热带森林正在接近临界温度值
Christopher E Doughty1, Jenna M Keany2, Benjamin C Wiebe2
1School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA. chris.doughty@nau.edu.
Nature
|August 23, 2023
概括
热带树叶可以达到临界温度,接近气温上升4.0°C的临界点. 这凸显了迫切需要采取气候行动来保护重要的森林生态系统.
科学领域:
- 植物生理学和气候变化对热带生态系统的影响.
背景情况:
- 热带树木光合作用的临界温度 (Tcrit) 约为46.7°C.
- 目前的叶子温度和气候变化对达到这一门的影响仍然不确定.
研究的目的:
- 评估热带森林当前和未来的叶子温度相对于光合作用关键温度.
- 确定热带森林能承受的潜在气温上升之前的代谢功能临界点.
主要方法:
- 使用叶子热电偶,气体测量仪和遥感器 (ECOSTRESS) 来测量热带天花板的温度.
- 在巴西,波多黎各和澳大利亚进行了受控的叶子加热实验 (+2-4°C).
- 开发并验证了使用实验数据预测代谢转折点的经验模型.
主要成果:
- 在干旱时期,天花板的高峰温度达到~34°C,尾部超过40°C.
- 在当前条件下,上层树叶超过Tcrit的0.01%.
- 升温实验显示,树叶的峰值温度在1.3%的时间内超过Tcrit,在升温时的比例更高.
- 经验模型预测在新陈代谢临界点之前,空气温度增加的容忍度为3.9±0.5°C.
结论:
- 热带森林面临一个关键的临界点, 气温可能上升3.9°C.
- 这一估计与最坏的气候变化情景 (RCP 8.5) 相一致.
- 缓解气候变化 (例如避免RCP 6.0或8.5) 对于这些重要生态系统的生存至关重要.
相关概念视频
02:45Responses to Heat and Cold Stress
13.6K
Every organism has an optimum temperature range within which healthy growth and physiological functioning can occur. At the ends of this range, there will be a minimum and maximum temperature that interrupt biological processes.
13.6K
01:28Factors Affecting Body Temperature
4.4K
As a nurse, it is vital to understand the factors affecting body temperature to monitor variations and effectively evaluate deviations from regular.
Factors may include:
Factors may include:
4.4K
01:29Decreased Body Temperature
647
A decreased body temperature can occur in patients with hypothermia and frostbite. Heat loss with extended cold exposure overpowers the body's ability to create heat, resulting in hypothermia. Core temperature readings help classify hypothermia. Mild hypothermia is temperatures between 32 °C (89.6 °F) and 35°C (95 °F) and is caused by impaired thermoregulation. Moderate hypothermia is temperatures between 28 C (82.4 °F) and 32 °C (89.6 °F) caused by...
647
01:26Requirements for Human Life
8.3K
The Earth and its atmosphere have provided humans with air, water, and food, but these are not the only requirements for survival. Humans also require a specific range of temperature and pressure that the Earth and its atmosphere provides.
Oxygen
Atmospheric air is only about 20 percent oxygen, but that oxygen is a key component of the chemical reactions that keep the body alive, including the reactions that produce ATP. Brain cells are susceptible to a lack of oxygen because they require a...
Oxygen
Atmospheric air is only about 20 percent oxygen, but that oxygen is a key component of the chemical reactions that keep the body alive, including the reactions that produce ATP. Brain cells are susceptible to a lack of oxygen because they require a...
8.3K
01:25Body Temperature
1.1K
The body's temperature, measured in degrees, is determined by the balance between heat production and dissipation to the surrounding environment. For instance, if exercising vigorously, the body will produce more heat, causing sweat and dissipating that heat. Despite extreme environmental conditions and physical exertion, the human temperature-control system maintains a constant core body temperature (the temperature of deep tissues, which are the tissues located beneath the skin and other...
1.1K
01:27Assessing Body Temperature - Rectal
4.6K
Rectal temperature measurement is considered the most precise method for assessing core body temperature and typically registers higher than oral temperature. For adults, the rectal thermometer should be inserted 1 to 1.5 inches into the rectum to obtain the most accurate reading.
Follow these steps for rectal temperature assessment:
Step 1: Perform hand hygiene and don clean gloves to prevent cross-infection.
Step 2: Position the patient in a side-lying position to better visualize the rectal...
Follow these steps for rectal temperature assessment:
Step 1: Perform hand hygiene and don clean gloves to prevent cross-infection.
Step 2: Position the patient in a side-lying position to better visualize the rectal...
4.6K