Biodiversity in the United States

Summary

NatureServe's Map of Biodiversity Importance (MoBI) is actually 4 main maps and 53 supporting maps.

The four maps showcase different aspects of biodiversity in the United States using Geographic Information System (GIS) technology. The maps are all based on data from NatureServe, which aims to assess the status and distribution of biodiversity across the United States. Each map uses a different metric to measure biodiversity and provides valuable insights into different facets of the complex and multifaceted concept of biodiversity. These maps can be used to inform conservation efforts and guide land use decisions to protect and preserve biodiversity in different regions of the United States. However, it is important to note that each map provides a limited view of biodiversity, and a comprehensive understanding of biodiversity requires consideration of multiple factors and metrics.

For example, it is difficult to determine which map shows the highest biodiversity in Arizona because each map uses a different definition of biodiversity. Map #1 shows the richness of imperiled species in the United States, but does not provide a total biodiversity count. The highest value in Arizona for this map is 11. Map #2 shows the summed range-size rarity of imperiled species in the United States, which measures the presence of imperiled species with small ranges, but does not necessarily capture total biodiversity. Maps #3 and #4 focus on areas of under-protected biodiversity importance of imperiled species and may not be as useful in determining total biodiversity.  It would be helpful to have a map that shows the total biodiversity of an ecoregion, which is not captured by any of these maps.

More resources

MoBI ESRI Overview

 Story map 

YouTube The Map of Biodiversity Importance | Dr. Healy Hamilton's Presentation at 2020 Esri UC

Detailed notes on each map

Map #1: Richness of Imperiled Species in the United States

1) Richness of Imperiled Species in the United States: link

a. High values identify areas where more imperiled species are most likely to occur.

b. Richness values are simply a tally of the number of species with habitat overlapping a cell.

c. Values range from 0 to 31, but the color ramp maxes out at 11.  

a. Highest value in AZ is 11.

b. Tenneessee has highest value upstream of Chattanooga and Knoxville along the Clinch river in the Cumberland river valley.

d. This is the prettiest map and easiest to interpret.

e. Most of the Sonoran desert has 0 imperiled species?  What about Pygmy owls?Sandhills east of Carlsbad only have 1 imperiled species (lesser prairie chicken).  What about lizards?  What about rare plants?

Map #2: Summed Range-size Rarity of Imperiled Species in the United States

2) Summed Range-size Rarity of Imperiled Species in the United States:  link

a. High values identify areas where species with very small ranges (and thus fewer places where they can be conserved) are likely to occur; the presence of multiple imperiled species contributes to higher scores.

b. Range-size rarity for each species is the inverse of the total area mapped as habitat. Summed range-size rarity is the sum of the range-size rarity values for all species with habitat that overlaps a cell.

c. The range for RSR values in cells containing species habitat is 0.0000002784 to 1.44584. A single species can have a value as high as 1.020335, which means just one 990-m cell contains all habitat for that species.  The RSR score for a species with habitat in two 990-m cells is 0.510167. 

d. This map is probably most important for conservation, and because its harder to interpret maybe is easier to use…less questions!

 Map #3: Protection-weighted Range-size Rarity of Imperiled Species in the United States

3) Protection-weighted Range-size Rarity of Imperiled Species in the United States: Link

a. High values identify areas where more unprotected, restricted-range species are likely to occur.  

b. Weighted based on how much of range is in protected areas.

c.  Each species was assigned a PWRSR score equal to the product of range-size rarity and the percent of habitat that is unprotected. The PWRSR raster sums these scores for all species with habitat that overlaps a cell.

d. Note:  Data based on USGS "GAP" analysis.  "Protected areas" include Wilderness and National Monument (GAP 1 and 2), but not Federal lands open to extraction like National Forests and BLM (GAP 3). 

Map #4: Areas of Unprotected Biodiversity Importance of Imperiled Species in the United States 

4)  Areas of Unprotected Biodiversity Importance of Imperiled Species in the United States: link

a. Values of “1” identify areas where under-protected and range-restricted species are most likely to occur, including areas where the presence of multiple imperiled species contributes to higher scores

b. This is the same as #3 above, but with a cutoff value to make the map black and white.

c. AUBIs (Areas of unprotected biodiversity importance)

Staying Realistic About Prescribed Burns

"In my 30 years with the U.S. Forest Service, I've worked on a number of prescribed burns.  In recent years they have become a popular thing to do.  In the flurry of burning stuff, the question we need to ask is not, "how many acres should be burned? But rather, "did the burn have the desired effect?" If the fire was to remove fuels and burn dead logs, did it replace that heavy fuel with waist-high weeds, brush and grasses -- more dangerous flash fuels?

Fire can be an excellent tool, but I think there are other tools that better manage certain public lands.  There are some places that are too valuable to risk a blackened landscape."
-Bob Damson response in The Nature Conservancy's September/October 2013 magazine.

Conceptual Alternatives in Classifying Ecosystems

Different descriptors used to classify ecosystems can be thought of as Venn Diagrams within a conceptual field, with e.g. playas and closed basins overlapping for those sites that are both, while acknowledging that not all closed basins are playas and not all playas are in closed basins. Under this framework, playas could be thought of as a subset of "Herbacious Vegetation" (although some playas may not be vegetated at all)

From Rio Puerco

Another way of thinking about ecosystem classifiers is as a rainbow of alternative systems. Each system, such as that developed by the Nature Conservancy, Roccio, or HGM, entails a complete and comprehensive analysis of any given field site. In other words, choosing to describe ecosystems using HGM entails that each ecosystem will be given an HGM classifier. The strength of this perspective is that it acknowledges the classifier is system-dependent, while the weakness is that it does not conceptually relate one system to another.

From Rio Puerco

Proposal to the Nature Conservancy, San Pedro River Preserve, AZ

I owe the San Pedro river a special debt of gratitude and would enjoy taking responsibility for its protection. I have also been impressed by the scope and professionalism of The Nature Conservancy, and surely your work on the San Pedro should count among its most important.

As you know, the future of your preserves on the San Pedro is far from certain. Congratulations on diverting AZDOT's attention from the San Pedro valley: that kind of preemptive vigilance will have to be sustained and expanded to other threats such as climate change. Continued aquifer drawdown will decrease perennial flow and in turn decrease biotic integrity by weakening native riparian forest growth and establishment, while boosting nonnative invasives. Flooding from increasingly impermeable rangeland and urban sprawl could change hydrology, bringing 100-year floods every decade.

With preparations today, many of these challenges can be anticipated and mitigated. Ecological integrity assessments can be developed and used to plan and measure the performance of restoration work. Neither assessment nor restoration efforts should be limited to TNC's preserves; it takes a whole watershed to raise a river, and non-point interventions are a key part of any restoration strategy. Whether working to secure water rights or educate and motivate water conservation in Sierra Vista, TNC cannot manage its San Pedro preserves without engaging diverse local stakeholders.

I am inspired by a desire to find creative solutions to problems that society is just beginning to acknowledge, but which TNC's San Pedro Preserves immediately face. The San Pedro river, especially in contrast to the Santa Cruz river, served as my ecological "wake-up call," and, in 2007, I decided to leave my position as lab manager for Dr. Hildebrand's neuro-ecology lab at the University of Arizona to pursue a career that combines science with conservation. Since then I have worked on wetlands ecology and restoration projects in Arizona, New Mexico, and Colorado. My restoration philosophy is inspired by principles I learned at DAWN/SW's Permaculture Design Course, by association with Brad Lancaster and his Rainwater Harvesting ideas, and by working closely on several restoration projects with Bill Zeedyk.

I am familiar with Natural Heritage methodology after working to develop an Ecological Integrity Assessment with Colorado Natural Heritage Program. I am on the Advisory Committee for NMNHP's EIA development, and would like to see AZ begin to take advantage of this EPA funding source. Since Arizona's Heritage Program isn't funded to take on work like this, perhaps TNC could step in. Just as TNC developed the Heritage Programs before spinning them off to state agencies, TNC AZ could develop an EPA-funded EIA program until the state can take it on. I argued in my final report to CNHP that EIAs, to address the kind of mitigation EPA is interested in, should be geared toward restoration objectives; another benefit of developing these metrics in-house would be increased specificity to San Pedro Preserve restoration and conservation needs.

My on-the-ground experience with restoration, as practiced in the SW, informs my appraisal of EIAs, and ecology and conservation biology in general. Restoration is also built into Heritage methodology where, in the scaling A-B-C-D, the line between C and D is crossed when an element occurrence is "no longer restorable". I believe that putting numbers on B and C occurences based on the monetary cost and time required to restore them to A will help managers more efficiently prioritize conservation and restoration work. A-occurences could be informed by the work of Dr. Betancourt at UA and Dr. Van Devender at the Sonoran desert museum, among others, whose paleoecology is helping redefine natural ranges of variation. Historic research, such as that by Diana Hadley, Arizona State Museum, is also invaluable. A better understanding of both historic and prehistoric ranges of variation can guide restoration work to dampen stressors and strengthen natural integrity.