Effectsof Soil Temperature and Moisture on Soil Respiration in Different Sand Dune Types

The effects of soil temperatures(8,18,28,38℃) and water content on soil respiration in three different sandy habitats(shifting,semi-fixed and fixed sand dune) inHorqinsandy land were evaluated using a laboratory soil incubation experiment.The results indicated that soil respiration rate was positively correlated to soil temperature from 8 to 38℃ and it increased with water content from 5 to 65 percent of water field capacity(WFC) in three soil types.Whenwater content was over the range,soil respiration rate in shifting sand dune increased continually,whereas it decreased at 38℃in semi-fixed and at 18～38℃in fixed sand dune.The results suggested the interactive effects of temperature and water content on soil respiration.There were significant differences in soil respiration among the varioussand dune types.The temperature coefficient Q_(10)varied from 1.90 to 2.15 in shifting sand dune,1.80 to 2.13 in semi-fixed sand dune and 1.82 to 2.16 in fixed sand dune,according to water content variation.