动物可以作为消防员或无意的纵火犯影响火灾

动物可以作为消防员或无意的纵火犯影响火灾

Following the astonishing expansion of fires in the Amazon, Arctic, and Australia recently scientists are considering where animals fit in. Besides being victims to an utterly horrifying extent, animals can reduced the circumstances under which fires reach such terrifying intensity, but sometimes they can also create those very conditions.

最近，随着亚马逊、北极和澳大利亚的森林大火惊人地蔓延，科学家们开始考虑动物的生存环境。动物们除了成为可怕程度的受害者外，还能减少火灾达到如此可怕程度的情况，但有时它们也能创造出这种情况。

Many local councils use grazing animals such as goats to keep down grasses that turn to fuel in a dry spell. Dr Claire Foster of the Australian National University notes it's not just animals specifically employed for the task who fill this role. In Trends in Ecology and Evolution, Foster gives examples of creatures as diverse as termites and elephants that contribute to hazard reduction.

许多地方议会使用食草动物，如山羊，来抑制草的生长，草在干旱期会变成燃料。澳大利亚国立大学的克莱尔·福斯特博士指出，不仅仅是专门为这项任务而雇佣的动物才担任这一角色。在《生态和进化趋势》一书中，福斯特列举了各种有助于减少危害的生物，如白蚁和大象。

"One of the most amazing examples is from savanna ecosystems with termites," Foster in a statement. "They create massive structures where a huge variety of other animals choose to live. These 'nutrient islands' attract large herbivores that preferentially graze around the termite mounds, making them less likely to burn and creating a safety zone during moderate-severity bushfires."

福斯特在一份声明中说:“最令人惊奇的例子之一就是热带草原生态系统中的白蚁。”“他们建造了巨大的建筑，其他种类的动物可以选择在这里生活。这些“营养岛”吸引了大型食草动物，它们喜欢在白蚁丘周围觅食，这使它们不太可能被烧毁，并在中度程度的森林火灾中形成了一个安全区。”

Stephen Luntz

On the other hand, Foster notes, some animals have the opposite effect. “A lot of the things that make a plant good to eat are the things that make it hard to burn. When you take out all the nutritious, palatable plants, those left over tend to be drier and more flammable."

另一方面，福斯特指出，有些动物却有相反的效果。“让植物好吃的很多东西都是让它难以燃烧的东西。当你把所有营养丰富、美味可口的植物都拔掉后，剩下的那些就会变得更干燥、更易燃。”

Grassland habitats are safest when grazed by large beasts, but alpine areas are often the opposite, Foster reports. Foster explained to IFLScience that grazing animals usually suppress fires in high productivity environments, but in places with less productivity, which usually includes alpine regions, removing the grasses “can lead to shrub or forest encroachment,” making for greater fire danger. “[Flatlands] have lots of grazing-resistant grasses, so they tend to stay as grasslands,” she said.

福斯特报告说，大型动物吃草时，草原栖息地是最安全的，但高山地区往往相反。福斯特向IFLScience解释说，放牧动物通常在生产力高的环境下抑制火灾，但在生产力较低的地方，通常包括高山地区，除去草地“可能导致灌木或森林的侵蚀”，从而导致更大的火灾危险。她说:“(平地)有很多抗放牧的草，所以它们往往是草地。”

"It's very clear that when used strategically, and in the right ecosystems, mammals like goats and cattle can have strong fire-suppressive effects, but I've also seen many examples where they actually do the opposite and increase the risk of severe fires," Foster said.

福斯特说:“很明显，如果在适当的生态系统中合理使用，像山羊和牛这样的哺乳动物可以起到很强的灭火作用，但我也看到过很多例子，它们实际上起到了相反的作用，增加了发生严重火灾的风险。”

Foster also describes a few species with more distinctive consequences. Certain Australian birds have been observed deliberately spreading fires to flush out prey, while beavers maintain ponds and wetlands that act as firebreaks, protecting areas downwind. Animals trails can prevent the spread of low-intensity fires, and astonishingly this even includes ant trails, with areas around leafcutter ants' nests less likely to be burnt than other parts of the same ecosystem. Vizcacha, rabbit-like South American creatures collect wood for their courtship displays. The areas around occupied vizcacha burrows don't tend to burn because the inhabitants keep the grasses down, but once abandoned, these sites become particularly fire-prone.

福斯特还描述了一些后果更为独特的物种。有人观察到某些澳大利亚鸟类故意放火驱赶猎物，而海狸则在池塘和湿地上筑起防火屏障，保护顺风的区域。动物足迹可以防止低强度火灾的蔓延，令人惊讶的是，这甚至包括蚂蚁足迹，与同一生态系统的其他部分相比，切叶蚁巢穴周围的区域更不容易被烧毁。Vizcacha是南美洲的一种类似兔子的生物，它们会收集木头来进行求爱表演。被占领的vizcacha洞穴周围的地区不容易被烧毁，因为居民们会把草压下去，但是一旦被遗弃，这些地方就特别容易着火。

A lot more research is required to identify better ways to use animals for fire control, but Foster told IFLScience some lessons could be applied immediately. “In Australia we have a lot of ground-dwelling animals (including bandicoots, bettongs, and Malleefowl) that turn over leaf litter, mixing it with soil to make it less flammable. Many have been killed by cats and foxes and their reintroduction could bring big benefits,” she said.

需要更多的研究来找出更好的方法使用动物来控制火灾，但是福斯特告诉IFLScience一些经验教训可以立即应用。“在澳大利亚，我们有很多生活在地面的动物(包括土匪、火钳和槌头猫头鹰)，它们把落叶翻过来，与泥土混合，使其不那么易燃。许多人被猫和狐狸杀死，重新引入它们可能会带来巨大的好处。”她说。