Biology subjects

Perez-Ramos, I. M.

Publications and source records attributed to Perez-Ramos, I. M..

3 recordsLinked to original sources

bioRxiv2020

Root economics spectrum and construction costs in Mediterranean woody plants: the role of symbiotic associations and the environment

O_LIQuantifying the functional variation of fine root traits and their interactions with symbiotic organisms is an uprising research topic to understand the overarching trade-off between maximizing resource acquisition or conservation (root economics spectrum -RES-). The currency of root traits economy is based on the carbon required to construct them; however, we lack a clear understanding of this question. C_LIO_LIOur main aim was to quantify construction costs (CC) of fine roots (<2 mm) and their underlying components (concentration of carbon, minerals and organic nitrogen) in 60 Mediterranean woody species with contrasting symbiotic association types (ectomycorrhizas, arbuscular and ericoid mycorrhizas and N-Fixing nodules). We examined (1) if the CC depended on the symbiotic type, and if they were associated with morphological traits; (2) the relation of each component of the CC with the root structure for each symbiotic type; and (3) whether soil water and nutrient availability determined differences in CC across sites and symbiotic types. C_LIO_LIThe multivariate analysis of root traits showed a main plane of covariation accordingly to the RES expectations, with contrasting symbiotic types at both ends of the spectrum. We found a significant relationship between root CC and RES; interestingly the slopes of this relationship differed among symbiotic types, which was mainly due to the different role that each specific components of CC plays across them. In addition, independently of the symbiotic type, the CC decreased linearly with the nutrient availability and quadratic with the water availability. C_LIO_LISynthesis. Our study demonstrates that woody plants have different strategies in their root carbon investment, which depend on their position along the economics spectrum (RES) and on their main symbiotic association preference. The intrinsic components of the cost of root production varied across species with contrasting symbiotic associations, pointing to a trade-off between structural and metabolic compounds. We also found that root CC are strongly modulated by soil resource availability, following a non-linear pattern with water availability. Thus, CC shifts from high to low at the most arid sites, which points to a strong role of symbiotic associations in this shift. C_LI

ecology↗

bioRxiv2019

A mechanistic path to maximize biomass productivity while maintaining diversity.

With ongoing biodiversity loss, it is important to understand how the mechanisms that promote coexistence relate to those that increase functioning in diverse communities. Both coexistence and biodiversity functioning research have unified their mechanisms into two classes. However, despite seeming similarities, theory suggests that coexistence and biodiversity mechanisms do not necessarily map onto each other, yet direct empirical evidence for this prediction is lacking. We coupled field-parameterized models of competition between 10 plants with a biodiversity-functioning experiment measuring biomass production, litter decomposition, and soil nutrient content under contrasting environmental conditions. We related biodiversity mechanisms (complementarity and selection effects), to coexistence mechanisms (niche and fitness differences). As predicted by theory, complementarity effects were positively correlated with niche differences and differences in selection effects were correlated with fitness differences. However, we also found that niche differences contributed to selection effects and fitness differences to complementarity effects. Despite this complexity more stably coexisting communities (i.e. those in which niche differences offset fitness differences) produced more biomass, particularly under drought. This relationship was weaker for litter decomposition rates and soil nutrient acquisition, showing that the mechanisms promoting plant coexistence may differ from those promoting high levels of functions that are less directly related to plant performance. We provide the first empirical evidence that the mechanisms promoting stable coexistence correlate with those driving high biomass production. These findings establish a link between stable coexistence and functioning, which could allow better predictions of how diversity loss induced by global change translates to changes in ecosystem function.

ecology↗

bioRxiv2019

Functional traits and phenotypic plasticity modulate species coexistence across contrasting environments

Functional traits are expected to modulate plant competitive dynamics. However, how traits and their plasticity in response to contrasting environments connect with the mechanisms determining species coexistence remains poorly understood. Here, we coupled field experiments under two contrasted climatic conditions to a plant population model describing competitive dynamics between 10 annual plant species in order to evaluate the associations of niche and fitness differences with 19 functional traits covering physiological, morphological and reproductive characteristics. We found a rich diversity of univariate and multidimensional relationships, in which outstand the primary role of traits related to water- and light-use-efficiency in modulating the determinants of competitive outcomes. Importantly, such traits and their plasticity promoted species coexistence across climatic conditions by enhancing stabilizing niche differences and by generating competitive trade-offs between species. Our study represents a significant advance showing how leading dimensions of plant form and function connect to the mechanisms determining the maintenance of biodiversity.

ecology↗