ecological

Rewilding The American West | Earth Wise

September 14, 2022 By EarthWise Leave a Comment

Oregon State University scientists have proposed a series of management changes for western federal lands aimed at re-establishing ecosystems there. Their proposal would result in more gray wolves and beavers in nearly 200,000 square miles of federal lands in 11 states.

In each of those states, the researchers identified areas containing prime wolf habitat. Gray wolves were hunted to near extinction in the West but have been gradually reintroduced in some areas starting in the 1990s. Wolf restoration offers significant ecological benefits by helping to naturally control the population of grazing animals such as elk. This in turn facilitates the regrowth of vegetation species such as aspen, which ultimately supports diverse plant and animal communities.

Beaver populations, which used to be robust across the West, declined roughly 90% after settler colonialism and are now nonexistent in many areas. By felling trees and shrubs and constructing dams, beavers enrich fish habitat, increase water and settlement retention, maintain water flows during droughts, and increase carbon sequestration.

According to the researchers, the biggest threat to these western lands is livestock grazing, which has degraded ecosystems to a great extent. They recommend the removal of grazing on about 30% of the federal lands being used for that purpose and instead would have rewilding efforts go on.

The American West is going through a period of converging crises including extended drought and water scarcity, extreme heat waves, massive fires, and loss of biodiversity. Rewilding is a way to reestablish long-standing ecosystems.

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More wolves, beavers needed as part of improving western United States habitats, scientists say

Photo, posted October 1, 2020, courtesy of Tina DaPuglet via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Can We Tow Icebergs To Use Their Water? | Earth Wise

February 23, 2021 By EarthWise Leave a Comment

At any given time, there are thousands of icebergs adrift in Antarctica that are hundreds or even thousands of feet across. For at least fifty years, there has been speculation about whether such icebergs could be towed from the Antarctic to places experiencing freshwater shortages. The feasibility of such a scheme is still the subject of studies that nowadays include sophisticated computer modeling.

Places like the Persian Gulf, Cape Town, South Africa, and Perth, Australia all experience water shortages and could benefit tremendously from having a large iceberg towed to their waters.

How big an iceberg would it take to quench the thirst of a city like Cape Town? Computer models show that an iceberg 2,000 feet long and 650 feet thick could produce enough water to supply the city for more than a year. However, with water temperatures in the 60s in the area, even such a large iceberg would melt away within weeks. So, to get enough water for a year, it would require a much larger iceberg – one at least a couple of miles long.

Daunting problems include figuring out how many and what sort of ships would be required. An alternative to such giant icebergs would be finding a way to insulate the icebergs so they don’t melt as quickly, thereby allowing much smaller and more towable icebergs to be harvested.

Beyond these issues, there are the ecological issues of the effects of huge amounts of very cold fresh water affecting local marine ecosystems.

Despite a wide range of challenges, there is continued interest in the idea of using icebergs as a source of very pure fresh water. In an increasingly thirsty world, it might someday actually happen.

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Can icebergs be towed to water-starved cities?

Photo, posted November 1, 2007, courtesy of M A Felton via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Hudson River Tidal Marshes And Sea Level Rise | Earth Wise

January 29, 2021 By EarthWise Leave a Comment

A new study at the University of Massachusetts Amherst looked at the resilience of Hudson River Estuary marshes to rising sea levels. They observed that these marshes are growing upward at a rate two or three times faster than sea level rise, suggesting that they should be resilient to accelerated sea level rise in the future.

The study documented the fact that more than half of Hudson River tidal marshes actually formed since 1850. In that year, the river channel was straightened, and a riverside railroad, berms, jetties and human-made islands of dredged soil were built. All of these human-made features trapped sediment and created backwaters that often turned into marshes.

The research centered on seven sites spanning more than 100 miles of the Hudson Estuary from Wall Street up to Albany. Although these marshes were an unintended result of early industrial development, they serve to protect the shoreline and provide rich ecosystems in terms of direct ecological and human benefits. Marshes are a first line of defense against coastal flooding, provide an essential habitat for juvenile commercial fish species, store huge amounts of carbon that mitigates climate change, provide habitat for migratory birds, and filter nutrients coming off the land.

The study determined that such marches form relatively quickly. When sediment is readily available, freshwater tidal wetlands can develop rapidly in sheltered settings. There is concern that marshes globally will be drowned by rising sea levels, but this Hudson River case study shows how marshes may be able to resist the rising seas. The research will help guide future land acquisition and land conservation strategies for areas adjacent to the river.

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New Study Finds More than Half of Hudson River Tidal Marshes were Created Accidentally by Humans; Resilient Against Sea Level Rise

Photo, posted December 4, 2008, courtesy of Daina Dajevskis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Replacing Plastic Tableware | Earth Wise

December 30, 2020 By EarthWise Leave a Comment

Plastics have been described as the “ubiquitous workhorse material of the modern economy.” But their versatility, pliability, and durability comes at a heavy price to the environment. Plastic pollution is quite literally everywhere. Plastic debris and microplastic particles can be found in every corner of the globe, including the Arctic and Antarctic.

The scourge of plastic pollution is driving scientists to create ecologically-friendly alternatives. According to a paper recently published in the journal Matter, scientists have developed “green” tableware made from sugarcane and bamboo that doesn’t sacrifice on convenience or functionality. This eco-friendly tableware could serve as a permanent replacement for plastic cups and other disposable plastic containers.

Traditional plastic polymers, a product of petroleum, can take as long as 1,000 years to decompose in landfills. The new material only takes 60 days to break down.

To create this material, scientists used bamboo and bagasse, also known as sugarcane pulp. Bagasse is one of the largest food-industry waste products. The researchers wound the fibers together to form a mechanically stable and biodegradable material. They added an alkyl ketene dimer, an eco-friendly chemical, to increase the oil and water resistance of the material. The green material is durable enough to hold liquids like hot coffee and hot greasy foods like pizza.

There’s another advantage: the green material’s manufacturing process emits 97% less CO2 than the process to make commercial plastic containers. The next step is to lower the manufacturing cost. While the cost of cups made from the green material is $2,333 per ton, traditional cups made from plastic are still slightly cheaper at $2,177 per ton.

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This tableware made from sugarcane and bamboo breaks down in 60 days

Photo, posted May 19, 2013, courtesy of Henry Burrows via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Planting Trees and Climate Change | Earth Wise

June 1, 2020 By EarthWise Leave a Comment

Forests are among the most important natural carbon sinks. Trees remove carbon from the air and store it in their trunks, branches, and leaves, and transfer part of it into the soil. But in some regions, these natural carbon sinks are starting to weaken due to deforestation, forest degradation, and the impacts of climate change. This problem has led some climate mitigation projects to focus on increasing the overall number of trees on the planet.

But, according to a paper recently published in the journal Science, “we can’t plant our way out of climate change.” That’s the simple message from Restoration Ecologist Karen Holl and University of São Paulo Professor Pedro Brancalion to anyone who thinks planting one trillion trees will reverse the effects of climate change. They say planting more trees is only one piece of the puzzle. Any initiatives like 1t.org or the Trillion Tree Campaign must be done carefully and be accompanied by commitments to long-term management.

Tree plantings can provide many environmental benefits, including improving water quality, biodiversity, and increasing shade. But trees can sometimes have undesirable impacts, such as harming native species and ecosystems or reducing water availability, depending on where and how the trees are planted.

The authors suggest four principles that should guide forest enhancement initiatives: reduce forest clearing and degradation, balance ecological and social goals, view tree plantings as one part of a multifaceted solution, and plan, coordinate and monitor the work.

While tree plantings can clearly be part of the solution, slowing the pace of climate change requires a comprehensive approach that must start with burning less fossil fuels.

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Challenges in tree-planting programs

Planting trees is no panacea for climate change

Photo, posted December 1, 2019, courtesy of Akuppa John Wigham via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Value Of Abandoned Agricultural Lands | Earth Wise

February 18, 2020 By EarthWise Leave a Comment

It is perhaps surprising to learn that more land is now being abandoned by farming than converted to it. In fact, abandonment of rural lands has become one of the most dramatic planet-wide changes of the modern era, affecting millions of square miles of land.

In part, it is due to rural flight driven by the economic, social, and educational appeal of cities. It is also a result of climate change and the globalization of the food supply chain. The global footprint of agriculture has been decreasing over the past twenty years but the global food supply isn’t shrinking. The lost land has generally been marginal and farming elsewhere has become more productive.

Many researchers see abandoned agricultural lands as a huge opportunity for ecological restoration and strengthening of biodiversity. Others see these lands as an opportunity for a massive program to plant trees to reduce carbon dioxide in the atmosphere. A recent study published in Science estimated that planting trees on abandoned agricultural lands could remove 25% of the carbon dioxide humans have added to the atmosphere.

There are strong criticisms to all of these ideas. In most cases, the studies don’t incorporate the social context of why these lands are in transition, the potential effects on local populations, whether the lands are publicly or privately owned, and whether lands now suitable for regeneration will remain so as climate change advances.

Current government initiatives on degraded lands typically lack even rudimentary planning. There are real opportunities presented by the vast amounts of abandoned agricultural lands, but there are many caveats and many issues to confront. As a society, we have barely begun to even think about what to do.

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Could Abandoned Agricultural Lands Help Save the Planet?

Photo, posted May 9, 2010. courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Community Action And Coral Reefs

January 1, 2020 By EarthWise Leave a Comment

Coral reef habitats are some of the densest and most varied ecosystems on earth. While coral reefs cover just 0.2% of the ocean floor, scientists estimate that nearly one million different species of fish, invertebrates, and algae can be found in or around coral reefs.

However, climate change is wreaking havoc on the health of coral reefs. Warming and acidifying oceans are resulting in enormous coral losses. Overfishing, development, and pollution are also threatening coral reef health.

According to new research, positive community action can help boost fish populations in coral reefs and safeguard future fish numbers. The paper, which was recently published in the journal Proceedings of the National Academy of Sciences, details the social and ecological outcomes of work being done in Papua New Guinea since 2001.

These communities have established a traditional system of rotational fishing closures in order to manage their fisheries resources. They ban fishing on part of their reefs for a few years, and then open these closures when village elders believe fish behavior has changed and fish populations have recovered. They then close a different part of their reefs, and repeat the process.

The researchers found that these rotational practices resulted in more than twice as many fish on the closed reefs as compared to open ones, and the closures made fish less scared of people and easier to catch. But the researchers did caution that this short term boost in fish numbers may not be enough to stop the overall impact of fishing.

Globally, more than 500 million people depend on coral reefs for food, income, and coastal protection. Balancing community needs with environmental needs can be tricky business.

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Positive community action can help coral reef health

Photo, posted October 11, 2011, courtesy of Paul Toogood via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Crop Diversity

March 22, 2019 By EarthWise Leave a Comment

A study at the University of Toronto suggests that on a global scale, we are growing more of the same kinds of crops, and this diminishing diversity presents major challenges for agricultural sustainability.

In some places, for example here in North America, crop diversity has actually increased. Back in the 1960s, North Americans grew about 80 crops. Now there are 93.

But on a global scale, more of the same kinds of crops are being grown on much larger scales. Just four crops – soybeans, wheat, rice and corn – occupy nearly 50% of the world’s entire agricultural lands. The remaining 152 crops cover the rest. Large industrial farms often grow one crop species – usually just a single genotype – across thousands of acres of land.

This decline in global crop diversity is problematic in several ways. On a cultural level, it threatens regional food sovereignty. If regional crop diversity is threatened, it makes it more difficult for people to eat or afford foods that are culturally significant to them.

On an ecological level, the dominance by a few genetic lineages of crops makes the agricultural system increasingly susceptible to pests or diseases. The deadly fungus that is threatening the world’s banana plantations is a prime current example. The Irish potato famine in the 19^th century is a tragic historical example.

As large industrial-sized farms in Asia, Europe and the Americas start to look more and more alike, the dangers of large monocultures of crops that are commercially valuable will only increase. It will be important for global governments to consider the impact of policies that affect the diversity of the agricultural system and its sustainability in an increasingly hungry world.

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A small number of crops are dominating globally. And that’s bad news for sustainable agriculture

Photo, posted August 13, 2012, courtesy of Alasdair McKenzie via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Social And Ecological Underpinnings Of Infectious Disease

April 1, 2016 By WAMC WEB

When it comes to addressing infectious disease, we have a short attention span. Forces are mobilized when we’ve crossed a tipping point, and demobilized when the immediate threat has passed. In the case of Zika, the World Health Organization declared a public health emergency based on a strong association between Zika infection and microcephaly in newborns and a spike in Guillain-Barré syndrome.