The soil is greater than the sum of its parts: potential functional diversity of microbial communities associated with different soil organic matter fractions

Abstract

Aims This study examines functional diversity of microbial communities from soils under different land uses in the Semiarid Chaco region, Argentina.

Methods We evaluated microbial communities in soil samples from native forests, croplands, and pastures using Community-Level Catabolic Profiling (CLPP). We introduced a novel fractionation method to separate soil into particulate organic matter (POM) and mineral-associated organic matter (MAOM), enhancing microbial survival.

Results The results reflected distinct physiological profiles across different land uses. Native forest soils showed lower functional diversity compared to pastures and croplands. While POM-associated microbial communities were similar across land uses, MAOM-associated communities differed between native forests and other land uses. This highlights that microbial responses to land uses vary by soil fraction, reflecting differences in carbon accessibility.

Conclusions The bulk soil microbial response cannot be fully understood by examining fractions alone, emphasizing the complexity of soil ecosystems. These findings contribute to a more nuanced understanding of land use impacts on soil health and ecosystem services.