Karen Murphy, U.S. Fish and Wildlife Service via Wikimedia Commons // CC BY-NC 2.0
Karen Murphy, U.S. Fish and Wildlife Service via Wikimedia Commons // CC BY-NC 2.0

Could Fire Be Good for Wild Ecosystems?

Karen Murphy, U.S. Fish and Wildlife Service via Wikimedia Commons // CC BY-NC 2.0
Karen Murphy, U.S. Fish and Wildlife Service via Wikimedia Commons // CC BY-NC 2.0

The natural world is a complex place. So complex, in fact, that it can be hard to tell whether something—be it a shark, flower, or bacterium—is good or bad, or even helpful. The same is true for a wildfire. After reviewing the evidence, ecologists writing in the journal Science say they’re still trying to figure out the complex relationship between wildfires and biodiversity.

In the 1990s, scientists hypothesized that pyrodiversity, or exposure to different types of fire, benefited an ecosystem’s biodiversity in the long run. Some fires appear more often or burn more intensely, thereby clearing out a range of habitats and making way for new species. The black-backed woodpecker, for example, was more likely to move into an area that had experienced severe burns. Many studies have supported that hypothesis. One found that sections of Yosemite National Park with higher pyrodiversity also had a significantly higher diversity of plants and their pollinators.

But other studies have found just the opposite. Biodiversity in Australia’s eucalyptus forests decreased as pyrodiversity went up, as safe plant habitats were harder to come by in the dry woodlands.

L.T. Kelly and L. Brotons. 2017. Science.

 
The authors of the new review found no tidy answers. Whether fire helps or hurts, they say, depends on the ecosystem itself. And the nature of fire’s effect on biodiversity is more than just a philosophical or theoretical question. In some places, the authors write, putting out wildfires will be essential; in other places, at other times, it could be better to let them burn.

“There is a need to further develop fire management approaches that, while supported by ecological theory, are better tailored to local conditions,” they write. “Interdisciplinary approaches involving ecologists, climate and fire modelers, scenario planners, and social scientists will help to ensure that we better understand and use fire to promote biodiversity.”

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Air Quality in American National Parks and Big Cities Is Roughly the Same
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National parks usually have more vegetation, wildlife, and open spaces than urban areas, but the two don't look much different when it comes to air quality. As City Lab reports, a new study published in Science Advances found that U.S. national parks and the nation's largest cities have comparable ozone levels.

For their research, scientists from Iowa State University and Cornell University looked at air pollution data collected over 24 years from 33 national parks and the 20 most populous metro areas in the U.S. Their results show that average ozone concentrations were "statistically indistinguishable" between the two groups from 1990 to 2014.

On their own, the statistics look grim for America's protected areas, but they're actually a sign that environmental protection measures are working. Prior to the 1990s, major cities had higher ozone concentrations than national parks. At the start of the decade, the federal government passed the Clean Air Act (CAA) Amendments in an effort to fight urban air pollution, and ozone levels have been declining ever since.

The average ozone in national parks did increase in the 1990s, but then in 1999 the EPA enacted the Regional Haze Rule, which specifically aims to improve air quality and visibility in national parks. Ozone levels in national parks are now back to the levels they were at in 1990.

Ground-level ozone doesn't just make America's national parks harder to see: It can also damage plants and make it difficult for human visitors to breathe. Vehicles, especially gas-guzzling trucks and SUVs, are some of the biggest producers of the pollutant.

[h/t City Lab]

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India's Supreme Court Demands That the Taj Mahal Be Restored or Demolished
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The Taj Mahal is one of the most recognizable monuments on Earth, but over the years it's started to look less like its old self. Smog and insect droppings are staining the once pure-white marble exterior an unseemly shade of yellow. Now, The Art Newspaper reports that India's Supreme Court has set an ultimatum: It's threatening to shut down or demolish the building if it's not restored to its former glory.

Agra, the town where the Taj Mahal is located, has a notorious pollution problem. Automobile traffic, factory smoke, and the open burning of municipal waste have all contributed to the landmark's increasing discoloration. Insects and acid rain also pose a threat to the facade, which is already crumbling away in some parts.

India's highest court now says the country's central government must seek foreign assistance to restore the UNESCO World Heritage Site if it's to remain open. Agra's state of Uttar Pradesh has taken some steps to reduce pollution in recent years, such us banning the burning of cow dung, which produces heavy brown carbon. In 2015, India's Supreme Court ordered all wood-burning crematoriums near the Taj Mahal to be swapped for electric ones.

But the measures haven't done enough to preserve the building. A committee led by the Indian Institute of Technology in Kanpu reportedly plans to investigate the exact sources of pollution in the area, a process that will take about four months. The Supreme Court plans check in on the status of site every day from July 31.

Air pollution isn't the only factor damaging the Taj Mahal. It was constructed near the Yamuna River in the 17th century, and as the water gradual dries up, the ground beneath the structure is shifting. If the trend continues it could lead to the building's total collapse.

[h/t The Art Newspaper]

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