Abiotic and biotic factors controlling the dynamics of soil respiration in a coastal dune ecosystem in western Japan

Abstract

AbstractIn this study, we examined the abiotic and biotic factors controlling the dynamics of soil respiration (Rs) while considering the zonal distribution of plant species in a coastal dune ecosystem in western Japan, based on periodic Rs data and continuous environmental data. We set four measurement plots with different vegetation compositions: plot 1 on bare sand; plot 2 on a cluster of young Vitex rotundifolia seedlings; plot 3 on a mixture of Artemisia capillaris and V. rotundifolia; and plot 4 on the inland boundary between the coastal vegetation zone and a Pinus thunbergii forest. Rs increased exponentially along with the seasonal rise in soil temperature, but summer drought stress markedly decreased Rs in plots 3 and 4. There was a significant positive correlation between the natural logarithm of belowground plant biomass and Rs in autumn. Our findings indicate that the seasonal dynamics of Rs in this coastal dune ecosystem are controlled by abiotic factors (soil temperature and soil moisture), but the response of Rs to drought stress in summer varied among plots that differed in dominant vegetation species. Our findings also indicated that the spatial dynamics of Rs are mainly controlled by the distribution of belowground plant biomass and autotrophic respiration.