VOA慢速英语2020 研究称到2050年全球外来物种将剧增（在线收听）

Study: Non-Native Species to Rise Sharply by 2050

研究称到2050年全球外来物种将剧增

Researchers are predicting that the number of non-native species will rise by about 36 percent worldwide by 2050.

研究人员预测，到2050年，全球非本土物种的数量将增加36%。

Non-native, or alien species, are plants or animals that humans have moved around the world to places where they are not naturally found. Sometimes the introduction of an alien species to an area is accidental. Sometimes, it is done on purpose.

“非本土物种”或“外来物种”是指人类在全球各地将非原生当地植物或动物迁徙到该地。有时外来物种进入某个地区是偶然事件，有时则是有意为之。

Research shows the movement of plants and animals rose across the planet over the last century as human trade and travel opened up new worldwide pathways.

研究表明，随着人类贸易和旅行开辟出新的全球航线，上世纪全球动植物的迁徙也有所增加。

A new study predicts such movements are likely to continue, with the largest increases expected to be big insects, birds and small creatures such as mollusks and crustaceans.

一项新的研究预测，这种迁徙活动可能会继续下去，预计增长最大的将是大型昆虫、鸟类以及像软体动物和甲壳类动物等小型生物。

Researchers are calling for more rules and better observation methods to help reduce the spread of alien species.

研究人员呼吁制定更多的规则和更好的观察方法来帮助减少外来物种的传播。

The findings were recently reported in the publication Global Change Biology.

这一发现最近发表于《全球变化生物学》期刊。

Scientists involved in the study say more than 35,000 alien species had been identified in the most recent report on the subject in 2005. Some of the species can go on to become invasive, meaning they spread quickly in undesirable and harmful ways.

参与这项研究的科学家们表示，在2005年关于这一课题的最新报告中，已经确认超过3.5万种外来物种。有些物种会随着迁徙演变成入侵，这意味着它们会以不受欢迎和有害的方式迅速传播。

The study suggests alien species introductions will increase on every world continent. But the largest increases are predicted to be in Europe. The researchers estimate such species will increase 64 percent across Europe by around 2050.

这项研究表明，世界各大洲外来物种的引进都将增加，而预计增幅最大的将是欧洲。研究人员估计，到2050年左右，整个欧洲的外来物种将增加64%。

Hanno Seebens is an ecologist at Germany's Senckenberg Biodiversity and Climate Research Centre. He was the lead writer of the study. "Together with climate change and land use change, invasive alien species are posing one of the greatest threats to biodiversity," Seebens said.

汉诺·西本斯是德国森肯伯格生物多样性和气候研究中心的一名生态学家。他是这项研究的主要作者。“外来物种入侵以及气候变化和土地利用变化正在构成对生物多样性的最大威胁，”西本斯说。

He added that a species can only arrive in a new area when human activity connects different areas. "When we extended our trade networks, we connected more and more (areas), which allowed more and more species to come."

他补充说，只有在人类活动连接不同区域时，一个物种才能到达一个新领域。“当我们扩展贸易网络时，我们连接的地区越来越多，导致越来越多的物种迁徙。”

The researchers developed a mathematical model to predict alien species introductions for each continent between 2005 and 2050. The model was based on past records of alien species introductions, as well as estimates of species that could end up becoming invasive if current movements continue.

研究人员开发了一个数学模型来预测2005年至2050年间每个大陆外来物种的引进情况。这个模型是基于外来物种引进的历史记录，以及当前的迁徙活动继续下去，最终可能演变为入侵物种的预估。

Cascade Sorte is a professor of ecology and evolutionary biology at the University of California Irvine. She was not part of the research. "We know that a certain proportion of alien species will be problematic, so the more of them that there are, the higher the likelihood that we'll have problems," she said.

凯斯凯特·索特（Cascade Sorte）是加州大学欧文分校的生态学和进化生物学教授。她没有参与这项研究。她表示：“我们知道，一定比例的外来物种会带来问题，所以（外来物种）数量越多，出现问题的可能性就越高。”

Sorte described the latest predictions as "shocking" because even with the past rises in alien species, "there's even a possibility that things can get worse."

索特将最新的预测形容为“令人震惊”，因为即使按照过去外来物种数量的增加来看，“情况也有可能变得更糟” 。

However, Hanno Seebens said it is possible the number of species could fall in the future based on continued rising movements. "We may just run out of species to be transported, because at some point, all species may have been transported already," he said.

然而汉诺·西本斯也表示由于迁徙数量持续上升，未来物种数量可能会减少。他说：“我们可能已经没有可供迁徙的物种了，某种程度上看所有物种都可能已经经历过迁徙了。”