Differentiation in seed mass and seedling biomass allocation in Prosopis laevigata throughout its distribution range in Mexico is associated to water availability

Abstract

Background: Seedling establishment depends on the quality of the seeds and environmental conditions. Differential biomass allocation in emergent seedlings probably constitutes a relevant adaptive response of populations along environmental gradients.
 Questions: Are there differences in seed mass and biomass allocation in seedlings among Prosopis laevigatapopulations? Is this variation correlated with environmental variables?
 Studied species: Prosopis laevigata (Humb. & Bonpl. ex Willd.) M.C.Johnst (Fabaceae).
 Study site and dates: Thirteen localities along the distribution of P. laevigata in México. From 2016 to 2020.
 Methods: Seeds were collected from four or five mother trees per locality. Seed mass (SM) was obtained in ten seeds per mother and six functional traits indicative of biomass allocation were measured in the seedlings after 10 days of germination. Population mean values were obtained for the six traits plus SM and subjected to a principal component analysis (PCA). Population scores on the first two axis of the PCA were regressed against environmental variables from the collection localities using a stepwise regression model.
 Results: Populations displayed functional variation congruent with alternative biomass allocation strategies. The conservative strategy was characterized by larger seeds and seedlings with denser tissues and a higher investment in root biomass, while the opposite characterized the acquisitive strategy. Actual evapotranspiration in May, isothermality and soil water content in February were environmental variables that significantly predicted population scores on the first two axes of the PCA.
 Conclusion: Water availability gradients influence seed mass and seedling biomass allocation variation among P. laevigata populations.

Crecimiento y asignación de biomasa de ocho especies de Mimosa (Leguminosae) y su relación con la nodulación y micorrización arbuscular

“…Altura del tallo 0.17 ns 0.76 Un diseño corresponde a un grupo de especies, en este caso de Mimosa, que reúnen un conjunto de características morfológicas, fisiológicas e, incluso, anatómicas, moldeadas por las características ecológicas relevantes para su crecimiento y reproducción (Rincón et al 2000) y, probablemente, heredadas a estas plantas a través de sus semillas como se ha demostrado en otras leguminosas como P. laevigata (Hernández-Madrigal et al 2022). La biomasa de las especies estudiadas de Mimosa está en el intervalo reportado en 34 especies de leguminosas leñosas, entre ellas, M. tenuiflora (Willd.)…”

“…M.C.Johnst. (Monroy-Ata et al 2007, Hernández-Madrigal et al 2022) y varias especies del género Mimosa (Huante et al 1995, Gavito et al 2008, Negreiros et al 2009, Camargo-Ricalde et al 2010a, Peña-Becerril et al 2016) generalmente, pueden aumentar su asignación de biomasa aérea y subterránea bajo condiciones de sequía, fertilización y en condiciones de colonización micorrízica y nodulación en sus raíces.…”