Kim Moonju, Sung Kyungil
Institute of Animal Resources, Kangwon National University, Chuncheon 24341, Korea.
Department of Animal Industry Convergence, Kangwon National University, Chuncheon 24341, Korea.
J Anim Sci Technol. 2021 Jan;63(1):77-90. doi: 10.5187/jast.2021.e9. Epub 2021 Jan 31.
This study aimed to assess the impact of abnormal climate events on the production of Italian ryegrass (IRG), such as autumn low-temperature, severe winter cold and spring droughts in the central inland, southern inland and southern coastal regions. Seasonal climatic variables, including temperature, precipitation, wind speed, relative humidity, and sunshine duration, were used to set the abnormal climate events using principal component analysis, and the abnormal climate events were distinguished from normal using Euclidean-distance cluster analysis. Furthermore, to estimate the impact caused by abnormal climate events, the dry matter yield (DMY) of IRG between abnormal and normal climate events was compared using a -test with 5% significance level. As a result, the impact to the DMY of IRG by abnormal climate events in the central inland of Korea was significantly large in order of severe winter cold, spring drought, and autumn low-temperature. In the southern inland regions, severe winter cold was also the most serious abnormal event. These results indicate that the severe cold is critical to IRG in inland regions. Meanwhile, in the southern coastal regions, where severe cold weather is rare, the spring drought was the most serious abnormal climate event. In particular, since 2005, the frequency of spring droughts has tended to increase. In consideration of the trend and frequency of spring drought events, it is likely that drought becomes a NEW NORMAL during spring in Korea. This study was carried out to assess the impact of seasonal abnormal climate events on the DMY of IRG, and it can be helpful to make a guideline for its vulnerability.
本研究旨在评估异常气候事件对意大利黑麦草（IRG）产量的影响，这些异常气候事件包括韩国中部内陆、南部内陆和南部沿海地区的秋季低温、冬季严寒和春季干旱。利用主成分分析，将包括温度、降水、风速、相对湿度和日照时长在内的季节性气候变量用于设定异常气候事件，并采用欧氏距离聚类分析将异常气候事件与正常气候事件区分开来。此外，为了估算异常气候事件造成的影响，使用显著性水平为5%的t检验比较了异常气候事件和正常气候事件下IRG的干物质产量（DMY）。结果表明，韩国中部内陆地区异常气候事件对IRG的DMY的影响按冬季严寒、春季干旱和秋季低温的顺序显著较大。在南部内陆地区，冬季严寒也是最严重的异常事件。这些结果表明，严寒对内陆地区的IRG至关重要。同时，在严寒天气罕见的南部沿海地区，春季干旱是最严重的异常气候事件。特别是自2005年以来，春季干旱的频率呈上升趋势。考虑到春季干旱事件的趋势和频率，干旱很可能在韩国春季成为一种新常态。本研究旨在评估季节性异常气候事件对IRG的DMY的影响，这有助于制定其脆弱性指南。
