Discipline: Ecology Environmental and Earth Sciences
Subcategory: Climate Change
Dorine Reed Bower - University of Arkansas
The correlation between average global temperature increases and rising atmospheric CO2 concentrations is well documented. Carbon management through biological/terrestrial carbon storage is a viable strategy to mitigate global deleterious effects. Today’s climate of carbon tax, credits and offsets calls for an accurate assessment of biological/terrestrial carbon stores. The National Park Service (NPS) in 2015 estimated that about 15 million metric tons of carbon worth approximately $600 million exist in the parks of the contiguous United States. In 2008, British Columbia instituted a carbon tax. The State of Washington’s November 2016 ballot includes a referendum for a state carbon tax. The NPS and United States Forest Service (USFS) in North Central Arkansas view carbon sequestration as a useful tool when evaluating burn vs. harvest of invasive species for the purpose of possible carbon tax offsets. The National Aeronautics and Space Administration (NASA) reports August 2016 as the “warmest August in 136 years of modern record-keeping … The record warm August continued a streak of 11 consecutive months dating back to October 2015 that have set new monthly high-temperature records.” Four terrestrial ecosystems where chosen to characterize carbon flux – oak-hickory forest, red cedar forest and two grassland communities (semi-native and managed) in the Pea Ridge National Military Park of NW Arkansas. The specific components within the ecosystems were living plants, soil, coarse woody debris (CWD) and litter. Also, changes that have occurred in the Park since the 1940s are assessed. After reaching a constant dried weight, samples were ground utilizing a choice of three methods; a small heavy duty grinder or mortar and pestle for soil samples, grinding mill for grasses, CWD and twigs, and a band saw and circular sander for larger CWD. The researcher then measured either 20 or 40 mg samples, depending on which component (e.g., plant or soil) were being examined. Samples were loaded into aluminum boats and placed in an Elementar vario El cube (Elementar Americas, Inc., Philadelphia, PA) for analysis of total C and N by high temperature combustion. Results of the C and N concentrations were then expressed as mg/kg on a dry weight basis. The results, when comparing soils and above ground biomass, indicate the highest proportion of carbon in the latter. A single hickory nut collected and examined during the course of this study exhibited comparatively high carbon content indicating the need for future work to include a more detailed examination of the propagules of plants (seeds and nuts). The results of this study will be instrumental in the decision-making process for land use and forestry management practices.
Funder Acknowledgement(s): This study is funded in part by the Slime Mold Project of the Stephenson Laboratory at the University of Arkansas.
Faculty Advisor: Steven Lee Stephenson, firstname.lastname@example.org
Role: All analysis of data was done by me. Some assistance was received from other individuals for some of the sample collection, grinding of some of the samples and placement of some of the samples in the Elementar.