Soil Respiration And Microbial Biomass Carbon At Different Land Uses

Wetland ecosystem plays an important role in the global carbon cycle with a strong carbon sequestration. Loss of soil organic carbon in the global climate change attracts close attention which caused by human use because of population growth and rapid economic development. There was an upsurge in reclaimed lakes in a large area of china. The type of land-use and history affected the changes of soil carbon pool following land reclamation. Therefore, more research on changes of carbon cycling in different land-use after reclaiming the land from the lakes has great significance in response to clarify the global carbon cycle.This study revealed soil respiration and microbial biomass carbon (MBC) in a northern subtropical area which showed changes in time and space at the different land use patterns after reclaiming land from lakes. The results showed that:1) Soil respiration in Cinnamonum campora forest was significantly lower than that in Phyllostachys heterocycla forest and Metasequoia glyptostroboides forest.2) During one year, soil respiration in cropland and Phyllostachys heterocycla forest were higher in July to October, soil respiration in Cinnamonum campora forest and Metasequoia glyptostroboides forest were higher in May to October. Soil respiration in the four land-use types were lower in December to February.3) Soil temperature was the dominant factor of soil respiration in changes of temporal and spatial.4) Soil respiration in Phyllostachys heterocycla forest had a greater sensitivity to temperature in four land-use types.5) MBC in cropland was significantly higher than that in Cinnamonum campora forest, Phyllostachys heterocycla forest and Metasequoia glyptostroboides forest, respectively.6) MBC was strongly correlated with pH, K and soil respiration; qMB was significantly correlated with soil moisture, TOC, TN, K, C/N, pH, bulk density and soil respiration.7) MBC changed significantly along the horizontal distribution, soil nutrients of the area was the dominant factor as horizontal distribution in soil.8) The overall trend of MBC in the season showed the maximum value appeared in August, the minimum value appeared in April, the seasonal fluctuations in the four land-use types were consistent.9) The seasonal fluctuations in MBC mainly were affected by seasonal change of soil temperature in four land-use types.