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Hi, I'm Scientific American podcast editor Steve Mirsky. And here's a short piece from the August 2018 issue of the magazine, in the section called Advances: Dispatches from the Frontiers of Science, Technology and Medicine.

大家好，我是《科学美国人》播客编辑史蒂夫·米尔斯基。下面是收录在本杂志2018年8月刊“进展：科学、技术和医学前沿快报”版块中的一篇短文。

Taking Stock of Life by Andrea Thompson

《盘点生命》 作者：安德里亚·汤普森

Plants rule the planet—at least in terms of sheer mass. Many tallies¹ of Earth's life use biodiversity as a measurement and simply count the number of species. A new census², based on biomass, compiled data from hundreds of studies to determine which kingdoms, classes and species carry the most global heft. The results show that plants (primarily those on land) account for 80 percent of the total biomass, with bacteria across all ecosystems³ a distant second at 15 percent. The findings were published in May in the Proceedings⁴ of the National Academy of Sciences.

植物统治着地球——至少从质量方面来说是如此。许多地球生命的记录用生物多样性作为度量，并简单地计算物种数量。一项以生物量为基础的新普查汇集了数百项研究的数据，目的是确定哪种生物界、纲目和物种的全球分量最大。结果显示，植物（主要是陆地植物）占总生物量的80%，而所有生态系统中的细菌以15%的占比排在第二位，远远落后于植物。这项研究发表在《美国国家科学院学报》五月刊上。

Higher-resolution satellite data and improvements in genomic sequencing have made such measurements possible by yielding more accurate estimates, but the uncertainty⁵ is still high for hard-to-count life-forms such as microbes and insects. Antarctic krill, a type of small crustacean⁶, have a total biomass comparable to that of humans. We makes up only a 100th of a percent of the total, but it still dwarfs⁷ that of all wild mammals. Livestock⁸ also dominate: chickens, for example, account for three times the biomass of wild birds. The study estimates that humans have decreased the biomass of wild mammals sixfold and plants twofold through actions such as hunting and deforestation.

卫星数据分辨率的提高以及基因组测序技术的改进，通过产生更精确的估计使这种测量成为可能，但是对于微生物和昆虫这种难以统计的生命形态来说，不确定性仍然很高。南极虾是一种小型甲壳动物，其总生物量与人类相当。我们人类只占总生物量的0.01%，但这一比例依然令野生哺乳动物的总量相形见绌。牲畜的比重也处于主导地位：举例来说，鸡类在生物总量中的占比是野生鸟类的三倍。这项研究估计，捕猎和砍伐树木等人类行为，使野生哺乳动物的生物量减少了6倍，植物减少了2倍。

That was Taking Stock of Life by Andrea Thompson.

以上是安德里亚·汤普森发表的文章《盘点生命》。