Seasonal dynamics of dominant species of arbuscular mycorrhizae in burned and unburned sand prairies

Abstract

Seasonal variation in abundance of spores of arbuscular mycorrhizal fungi was examined for four growing seasons on burned and unburned sand prairies in Illinois. The three leading mycorrhizal species were an undescribed species of Glomus, Scutettospora heterogama, and Sclerocystis rubiformis, in order of decreasing abundance. Mycorrhizal spore abundance for all species generally showed similar seasonal patterns on burned and unburned sites during the sampling period, i.e., minimal in the middle of the growing season and maximal near the end of the season. Individual species, however, exhibited different seasonal patterns of sporulation or sporulation strategies. Burning caused a 2-year depression in spore abundance for Glomus species and Scutellospora heterogama, and a 3-year long depression in spore abundance for Sclerocystis rubiformis. The seasonal patterns observed were more discernible in root zone than in randomly collected soil. Spore abundances were always significantly lower on burned sites than on unburned sites early in the growing season. The results of this study, and studies conducted parallel to this one, suggest that the greater decline in spore abundance in burned sites than in unburned sites early in the growing season may be indirectly due to greater root growth, and (or) related changes in host physiology, in response to fire. Key words: mycorrhizae, fire, sand prairie, grassland, sporulation, inoculum, fungi.

Seasonal Diversity of Arbuscular Mycorrhizal Fungi in Mangroves of Goa, India

“…Spore density showed variation, maximum in premonsoon and minimum in the monsoon season at both sites. Similar observations have been reported in earlier studies [29,30]. Higher spore density in premonsoon season is thought to be an indication of root senescence and available nutrients, stimulating fungal sporulation as plant nutrient requirement is reduced [31].…”

Macroecology of Microbes – Biogeography of the Glomeromycota

“…Fire can alter AM fungal species distributions depending on the timing, extent, and intensity of the burn (Bentivenga and Hetrick 1991;Eom et al 1999;Dhillion and Anderson 1993). Forces that initiate primary succession, such as glacial retreat and volcanic flow, create substantial soil disturbance and also influence AM fungal distributions.…”

Growth response of maize plants (Zea mays L.) to wheat and lentil pre-cropping and to indigenous mycorrhizae in field soil

“…Douds and Millner (1999) found that the study of AMF diversity in agricultural soils presents many challenges, including the difficulty in identifying field collected spores, the detection of non-sporulating members of the community, and the lack of correlation between functional and morphological features of the spores used to define the different species. Dhillion and Anderson (1993) showed that in sand prairies the abundance of spores was always significantly lower in burned than in unburned sites early in the growing season. Ortas et al (2000) reported that soil and crop management can help to get maximum benefit from indigenous mycorrhiza for sustainable crop production.…”