What are local ecotype plants and why do they matter to pollinators?

With the planting season upon us, many of us are starting to think about what flowers may be the best for our gardens and pollinators. We may have started to look into floral mixes or even flower starts, but probably there are too many choices and now we’re overwhelmed and don’t know what to do. In previous posts, we talked about the importance of diverse floral choices and how appropriate native species are when choosing plants for pollinators. There is, however, an extra twist that is becoming more mainstream in this story and today I want to talk about it. Let’s chat about local ecotypes, what they are, what they contribute, and how to get them (and how to not get them).

What are local ecotypes?

In a few words, local ecotypes are native plant species that have a genetic background typical for the local region and adapted to it. I know, there were a lot of technical words in that sentence, so let me break it down to make it easier to understand.

Like all organisms, plants have lineages that reflect their ancestry. In the same way that we as humans are genetically more closely related to members of our own family than to those of other families, plant populations are also more closely related to other plants of the same species that live close to them. From a genetic point of view, this means that plants that come from regions close to each other will tend to have more similar genetic characteristics than those from regions far apart from each other. This genetic makeup specific to a given region is what we call broadly a local genotype.

a variety of native plants in a garden
Green spaces that display native ecotypes are likely more adapted to the climate and soils of a place, can be more resistant to some herbivores, and can act as better sources of rewards for pollinators. Photo: R. Frazier.

These plant species that have local genotypes do not only share genes with each other; they also share their evolutionary history. This means that a plant species that has populations in a specific region has been adapting over many generations to the environmental conditions that exist(ed) in that specific region. Those conditions may include the climate, the soils, the pollinators, and the herbivores (animals that feed on plants). This means that because of that long adaptation to their local environment, local genotypes usually perform better in local conditions. These plant populations that have local genotypes then also have local ecotypes that are able to survive better in a specific region and provide better services to, for example, pollinators that are also native and local to the same region.

Why are local ecotypes usually recommended for gardens and yards?

As I was saying above, because of the long adaptive processes that the local plant populations of a species have been going through, plants from those populations often do better in local conditions than those of the same species but from other regions. This has several very practical consequences.

Local ecotypes usually do better in the local soil and climate conditions

The long-term adaptation to the local soil and climatic conditions make local ecotypes often perform really well in green spaces that display those local natural conditions. These plants will also tolerate better climatic conditions that are specific to the given region, suffering less from common local extremes than their non-local counterparts. For example, a columbine plant that naturally occurs in the Maryland Piedmont will likely do really well in a yard from that region, but seeds or starts of the same species but from a genotype/ecotype from Ohio may underperform in that same yard. In this respect, planting local ecotypes can lead to plants that establish more easily and thrive faster in our local green spaces.

Local ecotypes are usually better resources for local pollinators

Again, because of their long-term relationship and adaptation to the local conditions, local ecotypes are likely to have also been evolving to become more adapted to the local cohort of pollinators of the region. If we are trying to provide high-quality resources to our local populations of native pollinators, planting local ecotypes is probably the best choice. These plants are likely to provide the right type and amount of pollination rewards that pollinators in the local area seek, thus positively contributing to sustaining their populations.

Local ecotypes can be more resistant to local herbivores

In the same way that these ecotypes may be better adapted to the local pollinators, they may also be more adapted to dealing with and recovering from local native herbivores. This may mean that the plants are less palatable to local herbivores, or that they are able to bounce back better from an herbivore attack than their non-local counterparts. From a green space management point of view, this could mean being able to reduce the number of pesticide applications, or the need to replace the plants because they could not properly handle the attack.

Planting local ecotypes helps local wild populations of the plant

By choosing these local ecotypes for our green spaces, we also help wild plant populations to continue to maintain their genetic characteristics because crosses between the plants we plant and those that live naturally in the wild will lead to wild seeds that continue to carry the locally-adapted genetic characteristics. In this respect, planting local ecotypes prevents local natural populations to lose their local adaptations through crossings with non-local ecotypes. By planting local ecotypes in our spaces, we can then help wild populations continue to thrive.

native plant nursery with various potted plants next to a greenhouse
Several local nurseries produce and propagate local ecotypes. Next time you buy natives, make sure to ask your nursery about their origin! Photo: M. McClure.

OK, I want to plant local ecotypes. How can I get them?

Several nurseries and seed producers in our area specialize in the production and growing of local ecotypes, and it takes just asking them about the origin to make sure that one is making the right choice. These nurseries usually obtain plants or seeds from the wild using specific and certified procedures that are sustainable to the local wild populations (and that require holding specific permits). For this reason, it is important to understand that it is not a good idea (and in some cases, illegal) to collect plants from the wild to transfer them to our gardens. Instead, a visit to our favorite native nursery is the best way for us to support the local biodiversity through gardening!

For additional information on native plants and ecoregions, visit the Home & Garden Information Center page: What is a native plant? The bPlant.org website is another resource you can use to explore Ecoregions of Maryland and the plants adapted to each region.

By Anahí Espíndola, Assistant Professor, Department of Entomology, University of Maryland, College Park. See more posts by Anahí.

Anahí also writes an Extension Blog in Spanish! Check it out here, extensionesp.umd.edu, and please share and spread the word to your Spanish-speaking friends and colleagues in Maryland. ¡Bienvenidos a Extensión en Español!

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