1. 援用自原文
Earth’s boreal forests circle our planet’s far northern reaches, just south of the Arctic’s treeless tundra. If the planet wears an Arctic ice cap, then the boreal forests are a loose-knit headband wrapped around its ears, covering large portions of Alaska, Canada, Scandinavia and Siberia.
地球的北方森林，著咱地球的北方。就在北苔原南方，且的地。倘若地球戴著一北冰帽，那北方森林就是一，於耳朵上、的，覆了阿拉斯加、加拿大、斯堪地半及西伯利的大部分地。
The boreal region’s soils have long buffered the planet against warming by storing huge quantities of carbon and keeping it out of the atmosphere. Its remoteness has historically protected its forests and wetlands from extensive human impact.
These two traits rank boreal forests among the most important ecosystems on Earth. In addition, numerous species of mammals, fish, plants, insects and birds make these forests home.
北方地的土壤期以，一直藉由存大量的碳，其排除於大之外，了地球遭受暖化的影。史上，它的偏一直保著其森林及地，免於泛的人影。特性使北方森林，身地球上最重要的生系之列。此外，多的哺乳物、、植物、昆及，以此些森林家。
For over two centuries, scientists have recognized that climate plays a key role in determining the geographic zones of plant communities. Because boreal forests and soils face subzero winters and short summers, these forests and the animals that live in them are shifting northward as temperatures rise.
多世以，科家已到，在定植物群落的地理域上，候扮演一角色。由於北方森林及土壤面，度零下的冬季及短的夏季。著度上升，此些森林及生活其中的物，正向北移中。
However, boreal forests’ northward advance has been spottyand slower than expected. Meanwhile, their southern retreat has been faster than scientists predicted. As scholars who study northern ecosystems, forests and wetlands, we see concerning evidence that as the world warms, its largest forest wilderness appears to be shrinking.
不，北方森林向北的推一直不一致，而且比期慢。同，它向南的退一直比科家的快。身研究北方生系、森林及地的者，我了，著地球暖化，其最大的森林荒野，然正萎中之令人的。
Boreal forests contain billions of trees. Most are needleleaf, cone-bearing conifers, but there also are patches of broadleaf species, including birch, aspen and poplar. They support millions of migratory birds and iconic mammals like brown bears, moose and lynx.
北方森林具有十棵木。大多是、球果。不，也有一些小域的，包括、白及。它供著，以百的候及性哺乳物，如棕熊、麋鹿猞猁(山)。
These trees and the soils around their roots help regulate Earth’s climate, in part by pulling carbon dioxide out of the atmosphere, where it would otherwise act as a greenhouse gas. The trees use this carbon to grow roots, trunks and leaves, which eventually turn into carbon-rich soil once the tree dies. Significant changes to the forests will translate to changes in global climate.
些木及其根部周的土壤，有助於地球候。部分原因是，大中吸出二氧化碳，否在其中，充一室。些木利用此碳，生根部、及子。一旦木死亡，最成富含碳的土壤。森林的著改化成，於全球候上的。
These forests are warming at rates well above the global average. Rising temperatures directly affect the growth and survival of trees and, in turn, their ability to store carbon.
此些森林正以高於全球平均的速度暖化中。上升的度直接影木的生及生存，且依序影它存碳的能力。
2. 世界各地不同的森林型，存不同的碳量。暖的地向，於植物中，存更多的碳，而爽的北方森林，在土壤中，持有大量的碳。
Different forest types around the world store varying amounts of carbon. Warm tropical regions tend to store much more carbon in plants, while cool boreal forests have enormous carbon stores in soil.
As atmospheric warming frees trees from the icy grip of cold temperatures, adult trees can respond by growing faster. Milder temperatures also allow young seedling trees in the most northern boreal forests to gain a foothold where previous conditions were too harsh for them to become established.
著大的暖化使木了，寒冷冰冷的左右，成年木能藉由更快生，作出反。暖和的也使最北部之北方森林中的幼苗，得以在先前件，它是太劣、法定植的地方，得立足。
In the warmer, southern boreal forests, the situation is quite different. Here, conditions have become too warm for cold-adapted boreal trees, slowing their growth and even leading to their death. With warming comes dryness, and water stress leaves trees more susceptible to insect infestation and fires, as Canada has experienced in 2023 and Siberia in 2019 and 2020.
於南部、暖的北方森林中，情截然不同。在的件，於寒冷的北方木而言，得太暖和。了它的生，且甚至致它死亡。著候暖化，乾旱之而，果缺水使得更易遭受昆侵火的影。如同，加拿大於2023年，及西伯利於2019年2020年，曾的那。
If this happens at a larger scale, southern boreal forest boundaries will thin and degrade, thereby retreating farther north, where temperatures are still suitable.
倘若此情以更大模生，南部的北方森林界，稀疏及退，而更向北退。在那的度仍然宜。
If boreal forests expand northward and retreat in the south at the same rates, they could slowly follow warming temperatures. However, our combined research using satellite and field data shows that the story is more complex.
倘若北方森林向北，且在南部以相同的速度退，它可能慢慢地暖化的度之後。不，我使用星及田野，行的合研究示，情更。
3. 2023年7月2日，自沿著加拿大英哥比省，翰堡以北的山脊燃之唐尼溪野火的火焰。火是北方森林生的一部分，不候正在使得木得乾燥，因此使它更容易生火。
Flames from the Donnie Creek wildfire burn along a ridgetop north of Fort St. John, British Columbia, Canada, on July 2, 2023. Fire is part of the ecology of boreal forests, but climate change is drying out trees and making them more fire-prone.
Satellites are invaluable for tracking how boreal forests have changed in recent decades and whether these changes are consistent with an overall northward shift. Researchers can use satellites to monitor year-to-year changes in forest characteristics, such as annual tree growth and tree cover.
就追近十年，北方森林已如何改，及些改是否整向北移相一致而言，星是有用的。研究人能使用星，於森林特徵方面的逐年改，如每年的木生及木覆。
Our recent studies using satellite data showed that tree growth and tree cover increased from 2000 to 2019 throughout much of the boreal forest. These changes occurred mainly in the coldest northern areas. However, there was limited evidence to indicate that forests were expanding past current tree lines.
我最近使用星行的多研究示，2000年到2019年，遍及大部分北方森林的木，生及木覆增加。此些改主要生於，最寒冷的北部地。不，有限的示，森林正在展超目前的林木。
Our studies also revealed that tree growth and tree cover often decreased from 2000 to 2019 in warmer southern areas of the boreal forests. In these regions, hotter and drier conditions frequently reduced tree growth or killed individual trees, while wildfires and logging contributed to tree cover loss.
我的多研究也揭露，2000到2019年，在北方森林暖和的南部地，木生及木覆常下降。在此些地中，炎及乾燥的，常降低了木的生，或走了的木，而野火及伐木致了木覆少。
Satellite data makes it clear that climate change is affecting both the northern and southern margins of the boreal forest. However, if tree cover loss in the south occurs more rapidly than gains in the north, then the boreal forest will likely contract, rather than simply shifting northward.
星清楚示，候正在影，北方森林北部及南部的。不，倘若南部的木覆少比北部的增加更快速，那北方森林可能，而不是完全向北移。
4. 星量示，於最近十年中，植物生沿著北方森林寒冷的北大幅增加。不，往往沿著暖的南方少。是北方森林正始向北移的在早期指。
Satellite measurements show that plant growth widely increased along the cold northern margins of the boreal forest in recent decades, but it often decreased along the warm southern margins − potential early indicators that the boreal forest is beginning to migrate northward.
Forests advance when individual tree seeds germinate and grow, but boreal trees grow slowly and require decades to reach a size that’s visible from space. Finding young trees whose presence would signal tree-line movement requires data from the ground.
的木子芽且生，森林得展。不，北方木生慢，需要十年才能到，太空可的大小。找其存在能表明，林木移的幼，需要自地面的。
In the late 1970s, one of us (David Cooper) documented that young spruce trees were growing at altitudes hundreds of yards higher and locations miles north of the highest-elevation cone-bearing trees in Alaska’s Brooks Range.
於1970年代末期，我中的一位(David Cooper)引用料佐了，幼杉生於，阿拉斯加布克斯山最高海拔，球果之北部英里，海拔更高百的地方。
Returning in 2021, we found those little trees had grown to be several yards tall and were producing cones. More importantly, 10 times the number of young spruces now grow above and beyond the tree line than during our first field forays.
於2021年返回，我那些小已到高，且正在出球果。 更重要的是，目前生於林木上及之外的幼杉量，是我首次野地考察期的10倍。
Crisscrossing the boundary between Alaska’s boreal fores and its Arctic tundra on foot, we have found thousands of young boreal trees growing up to 25 miles north of established tree lines. Most grow where deeper snows fall, due to an Arctic Ocean version of the “lake effect”: Cold air moves across open water, picking up warmth and moisture, which then falls as snow downwind.
徒步交叉往返於阿拉斯加北方森林其北苔原之的界，我已千棵幼小的北方木生於，已立的林木北方25英里。由於北冰洋式的“湖泊效”(一象象，水上升的暖潮空上空的寒冷乾燥空混合，致降水，尤其是降水)，大多生於降雪深的地方：冷空穿放水域，吸收量及，然後落下雪。
Retreating sea ice leaves more open water. This generates stronger winds that propel tree seeds farther and more snowfall that insulates seedlings from harsh winter conditions. The result is that trees in Alaska’s Brooks Range are rapidly moving into the treeless tundra. However, these rapid expansions are localized and do not yet happen everywhere along the northern tree line.
海冰消退留下了，更多水域。生了，子推得更，及更多使幼苗免於酷冬季件影之更的。果是，阿拉斯加布克斯山的木，正在迅速移入木的苔原。不，此些快速是局部的，尚未沿著北方林木到生。
5. 於阿拉斯加苔原上，一棵移生的幼白杉植物，背景是布克斯山。
A young white spruce colonist on the Alaskan tundra, with the Brooks Range mountains in the background.
Our combined research shows that boreal forests are, in fact, responding to rising temperatures. But rapid rates of climatic change mean that trees likely can’t move northward at a pace that keeps up with their loss in the south.
我的合研究示，北方森林上，正在度上升作出反。不，快速的候意味著，木可能法以，跟上它於南方失的步，向北移。
Will trees in the far north ever catch up with climate and prevent forest contraction? At this point, scientists simply don’t know. Perhaps the newly established trees in the Brooks Range herald such an expansion. It’s also unclear whether the northern parts of boreal forests can accumulate enough carbon through increased growth to compensate for carbon losses in the south.
於北方的木能上候且阻止森林萎？目前，科家完全不知道。也，於布克斯山新移植生的木，示著的。北方森林的北部地，是否能透增多的生，累足的碳，以於南部的碳失，也不清楚。
If boreal forests are indeed on the verge of contracting, they will eventually disappear from their current southern edge. This would harm many native and migratory animals, especially birds, by reducing their boreal habitat. The forests also are culturally important to several million people who call them home, such as Canada’s aboriginal communities.
倘若，北方森林於，最它，其目前的南部消失。，因少了多本土及徙物的北方息地，而害它，特是。此些森林百其家的人，如加拿大的原住民社，文化上也是重要的。
Monitoring boreal forests around the world more closely, using both satellite data and on-the-ground measurements, will help fill out this picture. Only then can researchers hope to glimpse the future of one of the Earth’s last wildernesses.
利用星及地面量，更密切地世界各地的北方森林，有助於使更完。唯有到那候，研究人方能期待，瞥地球上最後荒野之一的未。
址：https://theconversation.com/the-worlds-boreal-forests-may-be-shrinking-as-climate-change-pushes-them-northward-211314
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