Land degradation affects the microbial communities in the Brazilian Caatinga biome

Considering that global land degradation and desertification are increasing nowadays, understanding how soil microbial communities are modulated by these drivers is of paramount importance to mitigate these processes. Here, we assessed the effect of land degradation, restoration, and native forest on soil microbial communities in a semiarid region from Northeastern Brazil. Thus, soil samples were collected at 0-20 cm depth, in three sites: native, degraded, and restored lands. The soil DNA was extracted, and the microbial community was assessed by next-generation sequencing through the Illumina platform. The composition of microbial communities and their potential functions were altered by the degradation process, thereby decreasing microbial diversity. Also, the changes in the microbial communities seem to be related to soil chemical alterations, which were changed by the process of degradation and restoration. Land degradation led to a loss of diversity and functions, and the restored area presented more resilience, which suggests that the microbial communities could recover their functions by adopting sustainable practices. Importantly, degraded lands reduced functions related to chemoheterotrophic metabolism, which can strongly impact carbon dynamics in the system. Finally, this study provided relevant evidence that land restoration practices can recover soil functions, which is extremely relevant for further research that is aimed at the development of sustainable practices in degradation hotspots around the world.

Automated summary

Considering the increasing global land degradation and desertification, understanding the modulation of soil microbial communities by these drivers is crucial in mitigating these processes. This study assessed the effects of land degradation, restoration, and native forest on soil microbial communities in a semi-arid region in Northeastern Brazil. The results showed that land degradation led to changes in microbial community composition and decreased microbial diversity. However, the restored area exhibited more resilience, suggesting that microbial communities can recover their functions through sustainable practices. Furthermore, degraded lands resulted in a loss of functions related to carbon dynamics in the system. This study provides important evidence that land restoration practices can recover soil functions and is relevant for further research on sustainable practices in global degradation hotspots.