Uncovering the secrets of monoculture yield decline: Trade-offs between leaf and root chemical and physical defence traits in a grasslands experiment

ABSTRACT:

Plant monocultures growing for extended periods face severe losses of productivity. This phenomenon, known as 'yield decline', is often caused by the accumulation of above- and below-ground plant antagonists. The effectiveness of plant defences against antagonists might help explain differences in yield decline among species. Using a trait-based approach, we studied the role of 20 physical and chemical defence traits of leaves and fine roots on yield decline of 4- and 18-year-old monocultures of 27 grassland species. We hypothesized that yield decline is lower for species with high defences, that root defences are better predictors of yield decline than leaf defences, and that in roots, physical defences better predict yield decline than chemical defences, while the reverse is true for leaves. We additionally hypothesized that the relationship between defences and yield decline increase with time and that species increasing the expression of defence traits after long-term monoculture growth would suffer less yield decline. We summarized leaf and fine root defence traits using principal component analysis and analysed the relationship between the most informative components as well as their temporal changes and monoculture yield decline. The significant predictors of yield decline were traits related to the so-called collaboration gradient of the root economics space (specific root length and root diameter) as well as their temporal changes and traits related to the leaf physical vs chemical defence trade-off (leaf dry matter, silicon and cellulose content, toughness and phytochemical diversity). We were unable to unequivocally identify the mechanisms relating the effect of those traits to yield decline as they could mediate plant responses to several stressor such as antagonist nutrient depletion and drought. Further studies are needed to differentiate between these alternative mechanisms and gain a comprehensive understanding of the drivers behind the impact of root and leaf defence traits on yield decline.

INSTRUMENT(S): Liquid Chromatography MS - positive - reverse phase

SUBMITTER: van Cong Doan  Leonardo Bassi 

PROVIDER: MTBLS4286 | MetaboLights | 2023-11-03

REPOSITORIES: MetaboLights