herbivores

Bringing Back Bison | Earth Wise

August 23, 2022 By EarthWise Leave a Comment

Over the past few decades, research has identified the importance of large mammals like bison as ecosystem engineers. These animals shape and maintain various natural processes and, in the process, are responsible for the sequestering of large amounts of carbon. But large mammals – both herbivores and predators – have seen their numbers dwindle over time. At this point, nearly two-thirds of large carnivores are threatened with extinction. Overall, less than 6% of worldwide ecosystems have the extensive, intact large-mammal communities that were dominant 500 years ago.

Conservationists around the world have embarked on programs of “rewilding”- reintroducing large mammals into ecosystems. Some of the animals involved in these programs include brown bears, wild horses, jaguars, reindeer, Eurasian beavers, elk, moose, wolverines, tigers, hippos, and bison.

A group of bison raised in South Dakota have recently been transplanted to the Chihuhuan Desert at the US-Mexico border across Arizona, New Mexico, and Texas. There used to be huge bison herds in that region, but it has been largely bison-free for 150 years.

Perhaps more remarkably, wild bison are also being reintroduced into a forest near Canterbury, England. There haven’t been bison in the United Kingdom for thousands of years. But conservationists are introducing European bison into the British forest to knock down trees, trample shrubs, and create space for a greater diversity of flora and fauna.

Apart from the ecosystem goals of the British project, people in the UK, for the first time in over a thousand years, will be able to experience bison in the wild.

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Gone for Thousands of Years, Wild Bison Return to the UK

Photo, posted December 31, 2018, courtesy of Marco Verch via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Reducing Agriculture’s Carbon Footprint | Earth Wise

September 29, 2021 By EarthWise Leave a Comment

Agriculture is responsible for about 10% of greenhouse gas emissions. Those emissions come from livestock such as cows, the disturbance of agricultural soils, and activities like rice production.

Recent research from Texas A&M University presents sustainable solutions for grazing agriculture. According to the research, published in the Journal of Soil and Water Conservation, ruminant animals like cattle contribute to the maintenance of healthy soils and grasslands, and proper grazing management can reduce the industry’s carbon emissions and overall footprint.

Grassland ecosystems co-evolved with herbivores over thousands of years. These complex, dynamic ecosystems include grasses, soil biota, grazing animals, and predators. The ecosystems degrade in the absence of periodic grazing.

The research contends that ruminant livestock are an important tool for achieving sustainable agriculture with appropriate grazing management. With such management, grazing cattle on permanent perennial grasslands helps develop soil biology to improve soil carbon, rainfall infiltration, and soil fertility.

Permanent cover of forage plants is highly effective in reducing soil erosion and increasing soil infiltration. Ruminants consuming grazed forages under appropriate management results in considerably more carbon sequestration than carbon emissions.

This overall approach is known as regenerative agriculture and is built around the ideas of practices that restore soil health and ecosystem function to support healthy agroecosystems.

These ideas constitute alternatives to ones that call for the reduction or elimination of cattle and livestock agricultural production. The future of agriculture needs to consider the full impacts of the entire food production chain and its environmental impacts.

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Grazing Cattle Can Reduce Agriculture’s Carbon Footprint

Photo, posted April 27, 2010, courtesy of Beverly Moseley/USDA NRCS Texas via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Too Many Bison | Earth Wise

May 8, 2020 By EarthWise Leave a Comment

The population of large herbivores in Yellowstone National Park has undergone many dramatic changes over the course of time. The numbers of both the iconic Rocky Mountain elk and bison have gone up and down as a result of human interactions.

Bison, of course, once were a dominant species from east of the Appalachians to west of the Rocky Mountains, with most of an estimated 30 million living on the Great Plains. As the west was settled, bison populations plummeted and by the late 1800s, they were nearly extinct.

When Yellowstone was established, there were exactly 22 bison in the park. By 1925, there were more than 750 in the park and culling of the herd in the park’s Lamar Valley was practiced for the next four decades.

The elimination of predators like grey wolves and cougars in the early 1900s caused both elk and bison populations to mushroom and both underwent culling. When culling was ended in 1968, there were 4,000 elk and 100 bison. Within 20 years, those numbers were 20,000 and 1,000. Reintroducing wolves and cougars reduced the elk population to about 5,000, but bison numbers have continued to grow, now reaching about 4,000.

While the long-term recovery of the Yellowstone bison herd is a major conservation success story, the fact is that bison are powerful ecosystem engineers. Large numbers of them disrupt species distribution across scrub steppe and grasslands because of what they eat, trample, and rub their horns and bodies on. They have a tremendous capacity to limit the structure and composition of ecosystems.

Park administrators have complicated management decisions to make to take into account the often wide range of ecological effects that abundant large herbivores can have on ecosystems.

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Bison in northern Yellowstone proving to be too much of a good thing

Photo, posted August 10, 2016, courtesy of Brian Gratwicke via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Saving The Arctic Permafrost | Earth Wise

April 17, 2020 By EarthWise Leave a Comment

Permafrost is frozen ground – a combination of soil, rock, sand, and ice – that remains at or below freezing for at least two consecutive years. Approximately 25% of the land in the Northern Hemisphere meets this criterion, the majority of which can be found in northern Russia, Canada, Alaska, Iceland, and Scandinavia.

But as a result of the changing climate, these permafrost soils in the Arctic are beginning to thaw. As they thaw, large quantities of greenhouse gases could be released, further accelerating climate change.

A new study recently published in the journal Scientific Reports explores an unconventional countermeasure: resettling massive herds of large herbivores. According to researchers from the University of Hamburg in Germany, herds of horses, bison, and reindeer could be used to significantly slow the loss of permafrost soils.

During Arctic winters, the air temperature is often much colder than the permafrost. Thick layers of snow can insulate the ground from the frigid air, keeping the permafrost warm (relatively speaking). But when the snow cover is scattered and compressed by the hooves of grazing animals, the insulating effect is reduced, which intensifies the freezing of the permafrost.

If climate change continues unchecked, the research team expects permafrost temperatures to rise 3.8-degrees Celsius. This would result in half of the world’s permafrost thawing by the year 2100. But in contrast, researchers found that the permafrost would only warm by 2.1 degrees Celsius with the resettled animals. This 44% reduction in permafrost temperature would preserve 80% of the existing permafrost by 2100.

Natural manipulations of ecosystems could have tremendous results.

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How horses can save the permafrost

Photo, posted July 17, 2012, courtesy of Kitty Terwolbeck via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Incredible Shrinking Bison

April 18, 2016 By WAMC WEB

As the climate warms, all sorts of things are happening in the environment. We know about shrinking ice caps, retreating glaciers, strange winter weather, and so forth. But there are other things that may happen that are unexpected and puzzling.