Research team

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

Expertise

Impact of climate change on plants and ecosystems, in particular the influence of climate extremes such as drought and heat. Role of biodiversity in ecosystems. Biological invasions by non-native plant species. Which ecosystems: grassland, tundra.

Real-time and spatially distributed monitoring of microclimate. 01/11/2021 - 31/10/2022

Abstract

Recently, climate change impacts have become strikingly tangible, with prolonged periods of drought and temperature records being broken. These weather extremes strongly impact soil ecosystem services, with potentially important economic consequences for agriculture, nature conservation, garden maintenance and other sectors. Society increasingly needs to cope with these impacts, thus spurring new economic activities that demand large-scale heat and drought monitoring. In this PhD project, I will pioneer cost-effective approaches for large soil microclimate networks that involve 1000s of monitoring locations. These allow to assess the vulnerability of soil ecosystems to heat and drought, and verify whether implemented adaptation measures are effective (e.g. water infiltration and soil moisture buffering). As a proof of concept, extensive microclimate networks will be deployed in gardens and nature reserves across Flanders, taking advantage of the new TMS-NB sensor, which enables low-cost and real-time measurements of soil temperature and moisture through the Internet of Things. This new data source will allow identifying the drivers of spatiotemporal variability in microclimate along the urban-rural gradient. Novel software tools will be developed for the data streams originating from these sensor networks, thus making the resulting data and insights readily available to relevant societal actors (e.g. farmers, garden maintenance, nature reserve managers).

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ASsessing and mitigating the effects of climate change and biological Invasions on the spatial redistribution of biodiversity in Cold environmentS (ASICS) 01/04/2021 - 31/03/2024

Abstract

ASICS is a global network of ecologists passionate about biodiversity in the earth's most remote areas: the cold north and south, and high-elevation areas. It brings together expertise on field observations, experiments and ecological modelling to answer one important question: how are global changes affecting cold-environment species redistributions, and can this knowledge help us halt the deterioration of these precious ecosystems?

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Project website

AnaEE-Flanders: Integrated infrastructure for experimental ecosystem research. 01/02/2021 - 31/01/2025

Abstract

ANAEE will provide Europe with a distributed and coordinated set of experimental, analytical and modelling platforms to analyse and predict in a precise manner the response of the main continental ecosystems to environmental and land use changes. ANAEE will consist of highly equipped in natura and in vitro experimental platforms associated with sophisticated analytical and modelling platforms, under a European umbrella of supranational entities. At UAntwerp these platforms will include both terrestrial and aquatic experimental facilities.

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The effectiveness of novel genotypes and soil organic matter to protect agricultural grasslands against increasingly persistent weather. 01/11/2020 - 31/10/2022

Abstract

Recent observations show that weather patterns are becoming more persistent in Europe. A growing number of studies indicates that average weather is being replaced by a sequence of anomalously long alternating wet and dry periods. This shift in climate regimes will likely have negative consequences for ecosystem functioning, particularly in agricultural grasslands which provide a variety of ecosystem services in Flanders. New insights suggest that recently developed drought resistant grass genotypes in combination with increased soil organic matter content can increase and stabilize productivity while reducing nutrient leaching throughout a fluctuating climate. However, knowledge of the interactions between these novel grass species, soil, and increased weather persistence is lacking. By mechanistically investigating their interrelationships, we intend to provide sustainable solutions that improve agricultural resilience in times of climate change.

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CurieuzeNeuzen in de tuin 23/09/2020 - 22/03/2023

Abstract

The citizen science project CURIEUZENEUZEN VLAANDEREN on air quality in 2018 will have a successor: "CURIEUZENEUZEN IN THE GARDEN". In the spring of 2021, 5000 families will have the opportunity to equip their garden with a soil weather station. This weather station will be centrally located in the lawn and will monitor the temperature and soil moisture online for six months (April 1 to September 30). With this research we want to obtain a large-scale picture of drought stress in Flanders. The 5000 participants will also collect soil samples in their gardens, which will provide a detailed picture of the carbon content in the garden soils in Flanders. Thanks to this research, we obtain important scientific insights into resilience against weather extremes, and we can sensitize the general public about climate adaptation.

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Project website

CurieuzeNeuzen duikt onder 01/01/2020 - 15/03/2023

Abstract

CurieuzeNeuzen is back, but now with a focus on climate adaptation. Whereas the original CurieuzeNeuzen citizen science project has moved mountains with respect to public participation in air quality, "CurieuzeNeuzen goes underground " wants to work on climate awareness in a large-scale way. To this end, we are going to monitor the impact of weather extremes and increasing drought, where citizens notice it first: in their own garden. This garden is close to the heart of Flanders, so the tens of thousands of lawns in Flanders are the ideal canvas for an innovative citizen science project on climate adaptation. Via a large-scale network of thousands of "mini weather station networks" we will measure the soil temperature and soil moisture throughout Flanders, both at home in gardens, as well as in public gardens and parks. This measurement campaign has a specific scientific purpose: we will answer the important question of how resilient our gardens are against future climate change and extreme weather conditions, and what the effect of our garden and landscape management is on that resilience. We take into account the effect of urban heat islands, but also the impact of small, local interventions, such as planting trees and the frequency of mowing. The result is a detailed drought map for Flanders in which risk areas are mapped and, for science, an extensive and internationally unique database on the impact of increasing weather extremes on the soil climate. But above all, we aim for a large-scale awareness of the drought problem in Flanders, and what we can do about this, both as individual and as society.

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'SoilTemp': naar een globale database van bodemtemperatuur 01/01/2019 - 31/12/2023

Abstract

In this Scientific Research Network, we bring together experts from all these fields to work on a growing database of soil temperatures and associated species data. We aim to complement the existing mechanistic models of soil temperature for use in ecological studies by bringing together regional datasets of topsoil (up to 10 cm below the ground surface) temperatures to work towards an open access global database of soil temperatures (the 'SoilTemp database'). We will use this database to explore general drivers (e.g. topography and vegetation parameters obtained with remote sensing techniques) of soil temperature in space and time, relate patterns in soil temperature to available surface and free-air temperature datasets, and calibrate and validate globally-valid hybrid (statistical + mechanistic) models of soil temperature. The ultimate result will be a set of maps of biologically relevant summary statistics based on interpolated and increasingly calibrated soil temperature across a wide range of habitats (grasslands, forests, croplands, wetlands, etc.) (the 'SoilTemp maps'). These gridded maps/products will be particularly useful to predict responses of biodiversity and ecosystem functioning near the soil surface to global change (the 'SoilTemp applications'). Ultimately, application of the database and its derived maps will facilitate conservation decision making across the world, as it will improve the accuracy of many of our ecological models.

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The potential for upward range expansion of alien plant species in cold-climate mountains in a warming world. 01/01/2019 - 31/12/2022

Abstract

This proposal explores the future of biological invasions by alien plant species in cold-climate mountain ecosystems. With a combination of observational, experimental and modelling techniques we identify the mechanisms that enable high-risk alien species to expand their range and disrupt local ecosystems in a warming climate. We propose an integrative, dynamic and mechanistic approach to tackle this question, by solving three timely methodological issues in alien species distribution assessments: 1) evolving towards the dynamic modelling of species ranges over time, 2), accounting for plant microclimate in both models and experiments, and 3) better integration of observations and experiments on the drivers behind species invasions in cold climates. Together these methodological advances will help us disentangle the role of several candidate mechanisms that define the current and future elevational limit of the focal species, including among others the temperature dependence of reproduction, the use of warm spots in the environment as stepping stones for dispersal, and the co-invasion of and interaction with mycorrhizal symbionts. The study is fundamental but at the same time allows one to assess which management measures might be feasible to control alien plant invasions in pristine cold regions

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Shifting rainfall regimes: a multi-scale analysis of ecosystem response (REGIME SHIFT). 01/01/2019 - 31/12/2022

Abstract

Recent climate change research reveals a novel and significant trend: weather patterns at mid-latitudes, such as in temperate western Europe, are getting more persistent. With respect to rainfall, this means longer droughts, but also longer periods with excessive rain. No comprehensive study has hitherto investigated the ecological consequences of such regime shifts. Can ecosystems adapt, or will the alternation between drought stress and soil water saturation exhaust them? Will this select for communities with novel trait combinations and more volatile species dynamics? And will these novel systems still be robust in the face of further changes in the environment? This study explores the potential impact of the ongoing shift in the frequency of dry/wet cycles at multiple, connected levels of biological organization. It does so in a new, large-scale set-up at UAntwerp built in the framework of the developing European infrastructure for ecosystem research 'AnaEE'. The design simulates changes in rainfall and associated temperature changes in the open air, using a gradient with eight precipitation regimes so that non-linearity and tipping points can be discerned with great precision. The project scope ranges from plants to soil biota such as bacteria and fungi, and from metabolism and genetic regulation assessed with bioinformatics to ecosystem processes. This multi-scale approach explicitly acknowledges the interwoven nature of ecosystems, with knowledge of molecular and cellular changes being instrumental to mechanistically explain the whole-system-scale effects on productivity, greenhouse gas fluxes and biodiversity dynamics. Different experiments are planned each year: (i) year 1 features a gradient in alternating dry/wet cycles, from 1 to 60 days, across a full growing season; (ii) year 2 focuses on legacy effects and the importance of changes of soil communities; (iii) year 3 matches precipitation regimes to corresponding temperature regimes to study the impact of drought-associated warming (an important natural feedback that can greatly increase plant stress). A series of connected, hypothesis-driven measurements is carried out, which will be integrated using structural equation modelling (path analysis) and ecosystem modelling. The project team has successfully collaborated in the past, and the complementary expertise brought together here should yield both significantly increased understanding of key processes as well as new avenues to climate change impact mitigation.

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Global Ecosystem Functioning and Interactions with Global Change. 01/06/2016 - 31/12/2022

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.

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Current and future distribution of invasive alien species in mountainous ecosystems. 15/07/2020 - 14/07/2021

Abstract

Understanding the current and future distribution of exotic species in mountains and the factors that determine their richness and abundance at multiple scales is of utmost importance for the conservation of these precious ecosystems, in times in which climate change and anthropic pressure are increasingly facilitating their spread. In this joint PhD, we aim to shed light on this question for the Chilean Andes, with the following research questions in mind: 1) What are the main factors (abiotic, biotic or anthropic) at play in defining the distribution of exotic species in the mountain ecosystems of Central-South Chile? 2) How does refining the spatial resolution of bioclimatic data (microclimate) and the incorporation of anthropic variables improve the performance of species distribution models and the prediction of the potential distribution of exotic species in the Chilean Andes?

Researcher(s)

  • Promotor: Nijs Ivan
  • Fellow: Fuentes Lillo Eduardo

Research team(s)

Elucidating the role of nutrient availability and mycorrhizae in the drought response of terrestrial ecosystem carbon cycling. 01/10/2019 - 30/09/2021

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.

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AnaEE-Flanders: Integrated infrastructure for experimental ecosystem research. 01/02/2019 - 31/01/2021

Abstract

ANAEE will provide Europe with a distributed and coordinated set of experimental, analytical and modelling platforms to analyse and predict in a precise manner the response of the main continental ecosystems to environmental and land use changes. ANAEE will consist of highly equipped in natura and in vitro experimental platforms associated with sophisticated analytical and modelling platforms, under a European umbrella of supranational entities. At UAntwerp these platforms will include both terrestrial and aquatic experimental facilities.

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Advancing predictions of Species Distribution Models by incorporating local-scale abiotic and biotic drivers. 01/10/2018 - 30/09/2021

Abstract

One of the main ecological challenges of our time is understanding how ecosystems deal with the various threats of global change. For many species, the effects of global change – either climate warming, land use changes or any other - result in significant changes in their distribution. To obtain reliable predictions of plant species range changes under global change, however, environmental conditions and species interactions at the local scale are key, and both are so far poorly studied. With this proposal, I aim to unravel the role of climate and land use change on range changes with the help of a set of local observations and experiments, building on a longterm global observational study on plant species distributions in mountains (hosted by MIREN, the Mountain Invasion Research Network). First, I will quantify the relative importance of local land use change (exemplified by mountain roads and trails) and microclimate on regional species distributions. Next, I will use local measurements to fully disentangle the mechanisms at work, ending with a field experiment to validate the observations and models. Altogether, this will help answering timely questions on the importance of local-scale mechanisms in defining species distributions, as well as on the impact of global change on mountain biodiversity.

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Elucidating the role of nutrient availability and mycorrhizae in the drought response of terrestrial ecosystem carbon cycling 01/10/2017 - 30/09/2019

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.

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Analysis and Experimentation on Ecocystems (AnaEE). 01/01/2017 - 31/12/2018

Abstract

ANAEE will provide Europe with a distributed and coordinated set of experimental, analytical and modelling platforms to analyse and predict in a precise manner the response of the main continental ecosystems to environmental and land use changes. ANAEE will consist of highly equipped in natura and in vitro experimental platforms associated with sophisticated analytical and modelling platforms, under a European umbrella of supranational entities. At UAntwerp these platforms will include both terrestrial and aquatic experimental facilities.

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Combination of field experiments and niche-based large-scale modelling to explain and predict future plant invasions in mountains. 01/10/2016 - 30/09/2018

Abstract

In this proposal, I aim to combine the strengths of different ecological methods. The international field campaign asks for practical knowledge of field ecology, as well as fundamental expertise on the environmental biophysics behind climate-driven processes. This is complemented in the second part with theoretical modeling with cutting-edge data manipulation methods.

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Interplay between soil heterogeneity and plant spatial pattern: an experimental mesocosm study including a climate extreme. 01/01/2016 - 31/12/2019

Abstract

"Spatial ecology" is a rapidly developing discipline in ecosystem science. While some ecologists explore the significance of the spatial heterogeneity in the soil for plant communities, others concentrate on the consequences of the spatial pattern of the plants. However, no studies have to our knowledge investigated how these two fundamental types of spatial heterogeneity work together in determining ecosystem functioning. Here we manipulate both types independently in mesocosms (simplified experimental ecosystems constructed from soil and plants), while additionally varying also species richness. Soil heterogeneity is experimentally varied in three dimensions with a novel technique. We also investigate the importance of heterogeneity for climate change impact.

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GCE - Global Change Ecology. 01/01/2015 - 31/12/2019

Abstract

This project represents a research contract awarded by the University of Antwerp. The supervisor provides the Antwerp University research mentioned in the title of the project under the conditions stipulated by the university.

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Combination of field experiments and niche-based largescale modelling to explain and predict future plant invasions in mountains. 01/10/2014 - 30/09/2016

Abstract

In this proposal, I aim to combine the strengths of different ecological methods. The international field campaign asks for practical knowledge of field ecology, as well as fundamental expertise on the environmental biophysics behind climate-driven processes. This is complemented in the second part with theoretical modeling with cutting-edge data manipulation methods.

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Design and supervise an irrigation experiment and a seed-addition experiment. 01/08/2014 - 31/12/2015

Abstract

This project represents a formal service agreement between UA and on the other hand King Saud University. UA provides King Saud University research results mentioned in the title of the project under the conditions as stipulated in this contract.

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ANAEE-Flanders. 29/07/2014 - 28/07/2018

Abstract

ANAEE will provide Europe with a distributed and coordinated set of experimental, analytical and modelling platforms to analyse and predict in a precise manner the response of the main continental ecosystems to environmental and land use changes. ANAEE will consist of highly equipped in natura and in vitro experimental platforms associated with sophisticated analytical and modelling platforms coupled to networks of instrumented observation and monitoring sites throughout Europe.

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Factors driving alien plant invasions in mountain regions. 01/06/2014 - 30/09/2014

Abstract

The goal of this project is to determine factors that influence the invasion of alien plant species in mountains, more in particular in the subarctic region around the Swedish field research station at Abisko. With the help of experiments the role will be examined of temperature, disturbance and propagule availability. The project is funded by the EU program INTERACT, which provides access to research stations in the Arctic.

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Trait variation in cryptogams – responses and feedback to climate change. 01/10/2013 - 28/02/2014

Abstract

This project aims to link phenotypic trait variation in cryptogams to microclimatic (temperature) conditions, and study how cryptogam species in turn influence microclimate. Specifically we are interested in the following questions: - Is trait variation in cryptogams related to temperature and soil parameters? - What is the contribution of cryptogam species to local microclimate?

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European gradients of resilience in the face of climate extremes (SIGNAL). 01/03/2013 - 31/12/2016

Abstract

Experiments on the effects of extreme weather events on biodiversity, ecosystem functions, resilience and tipping points in graslands along a pan-European climatic gradient. Assessment of resilience status and regionally differentiated policy decision support.

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Infrastructure for analysis and experimentation on ecosystems (ANAEE). 01/11/2012 - 31/10/2016

Abstract

ANAEE will provide Europe with a distributed and coordinated set of experimental, analytical and modelling platforms to analyse and predict in a precise manner the response of the main continental ecosystems to environmental and land use changes. ANAEE will consist of highly equipped in natura and in vitro experimental platforms associated with sophisticated analytical and modelling platforms coupled to networks of instrumented observation and monitoring sites throughout Europe.

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Influence of a future climate and interspecific interactions on the stress response of plants. 01/10/2012 - 30/09/2015

Abstract

It is currently unknown how plants will be affected by stress factors in a future climate with more atmospheric CO2 and higher air temperatures. This is important to know for agriculture because stress adversely affects crop growth and yield, but it is equally important for the conservation of biodiversity. For example, reduced stress resistance of plants in a future climate might lead to loss of sensitive species. Some global change factors have been shown to modify plant stress resistance in some species. However, the uncertainty is greater in more realistic, multi-species communities because interactions between the species are likely to alter the species-specific stress responses. Therefore, in the proposed research we want to disentangle abiotic factors (climate-warming and elevated CO2) and biotic factors (plant-plant interactions) that determine the stress response of a plant. An important question is whether neighbouring species modify the intrinsic stress response of a plant by changing the available resources. To solve these questions we will grow grassland communities (monocultures and mixtures) under different climate scenarios in sunlit, computer-controlled growth chambers.

Researcher(s)

  • Promotor: Nijs Ivan
  • Fellow: Van De Velde Helena

Research team(s)

The role of biodiversity and species traits in modulating the impacts of climate extremes in plant communities. 01/10/2011 - 30/09/2014

Abstract

Discrete climate events such as heat waves and droughts can have a disproportionate impact on ecosystems relative to the temporal scale over which they occur. The ultimate impact on the plant system is thought to depend on community properties such as the number of species and the species characteristics, although the few existing studies show contradicting results. Aided by experience gained on both climate extreme and biodiversity experiments throughout my scientific carreer, we propose a project to (i) predict the impact (damage) of heat waves and/or droughts based on the dominant plant interactions in an ecosystem and the species-specific traits; (ii) determine the potential of biodiversity in buffering negative effects of climate extremes; (iii) assess the risk of a possible acceleration of the spread of non-native plant species in a climate with more extreme events. Research will be conducted both on an experimental site and in the field, using an established method for creating droughts and a state-of-the-art technique for imposing heat waves. The project will increase understanding of ecosystem functioning, the importance of biodiversity and the significance of individual species, with relevance for fundamental ecology (e.g. improving ecosystem models) and nature conservation (e.g. identifying potentially vulnerable ecosystems).

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MOMEVIP - Molecular and metabolic bases of volatile isoprenoid-induced resistance to stresses. 01/01/2011 - 31/12/2013

Abstract

The MOMEVIP partners will integrate competences in ecology, physiology, biochemistry, molecular biology, functional genomics and bioinformatics to improve knowledge about the molecular and metabolic bases of VIP biosynthesis, and the functions of VIP (isoprene, monoterpenes and sesquiterpenes, collectively) in plant protection, per se and when interacting with other defensive pathways.

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EXPEER - Distributed infrastructure for experimentation in ecosystem research. 01/12/2010 - 31/05/2015

Abstract

EXPEER will bring together, major observational, experimental, analytical and modelling facilities in ecosystem science in Europe. By uniting these highly instrumented ecosystem research facilities under the same umbrella and with a common vision, EXPEER will form a key contribution to structuring and improving the European Research Area (ERA) within terrestrial ecosystem research.

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Influence of a future climate and interspecific interactions on the stress response of plants. 01/10/2010 - 30/09/2012

Abstract

It is currently unknown how plants will be affected by stress factors in a future climate with more atmospheric CO2 and higher air temperatures. This is important to know for agriculture because stress adversely affects crop growth and yield, but it is equally important for the conservation of biodiversity. For example, reduced stress resistance of plants in a future climate might lead to loss of sensitive species. Some global change factors have been shown to modify plant stress resistance in some species. However, the uncertainty is greater in more realistic, multi-species communities because interactions between the species are likely to alter the species-specific stress responses. Therefore, in the proposed research we want to disentangle abiotic factors (climate-warming and elevated CO2) and biotic factors (plant-plant interactions) that determine the stress response of a plant. An important question is whether neighbouring species modify the intrinsic stress response of a plant by changing the available resources. To solve these questions we will grow grassland communities (monocultures and mixtures) under different climate scenarios in sunlit, computer-controlled growth chambers.

Researcher(s)

  • Promotor: Nijs Ivan
  • Fellow: Van De Velde Helena

Research team(s)

Do sudden environmental changes in habitats induce biological invasions? 01/10/2010 - 30/09/2011

Abstract

In the proposed project we will test experimentally a new hypothesis in invasion biology, i.e. that invasion risk by exotic plants increases in habitats undergoing sudden a environmental change, in particular a change in the disturbance regime. By means of a factorial field experiment we will study the colonization risk by seeds of an invasive plant species in grasslands which are reclaimed after a long period of abandonment.

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Will a future climate change the stress tolerance of plant and ecosystems? A study on multiple stressors: heavy metal pollution, water shortage and eutrophication. 25/06/2010 - 24/04/2013

Abstract

Current adaptation strategies to climate change assume that the tolerance of plant communities to stress will not change in a future climate. We challenge this assumption by testing whether stress responses are different in a warmer, high-CO2 world

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Changes in the stress sensitivity of plants and ecosystems in a future climate. 01/10/2009 - 30/09/2011

Abstract

This project examines whether the resistance of plant communities and their composing species to stress will change in a future climate. Specifically, whether a future climate: 1) modifies the dose-response of stressors 2) modifies synergistic or anatagonistic effects between stressors 3) changes the influence of neighbours on the stress response of individuals.

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Unravelling the nebkha-ecosystem as a potential tool against desertification. 01/01/2009 - 31/12/2012

Abstract

The overall goal of this project is twofold: to investigate how nebkha landscapes are formed and maintained, and to test whether the presence of nebkhas in the landscape increases the reistance and resilience against climate change (aridification). To this end, the interactions between nebkha plants, wind, water and sediment are modelled first at the scale of the individual nebkha, and subsequently for the nebkha landscape as a whole.

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Impact of highly invasive exotic plants on biodiversity: mechanisms, reinforcing factors, and risk analysis. (ALIEN IMPACT - second phase) 15/12/2008 - 31/08/2011

Abstract

The ALIEN IMPACT project aims to provide a first integrated study of patterns and mechanisms of impact by alien invasive species in Belgium. It will consider multiple, highly invasive plant species (HIPS), and will combine large-scale screening of invader impact at different spatial scales (to characterize patterns) with highly mechanistic studies at fixed sites to characterize impact pathways. Both terrestrial and freshwater ecosystems will be studied.

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Impact of heat and drought extremes in experimental grasslands. 01/10/2008 - 30/09/2011

Abstract

The three main research questions are: - What is the separate and the combined influence of heat and drought extremes on grassland communities, and how do the responses differ seasonally? - How do plants respond to a climate with multiple periods of exceptional heat and/or drought in the same year, and how important is the time (recovery period) between such repeated extremes? - How important are the plants' interactions with its neighbours (con- or interspecific) in stress responses, and how do competitive interactions change because of extremes?

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THERMOTOL-Are plants raised in a warm, high-CO² world more tolerant to temperature extremes? 01/01/2008 - 31/12/2011

Abstract

Global temperatures and atmospheric CO² concentrations are expected to increase, and so is the frequency and intensity of climate extremes. The main aim of this project is therefore to test whether plants raised under warmer conditions and/or elevated atmospheric CO² concentrations are more tolerant to current and future heat stress than plants grown under current conditions. For this, we will grow wild-type Arabidopsis thaliana (Heynh.) plants throughout their entire life cycle under either current climate conditions or a variety of future climate scenarios, and expose these plants to one or several, two-day heat pulses of different intensity.

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Influence of climate change on the invasibility of subarctic plant communities. 01/10/2007 - 31/08/2010

Abstract

The research questions of this project are as follows: (a) Does climate change alter the invasibility of subarctisch plant communities? (b) Does climate change alter the ability to colonize of subarctic plant species?

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Changes in the stress sensitivity of plants and ecosystems in a future climate. 01/10/2007 - 30/09/2009

Abstract

This project examines whether the resistance of plant communities and their composing species to stress will change in a future climate. Specifically, whether a future climate: 1) modifies the dose-response of stressors 2) modifies synergistic or anatagonistic effects between stressors 3) changes the influence of neighbours on the stress response of individuals.

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Changes in the stress sensitivity of plants and ecosystems under climate change conditions. 01/07/2007 - 30/06/2011

Abstract

The central research question of this project is whether the resistance of species-rich plant communities to different stress factors will change in a future climate. To this end we will grow grassland mesocosms in sunlit controlled chambers under either the present or future climate conditions, and expose them to a wide range of stressors: tropospheric ozone, drought, nitrogen deficiency, nitrogen saturation (eutrophication), and heavy metals (cadmium). Stressors will be applied separately to assess dose-response relations, but also in combination to examine their interactive impact. By combining expertise from ecology, plant physiology, and biochemistry, we will evaluate the responses to stress in a future climate across a wide range of biological complexity, from cell to ecosystem.

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Project website

Impact of Global Change on terrestial ecosystems : multiscalar approach. 19/06/2007 - 18/06/2008

Abstract

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Impact of Global Change on terrestial ecosystems : multiscalar approach. (FWO Vis.Fel., Anna Shevtsova Chupina, Sweden) 15/03/2007 - 15/03/2008

Abstract

The project aims at studying the sensitivity to climate warming of a range of arctic/alpine and boreal species and plant functional types, in different stages of early seedling establishment. Warming is simulated by the exposure of field plots to controlled infrared irradiation, a technique developed at UA. We will also study changes in growth and chemical composition of full-grown vegetation in response to warming, to evaluate whether these changes induce a chemical-ecological barrier for the establishment of new seedlings. The working hypothesis is that climate warming deteriorates the capacity of Arctic plant communities to regenerate.

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Project website

Mycorrhizae impact on biodiversity and C-balance of grassland ecosystems under changing climate. (MYCARBIO) 15/12/2006 - 31/01/2009

Abstract

The research project MYCARBIO aims to investigate the impact of arbuscular mycorrhizal fungi (AMF) on biodiversity and on the carbon cycle in Belgian grassland ecosystems under changing climate conditions. To achieve this overall goal, five specific objectives have been identified: (1) the evaluation of AMF biodiversity in selected Belgian grasslands; (2) the determination of the role of AMF for seedling establishment, plant community structure, diversity and productivity in grasslands; (3) the understanding of the impacts of elevated CO2, temperature and water availability on AMF and plant biodiversity, on AMF-plant associations and on the carbon cycle; (4) the evaluation of the ecological significance of AMF-plant interactions on above- and below-ground biodiversity and the carbon balance; and (5) the modeling of the carbon balance processes in grassland ecosystems. The general methodology to address the overall goal of MYCARBIO is based on research at different scales in which the level of complexity increases from individual species to community, and from specific mechanisms to ecosystem functioning. The MYCARBIO project aims to provide significant insights on the impacts of climate change on grassland ecosystems and biodiversity, which would be valuable for scientists, stakeholders, and policy makers at national and international levels.

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Project website

Biodiversity impacts of highly invasive alien plants: mechanisms, enhancing factors and risk assessment. (ALIEN IMPACT) 15/12/2006 - 31/01/2009

Abstract

The ALIEN IMPACT proposal aims to provide a first integrated study of patterns and mechanisms of impact by alien invasive species in Belgium. It will consider multiple, highly invasive plant species (HIPS), and will combine large-scale screening of invader impact at different spatial scales (to characterize patterns) with highly mechanistic studies at fixed sites to characterize impact pathways. Both terrestrial and freshwater ecosystems will be studied.

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Changes in the stress sensitivity of plants and ecosystems under climate change conditions. 01/10/2006 - 30/09/2007

Abstract

The central research question of this project is whether the resistance of species-rich plant communities to different stress factors will change in a future climate. To this end we will grow grassland mesocosms in sunlit controlled chambers under either the present or future climate conditions, and expose them to a wide range of stressors: drought, nitrogen deficiency, nitrogen saturation (eutrophication), and heavy metals (cadmium). Stressors will be applied separately to assess dose-response relations, but also in combination to examine their interactive impact. Besides evaluating the responses to stress in a future climate the experiments address basic questions, such as: are resistances to different stressors coupled ('co-tolerance')? or, can stress resistance be predicted from plant or community characteristics measured under normal climate conditions?

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Impact of fast and slow climate change on biodiversity and landscape stability: study of the Late-Glacial and Early-Holocene as a reference for the present-day climate change. 01/07/2006 - 31/12/2010

Abstract

Recent research predicts that the present-day climate change threatens the biodiversity and landscape stability on earth. These predictions are, however, difficult to test. As a reference for the present-day climate change, we study in this project the impact of fast and slow climate changes, which happened during the past, on biodiversity and landscape stability. We study this, using alluvial deposits in Flanders and pollen preserved in these sediments. Special attention is paid to the interactions between vegetation and landscape changes in response to climate change.

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Mechanisms of carbon sequestration in grassland ecosystems: influence of climate warming and diversity loss. 01/01/2006 - 31/12/2007

Abstract

Several native plant species of Mediterranean-arid ecosystems naturally fix winblown materials in small, stable, phytogenic mounds or `nebkhas', but none of them are currently used to combat desertification. In this project we screen a variety of such species, not only for sand stabilisation, but also to promote biodiversity by creating habitats for other species, since nebkhas locally improve soil fertility and water status. The project explores the potential of a new, natural rehabilitation technique to control the leakage of scarce resources from degraded arid landscapes.

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Support maintenance scientific equipment (PLECO). 01/01/2005 - 31/12/2020

Abstract

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Phytogenic mounds (nebkhas) in Mediterranean-arid landscapes: ecological function, and potential for combating desertification and biodiversity loss. 01/01/2004 - 31/12/2007

Abstract

Several native plant species of Mediterranean-arid ecosystems naturally fix winblown materials in small, stable, phytogenic mounds or `nebkhas', but none of them are currently used to combat desertification. In this project we screen a variety of such species, not only for sand stabilisation, but also to promote biodiversity by creating habitats for other species, since nebkhas locally improve soil fertility and water status. The project explores the potential of a new, natural rehabilitation technique to control the leakage of scarce resources from degraded arid landscapes.

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Mechanisms of carbon sequestration in grassland ecosystems: influence of climate warming and diversity loss. 01/01/2004 - 31/12/2005

Abstract

Several native plant species of Mediterranean-arid ecosystems naturally fix winblown materials in small, stable, phytogenic mounds or `nebkhas', but none of them are currently used to combat desertification. In this project we screen a variety of such species, not only for sand stabilisation, but also to promote biodiversity by creating habitats for other species, since nebkhas locally improve soil fertility and water status. The project explores the potential of a new, natural rehabilitation technique to control the leakage of scarce resources from degraded arid landscapes.

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Developing a method to explain/predict invasive success as a framework for early warning of invasive plants. 01/01/2004 - 31/12/2005

Abstract

Invasive exotic species (animals as well as plants, terrestrial species as well as aquatic species) are characterized by extensive spreading capacities causing environmental damage when introduced out of their natural distribution area. The spread of invasive species is believed to be the second largest cause of current biodiversity loss worldwide. Numerous research programs have already been developed in countries (e.g. the United States of America) extensively affected by this phenomenon. Scientific concern now focuses on Europe, more recently affected by invasions. In Belgium, few data describe the characteristics and the distribution of exotic invasive species and many questions concerning processes, dynamics and consequences remain unanswered. The aim: explaining invasive success: trait analysis of species and communities. A method will be developed in order to explain invasive success based on a combination of ecophysiological traits of invaders and invaded systems. This consists of the following steps : 1. considering a suit of observed exotics with varying invasive success, including unsuccessful ones, in order to cover a wide spectrum of invasiveness and invasibility (Senecio inaequidens, Heracleum mantegazzianum, Solidago gigantea, Fallopia japonica, Rosa rugosa, Impatiens glandulifera, Impatiens parviflora, Prunus serotina, Xanthium orientale, Lathyrus latifolius and Cerastium tomentosum), 2. quantifying the invasive success of these exotics either from historical biogeographic presence/absence records (expansion rates) or from field observations, 3. regressing invasive success simultaneously on one selected invader trait and one selected trait of the invaded system, and 4. repeating step 3 for all possible combinations of invader traits and invaded-system traits. The key traits will be identified and subsequently used for the early detection of problematic species and threatened/vulnerable habitats. Furthermore, the response of invaders to competition with indigenous species will be assessed on the field by seedling monitoring and nutrient uptake estimations.

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Study of the actual, past and future biodiversity of protists and higher plants on a subantarctic island : role of dispersion, colonisation and resistance to climatic warming (DIVCRO). 01/01/2004 - 31/12/2004

Abstract

The proposed project studies the fundamental biological factors that determine the biodiversity and the evolution in this diversity in protistological and vegetal communities. The project aims to place the biodiversity in a temporal fi-amework: {I) do the dispersion and colonisation ofprotists influence the diversity in the communities, {II) how do the communities respond to changes in their physical environment {manipulation of temperature) and {III) what evolution is present in the subfossil material? {I) The unicellular organisms are easily transported by wind and animals. Therefor, their -dispersion determines the diversity of the present communities. What is the density, the quality and diversity of protists in the air on the subantarctic islands? Moreover, the colonisation is linked with the dispersion. What is the colonisation speed of protists on the new substrates? What is the colonisation sequence? {II) If we manipulate the microclimatic parameters on the vegetational stratum, how will the communities be affected? By heating small areas with infi-ared radiation systems, a future temperature increase is simulated in order to evaluate the responses of the protists and plants. {III) Even in the past, the climatic events had their influence. Using peat cores {already collected on previous summer campaigns), we will reveal the climatic history of lIe de la Possession and we will discuss the evolution in the diversity of protist communities during the Holocene.

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Effects of biodiversity and climate warming on carbon sequestration mechanisms in terrestrial ecosystems. 01/01/2003 - 31/12/2007

Abstract

The two research groups intend to quantify the carbon budgets (sources and sinks) and fluxes of a specific vegetation type (i.e. a temperate grassland ecosystem) using a core experimental facility built by the UIA research group. We option for an integrated mechanistic assessment of all major aspects of the C sequestration pathway, including the role of vegetation, micro-organisms and soil. Various global change scenarios (declining biodiversity, enhanced climate warming, and a combination of both) will be experimentally simulated in this central facility shared by both research groups. Studies will include carbon cycling (assimilation and release, storage in biomass and soil pools, residence time), carbon allocation below-ground (root growth, fine-root production and turnover, C-exudation) and trophic relationships (microbial C-utilization and immobilization, differences between bacterial and fungal decomposition). Biogeochemical as well as biotic interactions between plant diversity and climate warming will be investigated, with special emphasis on changes in nutrient uptake by plants or through bacterial immobilisation, and on the role of plant species phenology following exposure to a modified thermal environment.

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INPLANBEL : Invasive Plants in Belgium : Patterns, Processes and Monitoring. 01/01/2003 - 30/04/2006

Abstract

The specific aims of this project are (1) to provide a synthesis on plant invasion in Belgium in the form of a structured list of exotic species and an evaluation of their success ; (2) to identify universally valid principles of biological invasion through a combined analysis of ecophysiological species and community traits, as a basis for pre-invasion risk assessment; (3) to provide a detailed analysis of the spreading of a set of invasive species at the landscape level, for a better understanding of the relation between invasion and human land use; (4) to analysize the consequences of a set of invasive species on ecosystems.

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Mechanisms of carbon sequestration in grassland ecosystems: influence of climate warming and diversity loss. 01/01/2003 - 30/09/2003

Abstract

Because greenhouse gas concentrations in the earth's atmosphere continue to rise, the probability of significant climate change increases (IPCC, 2001a). There have been many studies concerning the effects of elevated CO2 concentrations on terrestrial ecosystems, and, to a lesser extent, the influence of higher temperatures. Another aspect of global change, declining biodiversity, is less well studied. This project investigates the single-factor and combined impact of elevated temperatures and diversity loss. Future carbon budgets will be the reflection of antagonisms and synergies between these 2 critical drivers of carbon sequestration, but studies of interactions are almost non-existent. The study uses artificially assembled grassland model ecosystems. In twelve sunlit, climate-controlled chambers at the UIA campus (F.W.O. project), half of the model ecosystems are subjected to a temperature increase of 3°C. In each chamber, 24 plant communities are grown containing either 1, 3 or 9 grassland species. The design of the growth chambers is multi-factorial, and contains all combinations of temperature and diversity, in 6 replicates. The study consists of 3 sections: (i) Carbon flux measurements and study of storage and turnover of soil carbon: CO2-flux measurements enable us to quantify inputs through photosynthesis and outputs through aboveground and belowground respiration. Because these fluxes cannot be measured continuously, they are recontructed from discrete measurements by interpolation, based on the relationships of the C-balance components with their dominant drivers (mainly radiation or temperature). To this end we use infrared gas analysis in dynamic closed systems. Soil carbon storage and turnover are analysed by d13C measurements of CO2 produced in the soil. Because C3 plants are grown on C4 soils, it is possible to separate soil respiration into root and microbial respiration. (ii) Ecophysiological measurements: Ecophysiological parameters will change in response to the 3 conditions simulated in this project (temperature increase, biodiversity change, and both), which can provide explanations for observed shifts in the carbon balance. We study (among other things) how stomatal resistance, nutrient uptake and nutrient use efficiency, and canopy temperature react to the induced changes. (iii) Study of phenology and competition: Changes in phenology can also have a large impact on the carbon balance, and temperature is an important factor in determining both the beginning and the end of the growing season. We are therefore monitoring changes in both the length and the dynamics of the growing season under conditions of elevated temperatures (and declining plant diversity), both in individual species and species assemblages. We are furthermore investigating alterations in species composition and we attempt to identify the type of plant characteristics that are favoured by exposure to the various factors of global change. These findings are linked to any observed changes in carbon fluxes.

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    Biodiversity in an arctic ecosystem : role of dispersal, colonization, and resistance to climatic extremes. 01/01/2002 - 31/12/2005

    Abstract

    Models show that if warming exceeds 2.7 °C, the Greenland icecap will probably melt (Pear-ce 2000). Almost all predictions demonstrate that the Greenland climate is likely to warm even more. Besi-des causing sea level rise, melting at higher latitudes will increase the availability of land for colonization by boita. Further, the current sout-hern border of the polar regions is likely to move north, shrinking the arctic biome, and favouring the establishment of new ecosystems on the icefree land. Why new ecosystems? Because the conditions with regard to dispersal and source areas of biota will have changed. As a consequence, shifts in diversity can be expected. In the current project we investigate this in a region with transition features, name-ly tundra on Disko Island (West-Geenland). This island is located at the border of two clima-to-logically defined zones: the transition between discontinu-ous and conti-nu-ous permafrost, and the transition between the Low Arctic and High Arctic. The region has quite high diversity, which can function as a source for nor-thern- or eastern-bound colonization in case of warming. In order to use the Disko Island situation as a model for other regions, the question must be answered what the sources of the cur-rent diver-sity are? Our attention will therefore focus on proces-ses which contributed to the `genesis' and the maintenance of this current diversity, i.e. disper-sal (I) and colonization (II). Furthermore, also stability (III) of the present populations (local extinction probability due to distur-ban-ce, especially climate-based) is critical to the regu-lation of local diversity. As a touchstone for current and future trends, paleo-fluc-tuati-ons (IV) of diversity will be examined in peat layers.

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    Fragmentation and extinction patterns in vegetation 01/01/2002 - 31/12/2002

    Abstract

    The goal of this project is to develop a series of possible extinction principles, and to mathematically simulate the changes in vegetation pattern that coincide with them. Three stages are foreseen: (1) Construction of theoretical 2-D vegetation patterns by computer simulation (2) Induction of local extinction in the model patterns developed under (1) by eliminating species according to various principles. (3) Study how the original structure of the vegetation is modified by the induced extinctions with a GIS.

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      Local extinction of plant species : searching for possible ecological determinants. 01/01/2002 - 30/09/2002

      Abstract

      In this research on local extinction of plant species, the emphasis will be mainly on the appraisal of deterministic and stochastic components of extinctions, in the case of anthropogenic stress (environmental pollution) causing the extinctions. Special attention will be paid to differences in extinction behaviour between common and rare species, and to the relation with invasion and biodiversity in grasslands. A combination of research techniques (mathematical modelling, field experiments, literature study) is used.

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        An experimental study of the carbon balance in high-arctic ecosystems exposed to a warmer climate. 01/01/2001 - 31/12/2002

        Abstract

        Heating of the lower atmosphere caused by increasing concentrations of greenhouse gases is most pronounced at higher latitudes. For a number of climatic variables Global Circulation Models (GCM) predict, not only a change of the average but also a rise in frequency and intensity of extreme values, e.g. heatwaves. The main objective of this research is a characterisation of the sensitivity of tundra to these two aspects of climate change. Because of the adaptation to low temperatures and the low metabolism of many tundra species, it can be expected that ecological communities of this biome will already be relatively strongly disturbed by small environmental fluctuations. Effects of extreme conditions on the other hand are almost completely unknown. Increased temperature is experimentally achieved by the Free Air Temperature Increase technique (FATI) in a tundra site in Northeast Greenland. Besides continuous thermal manipulations during the growing season also shockwise infrared radiation causing higher temperature increments will be applied over shorter periods of time, in order to simulate climatological extremes. Both the changes in carbon balance of tundra-ecosystems and the vegetation dynamics associated to this will be monitored. Characteristic plant communities are irradiated in selected test plots during a complete growing season, to quantify the physical-energetical impact of warming up on vegetation, air and soil. CO2-fluxes of the whole ecosystem, and the photosynthetically active component and the soil separately will be analysed as a function of their dominant drivers (radiation and temperature), in order to reconstruct a complete carbon-balance over the growing season. Soil respiration will be analysed in detail as a function of depth, water content, temperature, C- and N-level and time. Both the direct consequences of higher temperatures on soil activity and the indirect consequences can be determined this way. Aboveground, we will use a classical `point-quadrat' method, digital camera vegetation records, normalised difference vegetation index sensors (NDVI), destructive production determinations and chlorophyl measurements. In this way it will be studied whether leaf development is earlier in spring, whether complete seasonal dynamics are fastening and whether interactions of radiation and temperature change the timespan of the potential growing season. Also changes in species composition en diversity trends are determined. In the shock-wise manipulations, attention will be focused on the components of stability of the ecosystem (resistance and resilience). In order to extrapolate the obtained results from the continued heating experiment and the heat-wave experiment to the longer term, an existing model will be elaborated. This model (Huggett, 1993) starts with an `empty' system which gains carbon through photosynthesis and looses carbon by respiration. We will take into account measured relationships between microclimate, input and output. In the feedback between the carbon balance of this ecosystem to the atmospheric CO2-concentrations there is potential to speed up or slow down the actual rate of C-accumulation in the atmosphere, a crucial factor of uncertainty in predicting the future climate. This research investigates whether, besides steady changes also shockwise transitions should be taken into account. Logistically there is cooperation with the Danish Polar Center (DPC), Copenhagen, which operates an international research station since 1995 in Northeast Greenland (Zackenberg).

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          A pilot study on the complementary use of resources in diverse and less diverse plant communities 01/01/2001 - 31/12/2001

          Abstract

          Both at UIA and CEFE-CNRS Montpellier, ongoing research investigates the role of biological diversity in ecosystems. To this end the influence is examined of diversity on processes like productivity, nutrient acquisition, water household, etc., but also on resistance and resilience to disturbance. The approach is both experimental, by construction of synthesised model ecosystems (mediterrenean and temperate grasslands) and theoretical, by development of conceptual models. Recently, explanatory mechanisms were proposed for the first time in the literature regarding the influence of biological diversity on productivity (Tilman et al. 1997, Loreau 1998, Nijs & Roy 2000). However, the picture is gradually emerging that probably several mechanisms are operating simultaneously, and interact in a complex way. The aim of the current project is to epxlore an underlying mechansim of diversity which has not yet been examined in great detail: the complementary use of natural resources. According to Hooper (1998) addition of species to plant communities leads to niche-differentiation and additional nutrients becoming available, for example owing to differences between species in rooting depth or in timing of the growth cycle. Effects of increasing diversity on biomass production, as well as on other processes, may therefore ensue from a more efficient exploitation of the environment.

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            Invasion and biodiversity in grasslands and field borders 01/12/2000 - 28/02/2005

            Abstract

            Biological invasions are considered an increasing threat to biodiversity, but the underlying principles are poorly known. Also the way changes in the global climate will affect invasions is not well understood. The aim of the current project is to develop an improved mechanistic framework to (a priori) establish which communities are most susceptible to being invaded (`invasibility') and which species are expected to become invasive (`invasiveness') under given conditions. The project mainly focuses on grasslands since grasses have been responsible for some of the most harmful invasions in the past. A primary driver of biological invasions is land use change. Agricultural policies in Western Europe are developing towards reduction of unsustainable intensive farming and promotion of biodiversity in agricultural land, but it is uncertain how this will affect biological invasions. We investigate this question for the recent trend of field borders. The latter are installed on arable land to buffer nutrient and biocide efflux from crops and are considered to become new `reservoirs' of biodiversity in our fragmented landscapes. However, because their installation represents a severe disturbance and because species influx in field borders is not intensively controlled, they could become future hot spots for invasion. First, we will compare a series of methods to maximise diversity in field borders (spontaneous introgression of vegetation, sowing with commerical seeds vs. local seeds, etc.). Next, the invasibility of field borders is tested by introducing the species examined in our model ecosystems. The aim is to devise management options which minimise risks of invasion, both into field borders and from field borders into arable land. The overall goal of the project is to provide a better scientific foundation for protective strategies towards biological invasions in grasslands and field borders, so that management policies can eventually become pro-active rather than curative today.

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            Improvement of selection of tea clones and irrigation strategies for tea estates in the Northern province of South Africa by means of ecophysiological studies. 01/10/2000 - 10/03/2001

            Abstract

            A comparative study is proposed of water transfer (water use efficiency and water loss control) in a soil-tea plant-atmosphere continuum for adapted and non adapted clones. Water flux from the soil (source), through the plant into the atmos-phere (sink) will be studied as a catenary proces along decreasing water potentials over a series of resistances (control points).

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              Species diversity: importance for sustainable ecosystems and impact of climate change. 01/10/2000 - 28/02/2001

              Abstract

              This project investigates the importance of species diversity and diversity of functional groups for the functioning of grassland ecosystems. The main objectives are: 1) characterise the link between diversity and elementary ecosystem processes, 2) estimate the consequences of changes in diversity for stability, 3) determine the impact of climate change on diversity. biodiversity stabi1ity.

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                The response of protists in a microcosm to climatic extremes. 01/01/2000 - 31/12/2001

                Abstract

                The aim of this project is to investigate the evolution in biodiversity and community structures of unicellular organisms (testate amoebae and diatoms), in microcosms exposed to extreme environmental conditions. We will investigate two principle questions: (1) If we manipulate the diversity of plants in model grassland ecosystems, does this change the diversity of unicellular organisms? (2) Are more diverse communities of unicellulars better protected against extreme events (higher survival or better recovery)? Extreme climatic events will be simulated experimentally with electronically controlled radiation from infrared-heaters, by induction of a natural heat wave.

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                  Diversity of ecosystems and resistance and resilience to disturbance: an analysis at the species level. 01/10/1998 - 31/12/1999

                  Abstract

                  This study investigates the coupling between the diversity within ecosystems and their stability. We create model communities of different species richness and expose them to climatic extremes by inducing artificial heat waves (FATI-system). The resistance to these extremes and the rate of recovery (resilience) are investigated at the level of the individual species, both empincally and via modelling.

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                    Global change effects in high arctic ecosystems: experimental physical--ecological and paleo-ecological approach of tendenties in biodiversity and community structures. 01/01/1998 - 31/12/2001

                    Abstract

                    The aim of this project is to evaluate effects of global climatic changes on the diversity and the ecological processen in high arctic ecosystems, by: (a) manipulation of terrestrial habitats b) a paleo-ecological study of holocene sediments. The research area is the Zackenberg site in East Greenland. Research topics are temperature charges and UV-B, the research object is the microcosm of moss plants and their epifytic amoebae and diatoms.

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                      Stability and sustainable functioning of ecosystems: theoretical analysis and experimental validation of the role of diversity and the influence of climate change. 01/10/1997 - 30/09/2000

                      Abstract

                      The aim of this project is to explore the functional significance of biological diversity, especially to allow interpretation of shifts in diversity due to charges in the global climate or other anthropogenic disturbance factors. The objectives are: a) identify ecosystem promesses which depend on diversity b) analyse the relationship between diversity and stability, resistance and resilience c) assess climate change as disturbance factor in systems of different complexity.

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                        Impact of the greenhouse effect and of changes in atmospheric CO2 concentration on the functioning of grassland ecosystems : an integrated experimental and modelling approach. 01/10/1994 - 30/09/1997

                        Abstract

                        The aim of this study is : (1) modelsimulation of carbon and nutrient fluxes in a grassland ecosystem subjected to global changes (increased CO2 and temperature) (2) estimate future changes in the storage capacity of grasslands for carbon (3) study the influence of these new environmental conditions in complex multi-species ecosystems.

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