Arcadio Monroy-Ata

Mycorrhizal Symbiosis Organization of Dominant Tree Prosopis laevigata (Mesquite) in a Xeric Shrub of Central Mexico

The aim of this study was to obtain clues in view to understand plant mosaic assemblage in a plot of a shrubland, with a dominance of mesquite (Prosopis laevigata) trees at the Mezquital Valley, Hidalgo State, in Central Mexico. For this, the arbuscular mycorrhizal fungi (AMF) associated with the oldest tree of the study area and their nearest neighbors of the same species were sampled (in the dry period), in soil of the four cardinal points under the canopy of each tree, and analyzed in order to determine richness and abundance of AMF spores. The results show that 3 AMF genera species were present in all mesquite trees and that the oldest and youngest, the nearest and the furthest trees shared this same AMF consortium (Sclerocystis sinuosa and 2 Glomus spp.). This points out that the oldest mesquite can have the role of “mother tree” to spread fungal propagules in a semiarid environment, where the structure of plant mosaics has patched (dotted) or banded (brousse tigree) patterns derived by soil water potential. Also, the multivariate analysis of data shows a cluster grouping the oldest mesquite tree and the dominant AMF consortium. It was concluded that fungal network has an important role in the exploitation of scare soil resources (water and nutrients) and for determining the plant guild assemblages above- and belowground.

Jardín xerófito para divulgación científica

In this work, a xerophytic garden was designed and established for science popularization purposes. This was made on a green area of the Facultad de Estudios Superiores Zaragoza of the National University, at the East of Mexico City. The garden design was outlined by drawing on the soil surface, a logarithmic spiral, a Vitrubius star, a fractal pentagon and a golden rectangle. For this, white painted 10 cm high stakes were buried to delimit the curves, and succulent plants were planted to remark the geometric figures. Twenty nine plant species were transplanted, with 144 total individuals, and a catch-fog mesh device was installed with a view to exhibit an atmospheric water harvesting model for plant irrigation. The science popularization of geometric concepts was made by means of guided visits. It was concluded that it is feasible to establish an urban garden without irrigation in the East of Mexico City. Nevertheless, it is necessary to strengthen the structure of geometric curves. Also, it is required to install information panels about the soil drawings and technical fact sheets on plant species in order to facilitate popularization of the underlying scientific concepts of garden design and the explanation of catch-fog device function.