Total Nonstructural Carbohydrates in the Vegetation Components of a Shortgrass Prairie Ecosystem Under Stress Conditions

Abstract

Total nonstructural carbohydrate (TNC) contents and its distribution in five above- and belowground compartments of the producer subsystem were studied under control, water, nitrogen, and water + nitrogen treatments on the native shortgrass prairie ecosystem. Results indicated that water and water + nitrogen treated plants accumulated significantly greater amounts of TNC (g m-2) in both the aboveground and belowground compartments than the control and nitrogen fertilized plants. Greater amounts of TNC in the water and water + nitrogen treatments were accumulated primarily because of greater biomass production and not as a result of greater TNC concentration (percent dry weight). Significantly greater amounts of TNc (50% and 80%) were channeled below ground than above ground in all four treatments. Stepwise multiple regression analysis indicated positive relationship between TNC (g m-2), TNC concentration (percent dry weight), and certain abiotic variables that appear to limit growth and TNC accumulation in different treatments.