ISSN:
1573-515X
Keywords:
Amazonia
;
Brazil
;
carbon dioxide
;
13CO2
;
chronosequence
;
soil respiration
;
tropical forest
;
tropical pasture
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Geosciences
Notes:
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 δ13C of the soil CO2 emissions also was measured on chronosequence I; δ13C of the CO2 emitted from the C3 forest was −29.43%. Pasture13CO2 δ 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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00000804
Permalink
