切爾諾貝利核災給大自然帶來的意想不到的好處

How plants reclaimed Chernobyl's poisoned land

切爾諾貝利核災給大自然帶來的意想不到好處

Chernobyl has become a byword for catastrophe. The 1986 nuclear disaster, recently brought back into the public eye by the hugely popular TV show of the same name, caused thousands of cancers, turned a once populous area into a ghost city, and led to an exclusion zone 2,600 sq km (1,000 sq miles) in size.

切爾諾貝利（Chernobyl）已經成爲災難的代名詞。這起發生在1986的核災難導致成千上萬民衆患癌，曾經人口稠密的地區變成了鬼城，隔離區面積達2600平方公里（1000平方英里）。最近，一部同名電視劇將這起災難重新帶回人們的視野。

But Chernobyl's exclusion zone isn't devoid of life. Wolves, boars and bears have returned to the lush forests surrounding the old nuclear plant in northern Ukraine. And when it comes to vegetation, all but the most vulnerable and exposed plant life survived. Even in the most radioactive areas of the zone, vegetation was recovering within three years.

但切爾諾貝利的隔離區內並不是沒有生命。狼、野豬和熊又回到了烏克蘭北部老核電站周圍茂密的森林裏。在植被方面除了最脆弱和暴露在外的植物，大部分都存活了下來。即使是在該地區輻射最強的地方，植被也在三年內恢復了。

Humans and other mammals and birds would have been killed many times over by the radiation that plants in the most contaminated areas received. So why is plant life so resilient to radiation and nuclear disaster?

處在覈污染最嚴重地區的植物，所接受的輻射量足以讓人類、其它哺乳動物及鳥類喪命。那麼，爲什麼植物對輻射和核災難的抵抗力如此之強呢?

To answer this question, we first need to understand how radiation from nuclear reactors affects living cells. Chernobyl's radioactive material is "unstable" because it is constantly firing out high energy particles and waves that smash cellular structures or produce reactive chemicals which attack the cells' machinery.

要回答這個問題，我們首先需要了解核反應堆的輻射會對生物細胞造成什麼樣的影響。切爾諾貝利的放射性物質是“不穩定的”，因爲它在不斷地釋放高能粒子和波。這些高能粒子和波會破壞細胞結構，或者產生攻擊細胞器的活性化學物質。

Most parts of the cell are replaceable if damaged, but DNA is a crucial exception. At higher radiation doses, DNA becomes garbled and cells die quickly. Lower doses can cause subtler damage in the form of mutations altering the way that the cell functions – for example, causing it to become cancerous, multiply uncontrollably, and spread to other parts of the body.

如果受損，細胞中的大部分都是可替換的，但DNA卻是個例外。較高劑量的輻射會使DNA變得混亂，導致細胞迅速死亡。低劑量的輻射所造成的損害則更加微妙，會產生基因突變，改變細胞功能。例如，使細胞癌變，無法控制地繁殖，並擴散到身體的其他部位。

In animals this is often fatal, because their cells and systems are highly specialised and inflexible. Think of animal biology as an intricate machine in which each cell and organ has a place and purpose, and all parts must work and cooperate for the individual to survive. A human cannot manage without a brain, heart or lungs.

在動物身上，這通常是致命的，因爲動物的細胞和系統高度分化且不容變更。把動物想象成一臺複雜的機器，每個細胞和器官都有自己的位置和目的。爲了生存，各部門必須協同工作。沒有大腦、心臟或肺，人類無法生存。

Plants, however, develop in a much more flexible way. Because they can't move, they have no choice but to adapt to the circumstances in which they find themselves. Rather than having a defined structure as an animal does, plants make it up as they go along. Whether they grow deeper roots or a taller stem depends on the balance of chemical signals from other parts of the plant and nearby plants, as well as light, temperature, water and nutrient conditions.

然而，植物的生長方式要靈活得多。因爲無法移動，它們別無選擇，只能適應所處的環境。植物不像動物那樣有固定的結構，而是在生長過程中逐漸形成的。它們根莖的深度和長度取決於該植物其它部位和附近植物發出的化學信號，以及光照、溫度、水分和營養條件。

Critically, unlike animal cells, almost all plant cells have the capacity to create new cells of any type the plant needs. This is why a gardener can grow new plants from cuttings, with roots sprouting from what was once a stem or leaf.

植物細胞區別於動物細胞重要的一點是，幾乎所有的植物細胞都有能力產生植物所需要的任何類型的新細胞。這就是爲什麼園丁可以從插枝中培育出新的植物，從曾經的莖或葉中萌發出根來。

All of this means that plants can replace dead cells or tissues much more easily than animals, whether the damage is due to being attacked by an animal or to radiation.

所有這一切都意味着，植物比動物更容易替換死去的細胞或組織，無論這些損傷的原因是由於動物攻擊還是輻射造成。

And while radiation and other types of DNA damage can cause tumours in plants, mutated cells are generally not able to spread from one part of the plant to another as cancers do, thanks to the rigid, interconnecting walls surrounding plant cells. Nor are such tumours fatal in the vast majority of cases, because the plant can find ways to work around the malfunctioning tissue.

雖然輻射和其他類型的DNA損傷可以導致植物體內長出腫瘤，但由於植物細胞周圍的細胞壁是剛性的且相互連接，突變細胞通常無法像癌症那樣從植物的一個部位擴散到另一個部位。在絕大多數情況下，這樣的腫瘤並不致命，因爲植物可以找到方法，繞過失靈組織。

Interestingly, in addition to this innate resilience to radiation, some plants in the Chernobyl exclusion zone seem to be using extra mechanisms to protect their DNA, changing its chemistry to make it more resistant to damage, and turning on systems to repair it if this doesn't work. Levels of natural radiation on the Earth's surface were much higher in the distant past when early plants were evolving, so plants in the exclusion zone may be drawing upon adaptations dating back to this time in order to survive.

有趣的是，除了對輻射有天生的抵抗力之外，切爾諾貝利禁區內的一些植物似乎還有額外的機制保護DNA，改變其化學成分，使其能抵抗輻射。如果這不起作用，它們還會啓動修復系統。在遙遠的過去，早期植物進化的時候，地球表面的自然輻射水平要高得多，所以禁區內的植物爲了生存，可能利用了這個時期遺留下來的適應能力。

Life is now thriving around Chernobyl. Populations of many plant and animal species are actually greater than they were before the disaster.

現在，切爾諾貝利周圍的生命正在蓬勃發展。許多動植物的數量實際比災難前還要多。

Given the tragic loss and shortening of human lives associated with Chernobyl, this resurgence of nature may seem surprising. Radiation does have demonstrably harmful effects on plant life, and may shorten the lives of individual plants and animals. But if life-sustaining resources are in abundant enough supply and burdens are not fatal, then life will flourish.

切爾諾貝利事件造成了悲劇性的損失，縮短了人們的壽命，相比之下，大自然的起死回生令人震驚。輻射確實對植物有明顯的傷害，並可能縮短個別植物和動物的壽命。但是，如果有充足的資源維持生命，且所受到的影響不是致命的，那麼生命終將茁壯成長。

Crucially, the burden brought by radiation at Chernobyl is less severe than the benefits reaped from humans leaving the area. Now essentially one of Europe's largest nature preserves, the ecosystem around the wrecked power plant supports more life than before, even if each individual cycle of that life lasts a little less.

至關重要的一點是，人類離開該地區所帶來的好處比切爾諾貝利核電站輻射帶來的傷害還要大。現在這一區域成爲了歐洲最大的自然保護區之一，受損核電站周圍的生態系統比以前更加生機勃勃，即使是動植物的生命週期比以前縮短了一些。

In a way, the Chernobyl disaster reveals the true extent of our environmental impact on the planet. Harmful as it was, the nuclear accident was far less destructive to the local ecosystem than we were. In driving ourselves away from the area, we have created space for nature to return.

在某種程度上，切爾諾貝利之災揭示了人類對地球環境影響的真實程度。儘管這次核事故造成了損害，但它對當地生態系統的破壞遠遠小於人類行爲造成的破壞。在人類將自己驅逐出這片區域的過程中，爲大自然創造了恢復的空間。