Research Sara Vicca

Abstract

RESTOC aims to test the use of three CO2 removal (CDR) techniques - enhanced weathering (EW) of silicates, biochar (BC), and soil carbon sequestration (SCS) - for restoring degraded soils. Besides sequestering CO2, these combined techniques are expected to enhance soil water retention, to provide a natural source of essential micro- and macro-nutrients, and to create a stable soil matrix for agriculture. In this project, we will conduct a mesocosm experiment to assess in detail the impact of fundamental aspects of the method on soil development, plant growth and plant nutrients. These results will be used in a geochemical model, providing key insights into the processes involved in soil C sequestration, as well as a quantification of the long-term CDR potential of the technology.

Researcher(s)

• Promoter: Vicca Sara
• Co-promoter: Niron Harun

Research team(s)

• Biobased sustainability engineering (SUSTAIN)

Project type(s)

• Research Project

Abstract

This proposal aims to deepen our understanding of the carbon sequestration potential of enhanced weathering (EW), a promising carbon dioxide removal technology. The project addresses a critical gap in EW research by integrating organic carbon cycles into a geochemical modelling tool to unravel the organic-inorganic interactions in soil systems amended with EW. Specific objectives to reach this goal are: (i) integrating essential soil organic carbon (SOC) processes into the PHREEQC model to enable simulation of EW effects on SOC turnover and stabilisation; (ii) incorporating EW-plant interactions to assess their influence; (iii) including the synergistic effects of EW and biochar (BC) to further explore inorganic-organic interactions and to quantify potential synergies of EW and BC for carbon sequestration. The anticipated outcomes of this research project include the development of an EW model written in the PHREEQC 1D-reactive transport model including EW-SOC interactions induced by weathering and influencing weathering. Moreover, insights into plant-EW interactions are expected to be given by the development of a model that simulates these interactions. Additionally, the project attempts to generate a PHREEQC module that integrates geochemical reactions catalysed by a combined BC-EW amendment.

Researcher(s)

• Promoter: Vicca Sara
• Fellow: Vandenhove Charline

Research team(s)

• Biobased sustainability engineering (SUSTAIN)

Project type(s)

• Research Project

Abstract

Agriculture and synthetic fertilizers are responsible for 19% of global greenhouse gas emissions and significant reactive nitrogen emissions, contributing to environmental challenges. Seeking a natural solution, we turn to basalt weathering, a process that sequesters large amounts of CO2 over millennia while releasing essential nutrients vital for plant growth, soil health, and resilience to drought. We propose to harness this natural process in a controlled bioreactor enhanced by Bacillus subtilis. This bacterium augments mineral weathering through the production of organic acids, enzymes, and secondary metabolites that additionally bolster plant health and disease resistance. Our proposed method involves pre-weathering basalt in a bioreactor, enhanced by B. subtilis, and simultaneously sequestering CO2 while producing a fertilizer. The resulting climate- and nitrogen-friendly fertilizer will be used to cultivate the N-fixing alfalfa with further in-field weathering and CO2 capture. Key objectives include optimizing B. subtilis growth conditions, constructing and operating the bioreactor for fertilizer production, and assessing the resulting fertilizer's impact on crop yields, soil health, and CO2 sequestration rates during in-field weathering. A comprehensive evaluation will consider ecological and economic implications, guiding the development of sustainable agricultural practices.

Researcher(s)

• Promoter: Vlaeminck Siegfried
• Co-promoter: Vicca Sara
• Fellow: Czub Kaja

Research team(s)

• Biobased sustainability engineering (SUSTAIN)

Project type(s)

• Research Project

Abstract

CARBIZON provides a new technology for soil engineering. It is our ambition to achieve 'negative erosion with CO2 removal': rebuilding soils based on natural soil regeneration technology, combined with CO2 sequestration. To achieve this, CARBIZON combines three nature-based carbon dioxide removal methods (CDRs) to rapidly restore fertile topsoil. The technology provides a drastic solution to the longstanding issue of soil degradation in the Global South. With CARBIZON, we aim to reverse the effects of soil degradation and create healthy, fertile soils that can re-support sustainable agriculture, while also taking up massive amounts of carbon from the atmosphere. The issue of soil degradation is a major concern in the Global South, affecting millions of individuals who depend on agriculture for their livelihoods. Key value of CARBIZON technology lies in its potential beyond carbon sequestration. The CARBIZON approach improves soil water retention (rendering irrigation more efficient), it provides a natural source of essential micro- and macro-nutrients, fostering healthy crop growth, and creates a stable soil matrix that fosters soil health and prevents renewed erosion. Our approach ensures that the soil is not only climate-proof, but also resource-smart, making it suitable for sustainable agriculture in the long run. We envision that CARBIZON will deliver the crucial foundation to initiate the development of a carbon-as-a-service business model in soil restoration, providing landowners and governments with the innovation potential to restore degraded soils. Our approach puts a sustainable business model into future-proofing soils in the Global South, largely financed by the carbon market through the sales of the carbon credits obtained by CO2 sequestration.

Researcher(s)

• Promoter: Vicca Sara
• Co-promoter: Janssens Ivan
• Co-promoter: Struyf Eric

Research team(s)

• Biobased sustainability engineering (SUSTAIN)
• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

Given the current tenuous state of trust between institutions and actors at different levels in the EU governance system, the Jean Monnet Centre of Excellence STRATEGO aims to teach, research and disseminate knowledge on the dynamics, causes and effects of trust between the actors and institutions involved in EU multi-level governance of sustainable development, with a focus on business and entrepreneurship, climate and biodiversity, and health policies. This empirical scope of STRATEGO connects with the UN's sustainable development goals, the policy priorities of the European Commission and the priorities of the Erasmus+ programme. STRATEGO will develop interdisciplinary synergies on EU governance, trust and sustainable development by bridging teaching, research and outreach efforts across disciplines at the University of Antwerp. Throughout all activities, STRATEGO will go beyond the usual producers and consumers of EU studies. It will bring EU governance knowledge of the Social Sciences, Law and Economics faculties to students and staff of the Science and Health Sciences faculties, and it will reach out beyond the academic environment to foster a dialogue with professionals, civilsociety and the general public. In terms of teaching, STRATEGO will ensure interdisciplinarity through guest lectures, joint supervision of bachelor and master theses and innovative formats such as simulations and micro-credentials. In terms of research, STRATEGO will bring together staff from various disciplines through research seminars, PhD masterclasses and a visiting scheme for early career scholars. In terms of outreach beyond the academic context, STRATEGO will organise activities such as thematic webinars, outreach workshops and activities for specific audiences such as secondary schools.

Researcher(s)

• Promoter: Bursens Peter
• Co-promoter: Beutels Philippe
• Co-promoter: De Bièvre Dirk
• Co-promoter: Hoijtink Marijn
• Co-promoter: Matthysen Erik
• Co-promoter: Meeusen Johan
• Co-promoter: Meier Petra
• Co-promoter: Popelier Patricia
• Co-promoter: Vanderstraeten Johanna
• Co-promoter: Van Dooren Wouter
• Co-promoter: van Zimmeren Esther
• Co-promoter: Verhoest Koen
• Co-promoter: Vicca Sara
• Co-promoter: Wynen Jan

Research team(s)

• Politics & Public Governance

Project website

Project type(s)

• Research Project
• Education Project

Abstract

CO2 is a potent greenhouse gas and the primary cause of global climate change (GCC). Among others, GCC induces extreme weather events, producing an extensive impact on natural and agricultural systems. Climate change mitigation requires an urgent decrease in CO2 emissions together with active CO2 removal from the atmosphere. Enhanced silicate weathering (ESW) is a promising negative emission technology for CO2 removal but requires further research. ESW accelerates the natural process of weathering-based silicate to carbonate transformation, by increasing the surface area of silicate rocks. During the weathering process, CO2 is sequestered. Agricultural fields are ideal for ESW, due to ease of access, equipment availability and infrastructural capacity. In an agricultural setting, this application can be further beneficial as the silicate rocks like basalt contains elements that promote plant growth and soil health. In addition, GCC endangers crop production by inducing drought and salinity. Approximately 75% of the cropland is subjected to drought-related yield loss while salinity affects around 50-80% of global croplands. Moreover, impacts of drought and salinity are anticipated to rise in the future due to GCC. The negative effects of drought and salinity can be countered by ESW through (i) the preservation of crop yield and quality by the silicon (Si) mediated drought and salt stress tolerance in plants and (ii) the protection of soil microbiota by the stabilization of soil chemistry. Although ESW could contribute to climate change adaptation in agriculture, these promising co-benefits were never assessed, and further research is needed to evaluate this potential in different agriculturalsettings. In project CORES, I aim to examine the potential of ESW, with silicate mineral basalt, for the protection of yield and quality of major crop maize and associated soil microbiota under drought and saline conditions and establish the groundwork for future field trials.

Researcher(s)

• Promoter: Vicca Sara
• Fellow: Niron Harun

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change
• Biobased sustainability engineering (SUSTAIN)

Project type(s)

• Research Project

Abstract

Ecosystems sustain society by providing natural resources and socio-economic services. Understanding their functioning is thus vital for accurate projections of, among others, global climate and food production and prerequisite to drawing up policies for sustainable management of the planet. This proposal therefore aims at creating the scientific breakthroughs needed to make major advances in understanding of several critical processes that determine the functioning of ecosystems and their interactions with ongoing changes in climate and in resource availabilities. The overarching, long-term goal is to understand ecosystem functioning sufficiently well so that we can, in collaboration with modelling groups, confidently project how ecosystem functioning and services will change in the near and distant future. To pursue this goal, the following four research lines will be prioritized when allocating the Methusalem funding: 1. Obtaining a quantitative understanding of plant carbon allocation to growth, energy production (respiration), and nutrient acquisition (fine roots, root exudation, root symbionts). 2. Improving insight in, and measurements of, biomass production. 3. Better understanding soil carbon dynamics and sequestration. 4. Understanding spatial and temporal variation in carbon and greenhouse gas balances at ecosystem to regional scale and attribution to drivers. In each of these research lines, we aim to understand the mechanisms underlying the global and local spatial variation as well as those underlying the long-term trends and short-term temporal patterns. Focus is on how Global Changes (climate change including extreme events, increasing atmospheric CO2 concentration, nitrogen deposition, etc.) are affecting ecosystem processes and functioning. Many projects will be conducted with the research group of the Methusalem Chair at the University of Hasselt as prioritized partners.

Researcher(s)

• Promoter: Janssens Ivan
• Co-promoter: Campioli Matteo
• Co-promoter: Matthysen Erik
• Co-promoter: Nijs Ivan
• Co-promoter: Schoelynck Jonas
• Co-promoter: Temmerman Stijn
• Co-promoter: Vicca Sara

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

Carbon dioxide removal (CDR) will be needed to achieve Paris' agreement targets. Terrestrial Enhanced Weathering (TEW) is a promising CDR technique as it is simple, requires no additional land and is self-operational once installed with a range of potential co-benefits (e.g. increased plant productivity) along with permanent C capture on a human timescale. Only few studies exist on silicate amendment in forests relative to agricultural TEW. However globally, cropland and forests occupy a similar area and pioneered forest silicate amendment elevated wood production (biotic CDR) using the relatively scarce silicate wollastonite. Basalt is an attractive silicate for TEW as it is globally abundant, safe (low in heavy metals) and a by-product from mining. Nevertheless, to date, uncertain, unvalidated inorganic CDR model estimates & a lack of research on how TEW affects soil organic carbon (SOC) and biotic C sequestration hinder reliable carbon crediting and consequently large scale TEW adoption. Current models of inorganic CDR by TEW come with the disadvantage of either excluding biology or oversimplifying geochemical processes. Therefore, in this project, I aim to investigate inorganic and biotic CDR in a basalt-afforestation TEW field study and long-term effects on SOC stocks. Finally, I aim to construct an integrated model, including complex geochemistry and biological processes, validated by diverse experimental data.

Researcher(s)

• Promoter: Vicca Sara
• Fellow: Vienne Arthur

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change
• Biobased sustainability engineering (SUSTAIN)

Project type(s)

• Research Project

Abstract

An active removal of CO2 from the atmosphere will be necessary to limit global warming to 1.5 degrees. This project focusses on the novel CO2 capture method of enhanced weathering (EW), which involves the amendment of ground silicates to agricultural soils. Besides natural minerals, steel slags (silicates produced as a by-product in the steel industry) are also suitable for EW, making this technique even more sustainable. Recent scientific work has proven the inorganic carbon capture ability of this state-of-the-art method and revealed co-benefits for soil fertility (e.g. drought resilience, nutrient availability, etc.). This early research is however missing an important piece of the puzzle. Despite the well-known importance of organic matter for soil health and carbon storage, the impact of EW on organic carbon has not yet been studied. Considering known mechanisms governing organic carbon stocks in soils, I hypothesise that EW will lead to an increase of organic carbon sequestration and therefore to an amplification of the climate change mitigation potential. If confirmed, EW could aid in abating the problem of diminishing organic carbon stocks in agricultural soils, while improving soil fertility and capturing CO2 from the atmosphere. Hence, the proposed project would not only contribute to substantial progress within the emerging research field of EW but also to the creation of sustainable and resilient agricultural systems.

Researcher(s)

• Promoter: Vicca Sara
• Fellow: Steinwidder Laura

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change
• Biobased sustainability engineering (SUSTAIN)

Project type(s)

• Research Project

Abstract

The fate of the land carbon (C) sink is a major source of uncertainty in climate change projections. This uncertainty originates to a considerable degree from difficulties in estimating ecosystem responses to climate change itself, which depend on multiple factors. While moderating roles of for example ecosystem type and background climate are understood and accounted for in models, much less is known on how soil properties, resource availability and microbial symbionts influence global-scale responses to warming and precipitation change. I hypothesize that these soil-related factors explain to a significant degree why climate change responses vary so much, given their known role in determining ecosystem function. By using complementary benefits of ongoing, distributed climate change experiments and meta-analyses on a database I and international colleagues collaborated on, I aim to unravel global-scale patterns as well as in-depth mechanisms underlying soils' and symbionts' role in determining climate change responses. Using a novel approach to quantify nutrient availability, I here for the first time also plan to assess how climate change responses vary along resource availability gradients vs manipulations. Finally, I will evaluate if current land surface models realistically simulate soil/symbiont-dependent tradeoffs among C cycle pool and flux responses to climate change. Based on the findings, the project will contribute to more realistic projections of the land C sink.

Researcher(s)

• Promoter: Vicca Sara
• Fellow: Van Sundert Kevin

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change
• Biobased sustainability engineering (SUSTAIN)

Project type(s)

• Research Project

Abstract

Safe and scalable negative emission technologies (NETs), which actively remove CO2 from the atmosphere and provide long-term carbon sequestration, are needed to complement conventional climate change mitigation measures. There are low-tech and less expensive NETs that can provide additional benefits to society. One such NET is 'enhanced weathering' of silicate minerals (EW). EW is particularly promising as a NET because it can be associated with multiple societal and environmental benefits, as well as avoiding competition for land with food production. Greater crop yields, restoration of stocks of basic cations (e.g. Mg, Ca) and micronutrients (e.g. Zn, Se), less loss of N2O (a potent greenhouse gas) and NO3, higher pH. EW is not the only NET that can be applied in agriculture and provide additional benefits. The addition of organic matter (Soil Carbon Sequestration; SCS) and of biochar (BC) to soils is also being investigated. Research is needed to quantify impacts on climate change mitigation and adaptation, and the other environmental and societal benefits. The true potential of agro-NETs depends on the combination of net greenhouse gas emission reductions, agricultural benefits, positive side effects on the environment, societal barriers and economic feasibility. The most climate effective, environmentally friendly and cost-efficient options must be identified to enable rapid adoption by farmers and society. C-Farms will therefore not only assess climatic, technical and economic aspects, but also engage with farmers and industry to proactively address key opportunities and challenges in a co-creative process. Stakeholder engagement will culminate in a major joint pilot study. This will pave the way for policy measures (e.g. carbon pricing) to encourage this application.

Researcher(s)

• Promoter: Janssens Ivan
• Co-promoter: Vicca Sara

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

The European Green Deal relies on healthy forests to remove carbon (C) from the atmosphere, stabilize the water cycle and provide sufficient biomass for the future bioeconomy. The Flanders Forest Living lab realizes a specific breakthrough in the assessment of these crucial ecosystem functions, at spatial scales ranging from the individual tree to the entire forest. The Living Lab is situated in an ICOS flux-tower observatory, that currently already provides a permanent assessment of ecosystem scale CO2-fluxes, evapotranspiration and respiration. To date however, no technique is available to study the function of individual trees, at daily resolution, across a forest. achieving this is the groundbreaking objective of this new infrastructure. Its specific equipment allows for crucial realistic simulation of the water-, energy- and carbon fluxes by advanced vegetation models at spatial scales matching those of satellite imagery products, thereby creating new possibilities for applications such as automated precision forestry management, fire prevention and worldwide carbon budget quantifications. The new infrastructure involves an UAV and a set of linked validation sensors. Observations are steered by artificial intelligence, in order to be able to adapt the flight pattern to the fluctuating source area of the flux-tower, and in order to proactively adapt to specific weather patterns and potentially interesting ground-sensor observations.

Researcher(s)

• Promoter: Janssens Ivan
• Co-promoter: Campioli Matteo
• Co-promoter: Gielen Bert
• Co-promoter: Latré Steven
• Co-promoter: Nijs Ivan
• Co-promoter: Roland Marilyn
• Co-promoter: Scheunders Paul
• Co-promoter: Vicca Sara

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

At the 2015 climate summit in Paris, the world committed to limit warming to well below 2°C. Besides rapid and complete decarbonization of all sectors, achieving these targets will require deployment of negative emission technologies (NETs), which actively remove CO2 from the atmosphere and ensure long-term sequestration. Various techniques have been proposed, including several land-based solutions that involve the use of natural processes. However, no technique is yet available at scale and the lack of empirical data currently hampers development of realistic roadmaps for the necessary rapid, safe and large-scale deployment of NETs. A promising but yet poorly studied land-based NET is enhanced silicate weathering (EW). Thus far, research on the C sequestration potential of EW has been limited mostly to lab column experiments, which do not include soil and important biota and are thus still far from reality. Biota such as plants, mycorrhizal fungi and earthworms can be critical determinants of mineral weathering, but their influence on EW remains to be verified. On the other hand, field investigations face a major challenge because weathering products and hence C sequestration rates are very difficult to accurately quantify. This is especially due to the difficulty in determining leaching losses. The current project therefore envisions a crucial research step between the lab-based experiments and future applied large field-scale applications: mesocosm experiments which include important biota and at the same time allow for accurate quantification of weathering products and hence C sequestration rates. These mesocosm experiments will specifically test for the influence of important biota – plants, mycorrhizal fungi and earthworms – hence providing important information needed to extrapolate lab-based results to the real world.

Researcher(s)

• Promoter: Vicca Sara
• Fellow: Boito Lucilla

Research team(s)

• Biobased sustainability engineering (SUSTAIN)
• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

Conventional climate change mitigation alone will not be able to stabilise atmospheric CO2 concentrations at a level compatible with the 2°C warming limit of the Paris Agreement. Safe and scalable negative emission technologies (NETs), which actively remove CO2 from the atmosphere and ensure long-term carbon (C) sequestration, will be needed. Fast progress in NET-development is needed, if NETs are to serve as a risk-hedging mechanism for unexpected geopolitical events and for the transgression of tipping points in the Earth system. Still, no NETs are even on the verge of achieving a substantial contribution to the climate crisis in a sustainable, energy-efficient and cost-effective manner. BAM! develops 'super bio-accelerated mineral weathering' (BAM) as a radical, innovative solution to the NET challenge. While enhanced silicate weathering (ESW) was put forward as a potential NET earlier, we argue that current research focus on either 1/ ex natura carbonation or 2/ slow in natura ecosystem-based ESW, hampers the potential of the technology to provide a substantial contribution to negative emissions within the next two decades. BAM! focuses on an unparalleled reactor effort to maximize biotic weathering stimulation at low resource inputs, and implementation of an automated, rapidlearning process that allows to fast-adopt and improve on critical weathering rate breakthroughs. The direct transformational impact of BAM! lies in its ambition to develop a NET that serves as a climate risk hedging tool on the short term (within 10-20 years). BAM! builds on the natural powers that have triggered dramatic changes in the Earth's weathering environment, embedding them into a novel, reactor-based technology. The ambitious end-result is the development of an indispensable environmental remediation solution, that transforms large industrial CO2 emitters into no-net CO2 emitters.

Researcher(s)

• Promoter: Vicca Sara
• Co-promoter: Janssens Ivan

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change
• Biobased sustainability engineering (SUSTAIN)

Project type(s)

• Research Project

Abstract

Air pollution and ambient pollution, carbon-related issues ranging from GHG emissions to carbon shortages in soil, the opportunities provided by NBS and the intricacies of urban ecosystems present an extremely complex set of interdependent problems and opportunities that have to be addressed as such – interactively, mutually and innovatively. Upsurge is considering all these aspects and is providing evidence-based targeted responses that will enable EU cities to transition into a more regenerative future. At its core, Upsurge is presenting the European Regenerative Urban Lighthouse, which will enable cities to unlock their regenerative potential and provide them with knowledge and guidance in regenerative transition. Supported by an innovative continuous self-check progress mechanism (Regenerative Index) and by the Clearing House as a knowledge nerve centre, Upsurge will motivate cities and other clients through its networking activities to engage and step aboard the regenerative transition under Lighthouse's leadership. Upsurge is demonstrating technical excellence through a multimodal adaptable sensing system, through integrated and integrative digitalisation environment supported by IoT and AI, several real-life demonstrations and based on extrapolated criteria conducted simulative demonstrations showcasing the viability, feasibility and implementability of proposed technical solutions. The knowledge core of Upsurge will be introduced within the quintuple helix verification model bringing together all relevant factors affecting the implementation of NBS and thus regenerative change. Quintuple helix approach will truly enable the assessment and exploration of complementary beneficial effects provided by project solutions.

Researcher(s)

• Promoter: Vicca Sara

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change
• Biobased sustainability engineering (SUSTAIN)

Project type(s)

• Research Project

Abstract

We investigate the application of calcium silicate materials such as basalt and steel production residues for agricultural purposes. We want to answer the question whether such an application is a technically feasible, economically viable and environmentally preferred scenario to enhance carbon sequestration (climate mitigation) and drought resistance (climate adaptation) while also providing co-benefits such as increased crop yield and nutritional value. To this end, we combine in this interdisciplinary research project three types of expertise - chemical engineering and material science, biogeochemical and ecological research, life cycle and costing analyses - to identify the most environmentally and economically desirable approach. For each of these three expertise areas, we plan novel and timely research. Through a combined iterative and interactive approach we aim to maximize the applicability of the eventual results.

Researcher(s)

• Promoter: Vicca Sara

Research team(s)

• Biobased sustainability engineering (SUSTAIN)
• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

A promising but yet poorly studied negative emission technology (NET) is accelerated silicate weathering (EW). Thus far, research on EW has mainly been limited to laboratory experiments, without soil and important biota. However, biota such as plants and soil can strongly influence mineral weathering. On the other hand, field investigations face a major challenge because weathering products and hence C sequestration are very difficult to accurately quantify. In this project mesocosm experiments will therefore be conducted to determine the influence of important biota, hence providing critical information needed to extrapolate lab-based results to the real world.

Researcher(s)

• Promoter: Vicca Sara
• Co-promoter: Schoelynck Jonas

Research team(s)

• Biobased sustainability engineering (SUSTAIN)
• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

Climate change involves an increase in the frequency and intensity of regional drought events. Droughts can have substantial impact on the future functioning of land ecosystems, including their potential to mitigate further global warming. Drought impacts vary strongly, however, and factors determining drought sensitivity are not fully understood. Through meta-analyses, this project investigates how soil characteristics and nutrient availability may influence drought sensitivity of ecosystem productivity and CO2 exchange.

Researcher(s)

• Promoter: Vicca Sara

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

Besides rapid decarbonization of all sectors, limiting global warming to well below 2°C will also require active removal of CO2 from the atmosphere. A number of so-called negative emission technologies (NETs) have been proposed for this purpose, including several land-based solutions using natural processes. A promising but yet poorly studied land-based NET is accelerated silicate weathering (EW). When silicates weather, a slow dissolution process occurs, binding CO2 in aqueous form. This CO2 is sequestered for millennia. The idea behind EW is to speed up this natural process, by artificially increasing the weathering rate. This can be achieved by distributing finely ground silicate rock (e.g. basalt) or artificial silicates such as steel slag on soils. While the latter weathers more slowly, using waste streams has the advantage that source material is abundant and that it can be embedded in a circular economy. Thus far, research on EW has mainly been limited to laboratory experiments. Empirical research under more realistic conditions is urgently needed to determine the true climate change mitigation potential as well as the side-effects of EW. An essential step between the lab-based research and applications in the field are mesocosm experiments that allow accurate quantification of the CO2 sequestration and method development for practical C sequestration assessment in the field. In this project, a mesocosm experiment will be set up to accurately quantify CO2 sequestration by EW. Sideeffects on plant growth and plant nutrient concentrations will also be quantified. Specifically, 15 mesocosms will be filled with agricultural soil and planted with maize. Five receive only fertilizer, while the others receive also finely ground basalt (n=5) or steel slag (n=5), i.e., a natural and an artificial silicate. Weathering rates are monitored by analyzing top soil pore water samples as well as leachates for weathering products (DIC, alkalinity, Si, Mg and Ca). Weathering products can also precipitate in the soil and quantification of CO2 sequestration rates thus also requires analysis of carbonates in the soil after the experiment. Plants are harvested at the end of the experiment to quantify plant biomass (above- and belowground) and subsamples are analyzed for important plant nutrients, including N, P, K, Si, Ca, Mg.

Researcher(s)

• Promoter: Vicca Sara
• Co-promoter: Janssens Ivan
• Co-promoter: Meysman Filip

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

In a mesocosm experiment with potatoes, two negative emission technologies (NETs) are combined: biochar and enhanced weathering of basalt. We investigate the C sequestration rate as well as sideeffects on plant growth and nutrition.

Researcher(s)

• Promoter: Vicca Sara

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

This project investigates how terrestrial ecosystem functions (particularly carbon cycling) respond to environmental change (drought extremes) and how this depends on nutrient availability and mycorrhizal abundance. The fundamental research fits in the disciplines of ecosystem ecology and biogeochemistry.

Researcher(s)

• Promoter: Nijs Ivan
• Co-promoter: Vicca Sara
• Fellow: Van Sundert Kevin

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

Apart from gradual increases in atmospheric CO2 concentrations and temperature, climate change involves more frequent and intense extreme events, such as storms, heatwaves and droughts. Following a number of real-life cases in the last decades, such as the hot and dry summer of 2003 in Europe, we know that climate extremes can seriously diminish productivity in both natural and agricultural systems and moreover reduce carbon storage in ecosystems, and thus their potential to mitigate climate change. Experiments are improving our understanding of the effects of drought, but too many questions remain unanswered to be able to accurately predict how a particular ecosystem would respond to drought. Soil nutrient availability, which has been demonstrated to modify ecosystem responses to elevated CO2 and temperature, is likely to play a key role in responses to dry spells, among other through its influence on how much plants invest in roots and in their mycorrhizal symbionts. In this project, the influence of nutrient availability, plant carbon allocation and mycorrhizal fungi on drought responses will be investigated by using two ongoing drought experiments in a temperate and an alpine grassland where plant growth is already assessed, but nutrient availability and mycorrhizal fungi are not. These will be determined in the current project to then test their influence on the drought response of grassland productivity.

Researcher(s)

• Promoter: Vicca Sara

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

Tropical forests are among the most diverse ecosystems in the world and account for more than one third of global primary productivity. Tropical rainforests thus play a key role in the global carbon (C) balance. Most tropical forests are phosphorus (P) rather than nitrogen (N) limited, in contrast to the much better studied temperate and boreal forests. The effects of soil fertility on C cycling in tropical rainforests is, however, still poorly understood. The aim of this study is twofold: I want to improve our understanding of photosynthesis of tropical forests and how this changes along gradients of soil N and P availability. Further, I will investigate how plant C allocation varies along these gradients. Ecosystem C allocation is very important because it determines the residence time of C in the ecosystem and thereby the CO2 removal from the atmosphere. Both processes will be studied in the lowland tropical rainforests of French Guiana. The rainforests I will study are virtually undisturbed and cover a large gradient in soil fertility, which will be even enlarged by a fertiliser addition experiment. Therefore, these forests are ideally suited to study effects of nutrient imbalances on the functioning of tropical rainforests.

Researcher(s)

• Promoter: Janssens Ivan
• Co-promoter: Vicca Sara
• Fellow: Verryckt Lore

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

Support for the preparation of a new EU project application. The received budget will be used primarily for the compilation of preliminary data and insights from a few new test experiments at the campus.

Researcher(s)

• Promoter: Vicca Sara

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

Herbaceous Diversity Network (HerbDivNet, including 30 grassland sites distributed across 19 countries and 6 continents) recently demonstrated that grassland plant diversity peaks at intermediate productivity. While climate was accounted for in their analyses of the relationship between plant diversity and productivity, as usual, belowground factors such as nutrient availability and microbial diversity were not. However, nutrient availability is a crucial determinant of plant productivity and plant species composition and diversity. Microbial diversity is a key unknown link here as it is strongly driven by nutrient availability and plant diversity, but microbes too can feed-back to both by determining nutrient cycling and by acting as symbionts or parasites on plants. This study aims to evaluate to what extent different soil factors that determine nutrient availability, in combination with climate can explain plant biomass production, species diversity (plant and soil microbial diversity), and the relationship between these within and across the HerbDivNet sites. To this end, soil samples from HerbDivNet sites will be analyzed for nutrient availability and microbial diversity to determine: (1) how nutrient availability influences grassland productivity, diversity and their relationship, (2) how nutrient availability influences microbial diversity and (3) whether these factors can be integrated to better understand above- and belowground diversity patterns in grasslands worldwide.

Researcher(s)

• Promoter: Vicca Sara

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

This project investigates how terrestrial ecosystem functions (particularly carbon cycling) respond to environmental change (drought extremes) and how this depends on nutrient availability and mycorrhizal abundance. The fundamental research fits in the disciplines of ecosystem ecology and biogeochemistry.

Researcher(s)

• Promoter: Nijs Ivan
• Co-promoter: Vicca Sara
• Fellow: Van Sundert Kevin

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

Carbon taken up during photosynthesis is allocated to various processes and organs; this allocation determines its residence time in the ecosystem and ultimately the ecosystem carbon sink strength. Carbon allocation is poorly understood, mainly because allocation to the rhizosphere and especially to mycorrhizal symbionts remains unquantified. Earlier research has shown that some ecosystems invest only 30% of their photosynthates in growth, whereas others invest up to 70%. Evidence is growing that nutrient availability is behind this large variation, with a variable carbon cost of plantmycorrhizal symbiosis as the hypothesized underlying mechanism. The aim of this project is to unravel the process of plant carbon allocation, testing the hypothesis that the variation in terrestrial carbon sequestration is driven by nutrient availability via its control on mycorrhizal carbon use. To this end, a mesocosm experiment with Zea mays is currently being set up where carbon allocation to all carbon pools and carbon-consuming processes will be assessed under different nitrogen and phosphorus availabilities. The specific aim of the current project to obtain to quantify the carbon allocated to the mycorrhizal fungi.

Researcher(s)

• Promoter: Vicca Sara

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

Soils contain over three times as much carbon as the atmosphere in soil organic matter, and have the potential to slow down or accelerate climate change through altered rates of plant growth and soil organic matter decomposition. Cold, northern ecosystems in particular, store vast amounts of carbon in the soil, but these stocks are vulnerable to increased carbon losses due to warming temperatures and changes in the availability of limiting nutrients such as nitrogen. In addition to the direct effects of warming and increasing nitrogen availability on organic matter decay by microbes, plants also play a major role by changing the way in which they use their photosynthates. By allocating more or less carbon belowground to roots, symbionts, or exudation, plants can alter soil carbon input rates and pathways, and thereby change the way soil organic matter responds to warming and nitrogen enrichment. Our research will examine how warming and nitrogen availability impact on carbon dynamics of plants and soil microbes in order to improve our understanding of plant-soil carbon cycling under future global change scenarios. In order to do this we will carry out experiments in a subarctic grassland of Iceland, tracking carbon flows from plant photosynthesis into the soil and back to the atmosphere and input this data into mathematical models to help better predict ecosystem carbon cycling feedbacks to global warming.

Researcher(s)

• Promoter: Janssens Ivan
• Co-promoter: Soong Jennifer
• Co-promoter: Vicca Sara

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

Tropical forests are among the most diverse ecosystems in the world and account for more than one third of global primary productivity. Tropical rainforests thus play a key role in the global carbon (C) balance. Most tropical forests are phosphorus (P) rather than nitrogen (N) limited, in contrast to the much better studied temperate and boreal forests. The effects of soil fertility on C cycling in tropical rainforests is, however, still poorly understood. The aim of this study is twofold: I want to improve our understanding of photosynthesis of tropical forests and how this changes along gradients of soil N and P availability. Further, I will investigate how plant C allocation varies along these gradients. Ecosystem C allocation is very important because it determines the residence time of C in the ecosystem and thereby the CO2 removal from the atmosphere. Both processes will be studied in the lowland tropical rainforests of French Guiana. The rainforests I will study are virtually undisturbed and cover a large gradient in soil fertility, which will be even enlarged by a fertiliser addition experiment. Therefore, these forests are ideally suited to study effects of nutrient imbalances on the functioning of tropical rainforests.

Researcher(s)

• Promoter: Janssens Ivan
• Co-promoter: Vicca Sara
• Fellow: Verryckt Lore

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

Nutrients are key determinants of plant growth and are important influencing factors of terrestrial carbon cycling and its response to climate change. Although nutrients were long overlooked in carbon cycle studies, nowadays, an increasing number of empirical studies aim to unravel the mediating role of nutrient availability in terrestrial carbon cycling. However, despite the great potential of the increasing number of experimental and observational datasets, in-depth synthesis work to identify overarching patterns is currently hampered by difficulties comparing the nutrient status of different sites. The aim of this project is therefore to develop a standardized metric of nutrient availability that opens the door for in-depth analyses of the influence of nutrient availability on terrestrial carbon cycling and other important ecosystem functions. To this end, I will evaluate two existing metrics that include several important soil factors, but were never validated and, importantly, do not explicitly account for nitrogen (N) and phosphorous (P) availability. I will therefore test the applicability of both metrics, and especially how N and P availability should be considered. For this evaluation, I will use data from (1) European soil and plant surveys (ICP forests database), (2) three natural fertility gradients in different biomes, and (3) five nutrient addition experiments. Finally, I aim to develop one final standardized metric that can be widely applied.

Researcher(s)

• Promoter: Vicca Sara

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

The budget coming with this award will be invested in m y new project, TRACK-C, that aims to unravel plant carbon allocation in response to changes in nutrient availability. For more details, see TRACK-C project.

Researcher(s)

• Promoter: Vicca Sara

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

Nutrients are key determinants of plant growth and are important influencing factors of terrestrial carbon cycling and its response to climate change. Although nutrients were long overlooked in carbon cycle studies, nowadays, an increasing number of empirical studies aim to unravel the mediating role of nutrient availability in terrestrial carbon cycling. However, despite the great potential of the increasing number of experimental and observational datasets, in-depth synthesis work to identify overarching patterns is currently hampered by difficulties comparing the nutrient status of different sites. The aim of this project is therefore to develop a standardized metric of nutrient availability that opens the door for in-depth analyses of the influence of nutrient availability on terrestrial carbon cycling and other important ecosystem functions. To this end, I will evaluate two existing metrics that include several important soil factors, but were never validated and, importantly, do not explicitly account for nitrogen (N) and phosphorous (P) availability. I will therefore test the applicability of both metrics, and especially how N and P availability should be considered. For this evaluation, I will use data from (1) European soil and plant surveys (ICP forests database), (2) three natural fertility gradients in different biomes, and (3) five nutrient addition experiments. Finally, I aim to develop one final standardized metric that can be widely applied.

Researcher(s)

• Promoter: Janssens Ivan
• Fellow: Vicca Sara

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

Planten nemen koolstof op via fotosynthese en gebruiken die koolstof voor verschillende processen (o.a. ademhaling) en om biomassa te produceren. Dit allocatiepatroon bepaalt uiteindelijk de verblijftijd van koolstof in een ecosysteem en dus de capaciteit van een ecosystem ook koolstof op te slaan. Toch is koolstofallocatie in planten nog niet voldoende gekend, onder meer omdat de koolstofallocatie naar de rhizosfeer, en vooral naar symbionten zoals mycorrhizale fungi, nog niet gekwantificeerd werd. Eerder onderzoek toonde aan dat sommige ecosystemen 30% van de opgenomen koolstof investeren in groei, terwijl dit voor anderen opliep tot 70%. Er zijn steeds meer indicaties dat deze grote variatie in koolstofallocatie te wijten is aan de koolstofkost voor opname van nutrienten zoals stikstof en fosfor, en dat de mycorrhiza's hier een belangrijke rol in spelen aangezien zij de plant aan nutrienten helpen. Het doel van dit project is om koolstofallocatie te doorgronden, en de hypothese te testen dat de grote variatie in koolstofallocatie gedreven wordt doordat verschillen in nutrientenbeschikbaarheid leiden tot verschillen in koolstofkost van nutrientenopname via de symbiose met mycorrhiza's. Deze studie wordt uitgevoerd in een mesocosmos-experiment waarin Zea mays wordt opgegroeid onder verschillende bemestingsgraden en vervolgens koolstofallocatie naar groei, ademhaling, symbiose met mycorrhiza's allemaal gekwantificeerd worden.

Researcher(s)

• Promoter: Vicca Sara

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

Nutrient availability is a key determinant of ecosystem functioning and terrestrial carbon cycling. However, global analyses of how various ecosystem processes vary with nutrient availability are currently restricted by the lack of a standardized metric of nutrient availability. The aim of this project is to develop such metric based on data from a European forest database as well as two natural fertility gradients.

Researcher(s)

• Promoter: Vicca Sara

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

The aim of this project is to achieve an improved knowledge of the response of the terrestrial carbon cycle to climate variability and extremes. Specifically, effects of extreme weather events on plant growth and its underlying processes, crop yields and harvestable products, soil processes such as microbial respiration and water retention, soil carbon stocks and ecosystem carbon sequestration will be studied over a wide range of ecosystems.

Researcher(s)

• Promoter: Janssens Ivan
• Fellow: Vicca Sara

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

Increasing temperature and water level drawdown are two important factors of global change. Both factors are of high importance with regard to the carbon and greenhouse gas balance of peatlands. This project is set up to determine how temperature and groundwater level influence these balances. Furthermore, we give special attention to the underlying processes of methane and nitrous oxide emissions and how these are influenced by temperature and groundwater level. At the University of Antwerp, an experimental platform was established at which nine greenhouses each contain four mesocosms filled with fen peat. In these mesocosms, the groundwater level is regulated. From April till November, the groundwater level is set at 5, 10, 17 or 24 cm below the surface. During the other six months of the year, water levels are raised with 10 cm (except the highest level, which is only raised with 5 cm). In each greenhouse, temperature is regulated. Three greenhouses remain unheated, whereas the others are either heated by 3 °C or by 6 °C. At regular time intervals, we measure CO2, CH4 and N2O emissions with a dynamic closed chamber. Furthermore, we determine all components of the carbon balance (DOC, POC, VOC and DIC), some components of the nitrogen balance (NO3-, NH4+, DON and DIN) and several important parameters such as O2 concentration, temperature and soil water content. In addition, we also determine concentrations of CO2, CH4 and N2O at different depths in the soil in order to obtain more information about underlying processes. Besides this mesocosm experiment, some small experiments are performed in which the underlying processes of production and oxidation of CH4 and the formation of N2O are studied in more detail and in which some experimental procedures are tested. Furthermore, we also determine the fractionation factors (for 13C) of the two main pathways for CH4 production and of the oxidation of CH4.

Researcher(s)

• Promoter: Janssens Ivan
• Fellow: Vicca Sara

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project

Abstract

Increasing temperature and water level drawdown are two important factors of global change. Both factors are of high importance with regard to the carbon and greenhouse gas balance of peatlands. This project is set up to determine how temperature and groundwater level influence these balances. Furthermore, we give special attention to the underlying processes of methane and nitrous oxide emissions and how these are influenced by temperature and groundwater level. At the University of Antwerp, an experimental platform was established at which nine greenhouses each contain four mesocosms filled with fen peat. In these mesocosms, the groundwater level is regulated. From April till November, the groundwater level is set at 5, 10, 17 or 24 cm below the surface. During the other six months of the year, water levels are raised with 10 cm (except the highest level, which is only raised with 5 cm). In each greenhouse, temperature is regulated. Three greenhouses remain unheated, whereas the others are either heated by 3 °C or by 6 °C. At regular time intervals, we measure CO2, CH4 and N2O emissions with a dynamic closed chamber. Furthermore, we determine all components of the carbon balance (DOC, POC, VOC and DIC), some components of the nitrogen balance (NO3-, NH4+, DON and DIN) and several important parameters such as O2 concentration, temperature and soil water content. In addition, we also determine concentrations of CO2, CH4 and N2O at different depths in the soil in order to obtain more information about underlying processes. Besides this mesocosm experiment, some small experiments are performed in which the underlying processes of production and oxidation of CH4 and the formation of N2O are studied in more detail and in which some experimental procedures are tested. Furthermore, we also determine the fractionation factors (for 13C) of the two main pathways for CH4 production and of the oxidation of CH4.

Researcher(s)

• Promoter: Janssens Ivan
• Fellow: Vicca Sara

Research team(s)

• Plant and Ecosystems (PLECO) - Ecology in a time of change

Project type(s)

• Research Project