3.1 Geographic Information Systems (GIS)
A geographic information system (GIS) is a spatially referenced database that allows storage, manipulation and analysis of large volumes of geographic data (Lee 1993). Within the last decade, GIS has proven to be a useful and valuable decision-making tool in environmental and ecological modeling. For example, the U.S. Forest Service has begun an ‘ecosystem management approach' in the evaluation and use of forest lands (Overbay 1992). In other applications GIS has been used with remote sensing data for ecological land classification (MacKenzie 1994) and as a tool for designing temperature buffers for riparian habitat (Dick 1991).
These types of applications have given managers and planners of parks, nature reserves and natural resources new insight into the complex processes of ecosystems. Computer technology and geographic information software provide the tools and data storage capabilities to properly analyze and investigate these vital interconnections.
GIS was developed in the mid 1960's mainly due to the improved storage and processing capacity of computer technologies (Tomlinson 1985). The concept of geographically referenced maps had existed prior to this as a way to link "layers" of attribute information through transparent map overlay (McHarg 1969). Increased computer memory and faster processing capabilities of large volumes of information, as well as more powerful and affordable technology, have allowed GIS to become more accessible to scientists and researchers.
Computer assisted mapping (Berry 1987) replaced the tedious and time consuming manual overlaying of thematic layers to produce visual representations of spatial interactions. A GIS can accommodate many thematic layers and reference them to real-world coordinates. Map input is usually accomplished by digitizing points, lines, and areas as polygons within a map extent boundary or by processing already available maps through scanning or data conversion techniques (Burrough 1986).
Two data models are used to store the map data and attributes associated with them (Goodchild 1991). In a vector data model, points, lines and areas are established by digital input of x,y coordinates that "trace" the particular feature. Thus, coordinate points represent a length dimension of 0 and lines equal a length dimension of 1. The connectivity and adjacency of these dimensions represent a ‘topology' or specific geographic relationship of features and objects to one another in a 2 or 3 dimensional space (Gatrell 1991). Areas are closed line segments that represent a dimension of 2. A third dimension exists when points signify a height or depth (volume). Computer algorithms determine the association or topological relationships within the geographical area or region.
Once topology is established, attributes can be ‘linked' to specific dimensional objects (i.e., points, lines and areas). For example, in ARC/INFO (ESRI 1996) attributes entered into a tabular database can be ‘joined' to geographical objects using a common identifier. This joining of attributes to geographic locations comprises a relational database structure. In this type of database, items or attributes can be related to other attributes and their locations subsequently identified in geographic space.
In the raster data model, a grid or two-dimensional matrix is super-imposed over the features or, as is the case with remotely sensed images and aerial photographs, the features are represented by square pixels or cells. Raster/grid models allow spatial query of columns and rows using algebraic, logical and statistical functions. Grid cells represent location within a matrix which can be related to attribute information, such as x, y or z coordinates. The location will actually be an areal dimension since each cell is a square of some specified size. Depending upon the application, raster models may not represent as precise a location as vector data models. For example, locating one specific tree in a forest would be best identified by an exact point in a vector model. However, if the application required the area of the forest that the tree is located in a raster or vector model could be used.
Attribute values can be assigned and coded to grid cells, such as 0 = no data, 1=water and 2 =land surface. Overlay functions can be performed with grids that represent different features. An example would be overlaying a grid with cell values representing soil types on a grid of cell values signifying vegetation cover. The resulting grid is a correlation of soil type and vegetation at precise unit locations.
Raster or grid/lattice structures can represent elevation or surfaces such as digital elevation models (DEMs) for use in terrain modeling (Lee 1991). A DEM is best described as a digital representation of an area of the surface of the earth (Weibel and Heller 1991). In addition to 3D visual representation, (actually 2.5D since the DEM is visualized on a planar surface such as a paper map or computer screen) a DEM can be used to model hydrography, drainage patterns, surface shading or climate change.
The procedure used for establishing the GIS environment for Quail Hollow State Park was based on the following three stages of development (after Crain and MacDonald 1984):
1. Assembly and organization of inventory and features of interest including animal and vegetation habitats, trails, roads, hydrography, land use and land cover.
2. Analytical operations and criteria evaluation, e.g. land use identification and analysis.
3. Utilize the GIS as a decision support system for park management, specifically the Habitat Acquisition Model (HAM).
3.2 Data Quality and GPS
The effectiveness of a GIS depends on the quality and accuracy of the data acquired for input (Tomlin 1990). Primary digital data are usually the best choice in that quality can be known and managed by the user. Primary data are usually paper maps that can be digitized or scanned for input into a GIS.
Secondary data are available from a number of different sources including government agencies and private companies. A widely used secondary data source for elevational information are the 1:250,000 DEMs available via the USGS ftp (file transfer protocol) sites. USGS DEMs have elevation intervals of 120 meters with an RMSE (root mean square error) of approximately 15 meters in level terrain and 30 meters in moderate terrain. In this study user digitized data were considered more accurate in representing elevation details, especially since the available DEM from the USGS contained errors in the area of Quail Hollow State Park. The topographic map used in construction of the DEM in this thesis was from the Stark County Engineering Department and has 2 foot, (0.62 meter) contour intervals. Approximately 100 points per contour line were digitized to sample elevations accurately.
Another consideration of data accuracy in this study was related to the geographic coordinates of the study area for registration of data layers. A GIS database is dependent on exactness of position on the surface (Cassettari 1993). A Global Positioning System (GPS) is a series of satellites maintained by the U.S. Department of Defense that continually track their positional accuracy on the Earth's surface (Figure 4). By employing a surface-based hand held GPS unit as shown in Figure 4, satellite tracking yields precise ‘on the ground' (i.e., ground-truthed) positions. Examples of GIS applications using GPS are the registration of land surveys, aerial photographs, and satellite imagery. While GPS is an extremely effective tool it can be difficult to use. Signals can be hard to establish when there is thick cloud cover or even impossible to receive in dense forest.
GPS was implemented by the U.S. Department of Defense (DOD) to provide worldwide, all-weather, 24-hour-per-day geographic positioning and time information (U.S. Department of the Interior 1993). GPS is a satellite-based triangulation system that uses measurements of radiowave carrier frequencies and special transmitted codes. GPS can be used to determine relative distances and geographic coordinates.
An absolute coordinate system is necessary to ‘tie' together layers of geographic data to show the correct spatial relationships of points, lines and areas. Prior to 1960 many maps of natural resource and land management agencies were created with only relative locations to known, identifiable objects (U.S. Department of the Interior 1993). World-wide or absolute coordinate systems were established as a universal standard for map referencing. These include geographic coordinates (latitude and longitude) and two plane coordinate systems, Universal Transverse Mercator (UTM) and the State Plane Coordinate System (SPCS).
A GIS uses a planar coordinate system based on a map projection. Since the earth is a spheroid, mathematical conversion calculations are incorporated in GIS software, such as ARC/INFO, for projecting coordinates of spatial objects into flat maps (ESRI 1995). GPS coordinates are collected as latitude/longitude, then converted either as raw coordinates or after they are used as registration of a data layer. All data layers in this thesis were registered to the UTM coordinate system.
Many universities and government agencies now utilize GPS satellite remote sensing technology. GPS is being improved and made more affordable for use in more general research activities, such as this thesis. There are a number of GPS units available with prices ranging from $400 (+-10 meter accuracy) to over $20,000 (sub-meter accuracy). The latter employs differential correction capabilities, which is an interpolation of satellite signals received at the field unit, in conjunction with a ‘base' station which collects signals at a fixed point.
3.3 Aerial Photography and Remote Sensing
Remote sensing is the science of detecting and measuring or analyzing a substance or object from a distance (U.S. Department of the Interior 1993). Aerial photography and other remotely sensed data, such as satellite imagery, are excellent sources for identifying vegetation, wetlands, rivers, lakes or other natural resource landscape patterns. Wildlife habitat can be delineated and typed on aerial photos, Landsat images or digitally corrected orthophotos.
The first surviving aerial photograph is one taken by a J.W. Black over the city of Boston, Massachusetts, in 1860 at a height of 630 meters (Grahm and Read 1986). The new technology was supposedly used for military reconnaissance in the American Civil War, 1861-65. In 1898 Colonel Aime Laussedat of the French Corps of Engineers presented a paper suggesting the use of aerial photos for preparing topographic maps (Grahm and Read 1986). The invention of the airplane in the early 1900s expanded the use of aerial photography to commercial as well as military applications. Air survey increased dramatically during World War I (1914-1919). Photography using near-infrared (radiation just beyond the visible spectrum) was first used during World War II to detect camouflage consisting of dead or artificial foliage (Grolier 1995). Microwave radiometers were developed from sensitive radar receivers toward the end of World War II.
There are two basic classes of remote sensors: active and passive. Active remote sensors transmit some type of energy, such as an electromagnetic pulse, and detect the energy reflected or returned from an object. Passive remote sensors depend on emissions or reflections of energy from natural sources. Cameras are one of the oldest forms of passive remote sensors. Active remote sensors consist of X-ray devices, radar and sonar.
Unlike a map, an aerial photograph does not contain a common scale. Objects on a map have the same scale because a map is an orthographic projection, i.e. a view projected along lines perpendicular to both the view and the map surface. A photograph has a central projection where scale is affected by variations in terrain, flying height, and focal length of the camera.
Corrections must be made to remotely sensed data due to the distortion caused by the curvature of the earth's surface and variables in flight such as roll, pitch and yaw of the sensor vehicle (i.e. airplane or satellite). Distortion is defined as "any shift in the position of an image on a photograph that alters the perspective characteristics of the image" (Warner, Grahm and Read 1996, p.7).
The transformation of photo coordinates to ground coordinates requires ground control points (GCPs). The GCPs can be obtained with the use of a global portioning system (GPS) receiver (see Section 3.2). Coordinates can also be calculated from a reliable map source, such as the USGS 7.5 minute quadrangles, or from a digital orthophoto. GCPs are a critical element in converting aerial photography to digitally corrected orthophotos. Most aerial photography contains fiducial marks which provide a rectangular coordinate system for measurement of positions on a photo (see Figure 5).
A line drawn from northwest to southeast fiducials intersects a line drawn from northeast to southwest fiducials. The central point where these lines intersect is the principal point which serves as the ‘anchor' point for x,y, and z corrections in the photo. Each fiducial mark must be referenced to a coordinate obtained from a camera calibration report.
Digital elevation models (DEMs) are particularly useful for transformation of imagery to digital orthophotos. DEMs contain elevation data points that can be interpolated for orthophoto resection and correction (U.S. Department of the Interior 1993). The resection procedure determines the position and altitude of an image with respect to the GCPs. The result of these procedures is a digital orthophoto rectified and corrected so that each cell or point reference relates to a real-world geographic coordinate. The final orthophoto can be input to a GIS for use as a base layer and for further land use analysis.
3.4 Data Acquisition and Conversion
Creating a GIS database involves the acquisition and conversion of various primary and secondary data types and formats. Planning the database is a critical process if data accuracy and compatibility is to be maintained. Many GISs have never been implemented due to the lack of planning or even ignorance of the availability and format of data (Dymon 1994). While the number of failures due to this problem are seldom reviewed the successes are well documented.
Spatial data have been available in various formats for many years. Most familiar are data from large government agencies such as the United States Geological Survey (USGS) and state agencies such as the Ohio Department of Natural Resources (ODNR). Digital data were available in the past only if purchased from these agencies. Now, with the success of the Internet, much data can be downloaded via the ftp (file transfer protocol) sites. A number of private businesses, such as Environmental Systems Research Institute (ESRI), also offer free data through the Internet. Data sharing has become an important resource as well. Agencies such as the ODNR are very open to providing digital data at minimal cost or in exchange for other data.
There is still a matter of processing this ‘free' data correctly. In the case of U.S. Bureau of the Census spatial data such as the TIGER (Topologically Integrated Geographic Encoding and Referencing), USGS GIRAS (Geographical Information Retrieval and Analysis) and DEM files, the format must be altered by a program before they are useful input to a GIS (Tomlin 1990). Data conversion is not only a computing or programming skill, it has become an art. There are many options and solutions for data conversion problem-solving but intense practice and training are necessary. Inacurate processing and misuse of data can produce incorrect evaluations and results. Liability and legal problems can occur if errors in data precision are proven to be the cause of costly decision error (Goodchild 1993).
Data integration is "the combination of data bases or data files from different functional units of an organization or from different organizations that collect different data for the same features" (Huxhold 1991). Data sources must be compatible for a GIS database to be useful. In many cases, data from different agencies or businesses are in opposing formats. Image and remotely sensed data are usually in raster format, but many local governments maintain property boundary and ownership data in vector format.
Appraisers and engineering departments that maintain tax or parcel information usually use CAD (Computer Aided Design) software programs which can register line coverages for correct distance and geographic referencing but cannot link the coverage to attribute databases (Montgomery and Schuch 1993). CAD files stored in DXF (digital exchange format) can be converted into the format of the GIS software ARC/INFO.
3.5 Identifying Landscape Patterns
Establishment of land use patterns within parks and surrounding areas is necessary when planning new land acquisition. Boundaries of land that might enhance park habitats must be identified and analyzed to determine any beneficial or negative impacts on wildlife, vegetation, and wetland communities (see Appendix B for definitions of terms in ecology; e.g. habitat, wetland, etc.). Land acquisition decisions are not simply a matter of adding new land, but choosing the areas that can enhance the biodiversity within the park reserve. The U.S. Congress Office of Technology Assessment (1987) defined biodiversity as "the variety and variability among living organisms, and the ecological complexes in which they occur." Landscape ecology and nature reserve design are examples of scientific disciplines that examines habitat patches and corridors at a landscape scale. Theories of landscape ecology and nature reserve design address issues of biodiversity maintenance within ecological landscapes and ecosystems. Haeckel defined the term ecology as the interaction of biotic (living) and abiotic (non-living) components within the environment (as given in Schreiber 1990). These components form a complex ecological community. The interrelationships that these ecological communitites form with their environment is considered to be an ecosystem. Tansley (1935, p.285) defined ecosystem as;
"...the whole system (in the sense of physics), including not only the organism-complex, but also the whole complex of physical factors forming what we call environment of the biome...the habitat factors in the wildest sense...it is the systems so formed which, from the point of view of the ecologist, are the basic units of nature on the surface of the earth."
The word landscape was probably first used by A. von Humboldt, a German geo-botanist and physical geographer in the early 19th century. The origin of the word landscape comes from the Dutch word landschap. The similar word in German is Landschaft and both meanings suggest an area in space (Zonneveld 1990). In the 1930's, Carl Troll, a German geographer and ecologist, talked of landscape ecology as the "consideration of the geographical landscape and of the ecological cause-effect network in the landscape" (Troll 1939). Troll's concept of linking ecology and geography was further supported by H. Leser who used the words bioecology and geoecology to describe the physico-geographic elements within landscape research (Schreiber 1990).
Within the last decade, landscape ecology has been embraced in the United States as a transdisciplinary science enhanced by the increased interest in geographic information systems. Initial activity in the U.S. began with a National Science Foundation (NSF) funded workshop in 1983 organized by P.G.Risser, J.R. Karr and R. Forman who brought together 25 ecologists and scholars to develop guidelines for the new discipline (Forman 1990). Currently landscape ecology is being embraced by environmentalists, foresters, geographers and urban planners.
Three perspectives of current landscape ecology are:
1. Landscape scenery which relates to the original Dutch word pertaining to landscape paintings. The visual and aesthetic elements are of main importance.
2. Chorology which refers to the horizontal patterns and individual patches of landscape attributes of geology, soils, and vegetation.
3. The ecosystem which includes the physical, biological and noospherical (in the mind), factors of the holistic landscape (Zonneveld 1990).
The general accepted idea of landscape today is the "characterization of the physiographic, geological and geomorphological features of the Earth's crust (Naveh and Liebermann 1994).
Landscape ecology examines not only the physical features of the landscape but the anthropogenic effects as well and the intimate interactions and responses of wildlife, vegetation and other ecosystems. Within a regional concept, environmental conditions such as precipitation and temperature obviously have an effect on these systems (Thorne 1993). Humans or animals within landscapes are considered landscape elements. The effects on the landscape by the movements of these elements are a consideration in management planning and strategy.
Remote sensor data such as aerial photography or satellite imagery is an excellent source for use in identifying landscape patterns. GIS applications using remote sensing technology has produced a rapid increase in landscape analysis research (Allen 1994). Vegetation, open fields, rivers and lakes are easy to locate on most remotely sensed data. Many man-made features such as roads, buildings, agricultural use and cities are clearly identifiable on aerial photography or imagery.
3.6 Ecological Greenways
Fragmented landscapes are the result of developments and human modifications which can disrupt the natural succession of vegetation, wetlands and animal habitat. "Ecological greenways" (Smith 1993) such as parks, scenic sites and other nature reserves, provide the continuity for these sensitive systems. However, truly natural systems can benefit from some form of human control or interaction in the form of management and preservation. This necessitates foresight and planning when considering additions or changes to ecological systems.
A landscape can be viewed as "heterogeneous land area composed of a cluster of interacting ecosystems that is repeated in similar form throughout" (Forman and Godron 1988). Biodiversity is a necessary component of these heterogeneous systems. If habitats are fragmented or disrupted then species become isolated and reproduction cycles may be affected. Natural disturbances, such as fires or floods, may affect populations in the short term, but many species have adapted to these disruptions and may actually depend on them (Noss and Cooperrider 1994). Examples are species that require grassy areas that are replenished by fire. It is actually the disruption of these natural disturbance regimes that can have a negative effect on species biodiversity.
Theories of nature reserve design attempt to address the implications and concerns of habitat fragmentation on natural or environmentally sensitive areas. Ecotones or edge areas are especially important for many organisms and are usually characterized by high biological diversity (Holland and Risser 1991). Agricultural areas adjacent to a reserve or park boundary may be susceptible to development and urban encroachment could constrain wildlife movement, destroy sensitive bird habitat for nesting, or environmentally sensitive areas. Ecotones or edge areas are especially important for many organisms and are usually characterized by high biological diversity (Holland and Risser 1991). Agricultural areas adjacent to a reserve or park boundary may be susceptible to development and urban encroachment could constrain wildlife movement, destroy sensitive bird habitat for nesting, or eliminate wetland areas.
Parks and preserved "green" areas can be managed as "core reserves" (Noss 1993), with buffered corridors or linkages that connect them to other nature reserves as shown in Figure 6. The wilderness network will eventually circumvent the region and dominate the landscape.
Managing the reserve can be approached in many ways. Flora and fauna activity and habitats can be identified and classified into compartments (Quail Hollow State Park Management Plan 1993). Determination of the reserve areas for protection priorities should focus on species habitat, examples of natural communities and identification of landscapes compatible with management for conservation and human use (Scherff 1995).
Quantitative measures of changes and impacts on wildlife habitat are difficult to determine. Observations of a) occurrences of rare and endangered species and b) changes in the population size and diversity of common species are indicators of possible species isolation (Keyes 1976).
Land cover and land use surrounding core reserves can be analyzed and modeled to identify patches or land parcels that may be suitable as buffers, corridors or increased habitat area. It is necessary to design these models based on real-world locations and accurate spatial parameters.
Finally, the importance of landscape analysis and planning is stated as; "To enhance the ecological integrity of the landscape and achieve sustainable land use, landscape planning should consider natural and social processes and their spatial relationships in a comprehensive way" (Langevelde 1994, p. 27).
3.7 Land Acquisition
Conservation of sensitive or unique habitats , and parks or nature reserves is easier if these areas are connected (National Research Council [NRC] 1993). The knowledge of the various elements of landscape ecology brings up the questions of how to accomplish the interconnection or reconnection of habitats and/or ecosystems. A logical approach to connecting reserves to enhance biological diversity is the process of land acquisition of suitable habitat areas.
The NRC states that "usually acquisitions that provide corridors, connections and linkages between similar landscapes and habitats are enhanced in biological value....habitats in proper configurations can facilitate the persistence, movement, and dispersal of native biota" (NRC 1993, p. 203). The term ‘acquisition' does not only mean buying land outright. Options include purchase or allowance of conservation easements, land exchange and exercising ‘eminent domain'. Eminent domain is defined as the "right of a government to take private property for public use by virtue of the superior dominion of the sovereign power over all lands within its jurisdiction" (Webster's 1996).
Many environmental laws have been enacted in the last 25 years that address the need for land acquisition to preserve natural areas. Examples are the Uniform Relocation and Acquisition Policies Act of 1970, The Endangered Species Act of 1973, the Wild and Scenic Rivers Act of 1968, and the National Trails System Act of 1968 . Federal agencies have established acquisition policies such as the U.S. Fish and Wildlife Service (USFWS) Land Acquisition Priority System (U.S. Department of the Interior 1983), and the Bureau of Land Management (BLM) Federal Land Policy Management Act of 1976.
The land acquisition process requires an extensive search for candidates and careful considerations of benefits and costs. Extensive information and data are necessary to determine parcels or areas for acquistition. GIS technology is a valuable tool for storage and manipulation of large databases containing land use, landvalues or ownership information. The effectiveness of a GIS depends on the "adequacy of exisiting data and upon maps of ownership, inventories, population trends, and species distributions" (NRC 1993 p.8).
Some data may be available from county or local governments but data from different agencies are often in varying formats. The data may be in vector or raster formats which requires speciality GIS software for processing, such as ARC/INFO (ESRI 1996) , INTERGRAPH (Intergraph Corp., Huntsville, Alabama) or ERDAS (Erdas Inc., Atlanta, Georgia). Data often contains inaccuracies that hinder the conversion process or even makes it unusable. It is important that the user have expertise and training in the data conversion techniques as well as other GIS concepts. Data can be expensive to acquire if it requires scanning or digitizing from paper maps. There are numerous data for sale already processed but it is often expensive. For example, a single satellite image (scene) can cost up to $4,000.00. Other data can be acquired free via the Internet, such as USGS or ODNR data (see section 3.3).
Additional information for land evaluation and acquisition criteria can be evaluated with remote sensor data, such as digitally corrected orthophotos or satellite imagery. An example are the SPOT multispectral images. SPOT is an acronym for Satellite pour l'Observation de la Terre--a commercially successful series of French Earth-observation satellites. Narumalani and Carbone (1993) used SPOT images to classify land cover as scrub/shrub, forest, wetland forest, wetland marsh, water, urban and agricultural use.
A set of criteria is needed to establish areas for acquistion. Information that is gathered often pertains to acreage, location, price per acre and total cost (NRC 1993). An example of specific environmental criteria is the USFWS Land Acquistion Priority System (U.S. Department of the Interior 1983). LAPS outlines five target areas as criteria:
1. Endangered species
2. Migratory birds
3. Significant biological diversity
4. Nationally Significant wetlands
5. Fishery resources
The Nature Conservancy (TNC), a private land trust, uses a system of element occurrences (EO) and core rankings for determing land acquistion priorities. An EO is any type of biological or ecological entity, e.g. species or community, in a geographic area (TNC 1987). The rankings are at a global (G), national (N), or state (S) level. EOs at each of these levels receives a ranking from 1 to 5, with 1 being the most critical and 5 being least critical. An example ranking would be S1, which would designate a critical EO at the state level.
A system of coarse and fine ‘filters' classifies the EOs by community (coarse filter) and individual species and where they occur (fine filter). This system was refined by evaluations from Noss (1987) so that the coarse filter considered 1) disturbance and regeneration patterns, 2) landscape mosaics, and 3) surrounding habitat and corridors.
These criteria are based primarily on the goal of protecting biological and ecological diversity. To achieve this objective Natural Heritage inventory programs were established in all 50 states. Natural Heritage programs collect, manage and use biological, ecological and related information in cooperation with various state agencies. For this thesis, Natural Heritage data of endangered species was used to identify critical habitat within Quail Hollow State Park for identifying suitable habitats outside park boundaries.
3.8 Literature Review Summary
Management and park planning requires consideration of many environmental, social and economic factors. Concerns have focused on preservation of the environment and responsible land stewardship for the past 20 years and this trend is likely to continue due to public concerns for the environment. Focused and informed decision-making relies on the use of advanced and current technological tools to assist in the evaluation and analysis of complex
ecological relationships and land use patterns.
An established science that examines spatial interactions of vegetation, animal populations and human impacts on the environment is Landscape Ecology. Species and habitats must be managed if they are to be preserved. Buffering sensitive habitats can reduce "edge effect" and ecological greenways or corridors can provide connections and links to other "green islands". Connecting natural reserves and increasing habitat preserves biodiversity and survival of unique flora and fauna species.
Geographic information systems (GIS) can be utilized for coordination of time-consuming procedures such as overlays of attribute data, map automation, and display and database management/retrieval. A GIS offers park managers a useful tool for decision-making and visual planning. Data accuracy and quality are critical to the effectiveness of a GIS. Global Positioning Systems (GPS) are a precise method of control for ground-truthing accuracy of remotely sensed imagery and registration of GIS data layers.
The most costly and time-consuming entities of a GIS are the data acquistion and conversion. Data are available in many varied and opposing formats. A GIS specialist must not only know GIS software but must practice and update their skills in data conversion techniques.
Finally, planning for land acquisition requires numerous data and the ability to manipulate the data and display it in a clear and understandable format. Managers of nature reserves must have data that is current to address public concerns for the environment and for use in land acquisition negotiations.minate wetland areas.
Parks and preserved "green" areas can be managed as "core reserves" (Noss 1993), with buffered corridors or linkages that connect them to other nature reserves as shown in Figure 6. The wilderness network will eventually circumvent the region and dominate the landscape.