Sustainable Agriculture Sciences, Rothamsted Research, Harpenden AL5 2JQ, UK; Dept. of Biological and Environmental Sciences, University of Hertfordshire, Hatfield AL10 9AB, UK.
Centre for Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK.
Sci Total Environ. 2018 Sep 1;634:1108-1118. doi: 10.1016/j.scitotenv.2018.03.395. Epub 2018 Apr 11.
To optimise trade-offs provided by future changes in grassland use intensity, spatially and temporally explicit estimates of respective grassland productivities are required at the systems level. Here, we benchmark the potential national availability of grassland biomass, identify optimal strategies for its management, and investigate the relative importance of intensification over reversion (prioritising productivity versus environmental ecosystem services). Process-conservative meta-models for different grasslands were used to calculate the baseline dry matter yields (DMY; 1961-1990) at 1km resolution for the whole UK. The effects of climate change, rising atmospheric [CO] and technological progress on baseline DMYs were used to estimate future grassland productivities (up to 2050) for low and medium CO emission scenarios of UKCP09. UK benchmark productivities of 12.5, 8.7 and 2.8t/ha on temporary, permanent and rough-grazing grassland, respectively, accounted for productivity gains by 2010. By 2050, productivities under medium emission scenario are predicted to increase to 15.5 and 9.8t/ha on temporary and permanent grassland, respectively, but not on rough grassland. Based on surveyed grassland distributions for Great Britain in 2010 the annual availability of grassland biomass is likely to rise from 64 to 72milliontonnes by 2050. Assuming optimal N application could close existing productivity gaps of ca. 40% a range of management options could deliver additional 21∗10tonnes of biomass available for bioenergy. Scenarios of changes in grassland use intensity demonstrated considerable scope for maintaining or further increasing grassland production and sparing some grassland for the provision of environmental ecosystem services.
为了优化未来草地利用强度变化带来的权衡，需要在系统层面上对各草地生产力进行时空明确的估计。在这里，我们对草地生物量的潜在国家供应能力进行基准测试，确定其管理的最佳策略，并研究强化相对于逆转（优先考虑生产力还是环境生态系统服务）的相对重要性。使用不同草地的过程保守元模型来计算整个英国的 1km 分辨率的基础干物质产量（DMY；1961-1990 年）。使用气候变化、大气中[CO]升高和技术进步的影响来估计未来草地生产力（到 2050 年），以英国气候方案 09 中的低和中 CO 排放情景为基础。英国基准生产力分别为临时草地、永久草地和粗放草地的 12.5、8.7 和 2.8t/ha，占 2010 年生产力的增长。到 2050 年，中排放情景下的生产力预计将分别增加到临时和永久草地的 15.5 和 9.8t/ha，但在粗放草地不会增加。根据 2010 年英国大不列颠草地的分布调查，到 2050 年，草地生物量的年供应量可能从 6400 万吨增加到 7200 万吨。假设最优的 N 施用量可以弥补目前约 40%的生产力差距，那么一系列管理方案可以提供额外的 21∗10 吨可用于生物能源的生物质。草地利用强度变化的情景表明，有很大的空间来维持或进一步提高草地的产量，并为环境生态系统服务保留一些草地。
