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

Titre : The effect of soil disturbance on populations of endomycorrhizal fungi in rangelands of southern Arizona

Auteur : Clay, Jaquelin

Université de soutenance : University of Arizona

Grade : Master of Science (MS) 1981

Résumé
Three sites, representing three levels of soil disturbance, were chosen in southern Arizona to study the effect such disturbance may have on populations of endomycorrhizal fungi. A fallowed site, disturbed within the last two years had a 20.6% rate of infection, and 37.9 spores per gram soil. An abandoned site, disturbed six years previously had a 5.8% infection rate and 34.6 spores per gram soil ; and an undisturbed site had a 6.4% infection rate and 11.7 spores per gram soil. The data also suggested that the fungal populations were not uniformly distributed, but found in association with shrubs. Correia- tion tests show that there was a significant degree of correlation be tween spore numbers and per cent infection on the abandoned and undisturbed sites. SurVey for endomycorrhizal infection of the native plant species representing 90% of the cover indicated that the abandoned site had two out of seven species infected ; the undisturbed site had one out of six species infected. The influence that the plant communities on the site prior to sampling may have had on the results was discussed. Suggestions were made concerning refinements of the sampling method appropriate to the desert environment and population distribution of the fungus

Mots clés : Mycorrhizas. ; Soil fungi — Arizona.

Présentation

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