century

Declining pollinator populations

June 28, 2024 By EarthWise Leave a Comment

Scientists have been sounding the alarm on the global struggle of pollinators for decades. Many recent studies have highlighted alarming declines in pollinator populations, sparking concern about the potential negative impacts on ecosystems and agriculture. Habitat loss, invasive species, and climate change are some of the factors linked to the population declines. But most pollinator research has focused on well-studied species in easily-accessible regions.

In a new study recently published in the journal PLOS One, a research team led by Northern Arizona University compiled data on four major families of bees and butterflies to create species distribution models, allowing them to assess changes over time and space across North America.

The researchers confirmed that bee and butterfly populations are declining in major regions of North America due to ongoing environmental changes, and found that significant gaps in pollinator research limit the ability to protect these species.

The highest species richness was found along North America’s West Coast – especially in California. But the models showed a decline in species richness over the past century in western North America. In contrast, the research team found disproportionate increases in eastern North America.

Comparisons with climate data indicate that the pollinator population changes are at least partly due to the impacts of climate change, including prolonged drought and habitat degradation.

The study identifies regions of declining populations where officials can prioritize conservation efforts, and highlights how improved monitoring methods could address the knowledge gaps on pollinator populations.

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Bee and butterfly records indicate diversity losses in western and southern North America, but extensive knowledge gaps remain

Bees and butterflies on the decline in western and southern North America

Photo, posted April 3, 2017, courtesy of Tracie Hall via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Major species turnover forecasted for North American cities

May 2, 2024 By EarthWise Leave a Comment

Climate change affects animal species in many ways. It induces habitat loss, disrupts migration and breeding patterns, threatens marine life, and facilitates an increased spread of disease. It may also affect where animals can be found in the future.

According to a new study led by researchers from the University of Toronto Mississauga and Apex Resource Management Solutions in Canada, climate change may dramatically affect the animal species observed in North American cities by the end of the century.

The researchers used species distribution data combined with machine learning to study the impact of human-caused climate change on more than 2,000 animal species historically found in the 60 most populous North American cities.

According to the research team, changes in biodiversity are brewing for almost every city it studied by the year 2100. In fact, cities with a rich history of biodiversity are predicted to have the largest declines and fewest gains in species. Cooler and wetter cities like Quebec, Ottawa, Winnipeg, Kansas City, and Omaha are expected to welcome the most new species. Warmer cities with higher precipitation – like cities in coastal California – are projected to lose the most species.

More than 95% of bird and insect species are predicted to experience a change in the number of cities they call home. Canines, most amphibians, and aquatic birds are expected to experience the greatest losses. Toads, turtles, mice and pelicans are projected to become more common overall.

The researchers hope their findings will encourage more efforts to protect biodiversity.

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North American cities may see a major species turnover by the end of the century

Photo, posted September 29, 2013, courtesy of Jonathan Kriz via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

An ice-free Arctic

April 9, 2024 By EarthWise Leave a Comment

According to a new study by Colorado University, Boulder, the Arctic could see summer days with practically no sea ice as soon as sometime in the next few years. Earlier predictions for when the first ice-free day in the Arctic could occur were sometime well into the 2030s.

By mid-century, the Arctic is likely to see an entire month without floating sea ice. This would likely be in September, when ice coverage is at its minimum. By the end of the century, the ice-free season could last for many months during the year.

Technically, an ice-free Arctic does not mean zero ice in the water. The working definition is less than 386,000 square miles of ice, which represents less than 20% of what the minimum ice coverage was in the 1980s. In recent years, the coverage has been about 1.25 million square miles.

Sea ice coverage is a big deal because many Arctic animals rely on sea ice for survival, including seals and polar bears. With warmer ocean water, invasive fish species could move into the Arctic Ocean, upsetting local ecosystems. Sea ice loss also is a risk for coastal communities because the ice buffers the impact of ocean waves on the coastal land. As the ice retreats, ocean waves would get bigger, eroding the coasts.

At this point, an ice-free Arctic is basically inevitable, but its annual duration will depend on society’s efforts to reduce carbon emissions. Lengthy periods of minimal sea ice would transform the Arctic into a completely different environment with global effects that are mostly highly undesirable. However, Arctic sea ice is resilient and could return fairly quickly if the atmosphere cools down.

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The Arctic could become ‘ice-free’ within a decade

Photo, posted July 9, 2022, courtesy of Reiner Ehlers via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio