Microbial Biomass And Nutrients In Soil At The Different Stages Of Secondary Forest Succession In Southeast Of Hubei Province

Soil degradation is a major threat to sustainable use of soil ecosystem,because it decreases actual and potential level of vegetation cover.Local land use and land-cover change can play a pivotal role in environmental and ecological changes and furthermore contributes to global change. Consequently,improving the physical,chemical and microbial properties of degraded soil is very important for sustainable use of soil ecosystem.The results showed:1.After the abandonment of farmland,with the natural succession of vegetation,soil pH valued although lower,but still within the scope of the acid.It indicated that the soil of Southeast Hubei hilly region had a strong buffer capacity;2.After the abandonment of farmland,and with abandoned years going,soil organic matter,total nitrogen,microbial carbon,microbial nitrogen,determination of the use of FAME analysis of the overall pattern of biomass FAME,fungi,bacteria,gram-negative had the first decline in a rising trend overall,but showed no relationship with abandon years.It indicated that the content of the effective matrix which was used by soil micro organisms was decreased in the early succession, and increased in the late succession.3.Soil C/N value increased at first,then showed a downward trend.It came to the peak at the abandoned 13 years then decreased slightly,and stabilized between 23 years to 75 years.4.Entropy metabolism increased in the early vegetation succession,perhaps as a result of microbial activity after abandonment of arable land was relatively low,and the efficiency of the use of substrate was relatively low.with the progress of succession,the metabolic entropy increased rapidly,microbial activity decreased,in the late succession,with the increase of ground litter,qCO₂ had been gradually decreased,and microbial activity had been gradually increased.