未来气候变化对不同国家茶适宜分布区的影响

茶是对气候变化敏感的重要经济作物, 评价全球气候变化对茶分布和生产的影响对相关国家经济发展和茶农的生计至关重要。本研究基于全球858个茶分布点和6个气候因子数据, 利用物种分布模型预测全球茶的潜在适宜分布区及其在2070年的不同温室气体排放情景(RCP2.6和RCP8.5)下的变化。结果表明: 当前茶在五大洲均有适宜分布区, 主要集中在亚洲、非洲和南美洲, 并且最冷季平均温和最暖季降水量主导了茶的分布。预计2070年, 茶的适宜分布区变化在不同的大洲、国家和气候情景间将存在差异。具体来说, 茶的适宜分布区总面积将会减少, 减少的区域主要位于低纬度地区, 而中高纬度地区的适宜分布区将扩张, 由此可能导致茶的适宜分布区向北移动; 重要的产茶国中, 阿根廷、缅甸、越南等茶适宜分布区面积会减少57.8%-95.8%, 而中国和日本的适宜分布面积则会增加2.7%-31.5%。未来全球新增的适宜分布区中, 约有68%的地区土地覆盖类型为自然植被, 因此可能导致新茶树种植园的开垦和自然植被及生物多样性保护产生冲突。

Influence of future climate change in suitable habitats of tea in different countries

Tea (Camellia sinensis) is an important crop and is sensitive to climate change. Evaluating the impact of climate change on tea distribution and production is not only important for the global economy but also the livelihoods of farmers in many countries. Here we compiled data from 858 global occurrences of C. sinensis and six climatic variables, and used species distribution model (SDM) to predict the current potential distribution and possible range shifts in response to climate change in 2070 under Representative Concentration Pathway 2.6 and 8.5 (RCP2.6 and RCP8.5). The results indicate that the current potential distribution of tea is mainly confined to Asia, Africa and South America, and distribution is limited by mean temperature of coldest quarter (MTCQ) and precipitation of warmest quarter (PWQ). Under future climate change scenarios, by 2070 suitable habitat for tea could significantly shrink at low latitudes, but expand at middle latitudes, leading to a northward shift of the distribution. However, the influence of future climate change on tea distribution differed across regions. The climatically suitable areas in Argentina, Myanmar, and Vietnam are projected to decrease by 57.8%-95.8%, whereas those in China and Japan are projected to increase by 2.7%-31.5%. Moreover, 68% of the new suitable habitat for tea cultivation under future climate change are predicted to lie within areas of natural vegetation cover. Therefore, the establishment of new tea gardens in these areas may lead to conflicts between tea cultivation and conservation of natural vegetation and biodiversity.