Premium
Effects of Land Use on Soil Respiration
Author(s) -
Carlisle Eli A.,
Steenwerth Kerri L.,
Smart David R.
Publication year - 2006
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2005.0155
Subject(s) - environmental science , respiration , land use , soil respiration , hydrology (agriculture) , environmental chemistry , soil science , soil water , ecology , chemistry , geology , biology , geotechnical engineering , botany
We examined constraints on soil CO 2 respiration in natural oak woodlands, and adjacent vineyards that were converted approximately 30 yr ago from oak woodlands, in the Oakville Region of Napa Valley, California. All sites were located on the same soil type, a Bale (variant) gravelly loam (fine‐loamy, mixed, superactive, thermic Cumulic Ultic Haploxeroll) and dominated by C 3 vegetation. Seasonal soil CO 2 efflux was greatest at the oak woodland sites, although during the summer drought the rates of soil CO 2 efflux measured from oak sites were generally similar to those measured from the vineyards. Soil profile CO 2 concentrations at the oak woodland sites were lower below 15 cm despite higher CO 2 efflux rates. Soil gas diffusion coefficients for oak sites were larger than for vineyard sites, and this indicated that the apparent discrepancy in soil profile carbon dioxide concentration ([CO 2 ]) may be caused by a diffusion limitation. Soil profile [CO 2 ] and δ 13 C values showed substantial temporal changes over the course of a year. Vineyard soil CO 2 was more depleted in 13 CO 2 below 25 cm in the soil profile during the active growing season as indicated by more negative δ 13 C ratios. This result indicated that different C sources were being oxidized in vineyard soils. Annual C losses were less from vineyard soils (7.02 ± 0.58 Mg C ha −1 yr −1 ) as compared to oak soils (15.67 ± 1.44 Mg C ha −1 yr −1 ), and both were comparable to losses reported in previous investigations.