PARENT SESSION
Poster Session 23: Soil Ecology
Wednesday, August 10, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal

Carbon Dynamics Following Afforestation of Sandy, Native Prairie.

Mellor, Nathan^*,1, Hellerich, Jeff ², Drijber, Rhae ², Paul, Eldor^*,3, Morris, Sherri^*,1, ¹ Bradley University Biology Department, Peoria, IL² University of Nebraska, Lincoln, NE³ Colorado State University, Fort Collins, CO

ABSTRACT- Determining the amount of C stored and length of storage as a function of land-management is important for predicting changes in the global C cycle. Soil C is stored in pools that differ in residence times: the active pool stores C for hundreds of days, the slow pool stores C for tens to hundreds of years, and the resistant pool stores C for thousands of years. Carbon distribution within these pools can be determined using long-term incubations. The goal of this study was to determine the impacts of land-management on soil carbon pools. The Nebraska National Forest at Halsey contains pine and cedar stands planted on sandy, native prairie. Soil cores were taken at depths of 0-5, 5-15, and 15-30cm and long-term incubations were initiated. Total soil C was greatest in cedar stands compared to prairie and pine in the 0-5 depth. However, soil C in cedars did not differ from prairie in the 5-15 or 15-30 depths. Carbon evolution rates in the top 5cm were greatest in cedar plantations and lowest in pine, indicating greater active fraction C in cedar. C13 data shows pine stands contain more soil C from pines than from the original prairie, which, since there is less total C than cedars, suggests more rapid C turnover. Soil cations were greatest in cedar soils and lowest in pines with prairies intermediate. Phosphate was greatest in pine soils. Carbon content in cedar soils was strongly related to calcium content. Our research suggests changes in soil C and nutrient content following land conversion from prairie to forest. As cedars soil C content was greater than pine planted at the same time, the degree to which the C pools were altered was dependent on species planted. If ecosystems are to be used as sinks for atmospheric C, then we must know the relative impacts of different management strategies on soil C pools so that we may adequately model the impacts of climate change on SOC stocks and can prescribe management options that are likely to have the greatest C storage.

Key words: Carbon Sequestration, Sand Prairie, Afforestation, Soil Carbon