A census of Earthly life shows humans are few, but mighty BILLIONS of years ago a star began to die. In the process, it created something new: 65,500 billion tonnes of carbon that would later be incorporated into the nascent planet Earth.一项地球生物普查显示，人类规模虽小却力量强大 几十亿年前，一颗恒星开始陨灭，过程中创造出了一些新东西：65.5万亿吨碳 That carbon is still there, and nowadays a fair chunk of it makes up the bodies of living beings. 这些碳后来成为地球这颗新生行星的一部分，一直存在至今，其中很大一部分如今构成了生物的躯体A new study, published in May by Yinon Bar-On and others from the Weizmann Institute of Science, in Israel, provides a comprehensive estimate of how the Earth’s carbon stock is distributed among its inhabitants.5月，以色列威兹曼科学院（Weizmann Institute of Science）的伊农·巴龙（Yinon Bar-On）等人发表了一篇新的研究报告，全面估计了地球上的碳储存在各类生物中的分布情况 By estimating the amount of carbon stored in organisms, otherwise known as biomass, the scientists were able to compare the relative abundance of different kinds of Earth’s life, weighing both the microbes beneath the soil and the giraffes walking above it on the same scale.通过估计生物体内的碳储量，也就是所谓的生物量，科学家们已经能够比较出地球上不同物种的相对多度，即用同一尺度衡量地下的微生物和地上行走的长颈鹿的规模

The mammals known as human beings like to imagine themselves the lords of the planet. 被称为“人类”的哺乳动物喜欢将自己想象为地球的主宰But in terms of raw biomass, the results—published in Proceedings of the National Academy of Sciences—tell a different story.但就纯生物量而言，巴龙等人在《美国国家科学院院刊》上发表的这篇研究报告却给出了另一种结果 No animal comes remotely close to the domination of plants, which account for 80% of the planet’s biomass植物占地球生物量的80%，它们的绝对优势让任何动物都远远不及 (see chart). That makes sense: plants convert sunlight into food, and thus lie at the base of almost every food chain. 这不难理解：植物将阳光转化为养料，因此位于几乎所有食物链的底部Land plants account for the majority of that total, despite the fact that water covers almost three-quarters of the planet’s surface.陆生植物占据了植物总生物量的大部分，尽管水几乎覆盖了地球表面的四分之三 Bacteria take second place, with approximately 13%. The remainder is distributed among fungi, archaea, protists, animals and viruses, in that order. 细菌位列其次，大约占地球生物量的13%。其余依次为真菌、古生菌、原生生物、动物和病Even within the animal count itself, there is little for humans to boast of. There is about as much biomass in one species of Antarctic krill, tiny shrimp-like crustaceans eaten by blue whales, as there is in all 7.6 billion human beings.人类的生物量即使放在动物界内部也没什么可夸耀的。仅南极磷虾（一种很小的似虾的甲壳类动物，是蓝鲸的主要食物）这一个物种，就与76亿人的生物量相当 But size is not everything. Humans have had a profound impact on the prevalence of other species. 但生物量大小并非一切。人类就已对其他物种的种群规模产生了深远的影响Dr Bar-On’s research indicates that over the short span of human history on Earth (specifically after a large period of extinction that began 50,000 years ago) the biomass of wild mammals has decreased to a sixth of its previous value. 巴龙的研究指出，在地球上人类出现以后的短暂时间里（确切地说是在于五万年前开始的大灭绝期之后），野生哺乳动物的生物量已经下降到之前的六分之一Meanwhile, the carbon count of domesticated poultry grew to three times higher than that of every species of wild bird combined. 与此同时，家禽的生物量增长到所有野生鸟类的三倍。Humans and their livestock have come to outweigh all other vertebrates on the planet with the exception of fish. 人类及家畜的生物量已经超过了地球上除鱼类以外所有其他脊椎动物的生物量That is not to say fish were spared. The biomass of fish is thought to have decreased by around 100m tonnes during humanity’s tenure.这并不是说鱼类就得以幸免。自有人类以来，鱼类的生物量被认为已经减少了大约1亿吨 And the dominance of plants, although it is still overwhelming, was far greater before the start of human civilisation. 植物的生物量虽然仍有压倒性的优势，但也远不及人类文明开始之前的规模Dr Bar-On suggests that the total biomass of plants has fallen to just half its previous level. 巴龙认为，植物的总体生物量已经下降到仅为过去的一半Of course, these numbers are estimates. Dr Bar-On and his team could not individually count each organism they reported.当然，这些都只是估计数字。巴龙和他的团队无法逐一统计论文中记录的每个生物体 They relied on collating information from hundreds of other studies, public data when they were available, and their own analysis of the likelihood of a certain thing being in a certain place.他们查对了数百份其他研究报告、可获取的公共数据，并自行分析了特定生物存在于特定地点的可能性，然后将这些信息整合起来 They were able to be a lot more confident about visible organisms in well-explored ecosystems than they were about microscopic ones in the Earth’s deep subsurface or the ocean’s deep water, such as bacteria. 他们对熟知的生态系统中的可见生物体把握很大，对细菌等存在于地表深处或深海的微生物就差得多Future research may therefore change these numbers, possibly dramatically. 因此，未来的研究也许会改变这些数据，幅度或许很大But Dr Bar-On’s portrait of the planet is an impressive achievement—and a welcome dose of perspective.但巴龙描绘的这幅 “地球肖像”是一项令人赞叹的成果，也提供了值得欢迎的新视角。