The results of our work indicate that sagebrush restoration may have the potential to offset 23% of annual US carbon emissions. Invasion of native sagebrush (Artemisia tridentata) communities by cheatgrass (Bromus tectorum) in semi-arid ecosystems of the Intermountain Northwest is degrading ecosystem structure and function and can significantly decrease soil carbon contents. Remediation of invaded sagebrush-steppe communities may be accomplished by replacing cheatgrass with bunchgrass (Agropyron cristatum) and subsequently reestablishing native sagebrush. To evaluate how this remedial strategy affects soil carbon contents, we have quantified carbon associated with root biomass and soils under adjacent cheatgrass, bunchgrass and sagebrush communities at a site in the central Snake River Plain of southern Idaho. A large soil carbon dataset (n = 850) was generated allowing statistical distinction of belowground carbon pools (biomass and soil C). Our study led to two main results: (1) Soil carbon stores were greatest under sagebrush and lowest under cheatgrass (67 and 35 t C per hectare, respectively). Soil carbon was found to be significantly greater beneath sagebrush compared to cheatgrass (~90% increase) at all depths throughout a 60cm profile. (2) Belowground biomass was greatest under sagebrush and lowest beneath cheatgrass (31 and 14 t per hectare, respectively), which accounted for approximately 20% of the total increase in belowground carbon beneath sagebrush. The results of our work indicate that this stepwise reclamation strategy will produce significant increases in soil carbon storage with conversion of cheatgrass to bunchgrass facilitating carbon storage benefits of ~15 t C per hectare and a bunchgrass to native sagebrush benefit of ~17 t C per hectare. Extending these results to all ~10 million ha of cheatgrass-infested ecosystems in the Great Basin, suggests that sagebrush restoration may have the potential to compensate for 23% of US annual carbon emissions.
AGU Fall Meeting Abstracts
- Pub Date:
- December 2011
- 0428 BIOGEOSCIENCES / Carbon cycling;
- 0481 BIOGEOSCIENCES / Restoration;
- 0486 BIOGEOSCIENCES / Soils/pedology