Larre atlantiarretako landareen sustraien atributuak (traits)lurzoruko ur-edukiaren eta mikrobiotaren eragina

Abstract

In the future, drought is expected to increase in intensity and duration due to the reduced precipitation and high temperatures, leading to significant losses in crop production and its productivity worldwide. Research on the drought response of plants is therefore urgently needed. This experiment has analysed the response to drought of six plant species of Atlantic grasslands, in the presence and absence of micro-organisms, based on the root morphological traits. A design has been based on a split-plot design by randomised blocks in a greenhouse under controlled conditions, where the plants in 5 blocks were maintained at a capacity of 30% of their water content (simulating drought) and those in the other 5 blocks at 70% (simulating normal conditions). Two pots of the same species were placed in each block, adding the inoculum of the microorganisms only to one of them. As the main hypothesis, plants under drought stress would be able to develop strategies for conservation or acquisition of soil resources (such as water or nutrients) by modifying root traits. The second hypothesis stated that soil water content and the effect and response of micro-organisms would be interdependent. The results indicate that neither hypothesis was fulfilled. On the one hand, the effect of reduced soil water content was dependent of root traits and species, and the strategy followed by each species was identified: Festuca nigrescens, Lotus corniculatus, Trifolium repens and Jasione laevis followed a fast-growing strategy and Deschampsia flexuosa and Bellisperennis followed a slow-growing strategy. Moreover, reduced soil water availability did not affect the activity of the microorganisms, but it has been analysed whether the effect of those microorganisms has been positive or negative. In conclusion, the water content of 30% was insufficient to simulate drought.