Pinus densiflora is a fixed-growth coniferous species that elongates its shoot once a year and finishes growing in early summer. However, it may produce additional shoots in the same year in response to external stimuli, called abnormal shoot growth. This study investigated the effects of open-field summer warming and drought on the abnormal shoot growth of P. densiflora seedlings. In March 2022, two factorial combinations were constructed, including two temperature treatments (control and 4°C increase) and two precipitation treatments (control and drought), with five replicates for each combination. The temperature treatment was performed for 87 days from May 14 to August 8, 2022, and the precipitation treatment was performed for 33 days from May 14 to June 15, blocking 100% of the ambient rainfall. The abnormal shoot occurrence rate and leaf unfolding stages were measured in November, and the shoot and root collar diameter growth rates were calculated by comparing the seedling height and root collar diameter measured in August (after the cessation of treatment) and October (after the end of growing period) with the initial values (i.e., May 2022). The abnormal shoot occurrence rate significantly increased under the warming treatment, showing a 410.6% increase in the warming plots (38.4%) compared to the control plots (7.5%). There was no significant difference in the shoot and root collar diameter growth rate regarding warming and drought treatments. Abnormal shoots may have been affected by high temperatures by inducing early transition to the next ontogenetic stage.

규산 시용에 의한 하고기 오챠드그라스의 고온장해 경감 효과를 구명하기 위하여 온냉조절 온실에서 식양질토로서 Pot 재배하여 정상 관리한 상태하에서 오챠드그라스의 생육, 규산흡수능력 및 엽신중 에틸렌 생성량을 분석한 후 재배환경(온도, 토양수분등)이 불량한 야산지 토양에서 실증시험하여 하고기의 수양성과 식료영양가를 검토한 결과 ; 1. Pot 재배에서는 규산 시용량 증가로 오챠드그라스의 초장이 길어졌고 직립화 되었으며 생률중 및 건초중이 증가되었다. 또한 엽신중 규산함량은 증가된 반면 에틸렌 생성은 줄어들어 엽신고사율도 낮아졌다. 2. 야산지 토양에서도 규산 시용으로 에틸렌생성이 현저히 줄었고 사료생산에 있어서도 사료가를 낮추지 않으면서 하고기 이전에는 11 %, 하고기에는 9 %의 증수를 가져와 하고경감(고온장해) 효과가 인정되었다.