7/29/2023 0 Comments Co2 fixingSome studies have shown that with the increase of altitude, most mountain soil microbial diversity shows a monotonous decreasing trend 17, 18, 19, while the soil microbial diversity in some mountainous areas has a nonlinear relationship with the altitude gradient, which is manifested as a unimodal/inverted unimodal or bimodal/inverted bimodal distribution pattern 20, 21, 22. A variety of environmental factors change with the change of elevation gradient 4, so altitude is an important factor to detect the interaction between the autotrophic microbial community and environmental factors 16. At the same time, soil microbial diversity and composition are also affected by soil physical and chemical properties in different environments 15. The composition, distribution, and diversity of soil microorganisms are the keys to studying soil ecological functions. In extreme environments such as low temperature, drought, and high UV, soil carbon-fixing microbial communities may play an important role in CO 2 fixation but have rarely been investigated. The most common ones are soils in large farmland areas 13, 14. At present, the research on microorganisms with carbon-fixing function genes is mostly concentrated in aquatic ecosystems 11, 12, and most of the researches on carbon-fixing microorganisms in terrestrial ecosystems are also concentrated in areas with specific ecological conditions. The global terrestrial soil ecosystem can fix 0.68–4.9 pg of carbon annually through the CBB cycle, accounting for about 4% of the total annual CO 2 fixation in terrestrial ecosystems 10. It is also a pathway for photoautotrophic microorganisms and almost all aerobic autotrophic microorganisms to fix CO 2. The Calvin-Benson-Bassham (CBB) cycle is a CO 2 fixation pathway commonly found in plants and algae in nature 9. The autotrophic microorganisms in global terrestrial soils can capture 0.5–4.1% of the atmospheric CO 2 and total 0.6–4.9 Gt C each year 8. Autotrophic microorganisms are widely distributed in different ecosystems, and assimilation of CO 2 is a key microbial process in the carbon cycle of global ecosystems and plays an extremely important role in regulating the concentration of carbon dioxide in the atmosphere 7. As an important biological component of the soil, soil microbes are the main driving force of soil organic matter and nutrient cycles and are regulating the biogeochemical cycling 2, 3, 4 and maintaining ecosystem functions 5, 6. Microorganisms have large biomass, numerous species, diverse metabolism, and complex interactions 1. Our results are helpful to understand the variation in soil microbial community and its role in soil carbon cycling along elevation gradients. Therefore, altitude influences the structural characteristics of CO 2-fixing microbes by driving environmental factors. Altitude has the greatest influence on the structural characteristics of CO 2-fixing microbes, and other environmental factors are significantly correlated with altitude. In terms of microbial community composition, Proteobacteria is dominant, and the most abundant genera are Cupriavidus, Rhodobacter, Sulfurifustis and Thiobacillus. The diversity of CO 2-fixing microbes is the highest in the middle altitude area, and on the east slope is higher than those on the west slope. The overall OTU (Operational Taxonomic Unit) abundance is concentrated at an altitude between 43 m. The CO 2-fixing microbial communities were characterized by high-throughput sequencing targeting the cbbL gene, encoding the large subunit for the CO 2-fixing protein ribulose 1, 5-bisphosphate carboxylase/oxygenase. To understand carbon sequestration by soil CO 2-fixing microbes and the carbon cycling in alpine meadow soils, microbial diversity and their driving environmental factors were explored along an elevation gradient from 3900 to 5100 m, on both east and west slopes of Mila Mountain region on the Tibetan Plateau. Soil CO 2-fixing microbes play a significant role in CO 2-fixation in the terrestrial ecosystems, particularly in the Tibetan Plateau.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |