The Protection of Ecosystem
Services in the US‐ Mexico
Border
Lina Ojeda-Revah
El Colegio de la Frontera Norte
Christopher Brown
New Mexico State University
ACES 2010 Annual Meeting
Gila River Indian Community – 5-9 December 2010
Overview
• Study Area = U.S.-Mexico Border Ecoregions
• Research objectives
• Methods – Use of landscape ecology perspective
• Preliminary work on landuse pressure index
• Urban area and population
• Natural protected areas
• Impacts on watersheds in the border region
• Ongoing work
• Water Resources
• Human Development Index
Research objectives
• Map variables putting pressures on border
ecoregions & ecosystems services
• Develop indices of specific pressures
• Evaluate impacts of pressures on border
watersheds of interest
• Explore additional variables that reflect
human welfare
Methods
• Spatial focus = Binational watersheds
– Possess similar natural variables, but
– Possess different economies and social dynamics,
– Imposing divergent pressures on shared natural
resources.
• Data drawn from binational data sources
• USGS Binational Environmental Health Initiative
data on urban & protected areas
• Population drawn from INEGI & US Census
4. US-Mexico border watersheds & U.S.- Mexico Ecoregions
Ecological regions = similar
ecosystems in the type, quality
and quantity of environmental
resources (CEC 2006).
Urban and protected areas within shared
watersheds in the US-Mexico border.
Landscape ecology approach – spatial pattern,
functions and outcomes
• If spatial land use/cover configuration changes, functions
and processes will change (Blaschke 2006), and may
initiate events with long-lasting consequences (Saunders &
Briggs 2002),
• Ecosystems become less resilient, with fewer components
to buffer drought, fire, exotic species and climate change
(Saunders et al. 1991).
• “The spatial solution is a pattern of ecosystems or land
uses that will conserve the bulk of, and the most important
attributes of, biodiversity and natural processes in any
region or landscape.” ( Forman & Collinge 1997),
Methods
• Data were normalized in each subarea and used
as inputs in the following formula
• Pressure index = Urban Area + Urban Patches
+ Population + Population Density
• Following graphic provides basics to the
process, with input and output maps
Urban patches
Urban area
+
Population density
Population
+
Land use pressure index
-
4. Basin Impact
Pacific Basins Trough subarea.
2nd most impacted - most populated with the
greatest extent of urban areas. Population
mainly scattered in Mexico but with much higher
population densities than in the US.
30% protected - California Coastal Sage,
Chaparral and Oak Woodlands, and Sonoran
Desert ecoregions virtually all in the US.
Rio Grande: Elephant Butte Reservoir to
above Rio Conchos subarea.
Moderate spatial impacts of human activity. 70%
of population is concentrated in Mexico,
20% protected - Arizona/New Mexico Mountains,
Southwestern Tablelands and the Chihuahuan
Desert ecoregions; virtually all in the US.
Rio Grande: below Amistad Reservoir to
Falcon Reservoir subarea
Colorado River-Sea of Cortez subarea
Although second largest population it has the
highest population densities. Although not
considered in index, diversion of large volumes of
water from the Colorado River to other regions
generates a very large impact to ecosystem
services.
Moderate impact, with higher population and
urban spatial extent, yielding lower population
densities.
Only 0.13% protected – Southern Texas
Plains/Interior Plains and Hills with Xerophytic
Shrub and Oak Forest.
45% protected - Sonoran Desert Ecoregion on
both sides of the border.
Mexican Highlands Subarea.
Rio Grande: Rio Conchos to
Amistad Reservoir subarea.
Moderate overall spatial impact. In the US, with
more population, urban area extent and lower
population densities than in Mexico.
Least impacted subarea, with the lowest
population & least extensive urban areas
22% protected - Sonoran Desert, the Mandrean
Archipiealago and the Chihuahuan Desert
ecoregions, mostly in the US.
San Basilio-Mimbres subarea
Small amounts of urban area, smaller urban
patches the lowest population numbers and
moderate population densities.
20% protected - The Chihuahuan Desert
Ecoregion mostly in the US.
11% protected - Chihuahuan Desert
Ecoregion on both countries.
Lower Rio Grande Valley subarea.
Most impacted - scattered urban area, very low
population densities (especially in the US),
reflecting agricultural activity.
9% protected (in both countries) the Western
Gulf Coastal Plain ecoregion, leaving the
Southern Texas Plains/ Interior Plains and Hills
with Xerophytic Shrub and Oak Forest without
protection.
Urban and population pressure index and
protected areas per subarea and country
2.50
US Pressure
2.00
Mexico Pressure
US Protected
1.50
Mexico Protected
1.00
0.50
0.00
Pacific Basins- Colorado
Salton Trough River-Sea of
Cortez
Mexican
Highlands
San Basilio- Rio Grande:
Mimbres Elephant Butte
Reservoir to
above Rio
Conchos
Rio Grande: Rio Grande: Lower Rio
Rio Conchos below Amistad Grande Valley
to Amistad Reservoir to
Reservoir
Falcon
Reservoir
Ongoing work
• Previous work examined land use
pressures and protected areas
• What about water use and “the human
equation?”
• Ongoing work develops related indices for
water withdrawals and human
development variables
• Goal is to develop sub-indices, then work
these into more comprehensive index
Ongoing work
• Water withdrawal index derived from
County & Municipio data on Ag, M&I, and
other public uses
– USGS data for 2005 for US region
– CONAGUA data - 2005-2007 uses in Mexico
• Similar normalization method as deployed
previously
• Result is preliminary and spatially coarse
picture of water extraction
Ongoing work
• What about the “human equation?”
• Premise is human welfare is part of
ecosystem services
• Human development index (HDI) is
aggregate measure of human welfare
– Municipio level data in Mexico from UNDP
(2004)
– County level data in US are from Gerber and
Anderson/SDSU (2007)
Human Dimension Index
Future work
• Water index and human development
indices are spatially coarse.
• Can we drill down into finer spatial scale?
• How do we incorporate these new indices
into the existing land pressure index?
• How do we incorporate different regimes
of protected areas (US & Mexico) into
more comprehensive index?
A word on protected areas
• Protected areas are just one strategy used for the
conservation of natural resources, yet they vary
across the Border
– Mexican protected areas – Ejidos (commonly held
land) and private land holdings also exist.
– US protected areas – State and federal holdings are
prominent, ejidos and communal held property are
not common, yet private lands also exist.
• Following maps shows early work in area (not
included in previous formula)
Protected area with ejido conserved
Discussion and conclusions
• Future research will explore added dimensions
– What are health issues of ecosystems services?
– How can we dial water resources into analysis?
• Water withdrawals versus per capita use?
• Low efficiencies of agricultural and urban uses?
– How can we more actively explore protected areas?
• Formal protected areas in the U.S.
• Common property regimes in Mexico, can be
preserved, yet not formally protected.
– What common ground exists between the US and
Mexico?