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 botanic gardens, 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 crops 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 crop diversity 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 diversity-supportive processes.”
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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Crop diversity is needed today for tomorrow’s food security and nutrition (2021, October 20)
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NAIROBI, Kenya (AP) — The body of Ugandan Olympic athlete Rebecca Cheptegei — who died after being set on fire by her partner in Kenya — was received Friday by family and anti-femicide crusaders, ahead of her burial a day later.
Cheptegei’s family met with dozens of activists Friday who had marched to the Moi Teaching and Referral Hospital’s morgue in the western city of Eldoret while chanting anti-femicide slogans.
She is the fourth female athlete to have been killed by her partner in Kenya in yet another case of gender-based violence in recent years.
Viola Cheptoo, the founder of Tirop Angels – an organization that was formed in honor of athlete Agnes Tirop, who was stabbed to death in 2021, said stakeholders need to ensure this is the last death of an athlete due to gender-based violence.
“We are here to say that enough is enough, we are tired of burying our sisters due to GBV,” she said.
It was a somber mood at the morgue as athletes and family members viewed Cheptegei’s body which sustained 80% of burns after she was doused with gasoline by her partner Dickson Ndiema. Ndiema sustained 30% burns on his body and later succumbed.
Ndiema and Cheptegei were said to have quarreled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.
Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack. She finished in 44th place.
Cheptegei’s father, Joseph, said that the body will make a brief stop at their home in the Endebess area before proceeding to Bukwo in eastern Uganda for a night vigil and burial on Saturday.
“We are in the final part of giving my daughter the last respect,” a visibly distraught Joseph said.
He told reporters last week that Ndiema was stalking and threatening Cheptegei and the family had informed police.
Four in 10 women or an estimated 41% of dating or married Kenyan women have experienced physical or sexual violence perpetrated by their current or most recent partner, according to the Kenya Demographic and Health Survey 2022.
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.”
VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.
Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”
Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.
“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.
B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.
Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.
Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.
Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.
“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”
Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”
“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.
Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.
“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.
This report by The Canadian Press was first published Sept. 9, 2024.
