Numerical Terradynamic Simulation Group, Department of Ecosystem and Conservation Sciences, the University of Montana, Missoula, MT 59812, USA.
Science. 2010 Aug 20;329(5994):940-3. doi: 10.1126/science.1192666.
Terrestrial net primary production (NPP) quantifies the amount of atmospheric carbon fixed by plants and accumulated as biomass. Previous studies have shown that climate constraints were relaxing with increasing temperature and solar radiation, allowing an upward trend in NPP from 1982 through 1999. The past decade (2000 to 2009) has been the warmest since instrumental measurements began, which could imply continued increases in NPP; however, our estimates suggest a reduction in the global NPP of 0.55 petagrams of carbon. Large-scale droughts have reduced regional NPP, and a drying trend in the Southern Hemisphere has decreased NPP in that area, counteracting the increased NPP over the Northern Hemisphere. A continued decline in NPP would not only weaken the terrestrial carbon sink, but it would also intensify future competition between food demand and proposed biofuel production.
陆地净初级生产力（NPP）量化了植物固定大气碳并积累为生物量的数量。先前的研究表明，随着温度和太阳辐射的增加，气候限制逐渐放宽，导致 NPP 从 1982 年到 1999 年呈上升趋势。过去十年（2000 年至 2009 年）是有仪器测量记录以来最温暖的时期，这可能意味着 NPP 将继续增加；然而，我们的估计表明，全球 NPP 减少了 0.55 太字节的碳。大规模干旱减少了区域 NPP，南半球的干燥趋势减少了该地区的 NPP，抵消了北半球 NPP 的增加。NPP 的持续下降不仅会削弱陆地碳汇，还会加剧未来粮食需求与拟议生物燃料生产之间的竞争。
