Abstract

This study was carried out to investigate the growth and biomass production of Abies koreana seedlings under different relative light intensity. The 5-year-old potted seedlings were grown for 24 months under different light intensity of 100%, 50%, 30%, 10% and 2% of the natural full light intensity. The results were as follows: 1. Height growth was similar in the seedlings under different light intensities except in 2% of the full sun light intensity, having shown the lowest height growth. 2. Root collar diameter growth was reduced gradually by decreasing of the relative light intensity. 3. The seedlings which were grown under relatively low light intensity showed the later starting date of the stem growth in the next spring and showed the smaller number of new needles, and the smarter number and the shorter length of new shoot of the seedlings. 4. Total dry mass including the dry mass of leaves, shoot and root was reduced by decreasing of the relative light intensity. 5. In case of the seedling grown in one year shading condition, the ratio of the dry mass of current-year needles and stem to that of the above one-year-old needles and stem was ranged from 0.99$\pm$0.25 to 1.06$\pm$0.06 and was not significally different among the seedlings grown under 100%, 50% and 30% of the relative light intensity. And the radio was ranged from 0.60$\pm$0.04 to 0.52$\pm$0.03 in the seedlings grown under 10% and 2% of the relative light intensity, respectively. In case of the seedling grown in two years shading, the ratio of the dry mass of current-year needles and stem to that of the above one-year-old needles and stem was ranged from 0.79$\pm$0.04 to 1.00$\pm$0.03 and was not significally different among the seedlings grown under 100, 50, 30% and 10% of the relative light intensity. And the ratio was 0.29$\pm$0.03 in the seedlings grown under 2% of the relative light intensity, respectively. 6. T/R ratio of the seedlings grown in one year shading condition was ranged from 3.35$\pm$0.33 to 4.61$\pm$0.25 and was not significantly different among the relative light intensities of 100%, 50%, 30% and 10%. The seedlings grown under 2% of relative light intensity showed the highest T/R ratio of 7.36$\pm$0.15. In case of the two years shadings the T/R ratio was ranged from 1.76$\pm$0.11 to 3.12$\pm$0.19 and increased as relative light intensity decreased except 2.01$\pm$0.14 in 2% of relative light intensity.

본 연구는 상대광도 차이에 따른 구상나무(Abies koreana Wilson) 유묘의 생장과 물질생산에 대하여 구명하고자 자연전광이 100, 50, 30, 10% 및 2%로 조절된 피음포지에서 구상나무 5년생 포트묘를 사용하여 24개월간 실시하였으며 다음과 같은 결과를 얻었다. 1. 3회의 수고생장을 측정한 결과, 가장 낮은 생장치를 기록한 2% 처리구를 제외하고 처리구 간에 큰 차이를 보이지 않았다. 2. 근원경생장은 상대광도가 낮아짐에 따라 단계적으로 감소하는 경향이 뚜렷하게 나타났다. 3. 상대적으로 낮은 광도에서 자란 유묘의 다음해 생장시작 시기가 늦어졌으며, 신엽의 갯수 및 신초의 갯수, 신초의 길이도 감소하였다. 4. 지상부와 지하부, 엽중량을 포함한 총 건물생산량은 광도가 감소할수록 점진적으로 감소하였다. 5. 구엽의 건물량에 대한 신엽의 건물량의 비율은 1년간 피음처리한 경우 0.99±0.25∼1.06±0.06으로서 100, 50, 30% 처리구에서 비슷하게 높았고, 10%와 2% 처리구에서 각각 0.60±0.04, 0.52±0.03으로서 그 비율이 상대적으로 낮았다. 2년간 피음처리한 경우에는 0.79±0.04∼1.00±0.03으로서 100, 50, 30, 10% 처리구에서 비슷하였고, 2% 처리구에서 0.29±0.03으로 매우 낮은 비율로 나타났다. 6. T/R율은 1년간 피음처리한 유묘의 경우 3.35±0.33∼4.61±0.25로서 100, 50, 30, 10% 처리구 간에 비슷하였으며, 2% 처리구에서는 7.36±0.15로서 다른 처리구에서보다 높게 나타났다. 2년간 피음처리한 유묘의 T/R율은 상대광도 2% 처리구의 2.01±0.14를 제외하고는 1.76±0.11∼3.12±0.19로서 상대광도가 감소할수록 높게 나타났다.

Keywords

• Abies koreana Wilson;
• relative light intensity;
• biomass production;
• height growth;
• root collar diameter;
• T/R ratio