HERMAN, R. P., ADAM LANGLEY, SHARON AMBRO & SHARLENE JONES.
Department of Biology, New Mexico State University, Box 30001, MSC 3AF, Las Cruces, NM 88003 USA.
The frequency of root infection by arbuscular mycorrhizal fungi
(AMF) and AMF spores in soil were assessed in soil samples collected at grass
plant crowns and in interplant spaces from a nutrient poor upland (bajada) grassland
and a lowland playa grassland with 3-5 fold higher nutrient levels. In a parallel
study, nested grids were sampled to ascertain if there was a measurable pattern
of AMF colonization or spore production.
Despite the difference in nutrient levels, there was no difference in colonization
rates in the nutrient poor bajada compared to the relatively nutrient rich playa.
Colonization rates were higher in roots collected at the plant crown than in
roots further from the crown in both the bajada and playa grasslands. Spore
production was significantly higher in the playa than the bajada but there was
no significant difference between at-crown and inter-crown samples. There was
no discernable pattern of AMF spore or colonization patch distribution indicating
patches, if present were either greater than 6m or less than 0.375m on a side.