水保所知识产出(1956---)知识库

Sustainable management practices can enhance the capacity and potential for soil carbon (C) sequestration, sig-
nificantly contributing towards mitigating regional climate change. Here, we investigated how the microbial
characteristics of a Pinus tabulaeformis plantation responded to different management practices to identify the
role of microbial characteristics in influencing the stability of soil organic carbon (SOC). We chose a Pinus
tabulaeformis plantation on the Loess Plateau where forest management practices had been conducted since
1999. Five forest management practices were implemented: two at the forest level (P. tabulaeformis with and
without ground litter), and three using different vegetation restoration approaches after clear-cutting (P.
tabulaeformis seedlings, abandoned grassland, and natural shrub regeneration). Microbial biomass, soil respira-
tion, microbial community structure, microbial metabolic function, and soil oxidizable organic carbon (OC) frac-
tions were evaluated. Forest management practices changed SOC stability by adjusting the microbial
characteristics (e.g. soil microbial community diversity and microbial metabolic function diversity). The result
of path analysis was that the direct path coefficient of microbial biomass on soil oxidizable OC fractions was
thelargest,which was1.499.Pathanalysisandredundancyanalysisshowedthatmicrobialbiomasshadthelarg-
est direct influence on soil oxidizable OC fractions. Compared with other forest management practices, natural
shrub regeneration increased the nonlabile carbon fraction by increasing soil microbial characteristics, andcontributed the most towards stabilizing SOC, which enhanced the stability of the soil ecosystem on the plateau.
In conclusion, microbial biomass was the biggest influence factor of SOC stability. In contrast, the stability of SOC
may be most stable in the area of natural shrub regeneration.