This study was conducted to determine the relationship between stand and soil environmentalfactors, and soil respiration rates at various levels of basal area in a 40-year-old natural redpine(Pinus densiflora S. et Z.) stand in southern Korea. Soil respiration rates were measuredmonthly using an infrared gas analyzer system from six basal area treatments between 21.4 m2ha-1 and 46.7 m2 ha-1 for one year. Soil respiration at various levels of basal area showed aclear monthly variation, which had a similar pattern to soil temperature. The mean annualsoil respiration rates were positively correlated with increasing basal area(r=0.86, p<0.05),aboveground tree carbon (C) storage(r=0.85, p<0.05) and needle litter C fluxes(r=0.88, p<0.05),but the rates were not correlated by the soil environmental factors(p>0.05) such as the meanannual soil temperature, soil water content, soil pH, and soil organic C content during the studyperiod. The results indicate that it is important to understand the role of stand attributes in themean annual soil respiration rates in a stand level.

본 연구는 전라북도 동부 산악지역 낙엽송 임분의 흉고직경과 흉고단면적 생장모델을 개발하고, 지역․기 후 인자인 고도, 연평균 강우량 그리고 연평균 기온을 독립변수로 이용하여 모델의 정도를 향상시키기 위하여 수행하였다. 그 결과, Schumacher 다형방정식이 흉고직경과 흉고단면적 추정을 위한 최적의 모델인 것으로 분석되었다. 흉고직경 생장모델의 경우 고도와 연평균 강우량을 삽입하여 모델의 정도를 향상 시킬 수 있었으며, 흉고단면적 생장모델의 경우 연평균 강우량을 이용하여 모델의 정도를 향상시킬 수 있었다. 한편, 더욱 정도 높은 모델을 개발하기 위해서는 고도와 연평균 등 환경 인자와 더불어 임목본수, 고사율, 간벌율, 그리고 토양상태 등의 다양한 인자를 포함하는 모델의 추정 연구가 필요할 것으로 판단 된다.

This study was carried out to investigate the optimum application time of basal fertilization in direct-seeded rice on flooded paddy surface at medium saline soil in southwestern reclaimed saline area which is Munpo series and have 0.3 or more soil salinity. The nitrogen fertilizer level were 14, 17, 20kg per 10a, and the basal fertilization were applied before sowing, 10, 20, 30 days after sowing along with topdressing at tillering stage, respectively. The summarized experimental results are as follows. Seedling stand was proper when basal fertilization was applied before sowing, but lower than appropriate seedling stand when basal fertilization were applied 10, 20, 30 days after sowing along with topdressing at tillering stage. The rice yield were 509-541kg/10a when 14-20kg/10a basal fertilization was applied before sowing, and 368-481kg/10a when basal fertilization were applied 10, 20, 30 days after sowing along with topdressing at tillering stage. Considering the yield and salt injury at medium saline soil in southwestern reclaimed saline area, the application of basal fertilization before sowing was superior for improving seedling stand, and 14-20kg/10a fertilization rate was allowable.