BIO-ARID

In recent decades, drought episodes have been increasingly intense and frequent on a planetary scale, and the areas considered arid and semi-arid have increased significantly, and most projections project that this trend will accompany us in the coming decades. One of the potential consequences of this increase in aridity is the impact it may have on the carbon (C) cycles and of the main nutrients such as nitrogen (N), phosphorus (P) and potassium (K) in the plant-soil system of the affected areas.

The current available data at this regard is apparently contradictory to some extent, whether from drought simulation studies under field conditions or from observational studies along aridity gradients. For all that has been said, at this time there is a lack of joint analysis of data that allows acquiring an overall vision of the consequences of the increase in drought in different regions and its relationship with changes in concentrations, stocks, and stoichiometric relationships between C, N, P and K in the plant-soil set.

There are several questions to clarify: knowing the changes of C: N: P: K for example in microbial communities, in the assignments between the different organs of plants, in the proportional allocation between soil and plants, and also among the different compartments soil (litter, microbial community, matrix and rhizosphere). This should be able to relate these biogeochemical changes with changes in the communities of the plant-soil system and in their capacity for resistance and resilience on the horizon of future increases in arid conditions.

The present Bio-arid project aims to complete this puzzle of cascade changes as a consequence of aridity at the level of the relationships between changes at the biotic level with the use, allocation and stoichiometric relationships of and between C, N, P and K. To achieve this objective will use field experiments, observations of geographical and climatic gradients, remote sensing, data mining, and modeling. The field experiments will be carried out in humid temperate (Bélgica, Austria,..) and Mediterranean regions (Spain). The observational studies will be based on data mining (Web of Science, google scholar, Try, Dryad,..) that, together with remote sensing data, and statistical analyzes (neural networks, linear and mixed models, machine learning and training, Bayesian models, ..) will allow us to determine the world areas that have suffered an increase in aridity in recent decades, the relationships between drought, the availability of C, N, P and K and their stoichiometric imbalances with the structure and function of the plant-soil system. In collaboration with a wide range of international research groups, we will use this information to improve the projections of the C circulation and climate evolution models in different CO2 emission scenarios. Thus, we hope to achieve a significant advance in the knowledge of:

1. the impact of drought on the concentrations, stocks and stoichiometric relationships of C, N, P and K in the plant-soil system, and
2. the relationships of these changes with the corresponding changes at the level of structural and functional properties of the plant-soil system and finally
3. the projections of the C circulation and climate evolution models in different scenarios of CO2 emissions.

Proyecto PID2020-115770RB-I00 financiado por MCIN/ AEI /10.13039/501100011033