VOA科学技术2024--Study: Replanting Same Trees Cannot Replace Burned Forests

 

Camille Stevens-Rumann recently sat on the ground and measured small trees to see how much they had grown in seven months.

She found they had grown five to 10 centimeters. Her team had planted several different kinds of trees, known as evergreens¹, two years ago in an area of the Rocky Mountains in Colorado, which had burned in a fire in 2020.

Stevens-Rumann and other researchers want to learn the relationship between tree growth and elevation².

Researchers say there are not enough small trees or seeds from living trees to replace burned trees. Even if there were enough, they say the U.S. does not have the workers to plant and care for them.

The Forest Service said the biggest delays they meet while replanting on public land are preparing environmental and cultural studies and preparing burned areas, so they are safe to plant. That can take years.

Stevens-Rumann said, "We're in a place of such drastic climate change that we are not talking about whether or not some of these places will be a different kind of forest, but whether or not they will be forests at all."

Hotter fires

In the past, the U.S. was able to replant burned forests. But the researchers say larger, more intense fires are destroying trees that normally provide seeds. They say the fires leave burn scars so large trees cannot naturally regrow.

Solomon Z. Dobrowski is a University of Montana forest management expert. He said more areas in the West need replanting after fires than can be replanted. He said at least 1.5 million hectares need to be replanted but officials are unable to do so. He said that number could triple by 2050.

Targeted tree planting

Matthew Hurteau is a forest ecologist at the University of New Mexico. He studied the way scarred forests had been replanted after a fire in 2011 at Los Conchas. That fire destroyed huge areas of ponderosa pine trees. Hurteau found most of the seedlings⁴, or very young trees, had died from earlier replanting.

As a result, he planted seedlings of different species at several elevations⁵ and on hillsides facing different directions. Now he is watching carefully for changes in the soil and water.

Researchers say seedling³ survival is less likely at lower elevations. It is hotter, drier and more open there. Replanting the same trees in the same areas is likely to fail.

Jason Sieg is acting⁶ supervisor⁷ of the Arapaho and Roosevelt National Forests & Pawnee National Grassland⁸. He said the Forest Service rules require planting the same species at the same elevations as before a fire. But, he said, it is clear the agency will "need to be flexible moving forward."

For now, that might mean replanting at different elevations or collecting seeds from another place. Over time, researchers say it could require planting trees that are not native to the area. The idea has been debated but is gaining support.

"I've seen people go from saying, 'Absolutely, we cannot move trees around' to, 'Well, let's maybe let's try it at least, and do a few experiments to see if this will work,'" said Stevens-Rumann.

Environmental groups are working on private land burned by the Cameron Peak fire. They are replanting ponderosa pines 150 meters higher than where they used to grow, said Megan Maiolo-Heath. Maiolo-Heath is a spokesperson for the Coalition⁹ for the Poudre River Watershed¹⁰.

So far, 84 percent of trees planted there last year are still alive.

Problems with replanting

The Forest Service is modernizing¹¹ how it grows young trees. It is also studying ways to grow more or work with private industry, states and groups like the New Mexico Reforestation Center.

Experts say trees might never return to some areas. But it is important that the U.S. does as much as possible in a thoughtful way.

"Trees live for hundreds of years so we need to be thinking about what's right as we plant trees today," Hurteau said.

Words in This Story

various - adj. used to refer to several different or many different things or people

elevation - n. the height of a place in relation to the level of the sea

drastic - adj. extreme in effect or action; severe or serious

triple - v. to become three times as great or as many

species - n. a group of animals or plants that are similar and can produce young animals or plants

scar - n. a mark on something showing where it has been damaged

flexible - adj. able to change or to do different things

1 evergreens   

n.常青树，常绿植物，万年青( evergreen的名词复数 )

参考例句：

• The leaves of evergreens are often shaped like needles. 常绿植物的叶常是针形的。 来自《简明英汉词典》
• The pine, cedar and spruce are evergreens. 松树、雪松、云杉都是常绿的树。 来自辞典例句

2 elevation   

n.高度；海拔；高地；上升；提高

参考例句：

• The house is at an elevation of 2,000 metres.那幢房子位于海拔两千米的高处。
• His elevation to the position of General Manager was announced yesterday.昨天宣布他晋升总经理职位。

3 seedling   

n.秧苗，树苗

参考例句：

• She cut down the seedling with one chop.她一刀就把小苗砍倒了。
• The seedling are coming up full and green.苗长得茁壮碧绿。

4 seedlings   

n.刚出芽的幼苗( seedling的名词复数 )

参考例句：

• Ninety-five per cent of the new seedlings have survived. 新栽的树苗95%都已成活。 来自《现代汉英综合大词典》
• In such wet weather we must prevent the seedlings from rotting. 这样的阴雨天要防止烂秧。 来自《现代汉英综合大词典》

5 elevations   

（水平或数量）提高( elevation的名词复数 )； 高地； 海拔； 提升

参考例句：

• Weight of the crust changes as elevations are eroded and materials are deposited elsewhere. 当高地受到侵蚀，物质沉积到别的地方时，地壳的重量就改变。
• All deck elevations are on the top of structural beams. 所有甲板标高线均指结构梁顶线。

6 acting   

n.演戏，行为，假装；adj.代理的，临时的，演出用的

参考例句：

• Ignore her,she's just acting.别理她，她只是假装的。
• During the seventies,her acting career was in eclipse.在七十年代，她的表演生涯黯然失色。

7 supervisor   

n.监督人，管理人，检查员，督学，主管，导师

参考例句：

• Between you and me I think that new supervisor is a twit.我们私下说，我认为新来的主管人是一个傻瓜。
• He said I was too flighty to be a good supervisor.他说我太轻浮不能成为一名好的管理员。

8 grassland   

n.牧场，草地，草原

参考例句：

• There is a reach of grassland in the distance.远处是连绵一片的草原。
• The snowstorm swept the vast expanse of grassland.暴风雪袭击了辽阔的草原。

9 coalition   

n.结合体，同盟，结合，联合

参考例句：

• The several parties formed a coalition.这几个政党组成了政治联盟。
• Coalition forces take great care to avoid civilian casualties.联盟军队竭尽全力避免造成平民伤亡。

10 watershed   

n.转折点，分水岭，分界线

参考例句：

• Our marriage was at a watershed.我们的婚姻到了一个转折关头。
• It forms the watershed between the two rivers.它成了两条河流的分水岭。

11 modernizing   

使现代化，使适应现代需要( modernize的现在分词 )； 现代化，使用现代方法

参考例句：

• Modernizing a business to increase its profitability and competitiveness is a complicated affair. 使企业现代化，从而达到增加利润，增强竞争力的目的，是一件复杂的事情。
• The young engineer had a large share in modernizing the factory. 这位年轻工程师在工厂现代化的过程中尽了很大的“力”。