The Protection of Ecosystem Services in the US- Mexico Border

Transcription

1 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

2 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

3 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

4 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

5 4. US-Mexico border watersheds & U.S.- Mexico Ecoregions Ecological regions = similar ecosystems in the type, quality and quantity of environmental resources (CEC 2006).

6 Urban and protected areas within shared watersheds in the US-Mexico border.

7 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),

8 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

9 Urban area Urban patches Population Population density Land use pressure index

10 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. 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. 45% protected - Sonoran Desert Ecoregion on both sides of the border. Mexican Highlands Subarea. Moderate overall spatial impact. In the US, with more population, urban area extent and lower population densities than in Mexico. 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. 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 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. Rio Grande: Rio Conchos to Amistad Reservoir subarea. Least impacted subarea, with the lowest population & least extensive urban areas 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.

11 Urban and population pressure index and protected areas per subarea and country US Pressure Mexico Pressure US Protected Mexico Protected Pacific Basins- Salton Trough Colorado River-Sea of Cortez Mexican Highlands San Basilio- Mimbres Rio Grande: Elephant Butte Reservoir to above Rio Conchos Rio Grande: Rio Conchos to Amistad Reservoir Rio Grande: Lower Rio below Amistad Grande Valley Reservoir to Falcon Reservoir

12 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

13 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 uses in Mexico Similar normalization method as deployed previously Result is preliminary and spatially coarse picture of water extraction

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15 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)

16 Human Dimension Index

17 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?

18 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)

19 Protected area with ejido conserved

20 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?

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