The well-being effect: Why you’ll find more wildlife in affluent areas – and what it means for your health | Biodiversity

FOr for a long time, the environment tended to ignore people. I focused mostly on beautiful places far from large-scale human development: deep rainforests or pristine grasslands. Then, in the late 1990s, in the desert city of Phoenix, Arizona, scientists turned their sights closer to home.

A team of ecologists went to their region to map the distribution of urban plants in one of the first studies of its kind. Using measuring tapes and boards, they documented trees and shrubs, sometimes crawling on all fours through the undergrowth under the curious watch of local residents.

“We had a lot of fun,” says Professor Anne Kinzig, from Arizona State University. “The little kids loved our measuring wheel.” “It made me look at cities differently.”

Existing ecological theories have not explained the distribution of plants in cities. In wilderness areas, plants are usually arranged according to influences such as geography and weather: soil rockiness, level of rainfall, and exposure to light and shade.

Scientists wondered whether a new theory was needed. “And the answer was that we did,” Kinzig says.

The urban data kept telling them the same thing: the most important influence on plant distribution was not elevation, proximity to bodies of water, proximity to rural areas or soil type. It was the wealth of the people living nearby. In 2003, her team published The first paper is on “The Welfare Effect”.

This phenomenon describes how affluent parts of cities have more wildlife, and more wildlife diversity – a finding that can happen Profound effects on human health And luxury. In Phoenix, researchers wondered if heat was to blame. It is a desert environment where water is scarce and temperatures can be extreme.

When wealth rose in the Phoenix area, people generally planted and watered more plants. A $10,000 (£7,500) increase in median household income at the Phoenix study site It resulted in a drop of 0.3°C (0.54°F). At average surface temperature.

But since the initial studies in Phoenix, researchers have found a well-being effect in other cities of different types, and where heat was less important. Black-tailed deer in British Columbia live in the wealthier parts of the city that have more parks, golf courses and parks, according to the British Daily Mail. Study 2023.

Luxurious effect It was found In plants in North America, Burundi, China and Australia. It was so Documented in birds In North America, Europe and New Zealand. Birds depend on plant species or plants for food and shelter, so it is possible for them to follow plants into luxurious neighborhoods. And even some bats Attracted towards The wealthier areas of the city. Its history dates back to ancient Egypt, where workers lived Hosting different types of insects Compared to wealthier areas.

“I was surprised — not because human action might shape biodiversity patterns in unexpected ways, but because the welfare effect remains so good,” Kinzig says. “In other words, you might expect different types of people to create landscapes that support different types of other species, but you wouldn’t necessarily expect that richer people would always have higher biodiversity.” (Fewer studies have been conducted on the impact of well-being in the tropics – One study of Burundi found a positive relationship between plant diversity and wealth, however Another study In Puerto Rico you found no relationship, perhaps because there is a smaller income gap between neighborhoods).

In urban environments, “humans control everything,” says Jeff Ackley, a regulatory biologist for the U.S. government, who explored the effect of welfare on “affluent lizards” in Phoenix, and found that household income was one of the best predictors of nearby lizard diversity. “When people have the time and resources to do this, they can control what their backyards look like. For the most part, people seem to like more diverse plants.”

But the well-being effect is not limited to gardens, it seems to occur indoors as well. Richer homes have more insects and spiders living inside them, According to a study From the United States.

The researchers randomly sampled 50 homes in Raleigh, North Carolina, across the income spectrum. The richest homes had an average of 100 species of arthropods, twice the number in the least affluent homes, according to the study, which accounts for house size.

The findings were counterintuitive, the researchers wrote, because people typically think that wealthier people have cleaner homes, highlighting “much we have yet to learn about the indoor environment.”

No study has looked at how the millions of species of microbes that live in cities are affected by the well-being effect, but research shows that poorer people typically suffer from more inflammatory and immune diseases, which can be linked to a lack of exposure to microbial life. Contact with biodiverse environments, soils and animals has been linked to a range of positive health effects.

“Almost all diseases of the immune system are on the rise,” says Dr James Kinross, a consultant surgeon at Imperial College London and author of “Almost all diseases of the immune system are on the rise.” Dark Matter: The New Science of the Microbiome. “There is something in the way we build and construct our urban systems that separates us from nature, and therefore separates us from the kind of microscopic ecosystems that we need to maintain our health.”

Biodiversity loss is recognized as a pressing global issue, but it usually refers to extinction and decline of species in the wider environment around us, not to what is happening in the human body. However, a growing body of research shows that these are intertwined. last year, Paper coined the concept of “nature’s imperfection”In reference to how the loss of nature in the human body affects health.

To reverse these health inequalities, scientists point to the outside world, where preserving and expanding biodiversity can drive connectivity. A study in Finland showed For example, teens living in biodiverse parks had fewer allergy and autoimmune problems.

“The well-being effect does not merely represent an interesting ecological pattern,” wrote a group of researchers reviewing the phenomenon. “[It is] And also another layer of social and structural injustice that exists in cities.

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