The impact of climate change and climate extremes on sugarcane production
The impact of climate change and climate extremes on sugarcane production
复制标题
DOI：
10.1111/gcbb.12797
复制
发表时间：
2021-01-19
影响因子：
5.6
通讯作者：
Williams, Mathew
中科院分区：
文献类型：
--
作者：
Flack-Prain, Sophie;Shi, Liangsheng;Williams, Mathew
甘蔗生产支持着发展中国家数百万小规模农民的生计和数百万消费者的生物能源需求。然而，由于气候预测的差异，未来的甘蔗产量仍然不确定，因为甘蔗生态生理对单个气候驱动因素（即温度，降水，短波辐射，VPD和CO2）及其相互作用的敏感性在很大程度上尚未得到解决。在这里，我们要问：甘蔗产量对未来气候变化（包括极端气候）的敏感程度如何，其主要气候驱动因素是什么？我们结合联合收割机土壤-植物-大气模型与详细的时间序列测量，从实验区在广西，中国，和圣保罗州，巴西。我们首先校准和验证模拟碳和水循环对场通量和生物特征数据。其次，我们模拟了历史气候（1980-2018年）和未来气候预测（2015-2100年）下的甘蔗生长。我们通过生成合成气候强迫来计算每个气候驱动因子的“产量效应”，其中驱动因子时间序列与历史中位数交替。在广西，中位产量和产量低点（即下十分位数）对气候变化的预测相对不敏感。在圣保罗，根据所有未来气候预测，中位产量和产量低点都有所下降（柱线上的x分别为-4%和-12%）。在广西，水分胁迫较低，辐射是产量变异的主要驱动因素（产量效应x超过棒= -1.2%）。相反，在圣保罗的高水分胁迫提高了产量对温度的敏感性（产量效应x超过bar = -7.9%）。与此相反，其他一些模拟研究报告了温度升高对甘蔗产量的积极影响。我们归因于模型预测的代表性的关键物候过程之间的差距，包括叶片老化和热时间之间的联系，以及老化在驱动叶片衰老的作用。我们强调物候过程的气候敏感性作为未来研究工作的重点。
Sugarcane production supports the livelihoods of millions of small-scale farmers in developing countries, and the bioenergy needs of millions of consumers. Yet, future sugarcane yields remain uncertain due to differences in climate projections, and because the sensitivity of sugarcane ecophysiology to individual climate drivers (i.e. temperature, precipitation, shortwave radiation, VPD and CO2) and their interactions is largely unresolved. Here we ask: how sensitive is sugarcane yield to future climate change, including climate extremes, and what are its key climate drivers? We combine the Soil-Plant-Atmosphere model with detailed time-series measurements from experimental plots in Guangxi, China, and Sao Paulo State, Brazil. We first calibrated and validated modelled carbon and water cycling against field flux and biometric data. Second, we simulated sugarcane growth under the historical climate (1980-2018), and six future climate projections (2015-2100). We computed the 'yield-effect' of each climate driver by generating synthetic climate forcings in which the driver time series was alternated to that of the historical median. In Guangxi, median yield and yield lows (i.e. lower decile) were relatively insensitive to forecast climate change. In Sao Paulo, median yield and yield lows decreased under all future climates projections (x over bar = -4% and -12% respectively). At Guangxi, where moisture stress was low, radiation was the principal driver of yield variability (yield-effect x over bar = -1.2%). Conversely, high moisture stress at Sao Paulo raised yield sensitivity to temperature (yield-effect x over bar = -7.9%). In contrast, a number of other modelling studies report a positive effect of increased temperatures on sugarcane yield. We ascribe the disparity between model predictions to the representation of key phenological processes, including the link between leaf ageing and thermal time, and the role of ageing in driving leaf senescence. We highlight climate sensitivity of phenological processes as a key focus for future research efforts.