The responses of Growth and Physiological traits of Acer triflorum on Calcium Chloride () Concentration

To prevent freezing of the road by fallen snow, Calcium chloride($CaCl_2$) as a deicer is used to very often and it can be harmful to roadside trees. This study was conducted to investigate the effects of Calcium chloride($CaCl_2$) as a deicer on growth and physiological traits of Acer triflorum according to different concentration of $CaCl_2$. We measured growth, chlorophyll contents, gas exchangement characteristics, chlorophyll fluorescence and mineral nutrition concentration in plant and soil. The experimental group was composed of four treatments including 0mM(control), 9mM(0.5 %), 18mM(1.0 %), 54mM(3.0 %). Before germinating new shoot, the dissolution of $CaCl_2$ was irrigated twice interval of a week. At 30 days after treatment, all treatments decreased total cholorophyll content, photosynthetic rate, transpiration rate, stomatal conductance and photochemical efficiency($F_v/F_m$) with increasing concentration of $CaCl_2$ and especially, they significantly reduced in 3.0 % treatment. In contrast, chlorophyll a/b ratio increased with an increase of $CaCl_2$ concentration and water use efficiency increased in 1.0 % and 3.0 % treatments. At 50 days after treatment, all treatments were decreased in chl a, chl b, total chlorophyll content, carotenoid content, photosynthetic capacity, photochemical efficiency($F_v/F_m$) and quantum yield of photosystem II(${\Phi}_{PSII}$) compared with control and 3.0 % treatments were withered. $Ca^{2+}$ and $Cl^-$ were accumulated in leaves and soil, which inhibited water absorption and electron transport and it caused the reduction of height growth rate more than 50 %. Although there was a little difference according to time and $CaCl_2$ concentration, all treatments decreased in growth rate and physiological activity slowed down. As time passed, these results got worse. Therefore we need to take a measure earlier in order to minimize damage of trees.

염화칼슘 농도에 따른 복자기의 생장 및 생리적 반응 특성

겨울철 눈이 내린 도로의 동결을 방지하기 위해 염화칼슘을 제설제로 사용하는데 이것은 용해되어 도로주변의 수목에 피해를 줄 수 있다. 본 연구는 겨울철 제설제로 이용되는 염화칼슘 처리에 따른 복자기의 생장과 생리적 반응을 알아보기 위해 생장 특성, 광색소함량, 광합성 효율, 엽록소형광반응을 측정하고 식물체 및 토양 분석을 하였다. 실험구는 무처리(대조구), 9mM(0.5%), 18mM(1.0%), 54mM(3.0%)의 총 4개의 처리구로 나누어 용해액을 신초가 나기 전, 일주일 간격으로 2회 500ml씩 살포하였다. 염화칼슘 처리 결과, 처리 후 30일째 염화칼슘 농도가 증가함에 따라 0.5% 처리구부터 총엽록소함량, 광합성율, 증산율, 기공전도도, 광계 II활성이 감소하였고 특히 3.0% 처리구에서 두드러졌다. 반면, 엽록소a/b는 염화칼슘 농도가 높아짐에 따라 증가하였고 수분이용효율은 1.0% 처리구에서부터 증가하였다. 처리 후 50일째 3.0% 처리구는 고사하여 측정할 수 없었고, 모든 처리구에서 대조구에 비해 엽록소a, 엽록소b, 총엽록소함량, 광계II활성, 광계II광화학효율이 감소하였다. 이러한 결과는 $Ca^{2+}$와 $Cl^-$이 잎과 토양에 축적되어 수분의 흡수와 전자전달의 방해에 기인한 것으로 염화칼슘 처리구에서 수고생장율의 50% 이상 저하를 가져왔다. 염화칼슘의 처리 농도와 시기에 따른 차이는 있었지만 모든 염화칼슘 처리구에서 생장율은 감소하고 생리적 활성은 둔화되었고 이는 시간이 경과함에 따라 심해졌다.