Properties related to communities of arbuscular mycorrhizal fungi along an altitudinal gradient in a Brazilian cloud forest

ABSTRACT

This was the first study conducted on the diversity and abundance of arbuscular mycorrhizal fungi (AMF) species and quantification of glomalin-related soil protein (GRSP) fractions, as well as on their relationship with environmental and soil chemical and physical properties along an elevation gradient above 1000 m in a Brazilian Atlantic cloud forest. AMF diversity was assessed by examining spores extracted from soil samples collected near the roots of the 18 most common plant species in permanent plots established in the field at altitudes of 1500, 1700, 1900, and 2100 meters above sea level. Fifteen AMF species were found, most of them belonging to the families Acaulosporaceae, Glomeraeceae, and Gigasporaceae. Compositions of the AMF community varied among the altitudes; Acaulospora was the predominant genus, with six species. The total Bradford-reactive soil protein (BRSP) and the easily extractable BRSP (EE-BRSP) soil glomalin were the highest at the altitude of 2100 m (5.7 and 3.8 mg.g soil^-1, respectively). Altitude and environment and soil characteristics affected the composition and diversity (Shannon index) of the AMF communities. However, the effect of altitude on AMF diversity can be estimated, indirectly, through its effect on plant diversity.

Keywords: Glomeromycota; species richness; glomalin; tropical montane forest; upper montane forest; tropical montane ecosystem