Final Report Summary - INCITE (Integrated response of plant, microbial and N Cycling InTEractions to precipitation patterns)
Changes in temperature and precipitation patterns, including more intense drought periods and extreme precipitation events, have been documented globally in recent decades, and are predicted to carry on. It is urgent to evaluate the consequences of these change on ecosystems, and this strongly relies on the improvement of our functional understanding of the response of the plant-soil systems to altered precipitation patterns.
The overarching goal of the present project is to understand the temporal and spatial couplings between i) precipitation patterns, ii) the structure and activity of the soil microbial community, with a particular emphasis on soil nitrogen cycling, and iii) plant water and nitrogen uptake, and how these couplings affect the stability of ecosystem functions.
Using a multidisciplinary approach in a plant-soil system under controlled conditions, the project documents the response of plant-soil microbial interactions to large vs. small amplitude precipitation patterns using plant physiology, molecular microbiology and biogeochemistry methods. Next generation sequencing of soil microbial communities as well as stable isotope approaches provide cutting edge approaches to allow a mechanistic understanding of the experimental system.
A first experiment implemented the novel 18O stable isotope probing method, that allows to distinguish the microbial community that is actively growing when dry soil is rewet. Soil depth, rather than precipitation pattern, was most influential in shaping microbial response to rewetting, and had differential effects on active and inactive bacterial and fungal communities. Our results suggest that differences in fungal and bacterial abundance and relative activity could result in large effects on subsequent soil biogeochemical cycling. The second experiment focused on monitoring soil nitrogen cycling as well as the active soil microbial community over time after a rewetting event, in plant-soil systems that had experienced contrasted precipitation pattern and nitrogen availability conditions. The results indicate that precipitation regime legacy sets the scene for the response of the plant-soil system to rewetting, not only for the bacterial and fungal communities, but also for plant-soil carbon coupling as well as soil N cycling.
The two main experiments that have been completed tackle a level of complexity and integration that is at the cutting edge of the scientific front in understanding plant-microbial response to changes in water resource. Most experiments tackling soil microbial response to dry-wet cycles are undertaken in systems that are devoid of active plants. The INCITE project went beyond the state of the art in the field, by including both plant and the soil microbial compartments in the experimental design. The results shed light the different sensitivity of the soil bacterial and fungal communities to altered precipitation regimes in the presence of plants, the loss of coupling upon rewetting between plants and soil microbes that occurs under less frequent watering and the effect that these responses to water availability have on soil biogeochemical cycling. This increased knowledge will help improve predictions on the impact of future climate conditions in Europe on soil-plant systems, in particular when designing innovative agroecological strategies based on a better use of the soil microbial potential.
The overarching goal of the present project is to understand the temporal and spatial couplings between i) precipitation patterns, ii) the structure and activity of the soil microbial community, with a particular emphasis on soil nitrogen cycling, and iii) plant water and nitrogen uptake, and how these couplings affect the stability of ecosystem functions.
Using a multidisciplinary approach in a plant-soil system under controlled conditions, the project documents the response of plant-soil microbial interactions to large vs. small amplitude precipitation patterns using plant physiology, molecular microbiology and biogeochemistry methods. Next generation sequencing of soil microbial communities as well as stable isotope approaches provide cutting edge approaches to allow a mechanistic understanding of the experimental system.
A first experiment implemented the novel 18O stable isotope probing method, that allows to distinguish the microbial community that is actively growing when dry soil is rewet. Soil depth, rather than precipitation pattern, was most influential in shaping microbial response to rewetting, and had differential effects on active and inactive bacterial and fungal communities. Our results suggest that differences in fungal and bacterial abundance and relative activity could result in large effects on subsequent soil biogeochemical cycling. The second experiment focused on monitoring soil nitrogen cycling as well as the active soil microbial community over time after a rewetting event, in plant-soil systems that had experienced contrasted precipitation pattern and nitrogen availability conditions. The results indicate that precipitation regime legacy sets the scene for the response of the plant-soil system to rewetting, not only for the bacterial and fungal communities, but also for plant-soil carbon coupling as well as soil N cycling.
The two main experiments that have been completed tackle a level of complexity and integration that is at the cutting edge of the scientific front in understanding plant-microbial response to changes in water resource. Most experiments tackling soil microbial response to dry-wet cycles are undertaken in systems that are devoid of active plants. The INCITE project went beyond the state of the art in the field, by including both plant and the soil microbial compartments in the experimental design. The results shed light the different sensitivity of the soil bacterial and fungal communities to altered precipitation regimes in the presence of plants, the loss of coupling upon rewetting between plants and soil microbes that occurs under less frequent watering and the effect that these responses to water availability have on soil biogeochemical cycling. This increased knowledge will help improve predictions on the impact of future climate conditions in Europe on soil-plant systems, in particular when designing innovative agroecological strategies based on a better use of the soil microbial potential.