Fire Effects on Plant-Soil System in Taiga Forests in Interior Alaska

• Main Authors: Lina Koyama, Muneto Hirobe, Satoru Hobara, Naoko Tokuchi
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: nitrogen dynamics; pla; Moss Island; taiga; Alaska
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.511.9593; http://www.iarc.uaf.edu/workshops/terrestrial_team/indiv_pdf/fire_effects_plant_soil_system.pdf

Nutrient availability is assumed to increase and stimulate ecosystem productivity by global warming in many terrestrial ecosystems. Northern forests contain significant global carbon pools, and fire is a common component in these forests. Thus, concerns have recently been directed to fire effects on carbon and nitrogen cycles in plant-soil system. Our objective of this study is to clarify fire effects on 1) surface soil properties, especially soil N transformations, 2) dissolved organic matter characteristics in soil, 3) plant N use and 4) openness of N cycle. In Aug. 2005, a preliminary research was carried out in the Poker Flat Research Range located in the heavily burned area by a large forest fire in 2004. Pool size of inorganic N, metals, and dissolved organic carbon, and net rates of N mineralization and nitrification were compared (1) between burned and unburned areas in three different vegetation stands (black spruce, black spruce/paper birch, and aspen) and (2) between inside and outside of unburned “moss island”. Soil inorganic N pool size was larger in the burned stands than in the unburned stands, while rate of net N mineralization (measured using laboratory incubation) was greater in the unburned stands than in the burned stands. Between