干旱半干旱地区边际地种植能源作物的资源环境问题探讨

为减少对进口石油的依赖及应对燃烧化石能源造成的空气污染和温室气体排放问题,世界各国争相发展生物质能源产业。针对利用能源植物带来的粮价上涨和粮食安全问题,适应人多耕地少的国情,我国制定了"不与民争粮,不与粮争地"生物质能源的发展原则。许多学者提出利用边际性土地种植能源作物。多数边际性土地过于零散,不利于能源作物大规模种植和收获、运输,人们把注意力集中到草原及荒草地。干旱和半干旱地区天然降水不能满足植物旺盛生长的水分需求。大规模集约化种植一年生能源作物,主要依靠灌溉,消耗大量的水资源,同"与民争粮,与粮争地"一样威胁粮食安全,同时还可能会造成生物多样性丧失、植被破坏、土地沙化、土壤次生盐渍化等环境和生态问题,影响草原畜牧业发展,使牧民生活无靠,与现有的《草原法》等法律、法规相悖,且无异于"问题搬家"。本研究通过分析能源作物,特别是在干旱和半干旱区规模化、集约化种植,对资源、生态环境的影响,依据国家相关法律法规,提出了干旱和半干旱地区边际土地能源作物规模化种植准入政策建议,以期为生物质能源产业的健康可持续发展提供依据。

Resource and environment issues of energy plant culture on marginal lands in arid and semi-arid regions

In order to reduce the dependency on imported petroleum oil and cope with the issues arose by combustion of fossil energy resource,such as air pollution and emission of greenhouse gas,bio-energy industry is developed throughout the world.Taking into account the fact that energy crop cultivation may result in higher food price and arising food security issue,in China,with combination of scarcity of arable lands and a great population,the principle of bio-energy development is defined as "non competing food with people,and no competing lands with food crops".Many authors suggested to grow energy plants on marginal lands.As most marginal lands are too much fragmented to suit large-scale growth,harvest and transportation of energy crops,potential lands for energy crops were focused on grassland and barren lands.The natural precipitation in the arid and semi-arid regions is not sufficient for vigorous plant growth,and intensive large-scale culture of annual energy crops relies mainly on irrigation with consumption of large quantity of water resource,which amounts to the competition of food with people and lands with food crops.In addition,it may cause issues as reduction of biodiversity and lead to destruction of vegetation,desertification and induce secondary soil salinization.All this will impact the animal husbandry and the people living on the grassland,not only it is contradiction with current laws and regulation such as "Act of grassland of the Republic of China",also it displaces rather than resolves the problems.In the present paper,impact of large-scale intensive culture of energy plants especially in the (semi)-arid regions on resource,ecological environments was analysed.According to the current related laws and regulations,approval policy of large scale culture of energy plants on marginal lands in arid and semi-arid regions is proposed in order to provide guidance for health and sustainable bio-energy development.