ena-STUDY-Universidade Federal de Pernambuco-27-05-2021-13:07:42:607-451
Precipitation and temperature shape the biogeography of arbuscular mycorrhizal fungi across a 1500 km latitudinal transect in the Brazilian Caatinga
Arbuscular mycorrhizal fungi (AMF), an important group of plant root symbionts, remain poorly studied in the Neotropics. We used Illumina LSU amplicons sequencing to test whether AMF communities in soil and roots are shaped by deterministic or neutral processes along a 20° latitudinal transect in the Caatinga of Brazil, a unique eco-region. Glomeraceae was the most abundant and diverse family, resembling more to paleotropical Africa and European croplands than to tropical forests from South America. AMF communities showed strong biogeographic structure inconsistent with classic latitudinal diversity gradient, and further differed between soil and roots. Soil AMF biogeography was best correlated with precipitation : richness increased towards both ends of the latitudinal transect where precipitations increased, and community composition converged. Root AMF diversity weakened towards the equator, at a latitude where the soil diversity was the highest. Root AMF biogeography correlated to temperature, with decreasing diversity at higher temperatures. We found no evidence of niche phylogenetic conservatism among AMF taxa. Our results suggest that niche-based processes in relation to regional climate, most importantly precipitation and temperature, shape the biogeography of AMF across the Caatinga, with niche partitioning among closely related AMF taxa. Given the expected decrease in precipitation and increase in temperature in future, climate change may strongly affect AMF biodiversity in neotropical dry forests.
Arbuscular mycorrhizal fungi (AMF), an important group of plant root symbionts, remain poorly studied in the Neotropics. We used Illumina LSU amplicons sequencing to test whether AMF communities in soil and roots are shaped by deterministic or neutral processes along a 20° latitudinal transect in the Caatinga of Brazil, a unique eco-region. Glomeraceae was the most abundant and diverse family, resembling more to paleotropical Africa and European croplands than to tropical forests from South America. AMF communities showed strong biogeographic structure inconsistent with classic latitudinal diversity gradient, and further differed between soil and roots. Soil AMF biogeography was best correlated with precipitation : richness increased towards both ends of the latitudinal transect where precipitations increased, and community composition converged. Root AMF diversity weakened towards the equator, at a latitude where the soil diversity was the highest. Root AMF biogeography correlated to temperature, with decreasing diversity at higher temperatures. We found no evidence of niche phylogenetic conservatism among AMF taxa. Our results suggest that niche-based processes in relation to regional climate, most importantly precipitation and temperature, shape the biogeography of AMF across the Caatinga, with niche partitioning among closely related AMF taxa. Given the expected decrease in precipitation and increase in temperature in future, climate change may strongly affect AMF biodiversity in neotropical dry forests.