Landscape scale genomic-environment diversity data to model existing and novel agri-systems under climate change to enhance food security in Ethiopia

背景：埃塞俄比亚历来是世界上最大的有针对性的粮食援助接受国，然而，即使在20世纪80年代毁灭性的饥荒期间，埃塞俄比亚南部高地也几乎没有粮食不安全的报道。今天，埃塞俄比亚南部高地的农业系统成功地支持了非洲农村人口密度最高的地区之一（高达1000人/平方公里）。在这里，我们研究了这些农业系统的景观尺度动态、相互作用和复原力，使用跨学科的环境建模、作物基因组学和自然资本方法来了解如何最好地管理它们对气候变化的反应，同时继续为不断增长的埃塞俄比亚人口提供粮食安全——预计到2050年将达到1.72亿。埃塞俄比亚是重要的粮食作物多样性中心，其农业历史由咖啡，tef和enset等众多物种的驯化所定义。埃塞俄比亚南部的农业系统包括超过78种栽培物种，包括根、块茎、谷物、蔬菜、水果和豆类，其中包括非常高比例的本地作物。典型的农场平均有19种不同的作物和牲畜，120多种有用的树木和灌木共同出现在整个家庭花园景观中。对单个作物物种的研究也表明了极其高的多样性，例如，我们记录了近600个enset品种，其中一个农场多达24个，还有37个山药品种。这种在多个尺度上聚集的多样性可能是埃塞俄比亚南部高地过去在饥荒时期恢复力的关键，也是未来对气候变化恢复力的来源。目的：在以往研究的基础上，我们假设农业系统高生产力和弹性的生物驱动因素是：(1)农场内种植高作物多样性；(2)作物物种内培养高遗传多样性；(3)种植实践通常涉及一年生和多年生、本地和外来、半驯化和驯化作物的多样化混合。这种多尺度的丰富多样性原则上可以支持粮食安全和可持续集约化，同时缓解季节性粮食短缺、新出现的病虫害和促进农艺适应；尽管农场平均规模只有0.9公顷，灌溉系统和化肥等非农投入很少。与这种本土多样性相反，农民也种植高度驯化的引进作物，如玉米、鳄梨和香蕉，这为评估这些假设提供了理想的机会。这些作物产量高，但可能含有较少的遗传多样性。这可能会限制它们适应新的或改变的环境的能力，以及它们对气候变化的复原力。这些引进作物的流行程度正在增加，同时据报道，土著作物多样性正在丧失，农林业也在减少。这些趋势的影响以及预计的气候变化对埃塞俄比亚农业系统恢复力的影响尚不清楚。应用和效益：我们的研究将产生景观尺度的环境适宜性、基因组和自然资本数据，为该地区可持续农业系统发展和气候适应的决策工具奠定基础。通过加强未来的资源供应和抵御能力，我们将对它们所支持的生计产生明显的经济和社会影响。这里采用的新方法将在农学、作物育种和保护领域引起更广泛的学术兴趣，并为提高埃塞俄比亚的研究能力提供直接的知识转移和资源。最重要的是，利用我们现有的强大的英国-埃塞俄比亚伙伴关系以及与地区政府的联系，我们将寻求发展和实施基于科学的区域农业系统战略，以便在项目的生命周期内产生直接影响。

Context: Ethiopia has historically been the world's largest recipient of targeted food aid, yet little food-insecurity has been reported for the southern Ethiopian highlands even during the devastating famines of the 1980s. Today, the agri-systems of the southern Ethiopian highlands successfully support one of the highest rural population densities in Africa (up to 1000persons/sqkm). Here, we investigate the landscape scale dynamics, interactions and resilience of these agri-systems, using interdisciplinary environmental modelling, crop genomics and natural capital approaches to understand how best to manage their response to climate change whilst continuing to provide food security for a growing Ethiopian population - predicted to reach 172 million by 2050.Ethiopia is an important center of diversity for food crops, with an agricultural history defined by the domestication of numerous species including coffee, tef and enset. Southern Ethiopian agri-systems include more than 78 cultivated species encompassing roots, tubers, cereals, vegetables, fruits and pulses, including a very high proportion of indigenous crops. Typical farms average 19 different crop and livestock species underpinned by over 120 species of useful trees and shrubs co-occuring across the homegarden landscape. Research on individual crop species also indicates extremely high diversity, for example we have recorded >600 enset varieties, including up to 24 on a single farm, and 37 varieties of yam. This diversity aggregated at multiple scales may be the key to the past resilience of the southern Ethiopian highlands in times of famine, and the source of future resilience to climate change.Aims: Building on previous research, we hypothesize that the biotic drivers of high agri-system productivity and resilience are: (1) cultivation of a high crop diversity within farms, (2) cultivation of high genetic diversity within crop species and (3) cultivation practices that commonly involve diverse mixes of annual and perennial, indigenous and alien, semi-domesticated and domesticated crops. This rich diversity at multiple scales can in principle support food security and sustainable intensification whilst buffering seasonal food deficits, emerging pests and diseases and facilitating agronomic adaptation; despite an average farm size of only 0.9 hectares and very few off-farm inputs such as irrigation systems and fertilizers. In contrast to this indigenous diversity, farmers also grow highly domesticated introduced crops such as maize, avocado and banana, providing an ideal opportunity to evaluate these hypotheses. These crops are high yielding but likely to contain less genetic diversity. This may limit their capacity for adaptation to new or altered environments and their resilience to climate change. The prevalence of these introduced crops is increasing, together with a reported loss of indigenous crop diversity and a shift away from agro-forestry. The impacts of these trends as well as the projected impact of climate change on the resilience of Ethiopian agri-systems is unknown.Applications and benefits: Our research will generate landscape scale environmental suitability, genomic and natural capital data to underpin a decision making tool for sustainable agri-system development and climate adaptation in the region. By enhance future resource provision and resilience, we will generate clear economic and social impact on the livelihoods they support. The novel methods employed here will be of both broader academic interest in the fields of agronomy, crop breeding and conservation and provide immediate knowledge-transfer and resources to enhance Ethiopia's research capability. Most importantly, capitalizing on our strong existing UK-Ethiopian partnerships and links to regional government we will seek development and implementation of science-based regional agri-systems strategy to bring immediate impact within the life of the project.