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Ecoregion-Based Plant Lists and Search

March 30th, 2022 by Alex Zorach

We have published plant lists for particular ecoregions, and related to these lists, added the ability to search for plants within a specific region and see their establishment means (i.e. Native, Introduced, Expanded, etc.) in that region in searches.

This is super exciting as it was one of the original goals of bplant.org, and has been years in the making. This post highlights where to find these new features, and how to interpret them and best put them to use. It also explains some of the background work that went into building the lists, including recent progress since our last blog post, and lastly, outlines future improvements and features underway.

Where to Find The Lists and Search

The lists currently are only available for Level 3 ecoregions. You can find these lists from a new "Plants" section listed on each of these region's pages. For convenience, we also linked to the lists for the Level 3 regions on all of the Level 4 subregions, accompanied by a message explaining that we do not yet have the lists for the regions with a finer level of detail.

How to Get to These Ecoregion Pages

There are many ways to reach the page for a region. If you want to look up a region at a particular point on a map, you can use our ecoregion locator which is linked to from the footer of every page on our site. You can also browse our state ecoregion maps to see the entirety of the ecoregions in each state. Alternatively, you can explore the whole hierarchy of regions from the Regions tab at the top of our site. Once you are on the page for a Level 3 or 4 region that intersects the continental US, you will see the new "Plants" tab.
Cropped screenshot of Ozark Highlands region pageThis screenshot shows the new tab visible on the pages for Level 3 and 4 ecoregions in the continental US, which takes you to the new plant lists and search.

Some of the Level 3 regions extend outside the continental U.S., and some of them are completely located outside this region, including in Canada, Alaska, and Mexico. As we have not yet comprehensively built plant range maps into these regions, we do not yet have the data to generate plant lists for these regions.

For regions that are entirely outside the continental US, there are no lists yet. For regions that span part of the continental US but also have significant areas outside of them, we have published lists but with a warning that they are incomplete.
This screenshot shows the new Plants section of the region page, linking to plant lists and also allowing an in-region search. Regions intersecting, but also extending outside the continental US, display this warning.

In-Region Search and Improvements to Search

The in-region search has an exciting new feature, made possible by the fact that you are searching within a specific region: the notation of the plant's status in the region, in the search itself. For example, the following screenshot shows a search for "Magnolia" in the Northern Piedmont. The entries in the "Map" column are color-coded to show the plant's status in the region.
An illustration of the new in-region search with a legend explaining the color codes.

Note that there are now two separate pieces of information communicated in the Map column: both the completeness of the map (with the gray stripes through tentative maps that have not yet been completed for the entirety of North America) and the establishment means for the particular plant in the region. There is a legend at the end of the search, denoting what each color means.

Updates That Made The Lists Possible

Probably the most important progress reflected in these lists is a massive cleaning of the data on the presence/absence, and establishment means (i.e. native, introduced, or expanded) of each plant in each ecoregion.

We have also been cleaning up our data on the plants themselves, which includes things such as merging duplicate records (including taxa that have merged due to reclassification), correcting missing and/or erroneous data, and correcting mis-linked data and linking more records to other databases such as USDA PLANTS and BONAP. We have reduced the number of plants in our database to a more manageable 20,579, and may reduce it further as there are still some duplicates and otherwise problematic entries. Both as a result of cleaning out the entries, and completing more maps, a much greater portion of the listed plants now have range maps, and the portion verified for the entirety of North America is also increasing.

How To Use These Lists and Search Results

Keep in mind that, although our level 3 ecoregions are, on average, smaller than most US states, and they do a much better job of corresponding to plant distributions, they are still a coarse instrument. If we mark a plant as present in a region, it means only that it occurs in the wild somewhere in that region; it is not necessarily common (or even present) in all parts of the region. In many cases, such as where plants reach their range limits in a region, plants may only occur in a small portion of each region. This is particularly common for regions that span a long distance.
The Sonoran Basin and Range extends from southeast California and much of Arizona well into Mexico, in Baja California and Sonora. Many plants found in this region are only found in a small portion of it. For example, the Saguaro (Carnegiea gigantea) is only found at low elevations, and even there does not extend into Baja California. Public Domain photo by US Bureau of Land Management, Source.

These lists and searches are thus best used only as a starting point and/or an instrument to narrow down your consideration of certain plants. If you are considering choice of plants for an ecological restoration project or garden, you will still need to do additional work to determine the plant's range and status in your area, on a finer-tuned level.

To this end we recommend checking the BONAP and/or USDA PLANTS county-level range maps (When both exist, BONAP is usually more accurate), which we have linked to from the "Links" section in each article, for convenience. You may also want to use regional sources, such as Calflora, the Maryland Plant Atlas, or whatever other state and regional resources are suitable for your area.

If our article on a particular plant is complete, you may also find information about its distribution either in notes written under the range map itself, or in the "Habitat" section, which leads into our next consideration. Check the links section to see what is listed; there may even already be some links to other regional resources. Even if a plant occurs broadly in your region, it will only occur in certain habitats.

Future Improvements

The current state of our plant lists is only a beginning. In the future we aim to add a number of features, including:
  • Expanding our data to include ecoregions outside the continental US
  • Adding higher levels of detail, such as level 4 ecoregions
  • Allowing generation of lists and searches for lower levels of details or aggregate regions, such as the level 1 or 2 ecoregions.
  • The filtering of plants by various characteristics, including taxonomy (such as plant families or other broad groupings), a plant's growth habit or form (i.e. Tree / Shrub / Perennial / Biennial / Annual / etc.) or habitat preferences (i.e. wetland/upland or moisture preferences, sun/lighting conditions, soil types, etc).
  • The display of establishment means (Native/Introduced/Expanded/etc.) on general searches, for those plants that have a single status type in the entirety of North America.
Some of these changes will likely come sooner than others. We are already well on our way to expanding plant range maps outside the continental US, and the lists for aggregate regions (level 1 or 2 ecoregions) will likely require less work than some of the other features.

Until then, please enjoy what we have already published!