水保所知识产出(1956---)知识库

Soil prokaryotes composition and diversity are the key to uncovering the mechanisms that drive variations in soil
biogeochemical processes. Soil erosion is a primary factor that affects the spatial distribution of the soil pro-
karyotic community, but how soil prokaryotes in soil-eroding catena respond to environmental factors related to
topography remains largely unclear. In this study, topsoils were sampled from three typical erosion geomorphic
units (autonomous, transitional and depositional zones) in 2018 to identify the soil prokaryotic community and
interactions among the species on the Chinese Loess Plateau. The alpha-diversity was greater but the beta-
diversity was lower in the autonomous and transitional zones than in the depositional zone. Gammaproteo-
bacteria and Bacteroidetes were 73% and 68% lower in the autonomous and transitional zones than in the
depositional zone. In addition, Deltaproteobacteria, Acidobacteria, Firmicutes, Actinobacteria, Chloroflexi,
Gemmatimonadetes and Nitrospirae were significantly higher in the autonomous and transitional zones. A less
clustered network and fewer co-occurrences within the prokaryotic community and functional groups of pro-
cesses were found in the depositional zone than in the autonomous and transitional zones. The alpha-diversity
index was significantly negatively correlated with clay particles, soil water content, soil organic carbon (SOC),
and ratio of SOC and nitrogen (C/N) but positively correlated with total nitrogen (TN). The higher relative
abundances of copiotrophic groups (including Gammaproteobacteria, Bacteroidetes, etc.) in the depositional
zone was mainly due to the increased SOC caused by the deposition of SOC-rich clay. Reassembly of the soil
physico-chemistry characteristics among the topographic units significantly altered the soil prokaryotic com-
munity along the soil-eroding catena.