Seed banks boost biodiversity in the face of climate change


Lauren Lively

Cronkite News

With a changing climate causing extreme weather — such as frequent wildfires in California and relentless drought in Arizona — some species that were on the list of extinction are being given a second chance through seed banks.

More than 1,000 seed banks are positioned around the world, including 20 in the United States, working to preserve fragile ecosystems that are becoming less diverse as the planet warms. While some banks only specialize in their native species, some banks stock seeds from all over the world.

The California Botanic Garden at Claremont bank, which preserves the genes of more than 6,000 seed species, also hosts other living organisms and assists in broader conservation efforts, such as vegetation mapping and monitoring of rare plants.

The work counts for California Botanic Garden’s director of conservation programs, Naomi Fraga, a botanist specializing in plant conservation and floristics.

“Thinking about the extinction crisis and global change, it is possible that we will lose many plant populations in the near future,” Fraga said. “And in fact, we know that we have populations here that are actually extinct in the wild. Not entire species, but populations that no longer exist. And so these materials represent something absolutely irreplaceable.

Seeds are stored as a backup policy so that multiple varieties of a species are available somewhere in the world and can be cultivated or reintroduced into the wild at any time.

“Each seed represents a distinct genetic individual,” Fraga said. “And they’re usually small, so you can fit billions of genetically distinct individuals into a relatively small space and store huge amounts of genetic diversity.”

The seed bank has been around for a century, viewed in an agricultural context as it relates to food security, Fraga said.

“Now in agriculture they are not just focusing on the specific types of cultivars that are grown to produce food, but they are also wild relatives of seed bank crops,” she said. . “For example, the banana is a good example of a crop that is heading towards extinction, due to a fungal pathogen.”

When a fungal disease infected the beloved Gros Michel banana and nearly wiped out the entire species in the 1950s, the industry turned to another banana species, the Cavendish. Since bananas are from propagation and are genetic clones, there is concern that Cavendish bananas will suffer the same fate as Gros Michel.

“If we don’t support global banana diversity, there won’t be any more bananas to eat in the future,” Fraga said. “So we can’t just focus on the foods we’re currently consuming. We need to think about their wild relatives because that is the source of future genetic diversity that people will need to tap into for us to improve crops.

While it is important to save rare plants, the goal of seed banks is to collect and preserve as much genetic diversity as possible. And maybe even one day, entire ecosystems.

Since seed banking for biodiversity has only been practiced for the past 100 years, the duration of seed storage is not fully understood. However, scientists understand why seeds respond to different types of storage, and they are making more discoveries every day.

Cheryl Birker, seed saving program manager at the California Botanic Garden, recounted an accidental discovery.

When cold stratifying several varieties of seeds – an operation to induce the seeds to germinate – the refrigerator malfunctioned and the shelves collapsed causing the seeds to mix.

Although the seeds did not germinate long before the accident, the samples started to grow. Botanists have found that this variety of species prefers physical disturbance.

“We’ll do germination tests to try to detect if any of our (banked) species are dying,” Birker said, “and then we’d make plans either to remember, we could plant them in the nursery and do a second – collecting generation seeds or finding other ways if we really find that this species doesn’t seem to be living in storage at all, we would have to find another measure, like maybe having a living collection in the garden .

Sometimes scientists are lucky and find well-preserved samples in nature. In 2012, scientists were able to bring back Stenophyllous catchfly
because ancient Siberian squirrels stored berries of the flowering plant 32,000 years ago. Because examples like this exist in nature, scientists are optimistic that seed banks will be a barrier that secures biodiversity and helps create food security.

To ensure that biodiversity is never lost, the California Botanic Garden sends seed collections to the National Laboratory for Genetic Resources Preservation in Fort Collins, Colorado. Although seed banks try to preserve locally stored native seeds, the botanical garden shares their collections to preserve seed samples in the event of fires, floods or other disasters.

The garden has partnered with the nonprofit California Plant Rescue and other organizations to collaborate on conservation efforts, innovations, and sample collection.

Botanists go to great lengths to collect seeds from the field, which can be dangerous. Areas are often remote with no trails or roads, and unstable weather conditions can make conditions dangerous. There is no guarantee that the collection will be successful either.

Fraga said it can take several years of collecting effort to extract some seeds.

“Rare plants are rare for a reason,” she said. “They might have reproductive issues so we might only get 100 seeds a year. So that means we have to try again in other years to try and get enough seeds where we have a sufficient collection that we feel representative of the population.

Collectors don’t want to disturb the environment or do more harm than good. This is why guidelines are in place to ensure that seed extraction is efficient and sustainable.

“We have extensive protocols to optimize the collection of genetic diversity present at the site,” Fraga said. “We only collect a sample of plants, so we cannot collect seeds from each individual. And we only harvest less than 10% of the total seed production because we don’t want to harvest too much and harm the natural population.

Land development for housing and commercial interests also plays a role in the loss of biodiversity in natural ecosystems, which is why California has many restrictions to help species survive. But gaps in these protections have put additional pressure on already fragile populations.

Birker told the sad truth behind Linanthus maculatusa rare flowering herb found about a decade ago in Ocotillo, California, near the border with Mexico.

“They found a population in an area that needed to be developed remotely,” she said, “but since it was a plant that had not yet been described and was not on any list of rare plants, they didn’t have to stop their work, and so they went ahead and razed and installed these gigantic wind turbines, and unfortunately, this project was not very successful.

The wind farm has a troubled history, including several turbine meltdowns – most recently in September, as reported by local residents and media.

Although the California Botanic Garden has banked some samples of Linanthus maculatusthis is a good example of how easily it is possible to lose a population of wild plants.

“We never know when future breakthroughs might come,” Fraga said, “and how we might learn to better restore populations. When you have nothing, you have nothing. But to have the seeds and the banks seeds, it’s kind of an insurance policy that these genetic individuals are represented somewhere, and can potentially be grown and introduced at some point.

Seed banks around the world, who share information with each other, act to promote biodiversity in natural ecosystems. To further attract public support, some seed banks have the ability to sponsor collections through donations.

Connecting with local seed banks is a great resource for anyone who wants to help preserve biological diversity.

“It just adds to a kind of life data collection and it contributes to our understanding of biodiversity,” Fraga said. “We hedge our bets, thinking, what if all these populations disappear?

“To lose it to extinction is to lose it forever.”

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