Variation in below-ground carbon fluxes along a Populus hybridization gradient.
Here, soil CO(2) efflux, minirhizotron fine root production (FRP), and estimated total below-ground carbon allocation (TBCA) were examined along an elevation and hybridization gradient between two cottonwood species. FRP was 72% greater under high-elevation Populus angustifolia, but soil CO(2) efflux and TBCA were 62% and 94% greater, respectively, under low-elevation stands dominated by Populus fremontii, with a hybrid stand showing intermediate values. Differences between the responses of FRP, soil CO(2) efflux and TBCA may potentially be explained in terms of genetic controls; while plant species and hybridization explained variance in carbon flux, we found only weak correlations of FRP and TBCA with soil moisture, and no correlations with soil temperature or nitrogen availability. Soil CO(2) efflux and TBCA were uncorrelated with FRP, suggesting that, although below-ground carbon fluxes may change along environmental and genetic gradients, major components of below-ground carbon flux may be decoupled.
Fischer
Dylan G
DG
Environmental Studies, Evergreen State College, Olympia, WA 98505.
Hart
Stephen C
SC
School of Forestry, Northern Arizona University, Flagstaff, AZ 86011.|Merriam-Powell Center for Environmental Research, Northern Arizona University, Flagstaff, AZ 86011.
LeRoy
Carri J
CJ
Environmental Studies, Evergreen State College, Olympia, WA 98505.
Whitham
Thomas G
TG
Merriam-Powell Center for Environmental Research, Northern Arizona University, Flagstaff, AZ 86011.|Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, USA.
D002245:Carbon Dioxide / Q000378:metabolism*; D014644:Genetic Variation; D006824:Hybridization, Genetic; D008954:Models, Biological; D018517:Plant Roots / Q000378:metabolism; D032107:Populus / Q000235:genetics / Q000378:metabolism*; D012044:Regression Analysis; D012987:Soil; D013696:Temperature
D012987:Soil; D002245:Carbon Dioxide