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  • 11
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    Environmental Drivers of Gross Primary Productivity and Light Use Efficiency of a Temperate Spruce Forest (2023)
    Details
    Publication Date: 2024-03-18
    Description: Various environmental variables drive gross primary productivity (GPP) and light use efficiency (LUE) of forest ecosystems. However, due to their intertwined nature and the complexity of measuring absorbed photosynthetically active radiation (APAR) of forest canopies, the assessment of LUE and the importance of its environmental drivers are difficult. Here, we present a unique combination of measurements during the 2021 growing season including eddy covariance derived GPP, sap flow, Sentinel‐2 derived canopy chlorophyll content and in situ measured APAR. The importance of environmental variables for GPP models is quantified with state‐of‐the‐art machine learning techniques. A special focus is put on photosynthesis‐limiting conditions, which are identified by a comparison of GPP and sap flow hysteretic responses to Vapor pressure deficit (VPD) and APAR. Results demonstrate that (a) LUE of the canopy's green part was on average 4.0% ± 2.3%, (b) canopy chlorophyll content as a seasonal variable for photosynthetic capacity was important for GPP predictions, and (c) on days with high VPD, tree‐scale sap flow and ecosystem‐scale GPP both shift to a clockwise hysteretic response to APAR. We demonstrate that the onset of such a clockwise hysteretic pattern of sap flow to APAR is a good indicator of stomatal closure related to water‐limiting conditions at the ecosystem‐scale.
    Description: Plain Language Summary: The efficiency by which a forest uses sunlight to perform photosynthesis is an important feature for climate and ecosystem modeling. However, the light that is actually captured by forests and is useable for photosynthesis is difficult to assess. Here, we show a sophisticated approach to estimate the light use efficiency of a spruce forest in Germany and analyze environmental influences on it and on photosynthesis. Our results indicate that about 4% of the light useable for photosynthesis was actually used by the forest during the 2021 growing season and that seasonal variations of chlorophyll in the canopy are a good indicator for carbon capture.
    Description: Key Points: A seasonal variable such as canopy chlorophyll content was useful to predict gross primary productivity with machine learning models. A clockwise hysteretic pattern of sap flow to radiation is a good indicator of water‐related stomatal closure. The light use efficiency of green parts of a spruce forest was 4.0% with a standard deviation of 2.3% during the 2021 growing season.
    Description: RWTH Aachen University http://dx.doi.org/10.13039/501100007210
    Description: University of Alberta http://dx.doi.org/10.13039/501100000190
    Description: Excellence Strategy of the Federal Government and the Länder
    Description: Waldklimafonds http://dx.doi.org/10.13039/501100010297
    Description: German Federal Ministry of Food and Agriculture
    Description: German Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection
    Description: TERENO project
    Description: Helmholtz research infrastructure Modular Observation Solutions for Earth Systems
    Description: http://doi.org/10.5281/zenodo.7014604
    Description: https://www.opengeodata.nrw.de/produkte/geobasis/hm/3dm_l_las/3dm_l_las/
    Description: https://scihub.copernicus.eu/
    Keywords: ddc:634.9 ; photosynthetically active radiation ; canopy chlorophyll content ; hysteresis ; sap flow ; variable importance ; Picea abies
    Language: English
    Type: doc-type:article
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    CITATION GEO-LEO
  • 12
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    South American Expert Roundtable. Increasing adaptive governance capacity for coping with unintended side effects of digital transformation (2020)
    In:  Sustainability
    Details
    Publication Date: 2023-07-18
    Description: This paper presents the main messages of a South American expert roundtable (ERT) on the unintended side effects (unseens) of digital transformation. The input of the ERT comprised 39 propositions from 20 experts representing 11 different perspectives. The two-day ERT discussed the main drivers and challenges as well as vulnerabilities or unseens and provided suggestions for: (i) the mechanisms underlying major unseens; (ii) understanding possible ways in which rebound effects of digital transformation may become the subject of overarching research in three main categories of impact: development factors, society, and individuals; and (iii) a set of potential action domains for transdisciplinary follow-up processes, including a case study in Brazil. A content analysis of the propositions and related mechanisms provided insights in the genesis of unseens by identifying 15 interrelated causal mechanisms related to critical issues/concerns. Additionally, a cluster analysis (CLA) was applied to structure the challenges and critical developments in South America. The discussion elaborated the genesis, dynamics, and impacts of (groups of) unseens such as the digital divide (that affects most countries that are not included in the development of digital business, management, production, etc. tools) or the challenge of restructuring small- and medium-sized enterprises (whose service is digitally substituted by digital devices). We identify specific issues and effects (for most South American countries) such as lack of governmental structure, challenging geographical structures (e.g., inclusion in high-performance transmission power), or the digital readiness of (wide parts) of society. One scientific contribution of the paper is related to the presented methodology that provides insights into the phenomena, the causal chains underlying “wanted/positive” and “unwanted/negative” effects, and the processes and mechanisms of societal changes caused by digitalization.
    Language: English
    Type: info:eu-repo/semantics/article
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  • 13
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    Climate Change 2022: Impacts, Adaptation, and Vulnerability. Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (2022)
    Intergovernmental Panel on Climate Change (IPCC)
    Details
    Publication Date: 2022-09-29
    Description: The Working Group II contribution to the IPCC Sixth Assessment Report assesses the impacts of climate change, looking at ecosystems, biodiversity, and human communities at global and regional levels. It also reviews vulnerabilities and the capacities and limits of the natural world and human societies to adapt to climate change.
    Language: English
    Type: info:eu-repo/semantics/report
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  • 14
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    Assessing the impact of climate change on fluvial flood losses in urban areas: a case study of Pamplona (Spain) (2023)
    In:  Hydrological Sciences Journal
    Details
    Publication Date: 2024-01-30
    Description: Climate change is expected to increase the frequency and magnitude of flooding. Furthermore, in recent years, there has been an increase in city extent and population densities. This study considers the metropolitan area of Pamplona (Spain) as a case study. The delta changes in precipitation quantiles in the Arga River catchment, obtained from 12 climate models, have been transformed into peak flow delta changes using the Real-time Interactive Basin Simulator (RIBS) model. Also, three percentiles of flood quantile delta changes are selected. Water depths and flood extents expected in future flood events have been obtained using the two-dimensional Iber hydrodynamic model. The Safer_DAMAGE algorithm has been used to assess flood losses in urban areas at the building scale. The results show that flood losses are expected to be smaller for low return periods and greater for high return periods.
    Language: English
    Type: info:eu-repo/semantics/article
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  • 15
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    Global Assembly on the Climate and Ecological Crisis Evaluation Report (2023)
    University of Canberra
    Details
    Publication Date: 2023-11-28
    Description: The Global Assembly on the Climate and Ecological Emergency was a pioneering civil society-led initiative. It was the world’s first citizens’ assembly that brought together 100 randomly selected citizens from around the globe to deliberate on the topic: ‘how can humanity address the climate and ecological crisis in a fair and effective way?’ For 68 hours over 11 weeks, Assembly Members listened to expert evidence, exchanged their views in facilitated small group deliberations and plenary sessions, and developed the People’s Declaration for the Sustainable Future of Planet Earth, first disseminated at COP26 in Glasgow in 2021. The Assembly aimed to set an institutional precedent for bringing the voices of ordinary citizens to multilateral negotiations, a space where they are largely absent. The Evaluation Report examines the extent to which the Global Assembly upheld principles of good practice in the process design, deliberative experience, and impact.
    Language: English
    Type: info:eu-repo/semantics/report
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  • 16
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    International Scientific Collaboration Is Needed to Bridge Science to Society: USERN2020 Consensus Statement (2021)
    In:  SN comprehensive clinical medicine
    Details
    Publication Date: 2023-07-18
    Description: Scientific collaboration has been a critical aspect of the development of all fields of science, particularly clinical medicine. It is well understood that myriads of benefits can be yielded by interdisciplinary and international collaboration. For instance, our rapidly growing knowledge on COVID-19 and vaccine development could not be attained without expanded collaborative activities. However, achieving fruitful results requires mastering specific tactics in collaborative efforts. These activities can enhance our knowledge, which ultimately benefits society. In addition to tackling the issue of the invisible border between different countries, institutes, and disciplines, the border between the scientific community and society needs to be addressed as well. International and transdisciplinary approaches can potentially be the best solution for bridging science and society. The Universal Scientific Education and Research Network (USERN) is a non-governmental, non-profit organization and network to promote professional, scientific research and education worldwide. The fifth annual congress of USERN was held in Tehran, Iran, in a hybrid manner on November 7–10, 2020, with key aims of bridging science to society and facilitating borderless science. Among speakers of the congress, a group of top scientists unanimously agreed on The USERN 2020 consensus, which is drafted with the goal of connecting society with scientific scholars and facilitating international and interdisciplinary scientific activities in all fields, including clinical medicine.
    Language: English
    Type: info:eu-repo/semantics/article
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  • 17
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    A global observational analysis to understand changes in air quality during exceptionally low anthropogenic emission conditions (2021)
    In:  Environment international
    Details
    Publication Date: 2024-02-22
    Description: This global study, which has been coordinated by the World Meteorological Organization Global Atmospheric Watch (WMO/GAW) programme, aims to understand the behaviour of key air pollutant species during the COVID-19 pandemic period of exceptionally low emissions across the globe. We investigated the effects of the differences in both emissions and regional and local meteorology in 2020 compared with the period 2015–2019. By adopting a globally consistent approach, this comprehensive observational analysis focuses on changes in air quality in and around cities across the globe for the following air pollutants PM2.5, PM10, PMC (coarse fraction of PM), NO2, SO2, NOx, CO, O3 and the total gaseous oxidant (OX = NO2 + O3) during the pre-lockdown, partial lockdown, full lockdown and two relaxation periods spanning from January to September 2020. The analysis is based on in situ ground-based air quality observations at over 540 traffic, background and rural stations, from 63 cities and covering 25 countries over seven geographical regions of the world. Anomalies in the air pollutant concentrations (increases or decreases during 2020 periods compared to equivalent 2015–2019 periods) were calculated and the possible effects of meteorological conditions were analysed by computing anomalies from ERA5 reanalyses and local observations for these periods. We observed a positive correlation between the reductions in NO2 and NOx concentrations and peoples’ mobility for most cities. A correlation between PMC and mobility changes was also seen for some Asian and South American cities. A clear signal was not observed for other pollutants, suggesting that sources besides vehicular emissions also substantially contributed to the change in air quality. As a global and regional overview of the changes in ambient concentrations of key air quality species, we observed decreases of up to about 70% in mean NO2 and between 30% and 40% in mean PM2.5 concentrations over 2020 full lockdown compared to the same period in 2015–2019. However, PM2.5 exhibited complex signals, even within the same region, with increases in some Spanish cities, attributed mainly to the long-range transport of African dust and/or biomass burning (corroborated with the analysis of NO2/CO ratio). Some Chinese cities showed similar increases in PM2.5 during the lockdown periods, but in this case, it was likely due to secondary PM formation. Changes in O3 concentrations were highly heterogeneous, with no overall change or small increases (as in the case of Europe), and positive anomalies of 25% and 30% in East Asia and South America, respectively, with Colombia showing the largest positive anomaly of ~70%. The SO2 anomalies were negative for 2020 compared to 2015–2019 (between ~25 to 60%) for all regions. For CO, negative anomalies were observed for all regions with the largest decrease for South America of up to ~40%. The NO2/CO ratio indicated that specific sites (such as those in Spanish cities) were affected by biomass burning plumes, which outweighed the NO2 decrease due to the general reduction in mobility (ratio of ~60%). Analysis of the total oxidant (OX = NO2 + O3) showed that primary NO2 emissions at urban locations were greater than the O3 production, whereas at background sites, OX was mostly driven by the regional contributions rather than local NO2 and O3 concentrations. The present study clearly highlights the importance of meteorology and episodic contributions (e.g., from dust, domestic, agricultural biomass burning and crop fertilizing) when analysing air quality in and around cities even during large emissions reductions. There is still the need to better understand how the chemical responses of secondary pollutants to emission change under complex meteorological conditions, along with climate change and socio-economic drivers may affect future air quality. The implications for regional and global policies are also significant, as our study clearly indicates that PM2.5 concentrations would not likely meet the World Health Organization guidelines in many parts of the world, despite the drastic reductions in mobility. Consequently, revisions of air quality regulation (e.g., the Gothenburg Protocol) with more ambitious targets that are specific to the different regions of the world may well be required.
    Language: English
    Type: info:eu-repo/semantics/article
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