Influences of forest floor cleaning on the soil respiration and soil physical property of a larch plantation in Northeast China

Aimed to estimate how forest floor cleaning affected the carbon budget and soil physical feature, a 2-yr (2005–2006) measurement on soil respiration, soil bulk density, capillary porosity, soil temperature and soil volumetric moisture was carried out in a larch plantation. Firstly, forest floor cleaning evidently decreased soil respiration. Annual cumulative soil CO2 efflux decreased from 44.2 μmol•m−2 a−1 to 22.4 μmol•m−2 a−1. Secondly, cleaning practice slightly increased soil temperature at the growing season, but reduced it at the dominant winter season. It also made soil moisture higher in summer, but lower in spring and autumn. Moreover, the cleaning practice induced more compact soil compared with the uncleaned control. Thirdly, forest floor cleaning of litters and understory shrubs could cause non-respiratory carbon loss of about 175.0 mol•m−2. This loss decreased from 175.0 mol•m−2 to 137.4 mol•m−2 when soil respiratory carbon loss decreased. However, the alteration of soil physical characters in the cleaned plots should be carefully considered since this alteration was not favorable to the growth of larch plantation in a long run.