Vegetation: The New Urban Dividing Line | Way To Exist

Fences with blades, towering walls equipped with surveillance systems, directly draw the line between the swimming pool and the high- and low-income households that rely on patches to barely prevent the infiltration of rainwater, clearly separating indicators such as economic income and social class on both sides, but In addition to these "explicit" separation methods, with the increasing severity of global warming, a previously neglected divide between rich and poor has surfaced. This implicit indicator is no longer as cold as a fence or brick wall, but further , directly affect the safety of people's lives - the amount of vegetation.

The importance of planting shade plants and why they become the dividing line between rich and poor areas will be known after understanding the harm caused by overheating to the human body. Let’s explore step by step—

"The human body's perspiration mechanism."

Briefly, the mechanism of human self-heat resistance is a series of evolutionary, step-by-step systems:

• Hyperthermia detected - receptors in the superficial skin sense an increase in body temperature caused by external influences (clothing, air temperature, etc.).
• Start the operation of sweat glands - after the body's hypothalamus (hypothalamus) receives the message that the body temperature rises, it will send a signal to the sweat glands in the skin. Through the sweat glands, the human body can excrete about 1 liter of water per hour through the sweat glands. .
• Vasodilation - At the same time, the blood vessels dilate, allowing more blood to flow through the peripheral circulatory system, which helps the body divert the core temperature to the peripheral blood vessels to lower the temperature.
• Simultaneous action - The internal temperature of the human body can be reduced to normal temperature due to the dual action of the evapotranspiration caused by the sweat glands to bring water to the skin and the blood vessels to bring the core heat energy of the body to the peripheral circulation end to escape.

The above is a brief "how the human body cools down" steps.

"Hazards when the human body is overheated (mechanical malfunction)."

When the human body is continuously exposed to the external environment or high internal temperature, the heart and lungs must continuously send blood to the dilated blood vessels to achieve the cooling effect of the core of the body. Dilated blood vessels, blood pressure will plummet in an instant (acute hypotension), dizzy (Dizzy), unable to balance standing, unable to speak normally (Slur), and muscle spasms all have the chance to attack at this time, and the human body will enter into a mental disorder As long as the internal temperature of most people is around 40 degrees Celsius for a few hours, it is possible to have the above-mentioned cardiopulmonary overwork and heatstroke.

However, as the dizziness continues, if it is not relieved in time, more severe hallucinations and fainting will occur. At this time, most organs have been unable to function due to lack of oxygen and nutrients, and the digestive system and the overall circulatory system will all lose their functions. , resulting in death.

 **Information is based on Ollie Jay, University of Sydney / Jason Lee, National University of Singapore. The reference content is: the abnormality of the human circulatory system, the total amount of water that the human body can excrete through the sweat glands per hour**

"The Importance of Shade"

Planting is a very important part of urban landscape development. In the past, in addition to providing pleasing urban design, trees can also circulate carbon dioxide and release oxygen for people during sunlight.

As global warming worsens, scholars are beginning to see another importance of tree planting: providing a role in avoiding the urban heat island effect and shading the sun to achieve a cooling effect.

According to the research data of the non-profit organization TreePeople , under direct sunlight, the evapotranspiration of trees can reduce the surrounding air temperature by up to 5 degrees Celsius. Not only that, the temperature of the solid surface under the shade can reach a cooling effect of up to about 20 degrees Celsius ( The actual value is affected by factors such as humidity, surface material, residence time, etc.), that is to say, if the car is left in the sun for a long time, the surface temperature of the sheet metal will be about 20 degrees Celsius higher than that in the shade of trees. around, which is obviously a pretty staggering number.

From the above, it is known that once the human body temperature exceeds 40 degrees Celsius and continues for several hours, it will be fatal, and this highlights that in a city composed of cement, it is possible to avoid the heat generated by the operation of air-conditioning and the heat energy emitted by the fuel engine. heat island effect, reduce ambient temperature, and provide shade trees for natural air circulation.

"Expenses for planting and caring for plants"

To achieve a good cooling effect, there must be adequate urban planning, planned top-soil planting and subsequent careful care (pest inspection, artificial watering) to ensure that the tree can continue to grow even if pests and diseases occur or there is no rain for a long time. It is a pity that in the poor areas of most cities, public institutions have not paid attention to it, and people have no spare energy to take care of this matter.

Los Angeles is exposed to the sun for a long time throughout the year. Therefore, the local solar energy storage is quite high. However, solar thermal energy is not only beneficial. Long hours of sunshine and contemporary global warming make the temperature in Los Angeles generally biased. It is even estimated that in 2050, Los Angeles will have about 20 days of the year when the daily average temperature exceeds 35 degrees Celsius.

In parts of Los Angeles, urban planning (last century) divided housing into four classes, a direct reflection of the inequalities of the time:

Zone A - D (Rank A - D)

1. A. In the wealthy area, planned vegetation planning is carried out, which is neat and clean. In the last century, it was even explicitly pointed out that it is "suitable for investment, and it is suitable for Caucasian residents." %, and the cement coverage is about 40% .
2. B. The general class area still has a sound urban plan.
3. C. "Potential living risk" is mostly for the poor.
4. D. For example, the current Pico-Union area is mostly inhabited by low-income people. Due to lack of urban planning and care, the cement coverage of the entire area is nearly 67%, and the shade coverage of trees is only 17% , which is the lowest among all grades.

**The above image is from a street vegetation comparison photo taken by Elliot Ross for National Geographic Channel**

"Spontaneous planting action."

This sounds a lot like a charitable event for retirees with leisure time, but in the face of rising average temperatures and a worsening urban heat island effect, people living in cities will begin to realize that this is not a responsibility, but a responsibility Quality of life and self-interested behaviors that are critical to life and health .

At present, many companies and groups have begun to respond to this campaign, and the age group has begun to decline. This is an important start for people trying to save the environment and eliminate housing inequality.

 **The description of local conditions in Los Angeles and the city's resident ordinance in this article is based on "A Shady Divide" by National Geographic reporter Alejandra Borunda, which includes temperature records, street names, and local laws. **

"Conclusion"

After coming into contact with this topic, the author will also observe the changes in the vegetation distribution in Taipei while walking. Even if it is not obvious, "vegetation discrimination" still exists in society. I hope this issue can be discussed on a larger scale in the future. The promotion, discussion, planting and planning will also be given more equal attention by the competent authorities.