PARENT SESSION
Poster Session 2: Forest Ecology
Monday, August 8, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal
Measurement of soil dynamics for the resilience assay of soil ecosystem after forest fire at a Pinus densiflora stand in eastern Korea.
Park, Hyun*,1, Lee, Myung1, Kim, Pan2, 1 Korea Forest Research Institute, Seoul, KOREA2 Sangju National University, Sangju, Gyeongsangbuk-do, KOREA
ABSTRACT- Changes in soil respiration, microbial population, and dehydrogenase activity of soil were monitored for five years to figure out the resistance and resilience of soil ecosystem after forest fire. The stand was mainly composed of Pinus densiflora on loamy sand soils before the forest fire. The forest fire occurred in early April of 2000, and the experimental sites were established right after the fire with two kinds of fire intensity such as surface-fire and crown-fire. The surface-fired site was naturally restored by original forest vegetation, while the crown-fired site was restored by artificial plantation of 3-year-old Pinus densiflora seedlings during the spring of 2002 (2 years after the fire). While the rate of soil respiration was largely dependent upon soil moisture condition, the rate became relatively constant in 2004 (4 years after forest fire) regardless of fire intensities. The soil respiration rate at the patch of survived trees within crown-fired site showed similar pattern with that at the surface-fired site. However, artificial plantation resulted in unstable soil respiration rates with fluctuation of soil moisture condition since the plantation activity made an additional disturbances on surface soil. Microbial population showed rapid recovery in the fall of 2001 (1.5 years after fire), but the composition of microorganism was quite different to the original one. The vitality of mycorrhizal fungi such as Tricholoma matsutake was lowered and replaced by other rotting fungi within 2 years. By the way, the soil microbial population including soil fungi, bacteria and actinomycetes at the artificially planted site showed relatively lower density than those at naturally restored sites due to soil disturbances during site preparation. This phenomenon was the same for dehydrogenase activities at the experimental sites. Dehydrogenase activity, an indicator of decomposing activity in soil, was stabilized from the fall of 2002 (2.5 years after fire) at the naturally restored site while the activity was quite low at the artificially planted site until 2004 (4 years after fire). Although artificial plantation of original species may provide rapid restoration of forest stand, minimal site preparation is recommended for the resilience of soil ecosystem at forest-fired sites.
Key words: soil respiration, microbial population, dehydrogenase, restoration