- Seed banks are a cheap and effective way of protecting species against extinction and securing genetic diversity.
- The most important seed banks in Brazil are devoted to agricultural species and varieties. Seeds from native species and species that are threatened of extinction are still a minority.
- The Global Strategy for Plan Conservation, a program from the Convention on Biological Diversity, establishes that every country should keep 75 percent of its endangered plant species in off-site collections, such as seed banks, by 2020.
- Brazil will not meet the target and experts argue for the need of a national policy.
RIO DE JANEIRO — The botanical garden here sits just below Corcovado hill, at the feet of the iconic Christ the Redeemer statue. Boasting 54 hectares (133 acres) and more than 7,000 trees and plants, it is a favorite spot for visitors to roam and discover some of Brazil’s impressive biodiversity. But in addition to being a calming, beautiful green space for leisure, the Rio de Janeiro Botanical Garden is also one of the oldest scientific institutions in the country. Founded in 1808, it was originally created to acclimatize foreign species with commercial interest to the local climate and soil conditions.
That scientific spirit is still very much alive today.
Inside the Botanical Garden research facilities is one of the most important native seed banks in Brazil. Seed banks are collections of seeds that are kept viable by storing them at low temperatures.
In recent years, seed banks of native species have been gaining momentum as a way of preserving endangered biodiversity, a critical issue in Brazil, a megadiverse country with many threatened species.
“From the species conservation point of view, seed banks are probably one of the cheapest alternatives there are,” said Antônio Carlos Andrade, curator of the botanical garden. “We use the same principles used to preserve food, but in a more refined way.”
These principles allow researchers to store the seeds for very long periods at a relatively low cost. The procedure is simple: Following an expedition, the collected seeds are tested for germination. If they germinate well enough, the seeds are dried, put into waterproof bags, sealed, and stored in freezers at -20 degrees Celsius (-4 degrees Fahrenheit).
Under these conditions, they can be kept for years.
However, not all seeds can be stored this way. Iconic species from Brazilian forests, such as the endangered juçara palm tree (Euterpe edulis), cacao tree (Theobroma cacao) and rubber tree (Hevea brasiliensis) are examples of species that produce what researchers call “recalcitrant seeds,” which don’t take well to the process of dehydration and the low temperatures.
Brazil’s largest seed bank is located in the capital Brasilia, in the facilities of a national research institution called Embrapa, the Brazilian Agricultural Research Corporation. According to seed bank curator Juliano Pádua, the bank has around 130,000 samples from 1,019 different species, most of them related to agriculture and with an economic interest. For each species, the bank has thousands of accession numbers, each one corresponding to a specific variety.
“Our largest collections are those of Oryza (rice), with 18,347 accessions, Hordeum (barley) with 18,618 accessions, Phaseolus (bean) with 12,528 accessions, Glycine (soy) with 9,890 accessions and Triticum (wheat) with 5,150 accessions,” Pádua said.
Seed banks such as this one play a critical role in ensuring food security. Some of the varieties stored there have special features, such as being resistant to drought or less vulnerable to disease. This is critical for modern farmers, who are experiencing increasingly common episodes of extreme weather.
The road to Target 8
In contrast to the large figures for agricultural species, the storage of native seeds for conservation purposes is still rare. In 2002, the Global Strategy for Plant Conservation (GSPC), a program by the Convention on Biological Diversity (CBD), set up 16 targets that countries should achieve by 2020 in order to protect global forests and plant diversity.
One of those goals, known as Target 8, requires that countries keep “at least 75 percent of threatened plant species in ex situ collections, preferably in the country of origin, and at least 20 percent available for recovery and restoration programs.”
These collections can include seed banks, as well as other strategies where species are planted or kept alive in places different from their natural habitat, such as botanical gardens.
According to a recent survey, Brazil has 452 of its 2,113 endangered species in ex situ collections, most of them originally from the Atlantic Forest. Of these, only 52 species are stored in seed banks. Although that number is almost double last year’s figure, it is still very low, say Alberto Teixido and Fernando Silveira, researchers at the Federal University of Minas Gerais and two of the authors of the survey. To them, seed banks are the best ex situ conservation option, as it grants long-term conservation and genetic diversity.
“In a botanical garden you may have, let’s say, three planted individuals,” Teixido said. “If there were a plague or any other problem, they would be more susceptible to be damaged and disappear than if you had a collection of 1,000 or 2,000 seeds from different populations, different individuals.”
With currently only 21.4 percent of its endangered species in ex situ collections, Brazil is unlikely to meet the 75 percent target by 2020, according to Silveira and Teixido. They say one of the reasons is that Brazil, with its megadiverse biomes such as the Amazon and the Atlantic Forest, has an extremely rich biodiversity, which means that the number of collected species required to meet Target 8 is also very high. But there shortage of funding is also an issue.
“Countries such as Australia, France, the U.K. and the USA are investing in ex situ conservation,” Silveira said. “And it is not just developed countries, developing countries such as South Africa, Colombia or Mexico are way ahead of us.”
For Silveira, the main problem is not so much the low level of funding, as it is the lack of a national policy for ex situ conservation. He says that what is need is for the government to coordinate all the people working in seed banks and ex situ conservation, the same way it did for another GSPC goal, Target 1, which required countries to create an online flora of all known plants.
“For Target 1 they put together a network of 400 taxonomists to determine how many species the country has,” Silveira said. “We have the human resources to meet Target 8, what we need is to create an articulation between all the institutions involved.”
Next August, South Africa will host the Global Partnership for Plant Conservation Conference, where scientists and policymakers will discuss the implementation of the GSPC targets and plan future goals.
Banner image of germinating seeds in a seed bank by Ignacio Amigo for Mongabay.
Ignacio Amigo is a freelance journalist based in São Paulo, Brazil. You can find him on Twitter at @IgnacioAmigoH.
FEEDBACK: Use this form to send a message to the author of this post. If you want to post a public comment, you can do that at the bottom of the page.