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Crop diversity is needed today for tomorrow's food security and nutrition – Phys.org

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by The Alliance of Bioversity International and the International Center for Tropical Agriculture

Bean diversity at the CGIAR gene bank in Colombia. Credit: Neil Palmer / CIAT

Although scientists have been ringing bells for more than 100 years about the decline of crop diversity in agriculture, questions about the magnitude, causes, and significance of this loss remain unanswered.

A team of 15 scientists from a wide range of research centers and universities set out 18 months ago to answer these persisting questions, resulting in the largest review ever conducted of evidence about change in crop diversity over time worldwide. The team reviewed hundreds of primary literature sources published over the last 80 years that examine potential crop diversity loss, also called “genetic erosion”. The global collaborative effort found that 95% of all studies reported diversity change, and almost 80% found evidence of loss.

Economic, agricultural, technological, climatic, and political changes during the last 100 years have together led to the decline or disappearance of diversity important to agriculture, both from cultivated fields and from wild habitats. Much of the crop diversity that remains continues to face the threat of erosion or even extinction, while also becoming more homogenous across local landscapes and around the world.

“The global picture that emerges from our review is that of enormous loss over a relatively short period of time of traditional agricultural diversity, which was nurtured by many cultures around the world over the last 10,000 years,” said lead author Colin Khoury, Senior Director for Science and Conservation at San Diego Botanic Garden and research scientist at the Alliance of Bioversity International and the International Center for Tropical Agriculture (CIAT). “Yet the picture also provides hope, as considerable crop diversity persists, and because it shows that agriculture can be re-diversified.”

Khoury collaborated with scientists at international and national agricultural research centers in the U.S., Colombia, Germany, Italy, Mexico, and Peru, as well as universities including El Colegio de la Frontera Sur (Chiapas, Mexico), Ohio State University, Saint Louis University, the University of Arizona, the University of California at Davis, the University of Cambridge, and the University of Illinois to carry out the study, which published in New Phytologist as a Tansley review. This review series was named after the famous English botanist and ecologist Arthur Tansley, who coined the term ecosystem in 1935.

Crop diversity is a critically important resource for agriculture and for human nutrition. This diversity keeps crops productive as they face pests and diseases, provides resilience during extreme weather and other shocks and offers the potential to adapt to changing climates and meet new market demands. In contributing to crop productivity and also to dietary diversity, it underpins food security and nutrition.

“The magnitude of crop diversity loss we have seen in some regions of the world underscores the importance of conserving this diversity outside of these ecosystems as well as within them,” said Luigi Guarino, Director of Science at the Crop Trust, and one of the study’s authors. “Collections of crop diversity such as those in agricultural genebanks and botanic gardens can mitigate local and regional losses, enable the future reestablishment of diversity on farms, and preserve the availability of crops for future use by all. We need to strengthen these repositories and duplicate unique collections in other locations to insure against the risk of loss,” he said.

There are approximately 1,750 genebanks worldwide, maintaining over seven million samples of crop diversity, with , universities, nonprofits, community seed banks, and local conservation networks further contributing to ex-situ conservation. However, more work is needed to conserve the full range of diversity at risk of disappearing from farmers’ fields and, in the case of crop wild relatives, the wild progenitors and cousins of cultivated plants, from grasslands, forests and other natural habitats.

The study analyzed the change in the diversity of traditional crop varieties, or landraces, cultivated on farms; of modern crop cultivars in agriculture; of crop wild relatives in their natural habitats; and of crop genetic resources held in ex situ conservation repositories. The extent of change over time in these environments, while considerable, varied by crop, location, and analytical approach.

“The good news is that while we found evidence of enormous diversity loss over the past decades in each of the environments we studied, we also saw significant maintenance of that diversity in some contexts, and even marked increases in specific instances,” said Stephen Brush, second author for the study and Professor Emeritus of Human Ecology and former Master Adviser for International Agricultural Development at UC Davis.

Diversity of traditional crops remains high on farms and in gardens where landraces are valued for their unique agricultural and societal uses. One-third of the 139 studies of changes in traditional crop varieties reported the maintenance of this diversity over time, and almost one-quarter found evidence for the appearance of new diversity. Also, crop breeders have made significant strides toward diversifying modern crop cultivars in recent decades.

“For crop diversity to continue evolving alongside pests and diseases, in response to climate change, and to meet demands for improved that provide both economic products and ecological services, we need to redouble support for conservation efforts in situ, or in the field, as well as ex situ,” said co-author Allison Miller, Member and Principal Investigator at the Danforth Plant Science Center and Professor of Biology at Saint Louis University.

“In reviewing global change in the that underpins everyone’s food security and nutrition, it’s obvious that there has been major loss, but also that the tools, methods, and knowledge exist to stop its further erosion,” said Khoury. “It is a matter of priorities and resources. To go a major step further and start to reverse the diversity trend, though, is a much bigger task. It requires no less than reframing our food systems, and even the societies they nourish, as -supportive processes.”


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More information:
Colin K. Khoury et al, Crop genetic erosion: understanding and responding to loss of crop diversity, New Phytologist (2021). DOI: 10.1111/nph.17733

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The Alliance of Bioversity International and the International Center for Tropical Agriculture

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Here’s how Helene and other storms dumped a whopping 40 trillion gallons of rain on the South

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More than 40 trillion gallons of rain drenched the Southeast United States in the last week from Hurricane Helene and a run-of-the-mill rainstorm that sloshed in ahead of it — an unheard of amount of water that has stunned experts.

That’s enough to fill the Dallas Cowboys’ stadium 51,000 times, or Lake Tahoe just once. If it was concentrated just on the state of North Carolina that much water would be 3.5 feet deep (more than 1 meter). It’s enough to fill more than 60 million Olympic-size swimming pools.

“That’s an astronomical amount of precipitation,” said Ed Clark, head of the National Oceanic and Atmospheric Administration’s National Water Center in Tuscaloosa, Alabama. “I have not seen something in my 25 years of working at the weather service that is this geographically large of an extent and the sheer volume of water that fell from the sky.”

The flood damage from the rain is apocalyptic, meteorologists said. More than 100 people are dead, according to officials.

Private meteorologist Ryan Maue, a former NOAA chief scientist, calculated the amount of rain, using precipitation measurements made in 2.5-mile-by-2.5 mile grids as measured by satellites and ground observations. He came up with 40 trillion gallons through Sunday for the eastern United States, with 20 trillion gallons of that hitting just Georgia, Tennessee, the Carolinas and Florida from Hurricane Helene.

Clark did the calculations independently and said the 40 trillion gallon figure (151 trillion liters) is about right and, if anything, conservative. Maue said maybe 1 to 2 trillion more gallons of rain had fallen, much if it in Virginia, since his calculations.

Clark, who spends much of his work on issues of shrinking western water supplies, said to put the amount of rain in perspective, it’s more than twice the combined amount of water stored by two key Colorado River basin reservoirs: Lake Powell and Lake Mead.

Several meteorologists said this was a combination of two, maybe three storm systems. Before Helene struck, rain had fallen heavily for days because a low pressure system had “cut off” from the jet stream — which moves weather systems along west to east — and stalled over the Southeast. That funneled plenty of warm water from the Gulf of Mexico. And a storm that fell just short of named status parked along North Carolina’s Atlantic coast, dumping as much as 20 inches of rain, said North Carolina state climatologist Kathie Dello.

Then add Helene, one of the largest storms in the last couple decades and one that held plenty of rain because it was young and moved fast before it hit the Appalachians, said University of Albany hurricane expert Kristen Corbosiero.

“It was not just a perfect storm, but it was a combination of multiple storms that that led to the enormous amount of rain,” Maue said. “That collected at high elevation, we’re talking 3,000 to 6000 feet. And when you drop trillions of gallons on a mountain, that has to go down.”

The fact that these storms hit the mountains made everything worse, and not just because of runoff. The interaction between the mountains and the storm systems wrings more moisture out of the air, Clark, Maue and Corbosiero said.

North Carolina weather officials said their top measurement total was 31.33 inches in the tiny town of Busick. Mount Mitchell also got more than 2 feet of rainfall.

Before 2017’s Hurricane Harvey, “I said to our colleagues, you know, I never thought in my career that we would measure rainfall in feet,” Clark said. “And after Harvey, Florence, the more isolated events in eastern Kentucky, portions of South Dakota. We’re seeing events year in and year out where we are measuring rainfall in feet.”

Storms are getting wetter as the climate change s, said Corbosiero and Dello. A basic law of physics says the air holds nearly 4% more moisture for every degree Fahrenheit warmer (7% for every degree Celsius) and the world has warmed more than 2 degrees (1.2 degrees Celsius) since pre-industrial times.

Corbosiero said meteorologists are vigorously debating how much of Helene is due to worsening climate change and how much is random.

For Dello, the “fingerprints of climate change” were clear.

“We’ve seen tropical storm impacts in western North Carolina. But these storms are wetter and these storms are warmer. And there would have been a time when a tropical storm would have been heading toward North Carolina and would have caused some rain and some damage, but not apocalyptic destruction. ”

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Associated Press climate and environmental coverage receives support from several private foundations. See more about AP’s climate initiative here. The AP is solely responsible for all content.

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‘Big Sam’: Paleontologists unearth giant skull of Pachyrhinosaurus in Alberta

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It’s a dinosaur that roamed Alberta’s badlands more than 70 million years ago, sporting a big, bumpy, bony head the size of a baby elephant.

On Wednesday, paleontologists near Grande Prairie pulled its 272-kilogram skull from the ground.

They call it “Big Sam.”

The adult Pachyrhinosaurus is the second plant-eating dinosaur to be unearthed from a dense bonebed belonging to a herd that died together on the edge of a valley that now sits 450 kilometres northwest of Edmonton.

It didn’t die alone.

“We have hundreds of juvenile bones in the bonebed, so we know that there are many babies and some adults among all of the big adults,” Emily Bamforth, a paleontologist with the nearby Philip J. Currie Dinosaur Museum, said in an interview on the way to the dig site.

She described the horned Pachyrhinosaurus as “the smaller, older cousin of the triceratops.”

“This species of dinosaur is endemic to the Grand Prairie area, so it’s found here and nowhere else in the world. They are … kind of about the size of an Indian elephant and a rhino,” she added.

The head alone, she said, is about the size of a baby elephant.

The discovery was a long time coming.

The bonebed was first discovered by a high school teacher out for a walk about 50 years ago. It took the teacher a decade to get anyone from southern Alberta to come to take a look.

“At the time, sort of in the ’70s and ’80s, paleontology in northern Alberta was virtually unknown,” said Bamforth.

When paleontogists eventually got to the site, Bamforth said, they learned “it’s actually one of the densest dinosaur bonebeds in North America.”

“It contains about 100 to 300 bones per square metre,” she said.

Paleontologists have been at the site sporadically ever since, combing through bones belonging to turtles, dinosaurs and lizards. Sixteen years ago, they discovered a large skull of an approximately 30-year-old Pachyrhinosaurus, which is now at the museum.

About a year ago, they found the second adult: Big Sam.

Bamforth said both dinosaurs are believed to have been the elders in the herd.

“Their distinguishing feature is that, instead of having a horn on their nose like a triceratops, they had this big, bony bump called a boss. And they have big, bony bumps over their eyes as well,” she said.

“It makes them look a little strange. It’s the one dinosaur that if you find it, it’s the only possible thing it can be.”

The genders of the two adults are unknown.

Bamforth said the extraction was difficult because Big Sam was intertwined in a cluster of about 300 other bones.

The skull was found upside down, “as if the animal was lying on its back,” but was well preserved, she said.

She said the excavation process involved putting plaster on the skull and wooden planks around if for stability. From there, it was lifted out — very carefully — with a crane, and was to be shipped on a trolley to the museum for study.

“I have extracted skulls in the past. This is probably the biggest one I’ve ever done though,” said Bamforth.

“It’s pretty exciting.”

This report by The Canadian Press was first published Sept. 25, 2024.

The Canadian Press. All rights reserved.

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The ancient jar smashed by a 4-year-old is back on display at an Israeli museum after repair

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TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.

Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.

Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.

The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.

The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.

It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.

Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.

Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.

Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.

Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.

Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.

The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”

The Canadian Press. All rights reserved.

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