The potential of CAM crops as a globally significant bioenergy resource: moving from 'fuel or food' to 'fuel and more food'
The potential of CAM crops as a globally significant bioenergy resource: moving from 'fuel or food' to 'fuel and more food'
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DOI：
10.1039/c5ee00242g
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发表时间：
2015-01-01
影响因子：
32.5
通讯作者：
Thompson, Ian P.
中科院分区：
文献类型：
--
作者：
Mason, P. Michael;Glover, Katherine;Thompson, Ian P.
人们普遍认为生物能源与粮食争夺土地资源。本说明探讨了植物利用被称为景天科酸代谢（CAM）的光合作用模式产生全球大量可再生电力的潜力，而不会取代生产性农业，甚至可能增加粮食供应。CAM植物每单位干生物量所需的水比普通C-3和C-4作物少10倍，并且由于其多汁，具有大量的储水能力，有助于缓冲间歇性的水供应。这使得他们能够在传统农业挣扎的地区蓬勃发展，要么是因为降雨量少，要么是因为降雨的季节性或不可预测性太大，以至于无法进行有利可图的可耕种。虽然作为一个群体，这些工厂研究不足，但有足够的数据支持估计它们如果用作厌氧消化的原料，可能对全球电力供应作出的贡献。这里研究了两种CAM物种作为潜在的生物能源作物：梨果仙人掌和绿心大戟。这两种植物都表现出CAM植物典型的高度耐旱性，并在降雨量低的情况下产生有希望的产量。即使是半干旱地区的CAM植物也可能有机会成本，因为失去了农业潜力，但生物能源的替代方法可能会增加土地的粮食价值，同时将土地用于能源。全球天然气发电量每年约为5 PW h。数据表明，在1亿至3.8亿公顷的半干旱土地上种植的CAM植物每年可产生5 PW h的电力，相当于潜在资源的4%至15%。
Bioenergy is widely seen as being in competition with food for land resources. This note examines the potential of plants that use the mode of photosynthesis known as crassulacean acid metabolism (CAM) to generate globally significant quantities of renewable electricity without displacing productive agriculture and perhaps even increasing food supply. CAM plants require of the order of 10-fold less water per unit of dry biomass produced than do common C-3 and C-4 crops, and because of their succulence are endowed with substantial water-storage capacities that helps to buffer intermittent water availability. This allows them to thrive in areas where traditional agriculture struggles, either because of low rainfall, or because the seasonality or unpredictability of rainfall is too great to allow profitable arable farming. Although as a group these plants are understudied, sufficient data are available to support estimates of the contribution they might make to global electricity supply if used as feedstock for anaerobic digestion. Two CAM species are examined here as potential bioenergy crops: Opuntia ficus-indica and Euphorbia tirucalli. Both show the high degree of drought tolerance typical of CAM plants and produce promising yields with low rainfall. Even CAM plants in semi-arid areas may have opportunity costs in terms of lost agricultural potential, but an alternative approach to bioenergy may allow the food value of land to be increased whilst using the land for energy. Global power generation from gas is around 5 PW h per year. The data suggests that 5 PW h of electricity per year could be generated from CAM plants cultivated on between 100 and 380 million hectares of semi-arid land, equivalent to between 4% and 15% of the potential resource.