Project acronym DRY-2-DRY
Project Do droughts self-propagate and self-intensify?
Researcher (PI) Diego González Miralles
Host Institution (HI) UNIVERSITEIT GENT
Call Details Starting Grant (StG), PE10, ERC-2016-STG
Summary Droughts cause agricultural loss, forest mortality and drinking water scarcity. Their predicted increase in recurrence and intensity poses serious threats to future global food security. Several historically unprecedented droughts have already occurred over the last decade in Europe, Australia and the USA. The cost of the ongoing Californian drought is estimated to be about US$3 billion. Still today, the knowledge of how droughts start and evolve remains limited, and so does the understanding of how climate change may affect them.
Positive feedbacks from land have been suggested as critical for the occurrence of recent droughts: as rainfall deficits dry out soil and vegetation, the evaporation of land water is reduced, then the local air becomes too dry to yield rainfall, which further enhances drought conditions. Importantly, this is not just a 'local' feedback, as remote regions may rely on evaporated water transported by winds from the drought-affected region. Following this rationale, droughts self-propagate and self-intensify.
However, a global capacity to observe these processes is lacking. Furthermore, climate and forecast models are immature when it comes to representing the influences of land on rainfall. Do climate models underestimate this land feedback? If so, future drought aggravation will be greater than currently expected. At the moment, this remains largely speculative, given the limited number of studies of these processes.
I propose to use novel in situ and satellite records of soil moisture, evaporation and precipitation, in combination with new mechanistic models that can map water vapour trajectories and explore multi-dimensional feedbacks. DRY-2-DRY will not only advance our fundamental knowledge of the mechanisms triggering droughts, it will also provide independent evidence of the extent to which managing land cover can help 'dampen' drought events, and enable progress towards more accurate short-term and long-term drought forecasts.
Summary
Droughts cause agricultural loss, forest mortality and drinking water scarcity. Their predicted increase in recurrence and intensity poses serious threats to future global food security. Several historically unprecedented droughts have already occurred over the last decade in Europe, Australia and the USA. The cost of the ongoing Californian drought is estimated to be about US$3 billion. Still today, the knowledge of how droughts start and evolve remains limited, and so does the understanding of how climate change may affect them.
Positive feedbacks from land have been suggested as critical for the occurrence of recent droughts: as rainfall deficits dry out soil and vegetation, the evaporation of land water is reduced, then the local air becomes too dry to yield rainfall, which further enhances drought conditions. Importantly, this is not just a 'local' feedback, as remote regions may rely on evaporated water transported by winds from the drought-affected region. Following this rationale, droughts self-propagate and self-intensify.
However, a global capacity to observe these processes is lacking. Furthermore, climate and forecast models are immature when it comes to representing the influences of land on rainfall. Do climate models underestimate this land feedback? If so, future drought aggravation will be greater than currently expected. At the moment, this remains largely speculative, given the limited number of studies of these processes.
I propose to use novel in situ and satellite records of soil moisture, evaporation and precipitation, in combination with new mechanistic models that can map water vapour trajectories and explore multi-dimensional feedbacks. DRY-2-DRY will not only advance our fundamental knowledge of the mechanisms triggering droughts, it will also provide independent evidence of the extent to which managing land cover can help 'dampen' drought events, and enable progress towards more accurate short-term and long-term drought forecasts.
Max ERC Funding
1 465 000 €
Duration
Start date: 2017-02-01, End date: 2022-01-31
Project acronym KupfferCellNiche
Project Determining the instructive tissue signals and the master transcription factors driving Kupffer cell differentiation
Researcher (PI) Martin Wim V GUILLIAMS
Host Institution (HI) VIB
Call Details Consolidator Grant (CoG), LS6, ERC-2016-COG
Summary We have recently shown that contrary to common hypotheses, circulating monocytes can efficiently differentiate into Kupffer cells (KCs), the liver-resident macrophages. Using self-generated knock-in mice that allow specific KC depletion, we found that monocytes colonize the KC niche in a single wave upon KC depletion and rapidly differentiate into self-maintaining KCs that are transcriptionally and functionally identical to their embryonic counterparts. This implies that: (i) access to the KC niche is tightly regulated, ensuring that monocytes do not differentiate into KCs when the KC niche is full but differentiate very efficiently into KCs upon temporary niche availability, and (ii) imprinting by the KC niche is the dominant factor conferring KC identity. Understanding which cells represent the macrophage niche, which signals produced by these cells imprint the tissue-specific macrophage gene expression profile and through which transcription factors (TxFs) this is mediated is emerging as the next challenge in the field. We here propose an original strategy combining state-of-the-art in silico approaches and unique in vivo transgenic mouse models to tackle this challenge specifically for KCs, the most abundant macrophage in the body. We hypothesize that the liver sinusoidal endothelial cell (LSEC) to which the KC is attached represents the most likely candidate to sense KC loss, recruit new monocytes and drive their differentiation into KCs. Thus, this proposal aims to: (I) determine the TxFs through which the niche imprints KC identity, (II) map the LSEC-KC crosstalk during KC development, (III) generate LSEC-specific knock-in mice to study LSECs in vivo, (IV) demonstrate which LSEC factors influence KC development and function. Importantly, understanding how the KC-TxFs and the LSEC-KC crosstalk control KC development and function will be essential for the development of novel therapeutic interventions for hepatic disorders in which KCs play a central role.
Summary
We have recently shown that contrary to common hypotheses, circulating monocytes can efficiently differentiate into Kupffer cells (KCs), the liver-resident macrophages. Using self-generated knock-in mice that allow specific KC depletion, we found that monocytes colonize the KC niche in a single wave upon KC depletion and rapidly differentiate into self-maintaining KCs that are transcriptionally and functionally identical to their embryonic counterparts. This implies that: (i) access to the KC niche is tightly regulated, ensuring that monocytes do not differentiate into KCs when the KC niche is full but differentiate very efficiently into KCs upon temporary niche availability, and (ii) imprinting by the KC niche is the dominant factor conferring KC identity. Understanding which cells represent the macrophage niche, which signals produced by these cells imprint the tissue-specific macrophage gene expression profile and through which transcription factors (TxFs) this is mediated is emerging as the next challenge in the field. We here propose an original strategy combining state-of-the-art in silico approaches and unique in vivo transgenic mouse models to tackle this challenge specifically for KCs, the most abundant macrophage in the body. We hypothesize that the liver sinusoidal endothelial cell (LSEC) to which the KC is attached represents the most likely candidate to sense KC loss, recruit new monocytes and drive their differentiation into KCs. Thus, this proposal aims to: (I) determine the TxFs through which the niche imprints KC identity, (II) map the LSEC-KC crosstalk during KC development, (III) generate LSEC-specific knock-in mice to study LSECs in vivo, (IV) demonstrate which LSEC factors influence KC development and function. Importantly, understanding how the KC-TxFs and the LSEC-KC crosstalk control KC development and function will be essential for the development of novel therapeutic interventions for hepatic disorders in which KCs play a central role.
Max ERC Funding
1 996 705 €
Duration
Start date: 2017-07-01, End date: 2022-06-30
Project acronym WeThaw
Project Mineral Weathering in Thawing Permafrost: Causes and Consequences
Researcher (PI) Sophie OPFERGELT
Host Institution (HI) UNIVERSITE CATHOLIQUE DE LOUVAIN
Call Details Starting Grant (StG), PE10, ERC-2016-STG
Summary Enhanced thawing of the permafrost in response to warming of the Earth’s high latitude regions exposes previously frozen soil organic carbon (SOC) to microbial decomposition, liberating carbon to the atmosphere and creating a dangerous positive feedback on climate warming. Thawing the permafrost may also unlock a cascade of mineral weathering reactions. These will be accompanied by mineral nutrient release and generation of reactive surfaces which will influence plant growth, microbial SOC degradation and SOC stabilisation. Arguably, weathering is an important but hitherto neglected component for correctly assessing and predicting the permafrost carbon feedback. The goal of WeThaw is to provide the first comprehensive assessment of the mineral weathering response in permafrost regions subject to thawing. By addressing this crucial knowledge gap, WeThaw will significantly augment our capacity to develop models that can accurately predict the permafrost carbon feedback.
Specifically, I will provide the first estimate of the permafrost’s mineral element reservoir which is susceptible to rapidly respond to enhanced thawing, and I will assess the impact of thawing on the soil nutrient storage capacity. To determine the impact of increased mineral weathering on mineral nutrient availability in terrestrial and aquatic ecosystems in permafrost regions, the abiotic and biotic sources and processes controlling their uptake and release will be unraveled by combining novel geochemical techniques, involving the non-traditional silicon, magnesium and lithium stable isotopes, with soil mineral and physico-chemical characterisations. I posit that this groundbreaking approach has the potential to deliver unprecedented insights into mineral weathering dynamics in warming permafrost regions. This frontier research which crosses disciplinary boundaries is a mandatory step for being able to robustly explain the role of mineral weathering in modulating the permafrost carbon feedback.
Summary
Enhanced thawing of the permafrost in response to warming of the Earth’s high latitude regions exposes previously frozen soil organic carbon (SOC) to microbial decomposition, liberating carbon to the atmosphere and creating a dangerous positive feedback on climate warming. Thawing the permafrost may also unlock a cascade of mineral weathering reactions. These will be accompanied by mineral nutrient release and generation of reactive surfaces which will influence plant growth, microbial SOC degradation and SOC stabilisation. Arguably, weathering is an important but hitherto neglected component for correctly assessing and predicting the permafrost carbon feedback. The goal of WeThaw is to provide the first comprehensive assessment of the mineral weathering response in permafrost regions subject to thawing. By addressing this crucial knowledge gap, WeThaw will significantly augment our capacity to develop models that can accurately predict the permafrost carbon feedback.
Specifically, I will provide the first estimate of the permafrost’s mineral element reservoir which is susceptible to rapidly respond to enhanced thawing, and I will assess the impact of thawing on the soil nutrient storage capacity. To determine the impact of increased mineral weathering on mineral nutrient availability in terrestrial and aquatic ecosystems in permafrost regions, the abiotic and biotic sources and processes controlling their uptake and release will be unraveled by combining novel geochemical techniques, involving the non-traditional silicon, magnesium and lithium stable isotopes, with soil mineral and physico-chemical characterisations. I posit that this groundbreaking approach has the potential to deliver unprecedented insights into mineral weathering dynamics in warming permafrost regions. This frontier research which crosses disciplinary boundaries is a mandatory step for being able to robustly explain the role of mineral weathering in modulating the permafrost carbon feedback.
Max ERC Funding
1 999 985 €
Duration
Start date: 2017-09-01, End date: 2022-08-31
