, this resulted in a reduction of sap flux densities of the cork oaks by 25% (invaded), 23% (drought) and 34% (drought and invaded) over the course of the hydrological year 2019. The ongoing investigations aim to further determine the stress tolerance and critical physiological thresholds for both species and the entire ecosystem.

How to cite: Haberstroh, S., Caldeira, M. C., Lobo-do-Vale, R., Martins, J., Dubbert, M., Pinto, J. G., Cuntz, M., Bugalho, M. N., and Werner, C.: Mediterranean cork oak woodlands and global changes: Synergistic and negative effects of recurrent droughts and shrub encroachment, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-4901, https://doi.org/10.5194/egusphere-egu2020-4901, 2020

D372 |
EGU2020-10945
Marina Fischer-Kowalski

Transition pathways of the Greek island Samothraki from an agrarian sociometabolic regime to modern tourism and beyond: a real world lab in sustainability

Marina Fischer-Kowalski[1], Nikos Skoulikidis[2], Georg Gratzer[3]

 We reconstruct the developmental course of a small mountainous Greek island during the past decades in qualitative and quantitative terms. Conceptually, these efforts are integrated by a socio-metabolic system model (Fischer-Kowalski & Petridis 2016). The approaches from the angle of various disciplines (social ecology, land-use science, aquatic science, forest ecology) as well as the transdisciplinary collaborative approaches sought to compensate for the lack of long-term environmental monitoring data. Ultimate goal of this interdisciplinary and transdisciplinary research was (and is) giving scientific support to a local sustainability transition. We briefly describe the following sociometabolic stages of this process.

stage 1: traditional agrarian / foraging (fishing) socio-metabolic regime

Its features dominated up into the 1960s; the island sustained a population of 3-4000 people on livestock herding (sheep and goats), subsistence agriculture and fishing. Technical energy source: wood and charcoal from mountain forests (Quercus petraea). Grazing was the dominant land-use. Livestock breeding (mainly goats and sheep) was exclusively based on human manpower: free roaming animals, land management practices like regular burning of weeds on pastures.

stage 2: gradual transition to a modern industrial / touristic regime

Beginning with electrification (local diesel aggregate) and state services (schools, health care, road building, legal institutions, expansion of harbour and ferry services) in the 1960s, the island gradually turns into a (modest, national) tourist destination. Income for farmers/herders lags behind, and is supported by state, and later, EU subsidies. The coupling of subsidies to animal numbers leads to a substantial rise in small ruminants, serious overgrazing and decline in vegetation cover (Fetzel et al. 2018) and biodiversity (Biel and Tan 2014), lack of forest regrowth (Heiling 2019), increase in soil erosion (Panagopoulos et al. 2019) as well as rising demand for freshwater and a rising generation of wastewater (Skoulikidis et al. 2019a,b).

stage 3: designing a real-world experiment towards a sustainable future for the island

In the face of the Greek financial crisis, with support from Unesco, a team of scientists from various countries engaged in finding pathways to secure a sustainable course for the island’s future. Upon their advice, the municipality and the relevant Greek authorities in 2013 signed an application for the island to become a Man-and-Biosphere Reserve by Unesco standards, the municipality granted a local LTER-observatory, the regional authority rejected an industrial wind farm proposal, and Unesco welcomed these efforts. The municipality and grass roots actors use the support from international scientists to find sustainable solutions for problems that have been accumulating.

 

 

 

[2] Hellenic Centre for Marine Research, Athens

[3] Institute for Forest Ecology, University of Natural Resources and Life Sciences Vienna

 

How to cite: Fischer-Kowalski, M.: Transition pathways of the Greek island Samothraki from an agrarian sociometabolic regime to modern tourism and beyond: a real world lab in sustainability, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-10945, https://doi.org/10.5194/egusphere-egu2020-10945, 2020

D373 |
EGU2020-20249
| Highlight
Kaisa-Riikka Mustonen, Hannu Marttila, Kaisa Lehosmaa, Iina Koivunen, Jeffrey Welker, Annalea Lohila, and Jussi Jyväsjärvi

Carbon -water interactions are critical components of Arctic freshwater ecosystems. Dissolved organic matter (DOM) is the basis for in stream biological processes and is the foundation of biogeochemical linkages between terrestrial and aquatic landscapes, and also between the river bodies and the atmosphere via outgassing. Quantity and quality of DOM is further affecting the biochemical processes of aquatic ecosystems, as it is strongly related to the abundance, activity and composition of microbial communities. Microbes are an important part of the freshwaters biochemical cycle as they convert DOM into nutrients. They also play a vital role in carbon mineralization into carbon dioxide (CO2) and methane (CH4), which can further be released to the atmosphere resulting substantial greenhouse gas (GHG) emissions. Thus, streams play an important role in global carbon processing, storage and release. However, small Arctic streams and ecologically important interfaces between aquatic and terrestrial ecosystems, in particular, are under-represented in global atmospheric GHG emission estimates owing to a lack of spatial and temporal flux measurements in Arctic conditions.

The objective of our study was to improve understanding of the connections between hydrology, carbon cycle and GHG flux dynamics in Arctic watersheds. We used combination of multiscale measurements to quantify carbon availability (DOC/DIC concentrations) and quality (water absorbance, SUVA254 index), water sources (stable H2O isotope proxies), microbial community structure (rRNA sequencing), and CO2 and CH4 fluxes and stream water concentrations. Our study site is typical groundwater influenced peatland dominated second order watershed located at Pallas-Yllästunturi National Park in northern Finland. Sampling was conducted three times during summer 2019 at 20 locations along the stream gradient.

Preliminary results indicate this stream to be a significant contributor of CO2 and CH4. GHG fluxes increased from headwaters towards the stream outlet. However, the groundwater hotspots decreased, while runoff from peatland sections increased the fluxes. One particular groundwater hotspot was an exception, as its emission rates of CH4 were exceptionally high in June, probably due to increased anaerobic microbial activity within the groundwater system. Microbial contribution to carbon dynamics was evident during our study period as increased DOC loads due to late spring snowmelt dominated runoff from surrounding peatland was mineralized and DIC amount increased towards midsummer. This will be further supported by results from microbial community analysis. Same was evident also in spatial scale, as higher DOC values of headwater sites was reduced downstream and DIC values were increasing respectively. SUVA254 index, which correlates positively with higher DOC aromaticity and molecular weight, was lower at groundwater hotspots. This indicates that groundwater hotspots were producing better quality C for microbes, as microbes tend to prefer compounds with lower aromaticity and molecular weight.

Our study addresses the urgent need for catchment level studies on carbon and GHG cycling that focuses on terrestrial-aquatic linkages, and on the mechanistic processes involved, such as microbe-mediated mineralization. Catchment wide studies conducted in Arctic and Boreal regions including interactions between ecosystems are especially needed today as northern areas are experiencing unprecedented extreme warming, precipitation changes and shifting snow depths.

How to cite: Mustonen, K.-R., Marttila, H., Lehosmaa, K., Koivunen, I., Welker, J., Lohila, A., and Jyväsjärvi, J.: Understanding interacting dynamics of hydrology, carbon cycle, and greenhouse gas fluxes in Arctic watersheds, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-20249, https://doi.org/10.5194/egusphere-egu2020-20249, 2020

D374 |
EGU2020-22466
Jens C Nejstgaard, Stella Berger, Katharina Makower, and Iordanis Magiopoulos

Although processes in aquatic systems are closely connected to the terrestrial environment, these environments are often studied separately. We argue that for a better understanding of both aquatic and terrestrial ecosystems a combination of long-term data from connected environments, coupled with experimental ecosystem-scale experiments, have a greater potential for successful model testing and development of predictive concepts, than using only long-term data (without experiments) from separate systems. This talk will present the new EU-funded RI-project AQUACOSM-plus (www.aquacosm.eu, 2020-2024) that offers access to >50 research facilities across the EU and is linked to world-wide cooperation through the MESOCOSM.EU portal, a virtual network of >100 research facilities. Both networks include mesocosm facilities in all aquatic systems, including rivers, ponds, lakes, estuaries and marine systems – offering unique opportunities to conduct ecosystem-scale experimental studies of relevance to aquatic-terrestrial coupling. This network of research facilities can be used for large-scale process-based studies to test models based on trend or response observations from long-term-data, in order to understand underlying mechanisms of ecosystem functioning relating to the present global Grand Challenges (climate change, biodiversity loss, eutrophication, emerging pollutants, etc.). Interested parties are also welcome to suggest other uses of these research facilities, such as conducting ecosystem solution-based experiments to enable effective management in aquatic ecosystems. The network will fund access to >10.000 days for a wide range of external users, including scientists, students, industry and developers, from the whole world.

How to cite: Nejstgaard, J. C., Berger, S., Makower, K., and Magiopoulos, I.: AQUACOSM-plus: an International Network for Experimental Mesocosm Studies Supporting Experimental Studies of Aquatic-Terrestrial Coupling, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-22466, https://doi.org/10.5194/egusphere-egu2020-22466, 2020

D375 |
EGU2020-4463
Thomas Dirnböck, Heike Brielmann, Johannes Kobler, and Andreas Hartmann

Excess Nitrogen (N) deposition from industrial, domestic and agricultural sources has led to increased nitrate leaching, increased gaseous N emissions, the loss of biological diversity, and has affected C sequestration in forest ecosystems. Nitrate leaching affects the purity of karst water resources, which contribute around 50 % to Austria’s drinking water supply. Here we present the first comprehensive evaluation of a 26 years record of dissolved inorganic N (DIN) concentrations and fluxes from a karst catchment in the Austrian Alps (LTER Zöbelboden), which was not affected by local N sources but solely by long-range N deposition (20-25 kg N ha-1 y-1 total N deposition). We inferred from soil chemical and microbial data as well as nitrate leaching, that the forest ecosystems in the catchment are likely saturated with respect to nitrogen. Consequently, 60-70% of the atmospheric N input was lost via leaching of NO3- to the karst aquifer or emission of N2O to the atmosphere. However, due to high dilution DIN concentrations in the runoff rarely exceed 2 mg N l-1. An exception were periods of forest disturbances. A number of strong storms (2007-2008) caused some major windthrows as well as single tree damages (5-10% of the catchment). Runoff concentrations of DIN showed clear responses to the disturbances with an increase (~ 1 mg N l-1) until 2008/09 and a decreased again in 2010/11 to pre-disturbance levels. Apart from disturbances, drought years led to an increase in NO3- in the soil water in the following years. We observed the subsequent changes of the dynamics of DIN in runoff with a high-resolution water probe during 2018 and 2019. This data shows that the severity of the drought and the magnitude of the first rewetting event after a period of drought drives the size of the flush of DIN. It is likely that N deposition will lower with legislated emission reductions and that the currently N leaky ecosystems may immobilize more N when climate is becoming warmer in the future. However, we hypothesize that the karst aquifer will still receive DIN rich runoff water due to long-term lags in the recovery of a closed N cycle and because of expected climate events such as storms and droughts.

How to cite: Dirnböck, T., Brielmann, H., Kobler, J., and Hartmann, A.: Drivers of long-term and short-term Nitrogen concentrations and runoff dynamics in a forested karst catchment, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-4463, https://doi.org/10.5194/egusphere-egu2020-4463, 2020

D376 |
EGU2020-22465
| Highlight
Veronica Gaube, Claudine Egger, Christoph Plutzar, Andreas Mayer, and Helmut Haberl

Land use and climate change are important drivers of environmental change and pose a major threat to ecosystems. Although systemic feedbacks between climate and land use changes are expected to have important impacts, research has rarely focused on the interaction between the two drivers. One reason for this could be that forecasts of land use are hardly available on suitable spatial and thematic scales. Agent-based models (ABMs) represent a potentially powerful tool for creating thematic and spatially fine-grained land use scenarios. In order to derive such scenarios, the complex interaction between land users (e.g. farmers) and the broader socio-economic context in which they operate must be taken into account. On landscape to regional scales, agent-based modelling (ABM) is one way to adequately consider these intricacies. ABMs simulate human decisions, and with individual land owners/users as agents, they can simulate usage paths for individual plots of land in thematically fine resolution. Ideally, these simulations are based on an understanding of how farmers make decisions, including anticipated strategies, adaptive behavior and social interactions. In order to develop such an understanding, participatory approaches are useful because they incorporate stakeholders' perspectives into the model calibration, thereby taking into account culture and traditions that often play an important role in land use decisions. A greater proximity to stakeholder perspectives also increases the political relevance of such land use models. Here we present an example where we developed an ABM (SECLAND) parameterised for 1,329 stakeholders, mostly farmers, in the LTSER region Eisenwurzen (Austria) and simulate the changes in land use patterns resulting from their response to three scenarios of changing socio-economic conditions. Summarized in broad categories, the study region currently consists of 67% deciduous and coniferous forests (including logging), 19% grassland, 9% agricultural land and 6% alpine areas. SECLAND simulated small to moderate changes in these percentages until 2050, with little difference between the scenarios. In general, an increase in forests is predicted at the expense of grasslands. The size of agricultural land remains approximately constant. At the level of the 22 land use classes, the trends between the land use change scenarios differ more strongly. This ABM at the individual or farm level is combined with biodiversity and biogeochemical models that analyse how landowners' decision-making affects various ecosystem parameters. We conclude that agent-based modelling is a powerful tool for integrating land use and climate effects into ecosystem projections, especially at regional level.

How to cite: Gaube, V., Egger, C., Plutzar, C., Mayer, A., and Haberl, H.: Modeling Farmer’s Decision-Making to integrate climate, land use and ecosystem functions, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-22465, https://doi.org/10.5194/egusphere-egu2020-22465, 2020

D377 |
EGU2020-13698
Terhi Rasilo, Maria Holmberg, Anu Akujärvi, Saku Anttila, Iida Autio, Niko Karvosenoja, Pirkko Kortelainen, Aleksi Lehtonen, Annikki Mäkelä, Francesco Minunno, Paavo Ojanen, Ville-Veikko Paunu, Mikko Peltoniemi, Katri Rankinen, Tapani Sallantaus, Mikko Savolahti, Sakari Tuominen, Seppo Tuominen, Pekka Vanhala, and Martin Forsius

Natural ecosystems play an important role in regulating greenhouse gas (GHG) fluxes between land and water surfaces and the atmosphere. To evaluate the full GHG balance of a region, fluxes from natural ecosystems such as undrained mires, lakes and rivers, should be included in the GHG accounting together with fluxes from forestry, agricultural and anthropogenic activities. We present a method for collating regional GHG balances including natural ecosystem processes, to support strategies for climate change mitigation and adaptation. Our study area is Kokemäenjoki river basin (SW Finland), which includes two eLTER sites (Lammi and Hyytiälä/SMEAR). Empirical data of these sites are used for model developments and calibrations as well as regional extrapolation. We report spatially explicit estimates on sources and sinks of GHG such as carbon dioxide and methane, and nitrous oxide for some ecosystems, and aggregate the regional balance from vertical fluxes of these elements. Spatial data sources include CORINE land use data, soil map, lake and rivers shorelines, national forest inventory data, as well as statistical data on anthropogenic activities. The regionally aggregated vertical balance will be compared to observed total lateral flux to the Bothnian Sea. We quantify the fluxes on the basis of empirical evidence from eLTER site information, literature, as well as on calculations with a forest growth and gas exchange model (PREBAS).

 

Acknowledgements and funding:

Irina Bergström, Markus Haakana, Antti Ihalainen and Kari Minkkinen

eLTER H2020 GA 654359

IBC-Carbon Academy of Finland SRC 2017/312559

SOMPA Academy of Finland SRC 2017/312912

oGIIR

Freshabit LIFE IP LIFE14/IPE/FI/023

How to cite: Rasilo, T., Holmberg, M., Akujärvi, A., Anttila, S., Autio, I., Karvosenoja, N., Kortelainen, P., Lehtonen, A., Mäkelä, A., Minunno, F., Ojanen, P., Paunu, V.-V., Peltoniemi, M., Rankinen, K., Sallantaus, T., Savolahti, M., Tuominen, S., Tuominen, S., Vanhala, P., and Forsius, M.: Regional greenhouse gas (GHG) budget of Kokemäenjoki river basin, SW Finland, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-13698, https://doi.org/10.5194/egusphere-egu2020-13698, 2020

D378 |
EGU2020-5190
Katri Rankinen, Maria Holmberg, Seppo Hellsten, Lauri Arvola, Ninni Liukko, and Juha Riihimäki

Browning of surface waters due to increased terrestrial loading of organic carbon is observed in boreal regions. It is explained by large scale changes in ecosystems, including decrease in sulphur deposition that affects soil organic matter solubility, increase in temperature that stimulates export of dissolved organic carbon (DOC) from organic soils, and increase in precipitation and thus runoff. Land use changes and forestry measures are also observed to be one reason for increased transport of DOC. The effects of brownification extend to ecosystem services like water purification, but also freshwater productivity through limiting light penetration and creating more stable thermal stratification. The research question at the Lammi LTER area (Southern Boreal Aquatic and Terrestrial Long-Term Ecological Research Area) was brownification of the lake Pääjärvi. We studied both past trends of organic carbon loading from catchments and water colour in the lake based on observations since early 1990’s. We also made simulations of loading for future climate by the physical Persist and INCA models. DOC concentration in the lake was simulated by the physical MyLake model. Simulated DOC concentration was transformed to water colour and light climate of the lake by empirical equations to study the influence on macrophytes (as an indicator of the ecosystem state). In future growing depths might decrease from 2 m to 1.2 m corresponding to observed shift from reference lakes to impacted lakes. Brownification was driven mainly by the change in climate and decay of organic matter in soil, with smaller impact of land use change on organic soil types. Decrease in sulphur deposition had only minor effect on brownification.

How to cite: Rankinen, K., Holmberg, M., Hellsten, S., Arvola, L., Liukko, N., and Riihimäki, J.: Long term brownification process at the Lammi LTER area in Finland , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-5190, https://doi.org/10.5194/egusphere-egu2020-5190, 2020

D379 |
EGU2020-11251
Shayli Dor Haim, Daniel Orenstein, and Moshe Shachak

The concept of whole system approach offers a foundation for ecosystem studies. Identification of the components and interaction demonstrate the challenges in the field of ecology, due to the lack of a conceptual and applied framework. we attend to present a theoretical foundation and a methodology for identifying components and interactions of the whole system approach linking biodiversity and geodiversity processes into ecosystem diversity as a web of interactions (WoI).

The web of interactions model combines the geodiversity components that include climate, geology, geomorphology, and hydrology processes and their interactions and the biodiversity components that include population, community, ecosystem, and landscape levels of organization and their interactions. Linking biodiversity and geodiversity produces ecosystem diversity, which is represented as a web of diversity interactions that include climate, rock, soil, species, genetic, and functional diversities

In the talk we will present examples from our long term study in the Negev Highland, an arid water limited environment. The system is characterized by high geodiversity (topographic, geologic, geomorphic, and pedologic diversity) and high biodiversity with many unique and endemic species.

Our study presents the whole system approach of the Negev Highlands ecosystem as a web of interactions (WoI) among and between the diversity of components that links biotic and abiotic diversities. All the components and their interactions vary in time and space and together determine ecosystem diversity.

Long term study in the Negev Highland site revealed various of diversities of the ecosystem that can be linked by hydro-geo-ecological components, drivers, and feedbacks that control geodiversity and biodiversity. The main feedbacks are: the hydrological feedback that controlled by rainfall pattern and affects the pedological feedback by runoff generation that accumulates dust and regulates rock-to-soil ratio. These two feedbacks control soil moisture, which links geodiversity with biodiversity components. In addition, an energy and material feedback which is characterized by the producer–consumer and decomposer relationships supports ecosystem engineers that link geo and biodiversity. The functional interactions among the biodiversity and geodiversity components create ecosystem diversity that is the driver of whole system properties.

We suggest that the web of interaction approach can potentially be applied to understand whole system emergent properties of terrestrial ecosystem.

How to cite: Dor Haim, S., Orenstein, D., and Shachak, M.: The contribution of Web of Interactions framework to the whole system approach, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-11251, https://doi.org/10.5194/egusphere-egu2020-11251, 2020

D380 |
EGU2020-4613
Michael Tso, Peter Henrys, Susannah Rennie, and John Watkins

Long-term monitoring data that considers a wide array of environmental variables provides key insights to environmental change because responses of ecosystem functions and services to environmental drivers are inherently long-term and strongly interlinked. To ensure that the data are reliable for analysis and interpretation, they must undergo quality assurance procedures. However, the expected or acceptable range of data values vary greatly as the state of the ecosystem changes. Current quality assurance procedures for environmental data take no consideration of the system state at which each measurement is made, and provide the user with little contextual information on the probable cause for a measurement to be flagged out of range. We propose the use of data science techniques to tag each measurement with an identified system state. The term “state” here is defined loosely and they are identified using k-means clustering, an unsupervised machine learning method. The meaning of the states is open to specialist interpretation. Once the states are identified, state-dependent prediction intervals can be calculated for each observational variable. This approach provides the user with more contextual information to resolve out-of-range flags and derive prediction intervals for observational variables that considers the changes in system states. Our highly flexible and efficient approach is applicable to any point data time series in earth and environmental sciences, regardless of their sub-discipline. Such advantage is particularly relevant when conducting simultaneous analysis of multiple processes and feedbacks, where a wide variety of data is used.

We illustrate our approach using the moth and butterfly data from the UK Environmental Change Network (ECN), where meteorological variables are used to define system states. A web application is publicly available to allow users to explore the method on various ECN site, while a generic is also available for users to upload their own data files. Our work contributes to the ongoing development of a better data science framework that allows researchers and other stakeholders to find and use the data they need more readily and reliably.

 

How to cite: Tso, M., Henrys, P., Rennie, S., and Watkins, J.: State tagging for improved earth and environmental data quality assurance, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-4613, https://doi.org/10.5194/egusphere-egu2020-4613, 2020

D381 |
EGU2020-984
Nubia Marques, Fabio Miranda, Leticia Gomes, Felipe Lenti, and Mercedes Bustamante

Wildfire effects on riparian zones and stream water can be significant, particularly in the vegetation recovery and flow of nutrients between the terrestrial and aquatic ecosystem. However, the integrated knowledge about the impacts of fire on terrestrial and aquatic ecosystems in the Brazilian Cerrado is poorly known. In Brazilian Cerrado, wildfire is one of the main vectors of degradation of riparian vegetation, because the forest formation in riparian zones can be more sensitive to fire than the other savanna formation due to a less evident vegetation fire-adaptations. Our main objective was to understand the effects of fire on the resilience of riparian vegetation and their consequences to nutrient fluxes between terrestrial and aquatic ecosystem. This study was conducted in the Environmental Protection Area (APA) located in the Federal District - Brazil, which is one of Brazil’s Long-Term Ecological Research Site, after a wildfire (September 2011) that burned an area of about 140 km2. We analyzed the riparian vegetation resilience (for forests and surrounding savannas formations) and nutrients fluxes (in surface runoff and stream water) in five streams. We estimated the fire severity with Delta Normalized Burn Ratio index and the riparian vegetation resilience with the Normalized Vegetation Index and evaluated the changes in nutrient concentrations for nitrite + nitrate ([NO2- + NO3-]), ammonium (NH4+), and phosphate (PO43-) during 16 months on stream water and surface runoff solution in burned and unburned areas using the Generalized Linear Models. Our results show that fire severity was similar between forests and savannas formations, but in savannas we observed higher vegetation resilience, with faster vegetation regrowth and recovery after three weeks. The concentration of nutrients on both surface runoff and inside the stream have changed in burned areas regarding unburned areas, with an increase of PO43- and [NO2- + NO3-] and a decreased of NH4+. After 16 months of the fire event, the concentration of PO43-, [NO2- + NO3-] and NH4+ increased in surface runoff, while [NO2- + NO3-] decreased inside the streams in burned areas. Precipitation was a factor that caused the increase of concentrations of [NO2- + NO3-] and NH4+ and, the high precipitation on rainy season (October – March), that started after the fire, could have contributed to the input of these nutrients and particulate materials from ashes to streams. Our results showed that the occurrence of fire in riparian environments reduces the biomass of riparian forests and increases the concentration of nutrients on streams.  These elevated postfire nitrogen and phosphate loading can influence streams ecosystem health, especially in oligotrophic streams like those found in Brazilian Cerrado. It is known that phosphorus and nitrogen are limited nutrients for algal and cyanobacterial growth in freshwater ecosystem and an increase of these organisms can disrupt the ecosystem integrity. Fire is a pulsed disturbance and its effect on freshwater ecosystem depends on terrestrial ecosystem recovery, in this way, it is necessary to integrate the knowledge about the impacts of fire on terrestrial and aquatic ecosystems to better understand the effects on the entire ecosystem.

How to cite: Marques, N., Miranda, F., Gomes, L., Lenti, F., and Bustamante, M.: From burned vegetation to streams water: fire effects on vegetation resilience and nutrient fluxes, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-984, https://doi.org/10.5194/egusphere-egu2020-984, 2019

D382 |
EGU2020-3923
Jaana Bäck, Tuukka Petäjä, Mari Pihlatie, Janne Levula, Timo Vesala, and Markku Kulmala

The observations on global warming or elements relevant to climate change are frequently performed in isolation, which results in insufficient understanding of the whole Earth system functioning and feedbacks. Frequently CO2 emissions, atmospheric concentrations of greenhouse gases and the global air temperature records are pooled together to obtain statistical relationships and correlations between them. However, forecasting future changes and designing tools for mitigating their deleterious effects would require a more holistic and comprehensive observation scheme. We propose a concept of an integrated research infrastructure, where the feedbacks can be analysed with multidisciplinary and comprehensive observations. The SMEAR concept (Station for Measuring Earth system-Atmosphere Relations) has been developing into a powerful tool, allowing detection of trends in key climate, atmosphere and ecosystem parameters, providing detailed process understanding of atmosphere and ecosystem structure and functions, and facilitating deep insights on feedbacks between the ecosystems and atmosphere. The presentation gives examples of recent novel results, especially in the perspective of climate change feedbacks and mitigation in forest ecosystems.

How to cite: Bäck, J., Petäjä, T., Pihlatie, M., Levula, J., Vesala, T., and Kulmala, M.: An integrated research infrastructure concept with multidisciplinary observations on climate change, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-3923, https://doi.org/10.5194/egusphere-egu2020-3923, 2020

D383 |
EGU2020-5558
Nora Casson, Adrienne Ducharme, Geethani Amarawansha, Geoff Gunn, Scott Higgins, Darshani Kumaragamage, and Udayakantha Vitharana

Canada’s boreal zone is a complex mosaic of forests, wetlands, streams and lakes.  The pool of carbon (C) stored in each of these ecosystem components is vast, and significant to the global C balance.  However, C pools and fluxes are heterogeneous in time and space, which contributes to uncertainty in predicting how a changing climate will affect the fate of C in these sensitive ecosystems. The objective of this study was to investigate factors controlling spatial variability in soil C stocks and stream C export and assess the sensitivity of these stocks and fluxes to climatic factors. We conducted a detailed examination of soil C stocks and stream dissolved organic C (DOC) export from a 320 ha boreal forested catchment located in northwestern Ontario, Canada. High-frequency stream chemistry and discharge samples were collected from three inflow streams during snowmelt and rain events from 2016-2017. An intensive soil C sampling campaign resulting in 47 surface (0 – 30 cm) samples were collected during the summer of 2019. Stream hysteresis analysis revealed marked differences in flowpaths among sub-catchments during snowmelt and rain events. In the wetland-dominated catchment, near-stream sources contributed most of the DOC export during both rainstorms and snowmelt events, but in upland-dominated catchments, the sources of DOC depended on antecedent moisture conditions. Rainstorms in these catchments following prolonged droughts resulted in DOC flushing from distal regions of the catchment. Soil C stocks were also highly spatially variable, with much of the variability being explained by local-scale factors (e.g. gravel content, soil depth, distance to the nearest ridge). Taken together, these two findings emphasize the need to consider sub-catchment scale variability when calculating C pools and fluxes in boreal catchments. This is also important when predicting how C dynamics will shift in the future as a result of shorter winters, longer droughts and more intense rainstorms.

How to cite: Casson, N., Ducharme, A., Amarawansha, G., Gunn, G., Higgins, S., Kumaragamage, D., and Vitharana, U.: Spatial variability in terrestrial and aquatic carbon stocks and fluxes in boreal forested catchments, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-5558, https://doi.org/10.5194/egusphere-egu2020-5558, 2020

D384 |
EGU2020-6850
Xiaosong Zhao

The influence of natural hydrological factors on CO2 evasion from lakes has been widely studied. However, the long-term effects of man-made hydraulic infrastructures are not yet well understood. Here, we examined the multi-year (1961 - 2016) trend of the CO2 budget for Poyang Lake, a large ephemeral lake in China. Poyang Lake is situated downstream of the Three Gorges Dam (TGD), the world’s largest human-made hydraulic infrastructure. Using a combination of eddy covariance observations and artificial neural network modeling, we show that following the development of TGD in 2003, CO2 emissions of Poyang Lake significantly decreased by 77% (0.18 Tg C) compared with the pre-TGD period. The TGD can explained 21% of the CO2 flux decrease during impoundment period. The results imply that the TGD and other hydropower infrastructures potentially decrease the CO2 emission of lakes naturally connected or surrounded with Yangtze River in the middle and lower reaches.

How to cite: Zhao, X.: The decadal decline of CO2 emissions from a large ephemeral lake in China, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-6850, https://doi.org/10.5194/egusphere-egu2020-6850, 2020

D385 |
EGU2020-7684
Didac Pascual Descarrega and the Expert Assessment participants

Arctic and subarctic ecosystems are undergoing substantial changes in response to climatic and other anthropogenic drivers, and these changes are likely to continue over this Century. Due to the strong linkages between the biotic (vegetation and carbon cycle) and abiotic (permafrost, hydrology and local climate) ecosystem components, the total magnitude of these changes result from multiple interacting effects that can enhance or counter the direct effects. In some cases, short-lived extreme events can override climate-driven long-term trends. The field measurements can mostly tackle individual drivers rather than the interactions between them. Currently, a comprehensive assessment of the drivers of different changes and the magnitude of their impact on subarctic ecosystems is missing. The Torneträsk area, in the Swedish subarctic, has an unrivalled history of environmental observation over 100 years and encompasses the 12% of all published papers and the 19% of all study citations across the Arctic. In this study, we summarize and rank the direct and indirect drivers of ecosystem change in the Torneträsk area, and propose future research priorities identified to improve future predictions of ecosystem change. First, we identified the direct and indirect changing drivers and the multiple related processes and feedbacks impacting the local climate, permafrost, hydrology, vegetation, and the carbon cycle based on the existing literature. Subsequently, an Expert Elicitation with the participation of 27 leading scientists was used to rank the short- (2020-2040) and long-term (2040-2100) future impact of these drivers according to their opinions on the relative importance and novelty. These two key evaluation matrices form the basis for identifying the current research priorities for subarctic regions. The relatively small size of the Torneträsk area, its great biological and geomorphological complexity, and its unique datasets is a microcosm of the subarctic and the rapidly transforming Arctic ecosystems that can help understand the ongoing processes and future ecosystem changes at a larger circumpolar-scale. This in turn will provide the basis for future mitigation and adaptation plans needed in a changing climate.

How to cite: Pascual Descarrega, D. and the Expert Assessment participants: The missing pieces for better future predictions in subarctic ecosystems, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-7684, https://doi.org/10.5194/egusphere-egu2020-7684, 2020

D386 |
EGU2020-8444
Céline Le Bohec, Victor Planas-Bielsa, Emiliano Trucchi, Aymeric Houstin, Robin Cristofari, Norith Eckbo, Ben Fabry, Yvon Le Maho, Alexander Winterl, Sebastian Richter, Olaf Eisen, and Daniel Zitterbart

Long-term time series are essential to detect, understand and predict the impacts of anthropogenic pressures on ecosystems. This applies to both physical and biological data collections. However, systematic data collections on the biological component of the ecosystems are still scarce compared to Earth sciences, and biological time series are usually not sufficiently long to draw unambiguous inferences concerning trends. To fill this gap and assess the vulnerability of Antarctic and subantarctic ecosystems, but also develop tools for action plans to protect Southern Ocean, we aim (and already started) to setup a circumpolar network of Penguin Life Observatories. These upper-trophic-level seabirds can be considered as adequate bio-indicators of changes (due to e.g. climate change, overexploitation or pollution) occurring in the Southern Ocean food webs and ecosystems globally. Implementing cutting-edge technological innovations (e.g. automatic radiofrequency identification (RFID), weighing and camera-tracking systems, mobile RFID antennas deployable on site or mounted on remote-operated vehicles and biologgers), electronic Penguin Life Observatories gather information on land to assess population dynamics/trends, and at sea to explore their seasonal and inter-annual distribution and foraging strategies according to the environmental variability. In addition to increasing our knowledge on fundamental characteristics of these sentinel species, penguins play an important role as umbrella species, which offer us precious tools to map marine biological hotspots and design Marine Protected Areas (MPAs).

How to cite: Le Bohec, C., Planas-Bielsa, V., Trucchi, E., Houstin, A., Cristofari, R., Eckbo, N., Fabry, B., Le Maho, Y., Winterl, A., Richter, S., Eisen, O., and Zitterbart, D.: Penguin Life Observatories to monitor the health of the Southern Ocean ecosystems, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-8444, https://doi.org/10.5194/egusphere-egu2020-8444, 2020

D387 |
EGU2020-8737
Shengwei Zong and Christian Rixen

Snow is an important environmental factor determining distributions of plant species in alpine ecosystems. During the past decades, climate warming has resulted in significant reduction of snow cover extent globally, which led to remarkable alpine vegetation change. Alpine vegetation change is often caused by the combined effects of increasing air temperature and snow cover change, yet the relationship between snow cover and vegetation change is currently not fully understood. To detect changes in both snow cover and alpine vegetation, a relatively fine spatial scales over long temporal spans is necessary. In this study in alpine tundra of the Changbai Mountains, Northeast China, we (1) quantified spatiotemporal changes of spring snow cover area (SCA) during half a century by using multi-source remote sensing datasets; (2) detected long-term vegetation greening and browning trends at pixel level using Landsat archives of 30 m resolution, and (3) analyzed the relationship between spring SCA change and vegetation change. Results showed that spring SCA has decreased significantly during the last 50 years in line with climate warming. Changes in vegetation greening and browning trend were related to distributional range dynamics of a dominant indigenous evergreen shrub Rhododendron aureum, which extended at the leading edge and retracted at the trailing edge. Changes in R. aureum distribution were probably related to spring snow cover changes. Areas with decreasing R. aureum cover were often located in snow patches where probably herbs and grasses encroached from low elevations and adjacent communities. Our study highlights that spring SCA derived from multi-source remote sensing imagery can be used as a proxy to explore relationship between snow cover and vegetation change in alpine ecosystems. Alpine indigenous plant species may migrate upward following the reduction of snow-dominated environments in the context of climate warming and could be threatened by encroaching plants within snow bed habitats.

How to cite: Zong, S. and Rixen, C.: Links between spring snow cover and long-term alpine vegetation change, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-8737, https://doi.org/10.5194/egusphere-egu2020-8737, 2020

D388 |
EGU2020-9839
Johanna Girardi, Ralf Schulz, Mirco Bundschuh, Martin H. Entling, Eva Kröner, Andreas Lorke, Ralf B. Schäfer, Gabriele E. Schaumann, Klaus Schwenk, and Hermann F. Jungkunst

The propagation of environmental stressors from water (source) to land (sink) in aquatic-terrestrial meta-ecosystems, has not been intensively investigated. The other way around has been in the focus of linking terrestrial and aquatic domains. To start bridging that gap, SYSTEMLINK, a DFG Research Training Group, addresses the bottom-up and top-down mediated interactions in terrestrial ecosystems, which origin from anthropogenic impairments on aquatic ecosystems. Micropollutants (fungicides and insecticides) as well as invasive species (riparian plants and invertebrates) are considered as crucial forms of multiple stressors in disturbed aquatic ecosystems. SYSTEMLINK will examine the general hypotheses that 1) invasive invertebrates and insecticide exposure and 2) invasive riparian plants and fungicide exposure cause top-down and bottom-up mediated responses in terrestrial ecosystems, respectively. Collaborative experiments in replicated outdoor aquatic-terrestrial mesocosms (site-scale) amended by joint pot experiments (batch-scale), field studies (landscape-scale), and modelling are used to test these general and several more specific hypotheses. The experimental setups will all represent a multi-stress environment and will be derived from the landscape scale. The regular combination of several scales will allow to overcome scale-specific limitations and to ensure both cause-effect quantification and the environmental relevance of the results. Ultimately, SYSTEMLINK thrives to increase our knowledge on effect translation across ecosystem boundaries. By combining biological subsidies and biogeochemical fluxes we will be able to quantify their relative importance. Furthermore, we will closely incorporate the often separated aquatic and terrestrial research areas.

How to cite: Girardi, J., Schulz, R., Bundschuh, M., Entling, M. H., Kröner, E., Lorke, A., Schäfer, R. B., Schaumann, G. E., Schwenk, K., and Jungkunst, H. F.: SYSTEMLINK - a new project on the effects of stressors across ecosystem barriers, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-9839, https://doi.org/10.5194/egusphere-egu2020-9839, 2020

D389 |
EGU2020-16136
Aud Halbritter, Hans De Boeck, and Vigdis Vandvik and the Amy E. Eycott Sabine Reinsch David A. Robinson Sara Vicca Bernd Berauer Casper T. Christiansen Marc Estiarte José M. Grünzweig Ragnhild Gya Karin Hansen Anke Jentsch Hanna Lee Sune Linder John Marshall Josep Peñuelas Inger Kappel Schmidt E

Climate change is a world‐wide threat to biodiversity and ecosystem structure, functioning and services. To understand the underlying drivers and mechanisms, and to predict the consequences for nature and people, we urgently need better understanding of the direction and magnitude of climate change impacts across the soil–plant–atmosphere continuum. An increasing number of climate change studies are creating new opportunities for meaningful and high‐quality generalizations and improved process understanding. However, significant challenges exist related to data availability and/or compatibility across studies, compromising opportunities for data re‐use, synthesis and upscaling. Many of these challenges relate to a lack of an established ‘best practice’ for measuring key impacts and responses. This restrains our current understanding of complex processes and mechanisms in terrestrial ecosystems related to climate change.

To overcome these challenges, we collected best‐practice methods emerging from major ecological research networks and experiments, as synthesized by 115 experts from across a wide range of scientific disciplines. Our handbook contains guidance on the selection of response variables for different purposes, protocols for standardized measurements of 66 such response variables and advice on data management. Specifically, we recommend a minimum subset of variables that should be collected in all climate change studies to allow data re‐use and synthesis, and give guidance on additional variables critical for different types of synthesis and upscaling. The protocols are also available online on the ClimEx handbook webpage (https://climexhandbook.w.uib.no/) and we encourage scientists from the climate change research community to get involved, give us feedback and make suggestions for updates to specific protocols. We hope that this is a way to amend the protocols and extend the shelf life of the ClimEx Handbook.

The goal of this community effort is to facilitate awareness of the importance and broader application of standardized methods to promote data re‐use, availability, compatibility and transparency. We envision improved research practices that will increase returns on investments in individual research projects, facilitate second‐order research outputs and create opportunities for collaboration across scientific communities. Ultimately, this should significantly improve the quality and impact of the science, which is required to fulfil society's needs in a changing world.

How to cite: Halbritter, A., De Boeck, H., and Vandvik, V. and the Amy E. Eycott Sabine Reinsch David A. Robinson Sara Vicca Bernd Berauer Casper T. Christiansen Marc Estiarte José M. Grünzweig Ragnhild Gya Karin Hansen Anke Jentsch Hanna Lee Sune Linder John Marshall Josep Peñuelas Inger Kappel Schmidt E: The handbook for standardized field and laboratory measurements in terrestrial climate change experiments and observational studies (ClimEx), EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-16136, https://doi.org/10.5194/egusphere-egu2020-16136, 2020

D390 |
EGU2020-16543
Volodymyr Trotsiuk and the QUPFiS team

Under unprecedent climate change and increased frequency of extreme events, e.g. drought, it is important to assess and forecast forest ecosystem vulnerability and stability. Large volumes of data from observational and experimental networks, increases in computational power, advances in ecological models, and optimization methodologies are the main measures to improve quantitative forecasting in ecology. Data assimilation is a key tool to improve ecosystem state prediction and forecasting by combining model simulations and observations. We assimilated observations of carbon stocks and fluxes from 271 permanent long-term forest monitoring plots across Switzerland into the 3-PG forest ecosystem model using Bayesian inference, reducing the bias of model predictions from 14% to 5% for forest stem carbon stocks and from 45% to 9% for stem carbon stock changes, respectively. We then estimated the productivity of forests dominated by Picea abies and Fagus sylvatica for the period of 1960-2018 and tested for climate-induced shifts in productivity along elevational gradient and in extreme years. Overall, we demonstrated a high potential of using data assimilation to improve predictions of forest ecosystem productivity. Furthermore, our calibrated model simulations suggest that climate extremes affect forest productivity in more complex ways than by simply shifting the response upwards in elevation.

How to cite: Trotsiuk, V. and the QUPFiS team: Assessing the response of forest productivity to climate extremes in Switzerland using model-data fusion, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-16543, https://doi.org/10.5194/egusphere-egu2020-16543, 2020

D391 |
EGU2020-18377
Koen De Ridder, Filip Lefebre, Eline Vanuytrecht, Julie Berckmans, and Hendrik Wouters

Biodiversity is increasingly under pressure from climate change, which affects the habitat suitability for species as well as the efficiency of ecosystem services. Management of these issues, for instance through ecosystem restoration or species dispersal measures, is often hindered by a lack of appropriate information about (future) climate conditions.  To address this, an operational Sectoral Information System (SIS) for the Biodiversity sector (SIS Biodiversity) is designed within the Copernicus programme Climate Change Service (C3S). This new SIS provides tailored bio-climatic indicators and applications, and delivers novel evidence regarding impacts of past, present and future climate. As such, it provides support to decision making challenges that are currently facing unmet climate data needs.
 
The new climate service for SIS Biodiversity will be demonstrated, including the outline, workflow and outcomes of the use cases. The service is built upon the Copernicus Data Store platform (CDS; ), and takes into account (1) the barriers in ongoing bio-climate assessments and (2) the user requirements of diverse stakeholders (e.g. researcher institutes, local NGO’s, the International Union for Conservation of Nature and Natural Resources (IUCN),…). These have been collected during workshops and bilateral meetings in 2019. A common barrier is the lack of reliable and high-resolution information about states and dynamics of the soil, sea, ice and air for the past and the future climate. Therefore, the service provides relevant bio-climatic indicators on the basis of a wealth of available variables from the latest ERA5 reanalysis datasets and the CMIP5 global climate projections available in CDS. In order to provide information at high resolution and minimize inconsistencies between observed and modelled variables, different downscaling and bias-correction techniques are applied. A common requirement is a universal and flexible interface to the bio-climatic indicators in an easy-to-use and coherent platform that is applicable for different fauna and flora species of interest. Therefore, different applications have been developed within CDS for generating bio-climate suitability envelopes from the high-resolution indicators and to evaluate climate suitability and impacts for the species under present and future climate. Finally, the service is currently tested and refined on the basis of specific use cases. Special attention is given to their transferability to other global and topical studies, hence maximizing external user uptake throughout existing research and policy networks.

How to cite: De Ridder, K., Lefebre, F., Vanuytrecht, E., Berckmans, J., and Wouters, H.: Copernicus Sectoral Information System for the Biodiversity Sector , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-18377, https://doi.org/10.5194/egusphere-egu2020-18377, 2020

D392 |
EGU2020-18673
Michael Mirtl

Environmental research is challenged by the question, how lilfe supporting systems (ecosystems, the critical zone) and their services will develop in the next decades. However, addressing changes in structure and function requires an integrated approach from the subsurface to the vegetation and atmosphere, across scales and ecosystems, and combining observation, ecosystem theories and modelling. Such integrated approach affects most aspects of how environmental research and monitoring are shaped, comprising seamless collaborations amongst involved disciplines, the interactions of actual research with other stakeholders, research insfrastructure design and operation and – as a key factor – the structures and rulesets of related funding mechanisms.

A common conceptual framework is highly relevant for catalyzing integration efforts and implementing complementary modules of research infrastructures serving various user groups and disciplines towards a fundamental understanding and improved predictions of how structure and functions of ecosystems and ecosystem services will evolve and adapt under global change, with climate change, land use and societal change as key drivers.

Triggered by the challenge to streamline the ecoystem, critical zone and socio-ecological reasearch infrastructure at the Pan-European level in close collaboration with other ongoing European environmental RIs like ICOS and LifeWatch, the eLTER Research Infrastructure (RI) therefore strives for a Whole system Approach for In-situ & Long-term environmental System research on life supporting systems (WAILS), combining humans-environment interactions at a given scale and cross-scale interactions and feed-back loops across scales, which will be presented.

How to cite: Mirtl, M.: Whole system Approach for In-situ & Long-term environmental System research on life supporting systems (WAILS), EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-18673, https://doi.org/10.5194/egusphere-egu2020-18673, 2020

D393 |
EGU2020-19137
Man Zhao, Liesbet Jacobs, Steven Bouillon, and Gerard Govers

Rivers receive large amounts of terrestrial soil organic carbon (SOC) and transport them from land to the ocean. Mounting evidence indicates that a large fraction of the eroded SOC, which is often very old, is quickly decomposed upon entering the river and never reaches the ocean. The mechanisms explaining this rapid decomposition of previously stable SOC remain unclear. In this study, we investigated the relative importance of two mechanisms possibly explaining this rapid SOC decomposition: (i) in the river water SOC is exposed to a different microbial community which is able to metabolise SOC much more quickly than the soil microbial community and (ii) SOC decomposition in rivers is facilitated due to the hydrodynamic disturbance of sediment. We performed different series of short-term (168h) incubations quantifying the rates of SOC decomposition in an aquatic system under controlled conditions. Organic carbon decomposition was measured continuously through monitoring dissolved O2 concentration using a fiber-optic meter (FirestingO2, PyroScience). In the control treatment, bottles of 320 ml of river water sampled from Dijle river (Leuven, Belgium) were used, without headspace, under dark conditions in a temperature-controlled room (20℃). In a second treatment, soil material was added to river water filtered at 0.2 um to remove aquatic micro-organisms (MO) (SOC-MO treatment). The effect of the presence of an aquatic microbial community on SOC decomposition was simulated by adding an inoculum of unfiltered river water to a bottle containing the same soil material (SOC+MO treatment). Secondly, we investigated the effect of water motion on respiration rates by simulating the hydrodynamic disturbance of soil particles using a swing system to keep particles suspended in the water. All treatments described above were conducted under both standing- and shaking conditions. Each experiment was repeated six times and two types of soil were tested: one from arable land (sandy loam, 2.4%OC), and the other from a temperate forest site (sandy loam, 5.0%OC). Our result show that SOC indeed further mineralized in a riverine environment. Under both shaking and standing conditions, we found a significant difference between SOC-MO and SOC+MO treatments (paired t-tests, p<0.05), indicating that the presence of an aquatic microbial community enhanced the SOC decomposition process by 94%-131% depending on the soil type and shaking/standing conditions. In contrast, the effect of hydrodynamic disturbance was much less evident. When comparing SOC+MO at shaking vs. standing conditions for soil from arable land,  SOC decomposition was increased by 13% at shaking condition (p<0.05) while no significant effect was found for forest soil (p>0.05). While some recent studies suggested that aquatic respiration rates may have been substantially underestimated by performing measurement under stationary conditions, our results indicate that this effect is relatively minor, at least under the temperature conditions and for the suspended matter concentration range (500 mg/L arable land soil; 200 mg/L forest soil) used in our experiments.

How to cite: Zhao, M., Jacobs, L., Bouillon, S., and Govers, G.: Soil organic carbon decomposition rates in river systems: effect of experimental conditions , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-19137, https://doi.org/10.5194/egusphere-egu2020-19137, 2020

D394 |
EGU2020-19864
Carolina Voigt, Gabriel Hould Gosselin, Andrew Black, Charles Chevrier-Dion, Charlotte Marquis, Zoran Nesic, Taija Saarela, Evan Wilcox, Philip Marsh, and Oliver Sonnentag

The Arctic is currently warming faster than the rest of the world. Warming and associated permafrost thaw in Arctic landscapes may mobilize large pools of carbon (C) and nitrogen (N) and ultimately increase the atmospheric burden of the greenhouse gases (GHGs) carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). Arctic GHG dynamics and their environmental and hydrological controls are poorly understood. Whether Arctic landscapes act as a net GHG source or sink depends on the complex and spatially varying interactions between hydrology, active layer thickness, topography, temperature, vegetation, substrate availability and microbial dynamics.

Our study site, Trail Valley Creek (68°44’ N, 133°29’ W), is an upland tundra site characterized by small-scale (<10 m) land cover and soil type (mineral and organic) heterogeneity consisting of different land cover types: shrub, tussock and lichen patches, polygonal tundra and thermokarst-affected areas, wetlands, lakes, and streams. To understand the large spatial and temporal variability of GHG dynamics across these terrestrial and aquatic landcover types we use a nested observational approach at plot- (<1 m2), ecosystem- (~10 m2), landscape- (~100 m2) and regional (~50 km2) scale. Existing (since 2013) ecosystem-scale eddy covariance (EC) measurements of net CO2 and CH4 exchanges are complemented with landscape-scale EC measurements and plot-scale automated and manual chamber measurements within the EC tower footprint and beyond. To increase process-based understanding we complement these multi-scale GHG flux observations with a wide array of auxiliary measurements including soil profile dynamics of CO2, CH4, N2O, and oxygen, lake and soil pore nutrient concentrations, soil temperature and moisture profiles, thaw depth, leaf area index (LAI), normalized difference vegetation index (NDVI), lake catchment characteristics, and quality and microbial degradability of aquatic dissolved organic matter.

Preliminary results from manual chamber measurements show that tussocks were the largest net CO2 sink during the growing season. While the majority of terrestrial landcover types showed small but consistent and seasonally varying CH4 uptake, lake shore and thermokarst-affected areas displayed high nutrient loads and were hotspots of CH4 emissions. Therefore, capturing the landscape heterogeneity, areal coverage and hydrological connectivity of terrestrial and aquatic landcover types is important and our study highlights the need to combine belowground, plot-, ecosystem- and landscape-scale measurements to understand biosphere-atmosphere interactions in the Arctic.

How to cite: Voigt, C., Hould Gosselin, G., Black, A., Chevrier-Dion, C., Marquis, C., Nesic, Z., Saarela, T., Wilcox, E., Marsh, P., and Sonnentag, O.: Towards Resolving Spatial and Temporal Greenhouse Gas Dynamics across a Heterogeneous Arctic Tundra Landscape in the Western Canadian Arctic, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-19864, https://doi.org/10.5194/egusphere-egu2020-19864, 2020

D395 |
EGU2020-20462
Martin Škerlep, Ulf Johansson, Dan Berggren Kleja, Per Persson, and Emma S Kritzberg

Increasing surface water concentrations of Fe and DOC (browning), have been reported around the northern hemisphere in the last couple of decades. This increase has far-reaching ecological and societal implications, as it alters the light climate in water and decreases the quality of drinking water. One of the hypothesis behind the increase has been that afforestation and a dominance of coniferous forest have increased the availability of Fe and DOC for transport from soils into surface waters. The accumulation of organic soil layers in coniferous forests increases acidity and the amounts of organic acids in soils and may thus enhance weathering, solubility and mobilization of Fe as the forest ages. In this study we examined the effects of afforestation and growth of Norway spruce on the mobilization and potential leakage of Fe and DOC from soils to surface waters. To represent the effects of ageing forest we used plots with spruce stands of different ages (35, 61, 90 years) and unforested control plots in their immediate proximity, in Tönnersjöheden experimental forest (Sweden). Soil water collected in lysimeters (installed below the organic horizon and in the mineral soil) and analyzed for Fe, Fe speciation, using X-ray absorption spectroscopy (XAS), as well as DOC, metals, major anions and cations. Soil samples were analyzed for Fe speciation and crystallinity at different depths. Results from the soil water analysis show that more Fe was mobile in older spruce forest stands with higher DOC concentrations and lower pH. Covariation of Fe and DOC concentrations in soil waters, indicate the dependence of Fe on DOC to solubilize and stay in solution. Preliminary results from our XAS analysis also indelicate a considerable amount of Fe(II) in soil water that is likely stabilized from oxidation by organic complexation. Surprisingly Fe extracted from the organic (O) soil horizon showed the highest crystallinity and crystallinity did not vary much between soils of different stand ages.  The results of this study indicate that afforestation promotes Fe and DOC availability for export into surface waters as well as strengthens the notion that the effects of afforestation are not immediate, but take time as soils develop slowly. As afforestation and dominance of coniferous forest continues in many parts of the northern hemisphere, we can expect further increase of Fe and DOC in surface waters.

How to cite: Škerlep, M., Johansson, U., Berggren Kleja, D., Persson, P., and Kritzberg, E. S.: The effects of afforestation on Fe mobilization in soils and potential for leaking into surface waters, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-20462, https://doi.org/10.5194/egusphere-egu2020-20462, 2020

D396 |
EGU2020-20556
| Highlight
Giorgio Matteucci, Alessio Collalti, Ettore D'Andrea, Bruno De Cinti, Olga Gavrichkova, Gabriele Guidolotti, Giovanni Manca, Francesco Mazzenga, Negar Rezaei, Andrea Scartazza, Riccardo Valentini, and Giuseppe Scarascia Mugnozza

The long-term research and monitoring site of Collelongo - Selva Piana has been established in 1991 (Abruzzo Region, Central Italy, 1560 m elevation) in the framework of a project on ecology and silviculture of European beech. In 1993, the site was the first forest in Europe where canopy fluxes started to be measured with the eddy covariance technique. Since then, the site has been involved in several of the most important networks and projects, including ICP Forests, Euroflux, CarboEurope-IP, FluxNet and, in 2006, joined the Long Term Ecological Research network (LTER).

Measurements at the Collelongo site bridge two centuries, starting right at the end of the WMO and IPCC climate reference period (1961-1990) and extending, in continuous, over a period of great changes (the three warmest ever decades occurred since then), including a number of extreme events (heat waves, droughts, late frost). During these thirty years, more than 50 researchers from different parts of the world performed direct measurements at the site, flux datasets from the site (code IT-Col) had more than 1500 unique downloads and it is estimated that more than 300 people used the data for producing more than 150 ISI papers.

We will briefly present the main results on different ecosystem processes (Phenology, Net Primary Production, Carbon Allocation, Net Ecosystem Exchange, Nutrient and Water Cycling) emphasizing responses to drivers, including legacies from the past. Over these thirty years, the growing season length increased significantly (1.33 day yr-1 from 2000 to 2015), the studied beech forests absorbed between 120 and 150 tC ha-1 and showing plasticity and resilience to changing climatic conditions. However, increasing warming, drought and extreme events may impair adaptation capacity. In this respect, modelling offers a tool to evaluate long-term responses, including possible management options to increase both adaptation and resilience capacities.

How to cite: Matteucci, G., Collalti, A., D'Andrea, E., De Cinti, B., Gavrichkova, O., Guidolotti, G., Manca, G., Mazzenga, F., Rezaei, N., Scartazza, A., Valentini, R., and Scarascia Mugnozza, G.: Drivers and responses of ecosystem processes at the Collelongo beech forest: main results and lessons learned over 30 years of research and monitoring in a period of changes, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-20556, https://doi.org/10.5194/egusphere-egu2020-20556, 2020

D397 |
EGU2020-21620
Jim Yates, Laura Secco, and Francesco Carbone

Recent global efforts to reduce and abate forest declines i.e. deforestation, degradation and disturbance, forest ecosystems are extensive and well incentivised. Forests, however, remain as areas subject to competing resource objectives with complex socio-economic development paradigms and historical policy narratives. Indirect and direct causes forest decline are well cited across the literature. The concept that institutions are failing to secure positive outcomes for forest resources, however, is a somewhat new concept in resource management discourses. It is argued that formal institutions in forest management acting as developers, intermediaries, and the regulators of forest policy, having legitimized competency, are subject to meso-scale failure and in some circumstances contribute to forest decline. Adopting a mixed-method approach, application of a modified DPSIR framework, DPAESMR (Drivers-Policy-Actions-Effects-State Changes-Monitoring and Reporting) was combined with elements from the traditional policy cycle logic to develop a novel policy evaluation analysis tool or PEA. Using the PEA, analysis of classical literature and empirical experiences across four separate international and geographical case studies focused on formal institutions in forest management, their forest policy, actions and effects and are assessed against more recently reported state changes to respective forest resources, along with gaps in subsequent monitoring and reporting efforts. The analysis highlights land-use change and forest exploitation, intentional or not, demonstrates sustained losses in forest area, degradation processes and forest disturbance despite established/legitimized forest policy and robust formal intuitional direction and support. Forest policy interpreted and derived from acts, laws and norms vary across all cases naturally, although, similar themes such as gaps in institutional regulation, enforcement and information, subsequently result in weak forest administration. Evidence of robust, reasonably well covered and incentivized formal forest institutions exist irrespaective of forest administrative area and have failed to address forest decline and is highlighted as meso-scale failure or institutional failure. Understanding traditional issues such as property rights, path-dependence or re-orientation may succeed in strengthening institutional adaptation to triggers, crises and abrupt policy changes which will aid the effort in slowing forest decline.

Keywords

Forest decline, Institutional failure, DPSIR, forest management, policy analysis

How to cite: Yates, J., Secco, L., and Carbone, F.: The role of formal institutions in forest decline: exploring institutional failure, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-21620, https://doi.org/10.5194/egusphere-egu2020-21620, 2020

D398 |
EGU2020-21697
Cristina Tarantino, Maria Adamo, and Palma Blonda

Assessing and maintaining the conservation of natural and semi-natural grassland ecosystems is one of the most important actions of the Biodiversity Strategy by the European Commission.

The present study focuses on the detection of long-term changes, from 1990 to 2018, of natural grasslands ecosystem, at local scale, in the “Murgia Alta”, a National Park as well as a Natura 2000 protected area, Southern Italy. The study site represents one of the largest areas for the conservation of such ecosystem in Italy. It is under pressure and in danger of destruction due to soil graining for agricultural intensification, illegal expansion of extraction sites, fires and land abandonment with consequent biodiversity loss.

Land Cover (LC) changes and class trends are one of the measures (sub-indicator) required for the implementation of the Sustainable Development Goals (SDG) 15.3.1 Indicator (“Proportion of land that is degraded over total land area”) of the Agenda 2030 by United Nations.

Multisource/multiresolution free available satellite data (visible, near infrared and short wave infrared spectral bands) were considered. Historical images from Landsat (4 images per year, one per season) were analyzed to produce different LC multiclass maps for 1990, 2001, 2004, 2011 and 2018 at 30 m spatial resolution, with an automatic data-driven classifier (Support Vector Machine). For 2018 Sentinel-2 data, 10 m spatial resolution, were also considered.

The mean value of the Overall Accuracies obtained for the LC maps from Landsat was 95%. Similar value was obtained in the last year from Sentinel-2.

Then natural grassland layer was extracted from those maps to analyze the trend of the grasslands ecosystem over time. The findings obtained indicate a total loss in the extension of the ecosystem of about 18% from 1990 to 2018. The major decrease (26%) occurred in 1990-2001. Then a modest decrease followed up to 2004 (year of institution of the National Park). Finally a slight increase probably due to land abandonment followed to fire events was quantified after 2004.

From the comparison of the different LC maps obtained, the decrease of natural grasslands resulted mainly due to transformation into agricultural areas.

In addition, these results are consistent with those obtained using Corine Land Cover maps available for the same period although at a coarser scale.

The SDG sub-indicator was evaluated inside the protected area and in a buffer, 10 km, area around. This sub-measure, which can be evaluated from time-series of satellite free data, can support long-term monitoring of protected area and can be used not only for the resilience evaluation of the study site to climate changes but also for the evaluation of conservation policies and as input to scenario modelling.

How to cite: Tarantino, C., Adamo, M., and Blonda, P.: Long-term change monitoring of natural grasslands ecosystem in support of SDG 15.3.1, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-21697, https://doi.org/10.5194/egusphere-egu2020-21697, 2020

D399 |
EGU2020-21904
Maria Adamo, Valeria Tomaselli, Francesca Mantino, Cristina Tarantino, and Palma Blonda

Coastal wetlands are one of the most threatened ecosystems worldwide. In the Mediterranean Region, wetlands are undergoing rapid changes due to the increasing of human pressures (e.g. land reclamation, water resources exploitation) and climate changes (e.g. coastal erosion), with a resulting habitat degradation, fragmentation, and biodiversity loss.

Long-term habitat mapping and change detection are essential for the management of coastal wetlands as well as for evaluating the impact of conservation policies.

Earth observation (EO) data and techniques are a valuable resource for long-term habitat mapping, thanks to the large amount of available data and their high spatial and temporal resolution. In this study, we propose an approach based on the integration of time series of Sentinel-2 images and ecological expert knowledge for land cover (LC) mapping and automatic translation to habitats in coastal wetlands. In particular, the research relies on the exploitation of ecological rules based on combined information related to plant phenology, water seasonality of aquatic species, pattern zonation, and habitat geometric properties.

The methodology is applied to two Natura2000 sites, “Zone umide della Capitanata” and “Paludi presso il Golfo di Manfredonia”, located in the northeastern part of the Puglia region. These two areas are the most extensive wetlands of the Italian peninsula and the largest components of the Mediterranean wetland system.

Land Cover classes are labelled according to the FAO-LCCS taxonomy, which offers a framework to integrate EO data with in situ and ancillary data. Output habitat classes are labelled according to EUNIS habitat classification.

How to cite: Adamo, M., Tomaselli, V., Mantino, F., Tarantino, C., and Blonda, P.: Habitat mapping and change assessment of coastal wetlands by using Sentinel-2 time series and ecological expert knowledge, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-21904, https://doi.org/10.5194/egusphere-egu2020-21904, 2020