Climate risk zoning for gladiolus production under three climate change scenarios

ABSTRACT The objective of this study was to develop a climate risk zoning for damage to gladiolus due to low and high temperature under climate change scenarios projected by the end of the century in the Rio Grande do Sul State, Brazil. The PhenoGlad model was used in this study to determine the recommended periods for planting gladiolus throughout the year across the Rio Grande do Sul State. The model was run for daily planting dates (from 01 January to 31 December), for different gladiolus developmental cycles (Early, Intermediate I, Intermediate II and Late). The climate change scenarios were from CMIP5: RCP2.6, RCP4.5 and RCP8.5, representing optimistic, intermediate and pessimistic scenarios of greenhouse gases emission, respectively. Planting dates were considered recommended when crop damage, due to high or low temperatures, occurred in less than 10% of the years. Warmer regions like Uruguaiana and Iraí have the shortest recommended time for planting throughout the year in the three climate change scenarios. Plantings between August and December are predicted to be the most affected and are not recommended because of the higher chance of damage from high temperatures. Colder regions like Bom Jesus will be favored in climate change scenarios since there will be an extended recommended period for planting in the seasons of the year that currently suffer damage by low temperatures. To meet demands of gladiolus during the hottest period of the year, it will be necessary to develop techniques to reduce damage from high temperatures in the crop, such as more tolerant cultivars or the use of shading screens on the crop.

摘要 本研究旨在针对巴西南里奥格兰德州（Rio Grande do Sul State）在本世纪末的气候变化情景下，由高低温引发的唐菖蒲（gladiolus）灾害制定气候风险分区。本研究采用PhenoGlad模型，以确定该州全年唐菖蒲的推荐种植期。该模型针对不同唐菖蒲生育周期（早熟、中熟Ⅰ、中熟Ⅱ、晚熟）的每日种植日期（1月1日至12月31日）开展模拟运算。气候变化情景数据来自第五次耦合模式比较计划（CMIP5），包含RCP2.6、RCP4.5与RCP8.5三种情景，分别对应温室气体排放的乐观、中等与悲观情景。当高低温导致的作物灾害发生频次占总模拟年份的比例低于10%时，该种植日期可认定为推荐种植期。在三种气候变化情景下，乌拉圭亚纳、伊赖等温暖区域的全年推荐种植窗口期最短。模拟结果显示，8月至12月的种植安排受影响最为严重，因高温灾害发生概率较高，该时段不推荐种植。邦热苏斯这类寒冷区域将在气候变化情景中获益，因为当前因低温受损的种植季节的推荐种植窗口期将得到延长。为满足唐菖蒲在全年最热时段的种植需求，需研发降低作物高温伤害的技术手段，例如选育耐热性更强的品种，或在种植田布设遮阳网。