1 . High-resolution (高分辨率) satellite imagery has been used to map every single tree in Africa, showing a technique that could help improve the monitoring of deforestation (森林砍伐) across the world. Florian Reiner at the University of Copenhagen, Denmark, and his colleagues used images from sate lies to map canopy (树冠) across the entire African continent.
Modern sate lies usually catch tree canopies at a resolution of 30 meters — fine for measuring the size of forests, but less good at mapping individual trees. The satellite data Reiner and his colleagues used had a resolution of 3 meters, enabling the study to map all trees, including those not part of a forest.
The results suggest that 30 percent of all trees in Africa aren’t in a forest and instead are across farmland, savannah and urban areas. “Many countries in Africa lack thick forests, but have a lot of trees.” says Reiner. “These trees are extremely important to the local ecosystems, the people and the economy. By tracking every single tree, researchers can start to monitor how these trees are coping with climate change or whether they are sensitive to deforestation.” It could also improve the monitoring of reforestation efforts, which are growing in popularity as a way of removing carbon dioxide from the atmosphere.
“At a local level, being able to consistently monitor when and where trees are disappearing or reappearing can lead to more actionable insights,” says John Francis at the Alan Turing Institute in London.
“The study is a proof of concept rather than a map ready for immediate commercial use,” says Reiner. “It’s research work. It’s showing what could be done,” he says. But he is already working with colleagues to scale up the tracking approach to cover the entire global canopy: “We’re hoping that this will be seen as a way forward in monitoring tree resources.”
1. Why is high-resolution satellite imagery used to map every single tree?A.To know the exact height of the tree. |
B.To have a clear picture of the canopy. |
C.To help monitor the deforestation. |
D.To improve the satellite technology. |
A.Doubtful. | B.Disapproving. | C.Indifferent. | D.Favorable. |
A.Protect the trees only in Africa. |
B.Put the map into commercial use. |
C.Track the entire global canopy. |
D.Improve the imagery technology. |
A.Ways to Measure the Size of Forests in Africa |
B.Coping with Climate Change by Tracking Every Single Tree |
C.A Map from the Satellite Ready for Immediate Commercial Use |
D.High-resolution Satellite Imagery Used in Monitoring Deforestation |
2 . Yellow flower carpeted fields are a sure sign of summer. In Denmark alone, more than 200,000 hectares of rapeseed (油菜籽) are planted every year. But until now, the plant has only been used for oil and animal food, as it is both bitter and unsafe for human consumption.
To protect themselves, the rapeseed plants produce a group of substances (物质) called glucosinolates (硫苷), which give the plants a strong and bitter taste that scares off insects and disease. As a result rapeseed is unhealthy to eat and the rapeseed cake, which is the remains of the seeds after the oil has been squeezed out, has only been used as feed for pigs and chickens, despite its 30 — 40 percent protein content.
Now, researchers from the University of Copenhagen have discovered the three proteins that help to store the bitter substances in seeds of thale cress (阿拉伯芥), a plant closely related to the rapeseed. The new knowledge makes it possible to prevent the accumulation (积聚) of these substances in the seed by removing the proteins through “transport engineering” technology. In doing so, the defensive substances remain in all other parts of the plant, allowing it to continue to defend itself.
So far, the researchers have shown that their method works in thale cress. “The next task is to apply our method to the closely related rapeseed plant, which we are now working on,” says Professor Halkier, leader of the research.
“Half of plant proteins in the EU come from rapeseed. The climate crisis demands that we reduce meat consumption and eat more plants, which is where rapeseed has great potential as a new source of plant protein. Our latest research results bring us a step closer to making full use of rapeseed,” says Professor Halkier.
1. What is the function of paragraph 2?A.To state the reason. | B.To offer the solution. |
C.To give an example. | D.To introduce the topic. |
A.By selecting better seeds. | B.By removing the three proteins. |
C.By increasing sweet tastes. | D.By storing defensive substances. |
A.Researchers’ efforts to better the taste. |
B.Researchers’ progress in their experiment. |
C.Rapeseed’s role in relieving climate crisis. |
D.Rapeseed’s potential as a new protein source. |
A.Harmful proteins discovered in rapeseed |
B.Rapeseed widely used as oil and animal food |
C.Researchers closer to making rapeseed safe food |
D.New plant protein in rapeseed finally uncovered |
With high yield and superior quality, Chinese hybrid rice varieties have been introduced around the world,
In the past 40 years, Chinese scientists
Yuan Longping,
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