Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : The Effects of Biological Soil Crusts on Root-associated Fungi Colonization Rates of Vascular Plants Across Southwestern Deserts

Auteur : Tucker, Sallie Jane

Université de soutenance : University of Colorado at Boulder

Grade : Master of Arts (MA) Ecology and Evolutionary Biology 2022

Résumé
Biological soil crusts (“biocrusts”) are communities of cyanobacteria, moss, lichen, and fungi that grow in arid/semiarid soils. Biocrusts perform several ecosystem functions including increased soil stability and water/nutrient retention and aid in plant growth. Root associated fungi (RAF) form symbioses with plant roots by bringing them nutrients and water in exchange for photosynthates. This study aimed to understand if the biocrust type had an influence on the RAF under a field setting. Plant roots were collected throughout the US Southwest from four common crust types (bare ground, light cyanobacterial, dark cyanobacterial, and cyanolichen (lichen or moss present)) which represent increasing level of development. The dominant grass and shrub were sampled across four desert sites (Great Basin, Colorado Plateau, Sonoran, Chihuahuan) from each crust type, and the RAF colonization rates were measured. The results indicate that the roots from bare ground soils had the highest colonization rate, which steadily decreased through crust type maturation. With bare ground roots having 5.6%, 7.9%, and 13% higher than the light cyanobacterial, dark cyanobacterial, and cyanolichen crusts respectively.

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