Tag Archives: biodiversity

What is the West? 5 ways the region stands out

The “West” is as much a cultural invention as a geographical construct, so it’s a difficult place to define. Ranging from the driest of deserts to the wettest of rainforests, the lands of Western North America include an incredible diversity of ecosystems and people.

But in many ways, the American West does hang together as a region. The public domain dominates many states and the landscape tends to be much drier than the rest of the country. It is a land with limited water supplies, but vast tracts of open space, a region where extreme topography gives rise to an exceptionally rich array of species.

The West is complex and defies easy categorization, but below I explain EcoWest’s geographic focus and discuss the five characteristics that set the region apart. Links to a supporting PowerPoint deck are at the bottom of this post.

What is the West? from EcoWest on Vimeo.

The 11 Western states

Broadly speaking, EcoWest covers environmental trends in Western North America, but our research has focused on the 11 contiguous Western states: Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming.

EcoWest focus
Admittedly, this focus excludes parts of Western North America, including Alaska, Western Canada, and Northern Mexico. Some of EcoWest’s resources also cover these areas, but data availability and a need to constrain our research led us to concentrate on 11 states that share some common qualities.

Compared to the rest of the country, I think the 11 Western states stand out in five dimensions:

1)     Abundant public land

The West’s prevalence of public land—most of it federal—sets the region apart from the rest of the country and has played a pivotal role in its evolution. This pattern of land ownership explains why so much of the West has remained relatively wild. The Bureau of Land Management and Forest Service are the biggest landowners, but the West is also home to considerable tracts of tribal and state property. Public lands certainly aren’t immune to development pressures, especially because many are managed under the “multiple use” doctrine that allows grazing, mining, logging, energy development, motorized recreation, and other human activities. But all that public land is a major reason why so much of the West is unpopulated.
Federal land

2)     Aridity, with some exceptions

As you move west across the United States, the climate generally gets drier, with the notable exceptions of the Pacific Coast, Cascade Mountains, and Sierra Nevada Range. West of the 100th Meridian, irrigation is usually required to support agriculture and river flows tend to depend on melting snowpack from the mountains. Every Western state includes some very arid terrain that is far drier than anything back East, even Washington and Oregon, where the Cascade Mountains cast a stark rain shadow.  Another striking feature of the West’s climate is the spottiness of precipitation patterns and the close proximity of wet and dry areas.
Precipitation

3)     Rollercoaster topography

The West’s huge variance in precipitation is matched by its wild swings in temperature. Much of this is due to the region’s legendary topography. For example, the scorching desert of Death Valley, 282 feet below sea level and the lowest point on the continent, is only 85 miles away from the snow-capped peak of Mount Whitney, 14,505 feet above sea level and the tallest point in the contiguous 48 states.
temperature variation

4)     Diversity of species and ecosystems

The broad spectrum of elevations, temperatures, and precipitation patterns explains why the West is home to such a diverse set of ecosystems and species. In Southern Arizona, for instance, the valley bottoms are deserts filled with cacti, but the mountain ranges are two miles above sea level and support lush forests harboring moss and mushrooms. The map below shows the West’s various ecoregions, each of which is a unique ecological neighborhood that supports an impressive diversity of plants and animals, many of them found nowhere else on the planet.
Ecoregions

5)     Growing population

The preceding four factors are natural ones and are as true today as they were centuries or even millennia ago. But a final, human factor is also worth noting. The West’s population has been booming for decades. By 2030, the region is expected to be home to a quarter of all Americans, up from essentially 0 percent in 1830 and 9 percent in 1930. To be sure, other parts of the United States, such as the South, are also growing. But the steady influx of new residents in the West—and their growing demands on natural resources—is the fundamental challenge facing the region and the leitmotif in its environmental history.
western population

How would you define the West?

Defining the region as the 11 Western states has some shortcomings. Wildlife doesn’t respect lines on maps. Issues like the Keystone XL pipeline and the environmental impact of the border fence in the Southwest highlight how Canada, the United States, and Mexico are economically and ecologically integrated. We had to draw the line somewhere, but I’d be curious to hear feedback on this decision.

Likewise, I wonder if the five factors I describe above are the right ones. Are there other geographical, physical, cultural, political, or social dimensions that define the West?

Downloads

EcoWest’s mission is to analyze, visualize, and share data on environmental trends in the North American West. Please subscribe to our RSS feed, opt-in for email updates, follow us on Twitter, or like us on Facebook.

Hawaii, West and South have most at-risk species

The United States boasts the greatest diversity of ecosystems of any country and it’s home to more than 200,000 species. But about one-third of U.S. plants and animals are considered at risk by biologists, and at least 500 U.S. species are already extinct or missing.

How do the 50 states compare in terms of number of species—and their imperilment? I’ve created some simple dashboards that illustrate the state-by-state tallies. These graphics, which you can sort, print, and customize, show the number of various types of species found in each state and the fraction of those species that are imperiled.

Percent of species at risk

The data comes from Precious Heritage: The Status of Biodiversity in the United States, a great book produced by The Nature Conservancy and NatureServe in 2000. At-risk species have elevated risks of extinction, according to the system developed by the project, and therefore have the greatest conservation concern.

Here are some of the patterns I noticed in the dashboards:

  • Despite their aridity, many Western states have tons of species. Arizona and New Mexico, neither of which have any coastal habitat, rank third and fourth in total number of species.
  • Hawaii has by far the greatest percent of species at risk. The native biodiversity of this isolated archipelago has been devastated by the introduction of non-native species.
  • States in the West, especially the Southwest, also have many imperiled species. California, Arizona, Utah, and Nevada round out the top 5 states.
  • Freshwater fish are doing very poorly, especially in the West, where Arizona, Utah, Nevada, New Mexico, California, and Oregon all have at least 25 percent at risk.
  • Outside of Hawaii, birds tend to be doing better than many other types of species.

Using the dashboard

A couple of notes about the dashboards:

  • You can sort by state name or by any of the variables at the bottom.
  • Because Hawaii is such an outlier, I can be helpful to examine the dashboard by excluding that state (just click on the name and the option will pop up).
  • The toolbar at the bottom allows you to create an image or PDF, plus download the underlying data.
  • This dashboard reports the percent of a state’s species at risk, not the actual number, but that data is also provided in Precious Heritage.

Learn more in our biodiversity deck

These dashboards focus on the state level, but in our biodiversity slide deck we offer a slew of maps and graphics summarizing the national picture. The one below shows that many freshwater species are in jeopardy, whereas some of the best known types of species, such as birds and mammals, are doing comparatively better.

National species at risk

Data sources

Anyone doing research on U.S biodiversity should definitely check out the Precious Heritage book. It contains a wealth of information on the status of U.S. species and many of the graphics in the book are available for free download on this page.

EcoWest’s mission is to analyze, visualize, and share data on environmental trends in the North American West. Please subscribe to our RSS feed, opt-in for email updates, follow us on Twitter, or like us on Facebook.