Abstract: Taking the  Dongting Lake  wetlands with three typical vegetations (Phalaris arundinacea,    Carex brevicuspis,   and  Phragmites australis)  as the objects, this paper studied their soil microbial characteristics, including microbial  biomass carbon and nitrogen and  microbial  respiration,  and analyzed the related main affecting factors.  In the  test  wetlands,  the  soil  microbial biomass carbon (MBC) and nitrogen (MBN),   soil microbial respiration,  and the  ratio of  soil  MBC to soil organic   carbon (q_MBC)  were in the order of P.   arundinacea   > C.   brevicuspis  > P .  australis,  whereas  the soil  microbial metabolic quotient (qCO₂) had  an  opposite tendency to  q_MBC. The   correlation analysis  of the soil  microbial characteristics  and environmental factors showed  that   soil moisture  content,   bulk density,  and organic matter  content  were   the main  environmental factors  affecting the  soil microbial  characteristics, and soil  pH and total nitrogen content  also had  strong  relationships   with the  soil microbial characteristics.

Key words: Ebinur Lake region, landscape pattern, ecological risk, spatio-temporal variation.