Effects Of Highly Intensive Management On Soil Physicochemical Properties And Bacterial Community Diversity Of Moso Bamboo Forest

Intensive management plays vital role in plant growth and yield improvement by nutrient supply and soil condition amendment.However,long-term or highly intensive management have induced negative consequences,such as edaphic quality decline,forest recession,and environmental degradation.To alleviate bamboo forest recession,fallow was applied during practice,but its influences on microbial community and related functions remains to be checked.In this study,soil physiochemical properties,microbial diversity,community composition and potential functions across a chronosequence of highly managed Moso bamboo forests with fallow adopted were investigated by high throughput sequencing of 16S r RNA gene fragments.The experiment results show that:1.highly intensive management resulted in significant increase in the contents of ammonia(NH4~+),nitrate(NO3~-),available P,available K(AK)and organic matter,but not for total K(TK)and p H;2.The ABT model indicated TK to be the best factor in explaining microbial community variation(15.02%),followed by p H(11.29%)and AK(11.13%);3.A decreased alpha diversity of soil and rhizome root microbiota and reassembled community compositions were uncovered,but the abundance of metabolic pathways changed slightly responding to intensive practice;4.Comammox Nitrospirae and nitrogen-related functions were detected.It is worth noticing that Nitrospirae explained nearly 50%of soil physiochemical property variations,including p H,NO3~-,NH4~+and AK,indicating its importance in soil nutrient cycling,especially in nitrogen cycle;5.the excessive accumulation of NO3~-lead to denitrification.Another important finding is that moderate fallow contributed to the restoration of soil physiochemical properties.Accordingly,we proposed that highly intensive management induced alterations of soil physiochemical parameters along with soil environmental heterogeneity concurrently reshaped the microbial community structure and keystone microbes,leading to the differentiation of microbial ecology functions.We highly recommended to regulated the nutrient ratio(N:P:K)in compound fertilizer and reduce the amount of fertilizer in intensively managed bamboo forest.