水保所知识产出(1956---)知识库

Soil microbes are essential to biogeochemical cycling, soil organic matter decomposition and climate regulation
in terrestrial ecosystems. The biogeography of soil bacteria and fungi lags behind in animals and plants, espe-
cially in arid areas with alkaline conditions. Understanding the biogeographic of soil microbes and the inter-
actions with environmental factors will provide new insights into the ecosystem functions and services droved by
soil bacteria and fungi. Therefore, we chose 48 dryland sites from two transects (north-south and east-west
transects) on the Loess Plateau (an arid area) to determine soil bacterial and fungal diversity and community
compositions in response to environmental factors and geographic distance. The results showed that soil organic
carbon enhanced soil fungal diversity rather than soil bacterial diversity, while soil bacterial diversity was not
affected by the environmental factors on the Loess Plateau. The significant associations between the abundance
of main bacteria and fungi and soil pH, suggesting that soil pH was the predominant factor affecting soil mi-
crobial community structure. In the alkaline soils (pH = 7.4–9.1), soil bacterial community compositions were
limited by soil pH, while soil fungal community composition was less sensitive in response to the alterations in
soil pH, revealing soil fungi has a wider optimal pH range than bacteria. Compered to historical contingencies,
local environment mainly controlled the geography of bacteria and fungi in soils. On the Loess Plateau, soil
microbial communities diverge most by soil pH, especially for soil bacteria. These results provide a well un-
derstanding of soil microbial geography and associated biogeochemical cycling in arid areas with higher soil pH.