Temperature sensitivity of soil respiration is affected by nitrogen fertilization and land use

Abstract

Wetlands are an important component of the terrestrial ecosystem, and play a crucial role in sequestering carbon. However, to date, there is little information about the land use and nitrogen fertilization effects on temperature sensitivity of soil respiration in wetland. In this investigation, effects of land use and nitrogen fertilization on temperature sensitivity of soil respiration (Q10) in a freshwater marsh of northeast China were studied. The results showed that change of land use significantly affected Q110-value, which followed the order: Intact Deyeuxia angustifolia wetland soil > upland forest soil > abandoned cultivated soil > cultivated soil. Our data confirmed that soil temperature and moisture were important factors affecting Q10-values. Besides temperature and soil moisture, availability of C and N and microbial activity in soil were important factors affecting Q10-values. Nitrogen fertilization resulted in an increase in Q10 value not only in the intact wetland, but also in the cultivated soil. Although availability of N could stimulate temperature sensitivity of soil respiration, high nitrogen fertilization (i.e., 240 kg N ha-1 in this study) inhibited temperature sensitivity. Further studies are indicated as a means of answering these questions and providing additional information on the effects of nitrogen fertilization on Q10-value. © 2010 Taylor & Francis.