ecoystems

Megafires and ecosystems

November 15, 2023 By EarthWise Leave a Comment

Wildfires are a natural phenomenon. They have occurred long before there were people around. Ecosystems adapt to fires and some species can benefit from them or even depend upon them. But in recent times, fires have been intensifying and increasing in frequency and they are beginning to outstrip nature’s ability to bounce back from them.

So-called megafires – ones that dwarf typical wildfires in size – have an immediate ecological toll. They kill individual plants and animals that might have survived smaller fires.

Over millennia, many species of plants and animals have evolved to adapt to periodic fires. They are especially sensitive to smoke and take protective action in a timely fashion. Others take advantage of food sources that arise when trees burn.

But even species that capitalize on burned-out areas of forests require oases of healthy woodland for at least part of their activities. When fires are too widespread, such oases are too few and far between.

Animals that survive fires must find food, water, and shelter in the aftermath. And all air-breathing animals are going to be impacted by smoke exposure because the chemicals in smoke are toxic to them as well as to people.

In places like Canada’s Northwest Territories, repeated fires have transformed some forests, eliminating dominant tree species and replacing them with others whose light seeds were carried on the wind.

Scientists have estimated that increased global fire activity could push more than 1,000 threatened plant and animal species closer to extinction. Changing fire patterns are transforming landscapes and utterly remaking ecosystems.

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How Megafires Are Remaking the World

Photo, posted December 19, 2022, courtesy of Brian Pippin/USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Cleaning Up Urban Rivers With Nature’s Tools | Earth Wise

October 7, 2022 By EarthWise Leave a Comment

Fifty years after the passage of the Clean Water Act, urban waterways across the United States are continuing their comeback and are showing increasing signs of life. A strategy that is being adopted in many places is to use natural restoration techniques focused on bolstering plants and wildlife to improve water quality.

A nonprofit called the Upstream Alliance has focused on public access, clean water, and coastal resilience in the Delaware, Hudson, and Chesapeake watersheds. Working with the Center for Aquatic Sciences and with support from the EPA and the National Fish and Wildlife Foundation, the alliance has been repopulating areas of an estuary of the Delaware River near Camden, New Jersey with wild celery grass, which is a plant vital to freshwater ecosystems.

In many places, scientists, nonprofits, academic institutions, and state agencies are focusing on organisms like bivalves (typically oysters and mussels) along with aquatic plants to help nature restore fragile ecosystems, improve water quality, and increase resilience.

Bivalves and aquatic vegetation improve water clarity by grounding suspended particles, which allows more light to penetrate. These organisms also cycle nutrients both by absorbing them as food and by making them more available to other organisms.

Underwater restoration projects have been underway in New York Harbor for more than a decade, where the Billion Oyster Project has engaged 10,000 volunteers and 6,000 students.

The hope is that bringing back bivalves and aquatic plants can create a lasting foundation for entire ecosystems. It is restoring nature’s ability to keep itself clean.

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How Using Nature’s Tools Is Helping to Clean Up Urban Rivers

Photo, posted December 19, 2019, courtesy of Scott via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

What Does Conservation Really Mean? | Earth Wise

June 2, 2021 By EarthWise Leave a Comment

There is a great deal of interest in protecting nature and, in many cases, restoring aspects of nature that have been lost. But what do these things really mean?

What is most important? Protecting iconic species? Strengthening nature’s resilience? Several recent scientific papers address these questions and come up with rather different answers.

It isn’t even clear what constitutes a pristine ecosystem. According to some experts, ecosystems that have lost most of their large mammal species, for example, cannot be considered intact. By that standard, only a tiny fraction of the world’s ecosystems remains intact.

Other experts contend that preserving individual species is not what really matters. Studies have shown that many ecosystems have undergone and continue to undergo massive species shifts over time with frequent extinctions along the way. Nevertheless, the ecosystems continue to flourish with new species replacing others to perform the various functions required.

Some perspectives consider intact ecosystems to be those devoid of human influence. But that notion is not universally held. There is the idea that most of the world’s ecosystems were essentially untouched until perhaps 500 years ago when European exploration expanded greatly. But the reality is that even 12,000 years ago, nearly three-quarters of terrestrial nature was inhabited, used, and shaped by people. However, those human interactions were similar to how many indigenous and local peoples across the globe still live, not like the interactions of modern civilization that result in massive changes to ecosystems.

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