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Natural solutions for disappearing islands

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Atoll islands are made from sediment produced by corals, clams, snails, and varieties of algae that secrete carbonate.  Under the right conditions, over time, fragments of coral skeletons, shells, and other sediments made by marine life are piled up by waves.  Eventually, islands are formed – some large and some small.  Atoll islands are home to a diversity of human cultures and are important refuges for a quarter of the world’s seabirds as well as numerous nesting sea turtles and tropical plants.

Rising sea levels – the rate of which has more than doubled over the past 30 years – are a mounting challenge for atoll islands.  And by the end of this century, sea level is projected to rise between 11 and 40 inches, depending on the world’s actions with regard to greenhouse gas emissions.

The ability of atoll islands to persist depends on the health of their ecosystems and the extent to which their natural processes have been disrupted by human activity.  To protect the most vulnerable islands, some researchers now propose using nature-based solutions – like restoring and protecting coral reefs and native forests.

Reclaiming seabird habitat can help reefs persist and restore the resilience of atoll islands.  Seabird guano washes off islands and into reefs, providing nutrients that boost coral growth and fish populations. 

Nature-based solutions cannot help the most urbanized atoll islands.  These islands have already irreversibly lost their natural adaptive capacity.  For those places, engineered approaches such as concrete seawalls are needed.

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How Natural Solutions Can Help Islands Survive Sea Level Rise

Photo, posted July 3, 2014, courtesy of Roderick Eime / MG Media via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Parks for bugs

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Urban areas can have a variety of green spaces:  gardens, parks, and roadside and median plantings.  It turns out that these spaces can serve as pollinator refuges.

A study by researchers at the University of British Columbia found that reducing lawn mowing and creating pollinator meadows – essentially parks for bugs – significantly boosts pollinator diversity and creates healthier and more resilient ecosystems.

The 3-year study surveyed pollinators in 18 urban parks across the city of Vancouver.  It compared parks where meadows were planted and mowing was restricted with parks that were kept as standard turfgrass lawns.

Parks with meadows saw an immediate increase in pollinator species – from 21 to 47 more wild bee and hoverfly species – compared to parks without meadows.  These increases continued over the entire three-year study period.

The researchers identified more than 100 species of wild bees and hoverflies and 35 of them were only found in parks with meadows.

People think of urban landscapes as poor environments for biodiversity, but this study demonstrated that even relatively small changes can have significant impacts.  Even a patchwork of small habitats can allow species to move freely and settle into multiple areas quickly.

The researchers had advice for urban residents as well.  They suggest that people reduce mowing, plant native flowering shrubs and trees, create diverse habitats that incorporate a variety of plants that bloom at different times, avoid pesticide use, and leave natural nesting sites for pollinators.

Preserving pollinators is an important task and having a few parks for bugs can really help.

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How ‘parks for bugs’ boost pollinators in Vancouver

Photo, posted September 19, 2011, courtesy of Eric Bridiers / U.S. Mission Geneva via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Amphibians and climate change

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Amphibians are a group of vertebrate animals that include frogs, toads, and salamanders. They are unique for their ability to live both in water and on land during different stages of life. Amphibians play a crucial role in ecosystems, often serving as both predators and prey in food webs.

Amphibians are the world’s most at-risk vertebrates, with more than 40% of species listed as threatened.  They are cold-blooded creatures and rely on external sources to regulate their body temperature.  But needing to regulate their body heat this way makes amphibians particularly vulnerable to temperature change in their habitats. 

Researchers from the University of New South Wales in Australia can now predict the heat tolerance of 60% of the world’s amphibian species.  This new tool will allow scientists to better identify which amphibian species and habitats will be most impacted by climate change.  

The study’s landmark findings, which were recently published in the journal Nature, found that 2% of amphibian species are already exposed to overheating in shaded terrestrial conditions.  According to the research team, a 4°C global temperature increase could push 7.5% of amphibian species beyond their physiological limits. 

Local amphibian extinctions can trigger ecological repercussions, including reshuffling community compositions, eroding genetic diversity, and impacting the food chain and overall ecosystem health.

The researchers highlight the importance of vegetation and water bodies in protecting amphibians during heat waves, and emphasize the need to provide adequate water and shade during future conservation efforts. 

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The pot is already boiling for 2% of the world’s amphibians: new study

Photo, posted October 8, 2011, courtesy of Dave Huth via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Solar farms and pollinators

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Two important environmental challenges are finding some literal common ground:  the need to reduce carbon emissions and the fight to stave off global biodiversity collapse.  Both issues can be addressed at solar farms.

Solar energy is an important weapon in the battle against climate change.  But utility-scale solar farms take up large amounts of land.  Large-scale solar farms already take up nearly a thousand square miles of land in the US and will take up much more in the coming decades.

In the meantime, the biodiversity collapse is being driven in large part by habitat loss.

Given all this, solar farm operators, biologists, and environmentalists are teaming up to grow pollinator-friendly plants in and around solar farms. The plantings attract insects, birds and even mammals. The more plant diversity in the solar farms, the more environmental benefits can be achieved. 

There are costs associated with creating pollinator-friendly solar farms. Ideally, solar panels need to be installed at greater height than otherwise in order to permit growing many of the plants that attract bees and butterflies.  But there are economic benefits associated with attracting and sustaining pollinators.  On a cautionary note, there have already been cases of greenwashing, where solar operators claim environmental benefits far in excess of the scope of the actual efforts they have made. 

There are both governmental and non-governmental agencies seeking to assess and certify pollinator-friendly solar farms.  There is considerable variability in the ecological value of existing farms.  Pollinator-friendly solar farms are in their early days, but they have a lot to offer as a win-win strategy for the environment.

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Solar Farms Have a Superpower Beyond Clean Energy

Photo, posted December 4, 2014, courtesy of Juwi Renewable Energies Limited via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Another ban on neonics

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There have been ominous declines in many insect populations.  Chief among them have been declines in pollinators, which have severe consequences for our food supply.  There are multiple possible causes of these declines and undoubtedly several have been involved simultaneously.

A new study on butterfly populations in the Midwest indicates that agricultural insecticides exerted the biggest impact on the diversity of butterfly populations in the Midwest during the period 1998 to 2014.  The biggest culprits were the widely used insecticides called neonicotinoids that are absorbed into the tissues of plants.

Neonics are meant for targeted pesticide use but are often used more broadly, including for corn crops.

Neonics are already well-known to be especially harmful to bees and are gradually being restricted in various places.  Quebec province passed restrictions on neonic-treated seeds in 2019.  Last December, New York signed into law a phase-out of neonic-treated seeds and a ban on non-agricultural uses of them.

Vermont has now become the second state to ban the use of neonicotinoids by virtue of its state legislature overriding a veto from Governor Phil Scott.  The law minimizes the use of neonics by requiring potential users to obtain written exemptions. 

Opponents to neonic restrictions claim that slashing their use will greatly reduce crop yields.  The experience in Quebec over the past five years is that the Canadian neonic restrictions have reduced corn and soybean crop yields by about 0.5%.  As a result of this tiny reduction, there has been a strong reduction in the amount of neonics contaminating waterways.

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Vermont Becomes Second State to Ban Bee-Killing Neonic Pesticides

New ‘Detective Work’ on Butterfly Declines Reveals a Prime Suspect

Photo, posted September 7, 2017, courtesy of Watts via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Species and climate change

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Temperature extremes on Earth currently range from a low of -129°F to a high of 134°F.  But these climatic limits have changed throughout history.  In fact, during the last interglacial period 130,000 years ago, temperatures were warmer, resembling what we are projected to experience at the end of this century.

Species that evolved during such periods may possess pre-adaptations that could help them tolerate upcoming changes to the climate.  This factor is often overlooked by traditional statistical models predicting species’ responses to climate change.

But a new model, developed by researchers from Ifremer in France and Lausanne University in Switzerland, has taken this oversight into account, and reassessed the proportion of terrestrial and marine species threatened with extinction by climate change. 

In the study, which was recently published in the journal Nature Ecology and Evolution, the research team applied its model to nearly 25,000 terrestrial and marine species from around the world.  The researchers discovered that 49% of these species live in climate niches near the current climatic limits, and 86% could potentially extend beyond these limits. 

The most surprising result concerns tropical regions. While forecasts from traditional models estimate that the diversity of terrestrial species in tropical areas could decrease by 54% between now and 2041-2060, the new model predicts a more moderate decline of 39%.

The findings confirm the importance of taking urgent measures to mitigate climate change and its impact on biodiversity.

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Some species may better tolerate climate change than expected

Photo, posted October 23, 2015, courtesy of Anita Ritenour via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Greenland is greening

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Despite their names, Iceland is very green, and Greenland is very icy.  But in Greenland, that is changing.  Temperatures in the world’s largest island are rising twice as fast as they are in the rest of the world and, as a result, the icy rocky landscape is turning increasingly green.

Satellite records reveal that over the last three decades Greenland has lost 11,000 square miles of ice, which is an area about the size of Massachusetts.  As the ice melts off, tundra and shrublands takes its place.  The ice melt moves sediment and silt and eventually wetlands and fenlands are formed.

Between the late 1980s and the late 2010s, the areas of Greenland covered by vegetation have more than doubled.  The new green areas cover roughly 33,000 square miles, which is an area the size of Maine.

Greenland’s dramatic changes are the result of the warming climate, but in turn, those changes are accelerating climate change.  Land covered with dark green vegetation absorbs more energy from the sun thereby warming the air whereas ice-covered landscapes reflect much of the sun’s energy back into space.  In addition, the rapidly expanding wetlands are a significant source of methane, which traps even more heat in the atmosphere.

Greenland is a poster child for the effects of climate change.  Its glaciers and icecaps are shrinking, glacier-fed lakes are expanding, permafrost lakes are draining, and rivers are transporting vast amounts of sediment and widening.  All of this is going on as its vegetation cover and species diversity is expanding.

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In Icy Greenland, Area Covered by Vegetation Has More Than Doubled in Size

Photo, posted September 20, 2019, courtesy of Amanda via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Solar forests

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Forests are one of the most iconic symbols of the power and diversity of nature but beyond that, their thick vegetation is crucial to the stability and balance of the Earth’s climate.  This is because the photosynthesis that powers the growth of plants removes carbon dioxide from the air.  Cutting down forests – especially the evergreen forests of the tropics – has played a significant role in the increasing climate crisis.  For this reason, many environmental initiatives focus on restoring destroyed forests and planting new trees.

But the truth is, even if we were to cover the entire surface of the planet with trees, there would still not be enough photosynthesis going on to absorb the huge surplus of carbon dioxide that people have been pumping into the atmosphere for the past 150 years.

A study by the Weizmann Institute of Science in Israel looked at the impact of erecting fields of dark covered solar panels – so-called solar forests – that would generate electricity, thereby replacing power stations that use fossil fuels.  But dark fields absorb heat which eventually returns to the atmosphere.

The question is:  what is the best use of a plot of land in terms of the effect on the climate?  Planting a forest or erecting fields of solar panels?

The answer depends on where the land is.  In arid environments, building solar farms is far more effective and practical than planting forests.  But in humid places, forests currently absorb close to a third of humanity’s annual carbon emissions. 

The study concludes that combining planting and rehabilitating forests in humid regions and erecting fields of solar panels in arid regions is the most effective strategy.

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The Solar Forest

Photo, posted December 27, 2015, courtesy of Gerry Machen via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Flower power in agriculture

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Agriculture is the world’s largest industry.  When managed sustainably, agricultural operations can provide many environmental benefits, such as protecting watersheds and habitats, and improving soil health and water quality.  Sustainable agriculture also embraces biodiversity by minimizing its impact on wild ecosystems and incorporating numerous plant and animal varieties into farm ecosystems.

A new study of farms in India has demonstrated the power of incorporating flowers into farming practices.  According to the research by ecologists from the University of Reading in the U.K. and the M.S. Swaminathan Research Foundation in India, planting flowers beside food crops attracts bees, boosts pollination, and improves both the yield and quality of crops.

 The study, which was recently published in the Journal of Applied Ecology, is the first of its kind in India.  The researchers focused on moringa – which is a nutrient-packed superfood native to South India, and bees – the plants’ essential pollinators. 

Working alongside farmers, the researchers planted marigold and red gram crops alongside moringa trees across 12 moringa orchards.  They found that flower-visiting insect numbers and diversity were 50% and 33% higher, respectively, in orchards with floral interventions compared to those without them.  Floral interventions also led to larger moringa pods and a 30% increase in harvestable fruits.

India has many crops of high economic and nutritional value.  The study highlights how farmers can significantly improve crop pollination services and boost yields, while also managing their lands in a more sustainable manner.

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Flower power on Indian farms helps bees, boosts livelihoods

Floral interventions on farms boost pollinators and crop yields

Photo, posted June 24, 2008, courtesy of Jim via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The importance of Alaska’s National Forests

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The world’s forests play a crucial role in taking carbon out of the atmosphere and mitigating the effects of climate change.  An analysis of U.S. national forests shows that two southern Alaskan forests are key to meeting climate and biodiversity goals.

The Tongass Forest in Alaska is America’s largest national forest, encompassing 16.7 million acres.  Alaska’s Chugach Forest is the country’s second largest at just under 7 million acres.  These two forests are not only the largest national forests, they are also the most intact. 

A study by researchers at the Oregon State University College of Forestry looked at 152 national forests and compared them in terms of carbon density and accumulation, total biomass carbon stocks, habitat for eagles, bears, and wolves, and landscape integrity – which is the extent of modification by human activity.  According to the study, almost 31% of all high-landscape-integrity area found in national forests is in the Tongass and Chugach forests.  The Tongass alone represents over 25%.

These forests are cool and wet.  Their carbon stocks are only minimally affected by wildfire, unlike many other forests in the lower 48 states.  Given the size and stability of the two forests, protecting them is a high priority for making it possible to meet global goals relating to climate and diversity of species.

Ecosystems remove about 30% of all the carbon dioxide humans put into the atmosphere and intact forests with high carbon density do most of that work.  Protecting Alaska’s forests is crucial.

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Southern Alaska’s national forests key to meeting climate, conservation goals, OSU study shows

Photo, posted August 4, 2014, courtesy of Jeff Canon via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Coffee, cocoa, and pollinators

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Multiple forces have been at play that have been detrimental to pollinators including climate change, land use change, pesticide use, and more.  There have been substantial declines in both the abundance and diversity of insect pollinators.  There is increasing public awareness of this issue, but it hasn’t really risen all that high among many people’s concerns.

A new study by University College London looked at the effects of the global decline in pollinators on thousands of crop-growing sites around the world involving thousands of insect pollinator species.

About 75% of all crops grown depend on pollinators to some degree.  The UCL research created a model that looks at which pollination dependent crops are most threatened over the next 30 years in order to provide a warning to both the agricultural and conservation communities.

The research indicates that the tropics are likely to be most at risk with regard to reduced crop production caused by pollinator losses.  This is mostly due to the interaction of climate change and land use.  The risks are highest in sub-Saharan Africa, northern South America, and southeast Asia.

These areas are where the world gets most of its coffee and cocoa, two crops that are near and dear to most of us.  These crops, as well as others such as mangoes, play vital roles in both local economies and global trade and reducing them could lead to increased income insecurity for millions of small-scale farmers in these tropical regions.

If pollinator loss isn’t high up on your list of global concerns, perhaps you should think about it next time you have a cup of coffee or enjoy some chocolate.

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Coffee and cocoa plants at risk from pollinator loss

Photo, posted May 23, 2013, courtesy of McKay Savage via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Ocean Oxygen Levels And The Future Of Fish | Earth Wise

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Climate change is creating a cascade of effects in the world’s oceans.  Not only are ocean temperatures on the rise, but oceans are becoming more acidic, and oxygen deprived.  The warming temperatures and acidification have grabbed headlines and prompted academic research. Declining oxygen levels have not garnered as much attention.  But they spell bad news for fish.

Oxygen levels in the world’s oceans have dropped over 2% between 1960 and 2010 and are expected to decline up to 7% over the next century.  There are places in the northeast Pacific that have lost more than 15% of their oxygen.  There are a growing number of “oxygen minimum zones” where big fish cannot survive but jellyfish can.

Oceans are losing oxygen for several reasons.  First, warmer water can hold less dissolved gas than colder water.  (This is why warm soda is flatter than cold soda.)  Deeper in the ocean, oxygen levels are governed by currents that mix oxygen-rich surface water from above.  Melting ice in the warming polar regions add fresh, less-dense water that resists downward mixing in key regions.  Finally, increasing amounts of ocean bacteria in warming waters gobble up oxygen creating dead zones in the ocean.

In many places, fish species that cannot cope with lower oxygen levels are migrating from their usual homes, resulting in a decline in species diversity.  Our future oceans – warmer and oxygen-deprived – will not only hold fewer kinds of fish, but also smaller fish and even more greenhouse-gas producing bacteria.   

Climate change is bad news for fish and for the more than 3 billion people in the world who depend on seafood as a significant source of protein.

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As Ocean Oxygen Levels Dip, Fish Face an Uncertain Future

Photo, posted January 10, 2022, courtesy of Willy Goldsmith via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Why Are Insect Populations Declining? | Earth Wise

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The world is experiencing a decline in overall insect populations as well as a collapse in insect diversity.  A recent special issue of the journal Biology Letters discusses the major causes of this alarming trend.

According to the study, the primary causes of the worldwide decline in insect biomass are land-use intensification in the form of greater utilization for agriculture and building development, climate change, and the spread of invasive animal species as a result of human trade.

The study concludes that it is not just these factors that are driving the global disappearance of insects, but also that these three factors are interacting with each other.  For example, ecosystems that are deteriorated by humans are more susceptible to climate change and so are their insect communities.  Similarly, invasive species can establish themselves more easily in habitats damaged by human land-use and displace native species.  Many native insect species decline or go extinct while others – often invasive species – thrive and increase, leading to decreasing insect diversity.  Warming temperatures are making many locations undesirable for various insect species and they often cannot migrate to anyplace better.

Declining insect populations and diversity results in concomitant declines in plant species that depend on pollinators.  This in turn threatens the stability of entire ecosystems.

The researchers advocate for continued monitoring of insect diversity across many habitats and countries and propose the creation of a network of interconnected nature reserves such that species can move from one to another. 

We often think of insects as pests, but they are a crucial part of the world’s ecosystems.

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The reasons why insect numbers are decreasing

Photo, posted April 17, 2011, courtesy of Dean Morley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

An Accelerating Rate Of Mountain Forest Loss | Earth Wise

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Mountains contribute disproportionately to the Earth’s diversity of life.  While mountains account for about 25% of the land area on Earth, they are home to more than 85% of the mammal, bird, and amphibian species.  But alarmingly, forested mountain habitats in which these species live are disappearing, and they appear to be disappearing at an accelerating rate.

According to a new study recently published in the journal One Earth, more than 300,000 square miles of mountain forest has been lost globally since 2000, which is an area larger than the state of Texas. 

A research team led by scientists from Leeds University in the United Kingdom and the Southern University of Science and Technology in China tracked changes in mountain forests on an annual basis from 2001 to 2018.  The researchers found logging to be the biggest driver of mountain forest loss, responsible for 42% of the overall decline.  This is followed by wildfires at 29%, so-called “slash-and-burn” cultivation at 15%, and permanent or semi-permanent agriculture at 10%.  Significant losses occurred in Asia, Africa, Europe, Australia, and South America, but not in Oceania or North America.

The research team also found that the rate of mountain forest loss seems to be accelerating: in fact, the annual rate of loss increased 50% from 2010-2018 when compared with 2001-2009.

While developing additional forest protection strategies and interventions is critical, the researchers emphasize the importance of also considering food production, livelihoods, and human wellbeing in any new measures.

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Mountain forests are being lost at an accelerating rate, putting biodiversity at risk

Photo, posted December 6, 2018, courtesy of Lance Cheung / USDA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Corals Saving Corals | Earth Wise

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A new study by researchers at the University of California, Davis, has found that under the right circumstances, disease-resistant corals can rescue corals that are more vulnerable to disease.

The researchers monitored a disease outbreak at a coral nursery in the Cayman Islands.  They tracked the presence of disease in 650 coral fragments in various arrangements over a period of five months.  They found that some corals are more resistant to disease just by being around other corals that are particularly resistant.  In general, when there are only corals of the same genetic makeup, they are more vulnerable to disease than corals that grow among a mixture of genotypes.  But beyond that, some vulnerable corals become more resistant to disease just by being around other corals that are particularly resistant.  Proximity to the resistant genotypes helped to protect the susceptible corals from the effects of disease.

These findings provide new evidence that genetic diversity can help reduce disease transmission among corals and furthermore, it is important to consider how corals are arranged in coral nurseries or in reef restoration projects.

The ability of resistant coral to help protect vulnerable individuals appears to be similar to how vaccinations work among humans.  Vaccinated individuals resist a disease, which effectively erects a barrier that weakens a disease’s ability to move through a population.

The researchers hope that the findings of this study will be integrated into coral nursery and reef restoration projects.  By intentionally arranging corals with mixtures of genotypes, it will help rebuild coral resilience and help those corals that are vulnerable to disease to thrive.

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Corals Saving Corals

Photo, posted December 30, 2014, courtesy of NOAA’s National Ocean Service via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Making Cotton More Sustainable | Earth Wise

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In the United States, cotton is a $7 billion annual crop grown in 17 states.  Cotton plants in the largest producing countries in the world – India, China, and the U.S. – are genetically very similar and, like other crops that lack diversity, can be at risk.

Cultivated cotton around the world has been bred to look and act very similar.  It is high yielding and easy to harvest using machines.  But it is also wildly unprepared to fight disease, drought, or insect-borne pathogens.

Researchers are looking beyond breeding for ways to combat the low genetic diversity of cultivated cotton.  There are new approaches that combine breeding with elements of genetic modification.  Most cotton in the U.S. has already been genetically modified to resist caterpillar pests.  But as new problems emerge, new solutions will be needed that may require complicated changes to the cotton genome.  Getting regulatory approval for a genetically modified crop is a long and expensive process.

However, ordinary genetic modification is not the only possibility.  Modern genetic sequencing technology can allow researchers to examine various wild cotton varieties and identify the genetic markers for desirable traits.  Once valuable genes in wild species have been identified, traditional plant breeding techniques could be used to produce cultivated cotton varieties that are more resistant to disease and drought.

Climate change is raising average global temperatures and some important cotton-producing regions such as the U.S. Southwest are becoming drier.  Researchers are hoping to produce cultivated cotton that can tolerate drought at the seedling stage.  The ultimate goal is to create more sustainable and genetically diverse cotton that can thrive in a changing world.

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Cotton Breeders Are Using Genetic Insights To Make This Global Crop More Sustainable

Photo, posted November 9, 2008, courtesy of BP Takoma via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Healthy Soil Is Healthy For People | Earth Wise

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A new study by researchers at the University of Washington looked at the impact of regenerative farming practices on the nutritional content of the food that is grown. 

Regenerative agriculture involves farming practices that not only “do not harm” to the land but actually improve it by regenerating and revitalizing the soil.  The practices focus on topsoil regeneration, increasing biodiversity, improving the water cycle, and enhancing ecosystem services.  Examples are soil-building techniques that minimize plowing, the use of cover crops, and the planting of diverse crops rather than monocultures.

The study included 10 farms across the U.S. that followed soil-friendly practices for at least five years. The results were that the crops from those farms had a healthier nutritional profile than the same crops grown on neighboring, conventional farms.  In particular, there was a boost in certain minerals, vitamins and phytochemicals that are beneficial to human health.  Across the board, regenerative practices resulted in crops with more anti-inflammatory compounds and antioxidants.

The participating farms grew one acre of a test crop – peas, sorghum, corn, or soybeans – for comparison with the same crop grown on a neighboring farm using conventional agriculture.  Analysis showed that the farms practicing regenerative agriculture had healthier soils, as measured by their organic matter – or carbon – content and by other tests. 

Organic farms avoid chemical pesticides, but they operate with a variety of farming processes.  Nonetheless, they have also been found to produce crops with higher levels of beneficial nutrients.  The biology of the soil in which crops are grown is an important factor for human health.  It isn’t just what we eat that matters; it is how we grow it.

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Farms following soil-friendly practices grow healthier food, study suggests

Photo, posted January 10, 2020, courtesy of Les via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Fighting Disease in Cavendish Bananas | Earth Wise

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Cavendish bananas account for about half of global banana production and the vast majority of bananas entering international trade.  The plant is unable to reproduce sexually and instead is propagated via identical clones.  So, the genetic diversity of the Cavendish banana is exceedingly low. 

In 2008, Cavendish cultivars in Sumatra and Malaysia started to be attacked by Panama disease, a wilting disease caused by a fungus.  In 2019, Panama disease was discovered on banana farms in the coastal Caribbean region, its first occurrence in the Americas.  In the 1950s, Panama disease wiped out the Gros Michel banana, the commercial predecessor of the Cavendish.

Scientists at the University of Cambridge have found a novel way to combine two species of grass-like plants – which include bananas, rice, and wheat – using embryonic tissue from their seeds.  The technique allows beneficial characteristics, such as disease resistance, to be added to the plants.

Joining the shoot of one plant to the root of another to grow as one plant is known as grafting.  It was thought to be impossible to do with grass-like plants – called monocotyledonous  grasses – because they lack a certain tissue type in their stems.  But the new research, published in the journal Nature, showed it can be done with the plants in their earliest embryonic stages.

Cavendish bananas are sterile, so disease resistance can’t be bred into future generations.  But the grafting technique may provide a way to produce Cavendish banana plants that are resistant to Panama disease.  It may be possible to save an important food crop before it is too late.

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New grafting technique could combat the disease threatening Cavendish bananas

Photo, posted July 1, 2015, courtesy of Augustus Binu via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Crops Threatened With Extinction | Earth Wise

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Crop variety and diversity are critically important for global food security as well as for the livelihoods of millions of people.  This diversity entails both the different species of food crops as well as the so-called farmer varieties of crops that in many cases have been cultivated and safeguarded for millennia.

It is well-known that many of these crops and varieties have been rapidly disappearing, but data has been scarce on just how many have been lost, how many we are losing, and which ones are the most threatened going forward.

A new study utilizes a methodology known as the Varietal Threat Index, which was developed by the Alliance of Bioversity International and CIAT, the International Center for Tropical Agriculture.  The study assessed about 600 farmers from seven Indian states, covering five different agroecological areas.  The farmers were selected based on their knowledge of crops and varieties across the 17 study sites.

The farmers listed the crops and varieties grown in their households, noted their uses, and indicated their spread and abundance, including information on varieties grown during the previous ten years which were no longer grown.

The results of the study showed that while there is a significant diversity of landraces – which are local varieties of species developed over time – more than 50% are threatened.  The trend is that crops and varieties mostly used for consumption are most often under threat, whereas varieties with multiple uses are less likely to be threatened.

Studies of this type can aid the development of targets and indicators to monitor the global status of plant genetic resources for food and agriculture and help inform urgent priority conservation actions.

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More than half of surveyed crop varieties are under threat of extinction, according to study in India

Photo, posted February 21, 2014, courtesy of Atibordee Kongprepan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Coral Reefs And Ecosystem Services

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A new study led by the University of British Columbia provides the first comprehensive look at what climate change, overfishing, and habitat destruction of coral reefs mean for their ecosystem services.  For humans, this means how the global decline in coral reefs has affected their ability to provide essential benefits including food, livelihoods, and protection from storms.

The study found that global coverage of living corals has declined by about half since the 1950s and the diversity of reef species has declined by more than 60%.  So, it is no surprise that there has been a significant loss in the ability of reefs to provide ecosystem services.

The study analyzed data from coral reef surveys around the world, fisheries catches, indigenous consumption, and more.  Apart from the declines in reef coverage and biodiversity, the study found that fish catches on coral reefs peaked in 2002 and has steadily declined since then, despite increased fishing efforts.

The findings of the study led the researchers to conclude that continued degradation of coral reefs in the years to come threaten the well-being and sustainable development of millions of people in communities on the coast that depend on coral reefs.  Fish and fisheries provide essential nutrients in places with few alternative sources of nutrition.  Coral reef biodiversity and fisheries have added importance for indigenous communities, where important cultural relationships exist with reefs.

The study’s authors say that the results are a call to action.  The level of destruction happening all over the world’s coral reefs is threatening people’s culture, their daily food, and their history.  It is not just an environmental issue; it is a human rights issue.

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Photo, posted September 22, 2010, courtesy of David Burdick / NOAA Photo Library via Flickr.

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