GIS Methodologies for Developing Conservation Strategies Part 7 doc

Initially, due to limited funding, only the data layers that were re-quired to support the preliminary corridor potential study would be developed.Subsequently, with additional funding,

140 Lambert and Carr

hoped that analysis and mapping of a corridor network would assist CentralAmerican governments and nongovernmental organizations in the identificationand prioritization of key areas for preservation and protection A spin-off benefit

of this project is a preliminary GIS database of the entire Central Americanisthmus which has been shared with many government agencies in CentralAmerica, other scientists, land use planners, and conservation organizationsthat are also working to preserve and manage the natural treasures of CentralAmerica

Database Development and Evaluation

The GIS database development component of the corridor study was designed

as a two-phase process to complement the preliminary and more detailed sis efforts Initially, due to limited funding, only the data layers that were re-quired to support the preliminary corridor potential study would be developed.Subsequently, with additional funding, the team would develop more compre-hensive databases to support more detailed study of specific potential linkages.The logical first step for the team was the identification and collection ofexisting digital data sources that could be obtained inexpensively Unfortunately,the team found that, although there were several GIS projects being conducted

analy-in Central America, the GIS databases these projects were creatanaly-ing varied widely

in scale, projection, content, theme, date, and digital format There were ently no regional efforts being made to develop a standardized database for theentire isthmus

appar-Fortunately, an affordable source for base map features called the Digital

Chart of the World (DCW) had just become available (ESRI 1993) The DCW

provides base map features such as roads, hydrography, political boundaries,population centers, and topography (at 1,000-foot intervals) for the entire world.This database was created by digitizing the U.S Defense Mapping Agency’s1:1,000,000 scale Operational Navigation Chart map series A license for the

ARC/INFO version of the DCW database was purchased from Environmental

Systems Research Institute, Inc (ESRI) in the fall of 1992 At first, the team wasskeptical about the suitability of this database because the scale of the sourcedata limits typical spatial accuracy to approximately plus/minus one kilometer.However, the alternative of digitizing base map features for all of CentralAmerica motivated the team to test the database After working with the data-

base, the team found the DCW’s spatial and attribute accuracy to be quite

adequate and appropriate for the objectives of this preliminary, multinationalstudy

An important point to make about the DCW is that its availability allowed

The Paseo Pantera Project 141

the planning team to concentrate its own limited funding on the generation ofthe new databases required for analysis and on the preliminary design of thecorridor rather than on the digitizing of base map feature layers However, a

second important advantage to using the DCW was that it allowed the team to

get off to a quick start All too often in the past, ambitious GIS managers havepromoted this technology successfully to their cautious colleagues, only to findthemselves explaining later, to now impatient colleagues, why it takes so long todemonstrate any substantial results from a technology that was supposed to savetime and increase productivity Being aware of this potential scenario, and thefact that GIS technology and methods are still new to many of the participants inthe Paseo Pantera project (especially some of the cooperating institutions inCentral America), the corridor planning team recognized the need to demon-

strate the utility of GIS as quickly as possible to its sponsors The DCW made this possible Although the DCW will not be appropriate for all projects, this project demonstrates the potential value of the DCW to those faced with continental-

scale environmental problems and dwindling budgets

The second step in the initial phase of GIS database development involvedthe team in a process of weighing the costs of producing each new data layeragainst the relative potential contribution of that data to the preliminary analysis.Several new data layers were subsequently developed, including boundaries

of existing and proposed protected areas; forested/deforested areas; potentialbiological communities based on the Holdridge system of life zone classifications(Holdridge 1967); population density and major population centers; and areasoccupied by indigenous populations The GIS data layers listed above representthe conversion of more than seventy-five source maps to digital format It isimportant to point out that these data sets represent only a preliminary effort,limited by modest funding, and that the study team recognizes the need formuch more detailed information as it enters the second phase of this study.Once the databases described above were developed, the team explored ways

to use them to analyze the potential for a continuous biological corridor Thefollowing four criteria were selected for use in the model based on the evaluation

of the available data: (1) size of protected areas, (2) uniform national designation

of protected areas, (3) population densities, and (4) forested/deforested areas.The protected areas were divided into two size classes—large (50,000 hectaresand greater) and small (less than 50,000 hectares) These classes were based onsuggestions for minimum core area size in Noss (1991)

Because of the variations in terminology used by each country to classify itsprotected areas, the team developed a set of “uniform national designations”based on current management practices These designations were: national park(or equivalent), anthropological reserve, extractive reserve, private reserve, andproposed reserve “Uniform national designation” was selected as an importantcriterion because the management practices used in each protected area deter-

142 Lambert and Carr

mine its value to the preservation of biological diversity An uninhabited nationalpark will contribute differently than an inhabited anthropological reserve.Owing to variations in the ranges used for population density categoriesfor each country, the team had to determine a generalized population densityclassification scheme for the entire region Five density classes were used, withthe following ranges: 0 to 10 people per square kilometer, 11 to 25, 26 to 50, 51 to

100, and 101 people or more per square kilometer Population density wasconsidered a critical criterion because, according to Redford and Robinson (1992),where densities are higher there is less potential to maintain biodiversity

The fourth criterion utilized in the preliminary analysis was the classification

of “forested/deforested” (or natural/altered) areas This generalized data wasdigitized from the map supplement (“The Coexistence of Indigenous Peoplesand the Natural Environment in Central America”) contained in the spring 1992

issue of Research and Exploration, a publication of the National Geographic Society.

This classification was considered to be a significant discriminator, at this tion of analysis, because it is generally accepted that natural areas will havehigher “natural diversity” than deforested, human-altered areas

resolu-After an evaluation of the remaining available spatial databases, several werenot used in the model developed for our initial analyses because of their incom-plete classification or content These data sets included roads, hydrography, andpopulation centers Holdridge’s life zones and areas of indigenous populationswere not used because the team could not substantiate the prioritization of onelife zone over another, and there was controversy over whether or not historicalranges of indigenous populations were predictive of corridor potential

Biological Corridor Suitability, Potential, and Feasibility Analyses

All analysis from this point in the method was accomplished by using ESRI’sraster GIS software called GRID The vector data layers used in the analysis wereconverted into layers of four-square-kilometer grid cells This was the highestreasonable resolution based on the spatial accuracy of the combined source datalayers

A weighted criteria analysis method was used to generate a biological dor suitability map that would subsequently be used as an input to the corridorpotential and feasibility analyses There were three steps in the weighted criteriaanalysis The first was to determine the relative values for the range of optionswithin each of the four criteria discussed above The second was to determinethe relative importance among the four criteria (i.e., to assign a weight to eachcriteria) The third was to calculate the normalized, cumulative scores, whichresults in values ranging from 1 to 100 These values represent the relative overall

corri-The Paseo Pantera Project 143

suitability of any area for inclusion in a biological corridor Several alternativeweighting schemes have been explored for assigning the values within andamong the criteria

In the first step, for the criterion of “size of protected area,” lands contained

in larger protected areas were considered relatively more valuable than landsfound in smaller protected areas, based on theories put forth by MacArthur andWilson (1967) Lands with no protection received the lowest relative value forthis criterion Similarly, for the criterion of “uniform national designation,” lands

in “national park (or equivalent)” were determined to be of highest value, lands

in “proposed reserves” to be of a lower value, and lands not in a protected area

to be of no relative value For each category of protected area, the stricter thelimits on use (as determined by management practices), the more important itspotential contribution to protection of biodiversity was considered to be Withinthe criterion for population density, areas of high density were considered to be

a detriment to the development of a corridor network, whereas low-density areaswere assumed to be of higher relative value Finally, lands with natural forestcover were considered to be of much greater relative value than altered lands.The corridor suitability database provided the relative cost informationneeded for the next step in the corridor analysis The cells with high corridorsuitability were redefined as cells with low relative “costs” for inclusion in thecorridor The cells with low corridor suitability were redefined as having highrelative “costs” for inclusion The resulting “cost” surface was the input for theassessment of corridor potential This analysis used the GRID analysis functioncorridor to calculate the relative accumulated “cost” of developing a corridorbetween two sources In this case, the two sources were Mexico and Colombia.The corridor function generated a value for each four-square-kilometer pixelalong the least cost path to each of the sources In figure 11.1, the values havebeen divided into five classes of equal area These results represent continuousbiological corridor potential based on the criteria used

The areas of highest corridor potential were not simply along the shortestroute between Colombia and Mexico, but represented a combination of distanceand other influences assigned through the four criteria used in the weightedcriteria analysis The result was a bias toward large, forested national parks withlow population density in close proximity

In the final step of the analysis, the boundaries of the area represented by theclasses of highest corridor potential were used to “clip out” the correspondingsuitability classifications developed in the weighted criteria analysis step Theresulting map (figure 11.2) represents biological corridor feasibility The areawithin these limits had the highest potential for a continuous corridor, but thefeasibility factor was not homogeneous within the limits Three problem areasbecame evident: one in northwestern Honduras, another in northeastern CostaRica, and the third around the Panama Canal

144 Lambert and Carr

Conclusions from the Initial Corridor Study and Thoughts on the Next Phase of Study

The authors believe that the methods they used for this preliminary study havegreat potential to assist in the identification of corridor study areas and intheir prioritization The maps and reports generated from these preliminary (butpromising) results have been used widely throughout Central America and theUnited States to promote the concept of a Mesoamerican biological corridor.There has also been greater appreciation of the contribution that GIS technologycan make to conservation planning The study team is currently focusing onrefinements to its methodology to strengthen the relationships between current

F IG. 11.1 The continuous biological corridor potential in Central America (basedupon criteria described in the text)

The Paseo Pantera Project 145

scientific theories and the relative weights assignments, and on the development

of new and improved data sets to support more detailed planning

As a result of its experience with this study, the team has recommended theuse of, and begun development of, 1:250,000 scale data sets to support the next,more detailed phase of regional corridor analysis A second-phase pilot project,implemented at this scale, was completed by the authors in the fall of 1995 forthe trinational region of the Selva Maya (which includes Belize, the Peten district

of Guatemala, and southern Mexico) This project was supported by the FOR program of USAID / G-CAP The GIS database was created for the planning

MAYA-of biological corridors but has also been used more generally to support theRegional Conservation Assessment Workshop for the Maya Tropical Forest held

in San Cristobal de las Casas, Chiapas, Mexico, in August 1995 This workshop

F IG. 11.2 Corridor feasibility analysis results

146 Lambert and Carr

brought together more than sixty representatives from the region to establishconservation needs and priorities for the Selva Maya The new standardizedmultinational GIS database provided the participants with a common base mapand data which enabled multinational conservation planning that would nothave been possible before Instead of dealing with a different map for eachcountry, the regional database allowed the participants to more effectively planstrategies based on ecological boundaries rather than political boundaries Addi-tionally, the new standardized database was distributed to over thirty govern-mental, academic, and conservation institutions in the region in the hopes thattheir future conservation planning efforts would not be limited by nationalboundaries

Based on the experience gained through implementing the MAYAFOR GISdatabase, the authors recommend that a coordinated and cooperative effort beinitiated whereby a standardized GIS database would be developed for the entireisthmus It is further recommended that this database be freely shared with anyparties involved in conservation of the region’s natural resources in order toprevent duplication of effort and to make efficient use of limited funding Theteam believes that a 1:250,000 scale database has been shown to provide sufficientdetail and accuracy for many regional conservation planning needs and is rea-sonable to develop within the limited funding constraints of the conservationcommunity

References

Carr III, A F 1992 Paseo Pantera Project brochure New York: Wildlife ConservationSociety

Carr, M H., J D Lambert, and P D Zwick 1994 Mapping of biological corridor potential

in Central America In A Vega, ed., Conservation corridors in the Central American

region, 383–93 Gainesville, Fla.: Tropical Research and Development.

Environmental Systems Research Institute (ESRI) 1993 Digital chart of the world (CD-ROM

Cartographic Database) Redlands, Calif.: ESRI

Forman, R T T and M Godron 1986 Landscape ecology New York: Wiley.

Harris, L D and K Atkins 1991 Faunal movement corridors in Florida In W E Hudson,

ed., Landscape linkages and biodiversity, 117–38 Washington, D.C.: Island Press.

Holdridge, L R 1967 Life zone ecology San Jose´, C.R.: Tropical Science Center.

Lambert, J D and M Carr 1993 (May) Utilizing GIS to plan for a Central American

biological corridor Proceedings, Thirteenth Annual ESRI User Conference 1: 257–64

Red-lands, Calif.: Environmental Systems Research Institute

MacArthur, R H and E O Wilson 1967 The theory of island biogeography Princeton:

Princeton University Press

Noss, R F 1991 Landscape connectivity: Different functions at different scales In W E

Hudson, ed., Landscape linkages and biodiversity, 27–39 Washington, D C.: Island Press.

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Redford, K H and J G Robinson 1992 The sustainability of wildlife and natural areas

Proceedings of the International Conference on the Definition and Measurement of tainability, Washington, D.C.

Sus-Soule´, M E 1991 Theory and strategy In W E Hudson, ed., Landscape linkages and

biodiversity, 91–104 Washington, D.C.: Island Press.

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Part Four

The USAID Case Study in

Gap Analysis

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preserva-is used to overlay maps or layers that are geographically referenced to each otherand to create new information through the combination of those map files Imageanalysis is used to create the vegetation database that provides the frameworkfor the various GIS data layers GPS has been used in conjunction with fieldcomponents of image analysis and is beginning to be utilized as a wildlife datacollection technology.

One tool that was developed during this project was the Habitat tion Decision Cube The decision cube is covered in detail in chapter 15, but isintroduced at this time as it defined the database design for the USAID project.The decision cube can be represented as a three-dimensional box with eightinternal cubes (see figure 15.2) The eight cubes represent possible outcomeswhen three separate axes are viewed for the presence or absence of the threevariables used in gap analysis The three variables are the presence or absence of

Conserva-a species or group of species of wildlife; the presence or Conserva-absence of suitConserva-ablehabitat for that species; and the presence or absence of protected areas Each ofthe eight types of locations require different policy approaches For example, gapanalysis was designed to identify the locations where species and habitat arepresent that are outside of protected areas Such locations adjacent to or betweenprotected areas are prioritized in land acquisitions for conservation purposes

152 Basil G Savitsky

History and Status

There is growing recognition in the United States of the high cost and lowefficiency of the species level approach to conservation of biological diversityassociated with the 1973 Endangered Species Act (Edwards et al 1995) Gapanalysis is one approach in extending conservation of biological diversity fromreactive legislative battles over individual species to strategic planning for habitatconservation

The methodology for gap analysis is based upon the logic used in evaluatingthe representation of vegetation communities within protected areas, such asstudies performed in the United States (Crumpacker et al 1988) and Africa(Huntley 1988) Evaluation of wildlife in a gap analysis framework was firstperformed in the United States in a study in Hawaii The measurement of thegeographic intersection of the home range of endangered forest bird species withprotected areas indicated that less than 10 percent of the bird habitat was pro-tected (Scott et al 1987) In 1989 Idaho initiated a statewide gap analysis projectwhich addressed a wide variety of wildlife species and habitat Since that time,gap analysis projects have been completed for most of the western states in theUnited States

Gap analysis is a technique that is receiving a high level of attention fromconservation agencies and organizations (Machlis, Forester, and McKendry 1994)

It is an effective tool for decision-makers and policy analysts because it clearlymaps out potential conservation priorities and the path used to reach thosepriorities Gap analysis results can be combined with economic developmentneeds as constraints or opportunities in geographic selection of sustainable devel-opment projects Thus, gap analysis is likely to be a focal technique in biodiver-sity and sustainable development research in the future

The Application of Gap Analysis in the United States

Gap analysis is a biodiversity planning approach which has been embraced bythe U S Geological Survey, Biological Resources Division (Machlis, Forester, andMcKendry 1994) The state of Utah published a report that contained four maps,two CD-ROMs, and documentation of the methodology used and results ob-tained (Edwards et al 1995) The four maps include a mosaic of Landsat TMimages, habitat classes generated from the image analysis, distribution of publiclands, and a combination of habitat data and public lands suitable for consider-ation in wildlife management plans The two CD-ROMs contain data on thedistribution of 525 wildlife species

A gap analysis also has been completed for the southwestern portion of