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Sustainable, Secure Food Blog

Growing food for all, sustainable for our earth.

Why is it important to have seed banks and seed access?

Species extinction due to natural and man-made influences is undeniable and a serious threat to our planet. Once they are gone, we have lost them forever.

For plants, seed banks are a way to combat this threat. They are an important part of a robust seed system for food security. Seed banks protect and save plant genetic diversity, which is important for a number of reasons. These saved and viable seeds contain a treasure trove of useful genes that breeders can use for developing improved varieties of our major food crops. For example:

  1. Improve resistance to current and emerging plant diseases and insects.
  2. Provide drought or flood tolerance.
  3. Improve yields and nutrition to feed a growing global population.

Rare, heritage, indigenous, wild or regionally-specific plants are particularly vulnerable to extinction. Their loss over time also can lead to genetic erosion of our food system. In other words, we lose the genetic diversity of a variety of crops. Adapting to climate change or new pests can be difficult without good genetic diversity. Crop breeders need a variety of genetic resources to help our crops adapt to changing conditions. As modern cultivars gain acreage and sometimes replace these plants, it becomes increasingly important to make sure these historic genetics are preserved in seed banks for future use.

In the United States, our grocery store produce sections are full of “exotic” fruits and vegetables. But, most of these are not grown in the U.S. We benefit from agriculture worldwide. The coffee you drink in the morning is not “made in the USA.” But, worldwide markets do not have the wide variety of produce that we enjoy. In addition, some diets are driven by cultural practice. In the US, we may enjoy going to an ethnic restaurant – remember the food we get there is driven by their unique cultures.

An example of unique adaptation is crop evolution on many of the Caribbean islands. The islands are relatively isolated, so plants have fewer opportunities to naturally cross with other plants. The Caribbean also enjoys a full-year growing season. These island crop varieties are uniquely adapted to the region’s growing conditions. Caribbean cultural practices have value for improving island agriculture and preserving cultural heritage through food. Storing seeds of island varieties in seed banks will help to preserve these unique foods for future generations to enjoy and share.

Seed banks also allow for faster recovery from an environmental or natural disaster that can strike in an instant. It seems as if almost every day we hear about oil spills, wild fires, hurricanes, earthquakes and flooding. These events can lead to huge losses of plant life quickly.

An example of this is the effects of Hurricane Maria. On September 20, 2017, Maria caused severe crop loss in Puerto Rico. The loss of production crops from hurricanes is an immediate problem for food and economic security. Replacing crops quickly – once conditions for growing are safe – is an important goal in island recovery. And, having access to viable seeds ready to cultivate immediately is part of this recovery.

There was a clear need for seeds for Puerto Rican growers following Hurricane Maria. The University of Puerto Rico extension service responded by efficiently distributing an estimated 8,000 pounds of donated seed. The seeds went to small-scale farms, community gardens and individuals across the entire island. From mid-December through the start of the New Year, extension agents distributed seeds. This was despite many extension offices lacking phone and regular electric service! Within weeks of receiving seeds, growers were selling seedlings and microgreens. Home gardeners, retirees and school children, in addition to career growers, all received donated seeds to jump start their produce production on the island.

The large donation was the result of what was supposed to be a small seed drive to help a handful of community gardens. The initiative grew rapidly due to requests from growers on the island and the generosity of donors (individuals, garden clubs and seed companies) from the mainland with easy access to numerous seeds.

As of this writing, it’s only been two months since planting, so it is too soon to tell what effect the wave of donated seeds will have. Initial results of baby lettuce and 6-inch zucchini harvests are promising. If planting had occurred days after the hurricane with regional seed varieties, then harvest would be earlier and yields may be higher. However, on-island seeds were unavailable to growers.

What will be better than donations after the next hurricane season? A seed system in place on islands with backup stocks of common cultivars. This will help get plants back in the ground soon after the storm. Having a seed system where home gardeners and farmers have immediate access to high-quality seed builds security and autonomy into a food system, which is valuable for a community.

Preserving genetic resources takes both an appreciation of the value of the plants and funding to follow through. Raising awareness of the value of genetic diversity is a start.

Answered by Maria Gallo and Sarah Dohle, Delaware Valley University

About us: This blog is sponsored and written by members of the American Society of Agronomy and Crop Science Society of America. Our members are researchers and trained, certified, professionals in the areas of growing our world’s food supply while protecting our environment. We work at universities, government research facilities, and private businesses across the United States and the world.

Species extinction due to natural and man-made influences is undeniable and a serious threat to our planet. Once they are gone, we have lost them forever. For plants, seed banks are a way to combat this threat. They are an important part of a robust seed system for food security. Seed banks protect and save…

Seed Bank

A seed bank is the reservoir of viable seeds present in a plant community. Seed banks are evaluated by a variety of methods. For some species , it is possible to make careful, direct counts of viable seeds. In most cases, however, the surface substrate of the ecosystem must be collected and seeds encouraged to germinate by exposure to light, moisture, and warmth. The germinating seedlings are then counted and, where possible, identified to species.

In most cases, the majority of seeds are found in surface layers. For example, the organic-rich forest floor contains almost all of the forest’s seed bank, with much smaller numbers of seeds present in the mineral soil .

The seeds of some plant species can be remarkably long-lived, extending the life of the seed bank. For example, in northeastern North America, the seeds of pin cherry (Prunus pensylvanica ) and red raspberry (Rubus idaeus ) can persist in the forest floor for perhaps a century or longer. This considerably exceeds the period of time that these ruderal species are present as mature, vegetative plants during the initial stages of post-disturbance forest succession . However, because these species maintain a more-or-less permanent presence on the site through their persistent seed bank, they are well placed to take advantage of temporary opportunities of resource availability that follow disturbance of the stand by wildfire , windstorm, or harvesting.

The seeds of many other plant species have only an ephemeral presence in the seed bank. In addition to some tropical species whose seeds are short-lived, many species in temperate and northern latitudes produce seeds that cannot survive exposure to more than one winter. This is a common trait in many grasses, asters, birches, and most conifers, including pines, spruces, and fir. Often these species produce seeds that disperse widely, and can dominate the short-lived seed banks during the autumn and springtime. Species with an ephemeral presence in the seed bank must produce large numbers of well-dispersed seeds each year or at least frequently, if they are to successfully colonize newly disturbed sites and persist on the landscape.

Although part of the plant community, seed banks are much less prominent than mature plants. In some situations, however, individual plants in the seed bank can numerically dominate the total-plant density of the community. For example, in some cultivated situations the persistent seed bank can commonly build up to tens of thousands of seeds per square meter and sometimes densities which exceed 75,000 seeds per square meter. Even natural communities can have seed banks in the low tens of thousands of seeds per square meter. However, these are much larger than the densities of mature plants in those ecosystems.

The seed bank of the plant community is of great ecological importance because it can profoundly influence the vigour and species composition of the vegetation that develops after disturbance.

[Bill Freedman Ph.D. ]

RESOURCES

BOOKS

Harper, J. L. Population Biology of Plants. San Diego: Academic Press, 1977. Grime, P. Plant Strategies and Vegetation Processes. New York: Wiley, 1979.

Seed bank A seed bank is the reservoir of viable seeds present in a plant community. Seed banks are evaluated by a variety of methods. For some species , it is possible to make careful, direct counts of viable seeds. In most cases, however, the surface substrate of the ecosystem must be collected and seeds encouraged to germinate by exposure to light, moisture, and warmth. The germinating seedlings are then counted and, where possible, identified to species. Source for information on Seed Bank: Environmental Encyclopedia dictionary.