Influence of land-use changes on microbial community structure and diversity in a semiarid region

VÁZQUEZ CAROLINA ; VERDENELLI ROMINA A. ; MERLO CAROLINA; PÉREZ BRANDAN CAROLINA; KOWALJOW ESTEBAN; MERILES JOSÉ M.

LAND DEGRADATION & DEVELOPMENT

JOHN WILEY & SONS LTD

Lugar: LOndres; Año: 2022

1085-3278

Land-use change and the conversion of land into croplands is one of themain drivers of soil degradation and the loss of soil organic carbon. Fewstudies have evaluated the impact of the expansion of the agricultural frontieron soil microbial communities in the Gran Chaco region in South America;therefore, the objective of this study was to explore how soil microbialcommunities respond to land-use changes in a semiarid region of Argentina. Theland uses selected were total and selective clearing with livestock(TC-livestock and SC-livestock), total clearing with agriculture(TC-agriculture), and an undisturbed site (R-Chancaní). Ourresults suggest that microbial abundances were strongly influenced by seasonalchanges. In both seasons, the lowest values of total microbial biomass wereobserved in TC-agriculture and TC-livestock. In the wet season, TC-agriculturehad the lowest fungal abundance, and both total clearing sites (TC-livestockand TC-agriculture) had higher bacterial abundance than the other sites. Ourdata also showed that the Shannon and richness indexes were highest at thefarming sites, indicating a similar tendency in the diversity indexes in bothdry and wet seasons. According to Pearson correlation analysis, humic substance(HS) content was a key driver influencing soil microbial communities,demonstrating that high HS content may significantly increase bacteria, fungi,and total PLFAs. Microbial composition highly depended on seasonal changes.Overall, our results suggest that land-use change altered microbial communitystructure and bacterial diversity, and that HS content played a crucial role indriving changes in soil microbial composition.