The world is warming. All else being equal, that warming will promote wildfires. One job which human beings face in the future is therefore to ensure that all else is not equal. And that means understanding how those fires are regulated naturally.
世界正在變暖。在其他條件相同的情況下，氣候變暖將會促進野火的發生。因此，人類未來面臨的一項工作是確保其他一切不平等。這就意味著要了解這些火災是如何被自然調控的。
Part of such understanding, Claire Foster of the Australian National University, in Canberra, argues, is a better perception of the role in fires of animals. In a paper in Trends in Ecology and Evolution she examines ways that animals』 activities can suppress or promote the spread of fire.
坎培拉的澳大利亞國立大學的克萊爾·福斯特認為，這種理解的一部分是對動物火災中所起作用的更好理解。在《生態學與進化趨勢》的一篇論文中，她研究了動物活動抑制或促進火災蔓延的方法。
Some are obvious. That browsing and grazing animals like deer and wallabies keep under control the grasses and brushy plants through which fires spread is well known. The activities of invertebrates in the leaf litter are, by contrast, easily neglected. But two recent studies Dr Foster cites, conducted in Australian eucalyptus forests, have shown that excluding such litter-devouring critters almost halves the rate at which leaf litter decomposes, leaving more fuel on the ground for fires.
一些是顯而易見的。眾所周知，像鹿和沙袋鼠這樣的食草動物控制著野火蔓延的草類和灌木叢植物。相比之下，無脊椎動物在凋落葉中的活動很容易被忽視。但是福斯特博士最近引用的兩項在澳大利亞桉樹森林中進行的研究表明，排除這些吞噬垃圾的生物，幾乎會使落葉分解的速度減半，留下更多的燃料用於火災。
The role of large browsers, too, is more subtle than might at first appear. Their activities often destroy the lowest branches of a tree and thus create a gap between those branches that remain out of reach and the kindling of undergrowth and leaf litter scattered on the forest floor. These gaps act as fire breaks by stopping small fires climbing trees and turning into big ones that can jump from the crown of one tree to the next.
這些大型的食草動物的作用也比乍一看要微妙得多。它們的活動經常破壞樹的最低處的樹枝，從而在那些無法觸及的樹枝與林下灌木和散落在森林地面上的落葉之間形成空隙。這些縫隙起到了防火的作用，阻止小火災爬樹，變成可以從一棵樹的樹冠跳到另一棵樹的大火災。
Animals are also responsible for creating more conventional, horizontal fire breaks. Species like deer frequently stamp trails bare of vegetation as they travel over and over again along the same routes. Though narrow, these trails are surprisingly effective at preventing fires from spreading. Even more surprising is that some of the most striking examples of firebreak trails are created not by mammals but by ant colonies. Vast numbers of tiny feet repeatedly crossing the same ground more than make up, it seems, for the minuscule weight of the creatures doing the treading.
動物也有責任創造更傳統的水平防火帶。像鹿這樣的物種在沿著相同的路線反覆行走時，經常會踩到沒有植被覆蓋的小徑。雖然狹窄，這些小徑在防止火災蔓延方面卻出奇地有效。更令人驚訝的是，一些最引人注目的防火帶步道不是由哺乳動物創造的，而是由蟻群創造的。大量的小腳反覆地穿過同一塊土地，這似乎彌補了這些生物微不足道的重量。
Regrettably, some animal activities fan the flames. A number of herbivores—insects such as lace bugs as well as mammals—stimulate plants to increase the amount of lignin in their leaves. This makes those leaves less edible, and thus more likely to end up on the ground. It also makes them slower to degrade if they do end up there, and therefore more likely to build up as fuel.
遺憾的是，一些動物活動也助長了火勢。許多食草動物，如花邊蟲和哺乳動物，會刺激植物增加葉子中的木質素含量。這使得這些葉子難以食用，因此更有可能最終落到地面上。它還會使它們的降解速度變慢，因此更有可能作為燃料堆積起來。
Other species actually collect leaves and wood for various purposes. For example, plains viscacha, a type of South American rodent, pile them up to attract mates. These accumulations are bonfires in waiting. Tree-killing insects like pine-bark beetles generate fuel in large quantities, too, since the dead trees they leave behind burn more easily than living ones do. And, ironically, the vertical firebreaks created by branch browsers also clear space for fire-friendly conifers to establish themselves.
其他物種實際上為了各種目的收集樹葉和木材。例如，南美嚙齒類動物平原鼠兔會把它們堆起來吸引配偶。這些堆積物就是等待著的篝火。像松樹皮甲蟲這樣的殺樹昆蟲也能產生大量的燃料，因為它們留下的死樹比活著的樹更容易燃燒。而且，具有諷刺意味的是，由食草動物創建的垂直防火屏障也為防火的針葉樹提供了建立自己的空間。
Dr Foster and her colleagues suggest that an understanding of the activities of animals in an area would thus help those fighting fires there predict how big a fire is likely to get, how quickly it is likely to spread, how patchy it will be and whether or not it has a good chance of spreading to the canopy. There may even be the potential to shape the behaviour of future fires through measures that increase the populations of fire-suppressing species.
福斯特博士和她的同事表明：了解一定區域內動物的活動將幫助那些消防人員預測火災可能會多大,可能蔓延的速度,著火點的分布,是否很有可能蔓延到樹冠。甚至有可能通過增加能夠滅火物種的數量來塑造未來火災的行為。
The Economist March 7th 2020