Controls Over Nutrient Flow Through Plants and Microbes in Arctic Tundra

• Main Author: Schimel, J.P.
• Other Authors: United States. Department of Energy.
• Format: Report
• Language: English
• Published: University of Alaska Fairbanks. Institute of Arctic Biology. 1990
• Subjects: Elements; 540210 > Environment; Terrestrial > Basic Studies > (1990-); Progress Report; Tundra; Deposition; 54 Environmental Sciences; Soil Chemistry; Sulfates; Ammonium Sulfates; Ammonium Compounds; Nitrogen Cycle; Dusts; Nitrogen 15; Tissue Distribution; Kinetics; 550200 > Biochemistry; Phosphorus; Chemistry; Root Absorption; Biological Effects; Biological Recovery; Isotopes; Plants; Nitrogen Isotopes; 59 Basic Biological Sciences; Odd-Even Nuclei; Growth; Sulfur Compounds; Nuclei; Microorganisms; Document Types; Isotope Applications; Plant Growth; Oxygen Compounds; Biochemical Reaction Kinetics; Recovery; Reaction Kinetics; Absorption; Tracer Techniques; Nonmetals; Light Nuclei; Stable Isotopes; Uptake 550501* > Metabolism > Tracer Techniques; Distribution; Arctic; Eriophorum
• Online Access: https://doi.org/10.2172/6144289; https://digital.library.unt.edu/ark:/67531/metadc1110073/

Plant growth in arctic tundra is generally strongly limited by nutrient availability, particularly by nitrogen. The purpose of this sub-project of the R4D program was to examine plant N-uptake and the competition for N between plants and microbes in tundra. This competition can be an important control on N-flow and plant uptake but its significance in tundra has not been studied intensively. How the factors controlling the outcome of competition are altered by disturbance has also received very limited study, yet this is important facet of the R4D program. The primary goal for this project in 1990 was to initiate studies on N-partitioning and turnover in tussock tundra and how this is affected by dust deposition. Secondary goals were to examine the effect of differential dust deposition on microbial activity and nutrient cycling processes (mineralization and nitrification), and begin studies on the control of microbial N-uptake. The N-partitioning studies used {sup 15}N injected into Eriophorum tussocks to examine both the short-term (1 day) partitioning of N and the long-term (1 month and 1 year) redistribution of N through the plant-soil system. These experiments were done in both the early season (June) and peak season (July). To examine the effect of dust on N-partitioning tussocks in the heavy dust zone and in a control site were labeled with {sup 15}N and harvested at the end of the growing season. 4 refs., 1 tab.