Table of Contents
Journal of Ecosystems
Volume 2014, Article ID 729294, 13 pages
http://dx.doi.org/10.1155/2014/729294
Research Article

Seasonal/Interannual Variations of Carbon Sequestration and Carbon Emission in a Warm-Season Perennial Grassland

1Nepal Academy of Science and Technology (NAST), GPO Box 3323, Khumaltar, Lalitpur, Nepal
2Faculty of Education and Integrated Arts and Sciences, Waseda University, Shinjuku 162-8480, Japan

Received 25 March 2014; Accepted 16 October 2014; Published 11 November 2014

Academic Editor: Wen-Cheng Liu

Copyright © 2014 Deepa Dhital et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Carbon sequestration and carbon emission are processes of ecosystem carbon cycling that can be affected while land area converted to grassland resulting in increased soil carbon storage and below-ground respiration. Discerning the importance of carbon cycle in grassland, we aimed to estimate carbon sequestration in photosynthesis and carbon emission in respiration from soil, root, and microbes, for four consecutive years (2007–2010) in a warm-season perennial grassland, Japan. Soil carbon emission increased with increasing growing season temperature which ranged from 438 to 1642 mg CO2 m−2 h−1. Four years’ average soil carbon emission for growing season, nongrowing season, and annual emission was 1123, 364, and 1488 g C m−2, respectively. Nongrowing and snow covered season soil carbon emission contributed 23–25% and 14–17% to the annual emission. Above-ground biomass varied seasonally and variation in green biomass affected soil carbon emission with increasing temperature and precipitation. Temperature effect on root carbon emission contributed about 1/4th of the total soil carbon emission. Variation in soil and root carbon emission is affected by below-ground biomass. Long-term estimation concluded that seasonal and interannual variations in carbon sequestration and emission are very common in grassland ecosystem.