VOA慢速英语--巴西科学家计算亚马逊雨林的碳含量

Brazilian Scientists Count Carbon in Amazon Rainforest

A small group of scientists carried machetes through the Amazon Rainforest. They cut through dense¹ plant life as the mid-morning temperature rose above 38 Celsius².

The group of men and women cut into trees. They dug into the soil and painted words across tree parts.

"It's destructive, but we only do it for a few trees," said Carlos Roberto Sanquetta. He is a forestry³ engineering professor at the Federal University of Paraná in Brazil.

Sanquetta led the weeklong research trip in November. The team of scientists included a botanist⁴, agronomist⁵, biologist and other forestry engineers. They took several samples of plants, both living and dead.

The Brazilian researchers are studying how much carbon different parts of the world's largest rainforest can store. Such storage can help remove carbon, a greenhouse gas, from the atmosphere. Greenhouse gases trap heat in the earth's atmosphere.

The scientists are working in a part of the forest about 90 kilometers from Porto Velho in Rondônia state.

"We need to understand what is the role that forests play," said Sanquetta, a member of the U.N. Intergovernmental Panel on Climate Change. The panel is the world's top group of climate science experts.

Sanquetta said it is important to know how much carbon the Amazon's trees take in when unharmed and how much they can release when destroyed.

In the rainforest, it is hard work, in hot, wet conditions filled with insects. And it involves use of several tools for cutting, digging and measuring.

Raoni Rajão specializes in environmental management at the Federal University of Minas Gerais. He is not involved with Sanquetta's team but said, "These are hardworking people [willing to] get their hands dirty."

Holistic⁶ methods

The Brazilian team is just one group among hundreds of researchers seeking to measure carbon in the Amazon rainforest. The massive forest covers more than six million square kilometers in nine countries.

Some research seeks only to measure carbon in trees, but Sanquetta says his team's effort is all-inclusive. It measures carbon in soil, underbrush and dying plant matter. In addition, his team is studying carbon in reforested areas. This can offer information needed to push for reforestation efforts.

Carbon dioxide, or CO2, is the most widespread of the greenhouse gases. Trees take it in from the atmosphere and store it as carbon.

But the process also works the other way. When trees are cut down or burned, the wood releases CO2 back into the atmosphere. In Brazil, parts of the Amazon are often cut to make room for agriculture and grassland⁷ for cows.

Deforestation in the Amazon has sped up under President Jair Bolsonaro. Since he took office in 2019, at least 825 million tons of CO2 have been released from deforestation in the Brazilian Amazon. That is more than is released by all U.S. passenger cars in a year.

The office of Brazilian Vice⁸ President Hamilton Mourão leads the government's Amazon rainforest policy.

In a statement, the office said the rise in deforestation happened before the current leadership. It also said the government has been working hard to end destructive mining and lumber⁹ trafficking.

Measuring carefully

Central to dealing¹⁰ with the climate threat is the need to improve carbon measuring methods for more exact readings.

"Everyone wants this information," said Alexis Bastos, project leader of the nonprofit group Rioterra Study Center. The Brazilian organization provides financial support and several scientists to Sanquetta's team, which began its current line of research in 2016.

What they know so far

Early findings show that planting a mix of Amazon species leads to better carbon storage than letting the area regrow naturally.

But the findings also suggest that nothing is better than leaving forests untouched.

One hectare of untouched Rondônia forest holds an average 176 tons of carbon, based on Sanquetta's examination of Brazilian Science Ministry¹¹ numbers. By comparison, a replanted hectare of forest after 10 years holds about 44 tons, and soy farms hold an average of only two tons.

After the work, the samples were taken back to the laboratory. There, the team dried and weighed them, before burning them. This lets them measure how much carbon is contained.

The team measured samples from 20 pieces of land in November. The final goal is 100 pieces of land by later in 2021.

The work could tell us "how quickly the planet could be healed," Rajão said.

Words in This Story

machete – n. a large, heavy knife that is used for cutting plants and as a weapon

sample – n. a small amount of something that gives you information about the thing it was taken from

role – n. a part that someone or something has in a particular activity or situation

management – n. the act or process of deciding how to use something

panel – n. a group of people with special knowledge, skill, or experience who give advice or make decisions

underbrush – n. plants, bushes, and small trees growing under larger trees in a forest

lumber – n. wooden boards or logs that have been sawed and cut for use

species – n. a group of related animals or plants that is smaller than a genus

1 dense   

a.密集的，稠密的，浓密的；密度大的

参考例句：

• The general ambushed his troops in the dense woods. 将军把部队埋伏在浓密的树林里。
• The path was completely covered by the dense foliage. 小路被树叶厚厚地盖了一层。

2 Celsius   

adj.摄氏温度计的，摄氏的

参考例句：

• The temperature tonight will fall to seven degrees Celsius.今晚气温将下降到七摄氏度。
• The maximum temperature in July may be 36 degrees Celsius.七月份最高温度可能达到36摄氏度。

3 forestry   

n.森林学；林业

参考例句：

• At present, the Chinese forestry is being at a significant transforming period. 当前, 我国的林业正处于一个重大的转折时期。
• Anhua is one of the key forestry counties in Hunan province. 安化县是湖南省重点林区县之一。

4 botanist   

n.植物学家

参考例句：

• The botanist introduced a new species of plant to the region.那位植物学家向该地区引入了一种新植物。
• I had never talked with a botanist before,and I found him fascinating.我从没有接触过植物学那一类的学者，我觉得他说话极有吸引力。

5 agronomist   

n.农学家

参考例句：

• The agronomist suggested growing rice on the dried river bed.那位农学家建议在干涸的河床上种水稻。
• She has elected to become an agronomist.她决心做一个农学家。

6 holistic   

adj.从整体着眼的，全面的

参考例句：

• There is a fundamental ambiguity in the use of word "whole" in recent holistic literature.在近代的整体主义著作中，“整体”这个词的用法极其含混。
• In so far as historicism is technological,its approach is not piecemeal,but "holistic".仅就历史决定论是一种技术而论，它的方法不是渐进的，而是“整体主义的”。

7 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。

8 vice   

n.坏事；恶习；[pl.]台钳，老虎钳；adj.副的

参考例句：

• He guarded himself against vice.他避免染上坏习惯。
• They are sunk in the depth of vice.他们堕入了罪恶的深渊。

9 lumber   

n.木材，木料；v.以破旧东西堆满；伐木；笨重移动

参考例句：

• The truck was sent to carry lumber.卡车被派出去运木材。
• They slapped together a cabin out of old lumber.他们利用旧木料草草地盖起了一间小屋。

10 dealing   

n.经商方法，待人态度

参考例句：

• This store has an excellent reputation for fair dealing.该商店因买卖公道而享有极高的声誉。
• His fair dealing earned our confidence.他的诚实的行为获得我们的信任。

11 ministry   

n.(政府的)部；牧师

参考例句：

• They sent a deputation to the ministry to complain.他们派了一个代表团到部里投诉。
• We probed the Air Ministry statements.我们调查了空军部的记录。