The amount of soil microbial biomass carbon and nitrogen in global
dryland regions
Abstract
Abstract: Dryland regions cover 41% of the Earth’s land surface and
support the livelihood of half of the world’s population. Soil microbes
play an important role in carbon (C) and nitrogen (N) cycling, therefore
affecting soil health. Soil microbial biomass C (SMBC) and N (SMBN) are
indicators of soil microbial activities. A better understanding of
patterns and drivers of SMBC and SMBN in global dryland regions can
provide important insights to enhance ecosystem functioning services.
Here, we compiled 109 observations of SMBC (0-30 cm) and 79 observations
of SMBN (0-30 cm) from 100 sites across global dryland regions with
aridity index less than 0.65. The results showed that the average amount
of SMBC and SMBN in dryland regions were 358.47 ± 25.45 mg kg-1 and
51.86 ± 4.59 mg kg-1. The amount of SMBC and SMBN did significantly vary
among different dryland types and ecosystem types. Meanwhile, the ratio
of SMBC to SMBN in global dryland regions was 8.73. Soil sand fraction
and pH had significant negative effect on the ratio of SMBC to SMBN. Our
research has initially explored the pattern and control factors of soil
microbial biomass in dryland, and provided basic research data for
dryland management in the future.