Effects of pasture introduction on soil CO2 emissions during the dry season in the state of Rondônia,Brazil |
| |
Authors: | B J Feigl P A Steudler C C Cerri |
| |
Institution: | (1) Centro de Energia Nuclear na Agricultura, CENA/USP, CP 96,13416-000 Piracicaba-SP, Brazil;(2) The Ecosystem Center, Marine Biological Laboratory, Woods Hole, Massachusetts 02543, USA |
| |
Abstract: | Soil CO2 evolution rates, soil temperatures and moisture were measured during the dry season in two forest-to-pasture chronosequences in Rondônia, Brazil. The study included pastures ranging from 3 to 80 years-old. Mean dry-season CO2 evolution from the forest in chronosequence 1, 88.8 mg CO2-C m–2h–1 was lower than from the pastures which ranged from 111 to 158 mg CO2-C m–2h–1. We found that temperature was not a good predictor of CO2 emissions from pasture but that there was a significant relationship (r = 0.72,p < 0.05) between soil moisture and pasture emissions. The 13C of the soil CO2 emissions also was measured on chronosequence I; 13C of the CO2 emitted from the C3 forest was –29.43%. Pasture13CO2 values increased from –17.91%. in the 3 year-old pasture to –12.86% in the 80 year-old, reflecting the increasing C4 inputs with pasture age. Even in the youngest (3 year-old) pasture, 70 percent of the CO2 evolved originated from C4 pasture-derived carbon. |
| |
Keywords: | Amazonia Brazil carbon dioxide 13CO2 chronosequence soil respiration tropical forest tropical pasture |
本文献已被 SpringerLink 等数据库收录! |
|