Impact Assessment for Lesser Prairie-Chicken Conservation in Eastern New Mexico

Transcription

1 Impact Assessment for Lesser Prairie-Chicken Conservation in Eastern New Mexico Thomas M. Mayer, Lara W. Miller * The Nature Conservancy, New Mexico Chapter *Contact: lwood@tnc.org, (505)

2 Table of Contents List of Tables... 3 List of Figures... 3 Introduction... 4 Model Overview... 6 Methods... 6 Spatial Extent... 6 Data and Format... 7 Ranking Process... 7 Ranking Factors... 7 Factor 1. Model Extent (historic range)... 9 Factor 2. Current Range Factor 3. Leks Factor 4. Core Habitat Factor 5. Core Buffer Habitat Factor 6. Managed and Protected Land Factor 7. Suitable Habitat Factor 8. Avoided Obstacles LEPC Impact Map Applications of the model Application Example 1. Wind energy production Application Example 2. Transmission line routing Limitations of the model Model Use and Application Acknowledgements References NM LEPC Impact Model (10/2010) Page 2

3 List of Tables Table 1. Ranking factors, criteria, and categories for pixel value assignment... 8 Table 2. List of avoidance features, associated buffers, and data sources List of Figures Figure 1. Historic and current range of the Lesser Prairie-Chicken in New Mexico and the five state southern high plains region (inset) Figure 2. Model extent including land within 10 mi. of historic range Figure 3. Current Range of LEPC in New Mexico Figure 4. Active leks including 3 mi. buffer Figure 5. LEPC core habitat Figure 6. LEPC core buffer habitat Figure 7. Managed and protected properties Figure 8.Suitable and potentially suitable LEPC habitat Figure 9. Area outside of LEPC avoidance feature buffers Figure 10. NM LEPC impact model, ranking from least (1) to greatest (8) development impact Figure 11. Wind power classification for eastern New Mexico Figure 12. Contiguous areas >5000 acres with minimum impact on LEPC habitat (LEPC impact factor 3), and high wind energy development potential (wind power class 3) Figure 13. Detail of LEPC impact map and proposed transmission line route in northern Curry county.. 25 NM LEPC Impact Model (10/2010) Page 3

4 Introduction The high plains of central North America, once described as the Great American Desert (Meinig, 1993), evokes images of empty, treeless, windswept prairie of little value stretching to the horizon. However, this semi-arid region fronting the Rocky Mountains and extending from Canada to Mexico, has sustained native cultures and a rich diversity of flora and fauna for millennia. Since the beginning of European exploration and settlement the high plains has seen domestic livestock replace native herbivores and alter established grazing patterns; been ravaged by destructive agricultural practices, fire suppression, and a capricious climate; had it s surface disturbed in countless places to extract oil and gas; and watched agriculture blossom with mining of groundwater. The region is now recognized as a valuable wind energy resource, and large areas are being devoted to electricity generation and transmission. Throughout the past century and a half of exploitation and development natural habitats have been altered, fragmented, and destroyed, leaving the high plains grasslands some of the most imperiled ecosystems in the world (Sampson and Knopf, 1994). As a consequence many of the animal species that evolved to thrive in this habitat are now imperiled as well. Grassland-nesting birds, in particular, are the fastestdeclining suite of avian species in North America (Brennan and Kuvlesky, 2005). The Lesser Prairie-Chicken (Tympanuchus pallidicinctus; LEPC) is a once-common species of prairie grouse endemic to the southern high plains of Kansas, Oklahoma, Colorado, Texas and New Mexico. Since the beginning of the 20 th century population of the LEPC has declined by 95% and its range has been reduced by 90% due to habitat loss and fragmentation (Hagen et al., 2004). As a result the LEPC has become a target species for wildlife conservation and management. The LEPC survives in a small portion of its historic range in eastern New Mexico, primarily in southern Roosevelt, eastern Chaves, and northern Lea counties (see Figure 1). Threats to this remnant population and barriers to restoration of the species over portions of its former range remain, due to habitat loss and fragmentation from many human activities. Contributing factors include (but are not limited to) conversion of grassland and scrub to agriculture, livestock grazing, oil and gas development, fire suppression, fencing and road construction, and increasingly, wind energy generation and transmission. Survival of the LEPC, and other species that depend on this ecosystem, in the face of continued development, will only occur if we recognize and attempt to minimize the impact of our activities on the resources they need to live. NM LEPC Impact Model (10/2010) Page 4

5 Figure 1. Historic and current range of the Lesser Prairie-Chicken in New Mexico and the five state southern high plains region (inset). Here we describe a GIS-based spatial model designed to assess the impact of future development on LEPC conservation in eastern New Mexico. This tool is intended for use in planning for future development, minimizing negative impacts of future development on current LEPC habitat, and in planning conservation and restoration efforts for LEPC in eastern New Mexico. The model aims to provide industry and wildlife professionals a tool that can help: 1) site development projects with LEPC conservation in mind, 2) identify areas of critical habitat for LEPC conservation, and 3) identify areas for potential habitat restoration and/or species reintroduction, including offsets for the impact of future development activities. NM LEPC Impact Model (10/2010) Page 5

6 It is important to note that this study does not address any potential concerns other than the LEPC. There may be additional natural resource concerns (e.g., wetlands, rare or sensitive habitats, state and federal trust species, etc.) within the study area which require evaluation in the planning phase of development projects to ensure compliance with appropriate state and federal laws and ongoing conservation initiatives. Information regarding other resources in New Mexico is available from a variety of sources, including the New Mexico Department of Game and Fish, U.S. Fish and Wildlife Service, U.S. Bureau of Land Management, Playa Lakes Joint Venture, New Mexico Chapter of The Nature Conservancy, and Natural Heritage New Mexico. Model Overview The model described here (hereafter called the NM LEPC model) emulates the Oklahoma Lesser Prairie-Chicken Spatial Planning Tool (hereafter called the OK model), a product of a collaboration including the Oklahoma Department of Wildlife Conservation (ODWC), the U.S. Fish and Wildlife Service, the Playa Lakes Joint Venture, the Oklahoma Chapter of The Nature Conservancy, the University of Oklahoma, and Oklahoma State University. Only a brief description of model, methods, data sources, and analysis procedures will be given here. The OK model report (Horton, et al, 2010) should be consulted for further details and original literature citations. The NM LEPC model is a GIS-based spatial grid spanning the historic range of the LEPC in New Mexico in which each 30m x 30m pixel is numerically ranked according to its importance to LEPC conservation. The higher the rank, the more valuable that pixel is to the LEPC, and the higher the impact of development. Ranks are determined by evaluating each pixel in the grid using a set of eight ranking factors addressing LEPC occurrence, habitat requirements and threats. The OK model further assigns monetary value to each ranking factor in an economic analysis of development impact. We do not attempt an economic analysis in the NM LEPC model. The model can be used to evaluate any type of potentially detrimental development (e.g. wind energy farm, road construction, oil and gas wells, transmission lines, etc.). Methods This section describes the components and design of the model including information on ranking factors. Spatial Extent The spatial extent of the model includes the area within 10 miles of the LEPC historic range in New Mexico (Figure 1), including a ten mile buffer area in the adjoining states of Texas and Oklahoma. However, the NM LEPC model should only be used for evaluation of projects located in New Mexico. Any questions regarding potential for impacts to LEPC in any portion of NM LEPC Impact Model (10/2010) Page 6

7 the adjacent states should be referred to the appropriate state wildlife management agency (i.e., Oklahoma Department of Wildlife Conservation, or Texas Parks and Wildlife Department). Data and Format All GIS work was conducted in raster format using the Spatial Analyst extension of the ArcMap software package (Environmental System Research Institute (ESRI), Version 9.3.1). All maps are presented in the projected coordinate system of North American Datum 1983, Universal Transverse Mercator Zone 13 North (NAD83, UTM Zone 13N). The model will be updated periodically as new data become available. Ranking Process The NM LEPC model assigns each pixel a rank of 1 to 8 by comparing each pixel to a set of eight ranking factors. Each ranking factor addresses one of the following categories: LEPC occurrence, habitat requirements, or threats. Criteria are distinct for each ranking factor and are based on published scientific literature or expert opinion from biologists. If a pixel meets the criteria of a ranking factor, it is assigned a value of 1, otherwise 0. This process produces a binary (1 or 0) grid for each ranking factor. The addition of these eight binary grids produces the final result of the model, a grid with values ranging from 1 to 8, where pixels with a value of 8 have the highest value for LEPC conservation and greatest development impact. Each factor is given equal weight in this process. By virtue of having several correlated factors, occurrence and habitat are effectively weighted higher than threats, but the weighting procedure is still rather arbitrary. The upshot is that the final ranking is not intended to be a quantitative value assessment but rather a relative order of importance for LEPC conservation. Ranking Factors The eight ranking factors are listed in Table 1 along with a brief description of the criteria against which pixels are evaluated and assigned a value of 0 or 1. The ranking factors used in the NM LEPC model closely follow the procedures and data used in the OK model, with a few exceptions. A detailed account of each ranking factor can be found in the OK model report (Horton, et al, 2010), and includes: 1) Description of the function of the factor in the model, 2) Criteria used to evaluate pixels and assign binary values (1 or 0), 3) Justification for including the factor in the model, 4) Description of the data used to evaluate the pixels, 5) Source of the data, 6) Resultant binary grid as a map. NM LEPC Impact Model (10/2010) Page 7

8 A brief summary of the ranking factors follows, with deviations from the OK model noted. Binary maps were generated for each ranking factor, shown in Figures 2 9, where green pixels have a value of 1 and white pixels have a value of 0. Pixels outside the model extent, represented by the blue line, are not valued. The maps of the entire model extent provided below do not reflect the high resolution of the model (30 x 30 m pixels) and are for illustrative purposes only. For a representation of the ranks at a project level, contact the authors at the New Mexico Nature Conservancy. Table 1. Ranking factors, criteria, and categories for pixel value assignment Ranking Factor Pixel Criteria Category True Value False Value Historic range Within 10 mi. of boundary Occurrence 1 0 Current range Within boundary Occurrence 1 0 Leks Within 3 mi. radius Occurrence 1 0 Core habitat Within core patch Habitat 1 0 Core buffer habitat Within core buffer Habitat 1 0 Protected properties Suitable habitat Avoided obstacles Within 1.24 mi. buffer of boundary Suitable or Potentially Suitable Outside all avoidance areas Habitat 1 0 Habitat 1 0 Threats 1 0 NM LEPC Impact Model (10/2010) Page 8

9 Factor 1. Model Extent (historic range). Gives value to land within 10 miles of the historic range of the LEPC in New Mexico regardless of habitat suitability (Fig. 2). Historic range boundary was determined as described in the OK model. This buffered area serves as the model extent for the current study, and provides a baseline for the ranking procedure. Figure 2. Model extent including land within 10 mi. of historic range. NM LEPC Impact Model (10/2010) Page 9

10 Factor 2. Current Range. Gives value to all land within the current range of the LEPC regardless of habitat suitability (Fig. 3). Current range boundary was determined by Playa Lakes Joint Venture, as described in the OK model. Figure 3. Current Range of LEPC in New Mexico. NM LEPC Impact Model (10/2010) Page 10

11 Factor 3. Leks. Gives value to land within 3 miles of known leks (Fig. 4). A lek is a gathering of males at a traditional location for the purposes of competitive mating display. Leks assemble on a daily basis before and during the breeding season. Leks observed to be active between 1971 and 2010 were compiled by the Natural Heritage New Mexico Program from data provided by the New Mexico Nature Conservancy, NM Dept. of Game and Fish, US Bureau of Land Management, and US Fish and Wildlife Service. It is highly probable that not all lek locations in the model extent are known or available to the public. Figure 4. Active leks including 3 mi. buffer. NM LEPC Impact Model (10/2010) Page 11

12 Factor 4. Core Habitat. Gives value to large contiguous patches of suitable and potentially suitable habitat (Fig. 5). Core habitat was determined by Playa Lakes Joint Venture, as described in Appendix A of the OK model report. Figure 5. LEPC core habitat. NM LEPC Impact Model (10/2010) Page 12

13 Factor 5. Core Buffer Habitat. Gives value to areas that meet minimum habitat composition ratios considered suitable for LEPC (Fig. 6). Core buffer habitat was determined by Playa Lakes Joint Venture, as described in Appendix B of the OK model report. Figure 6. LEPC core buffer habitat. NM LEPC Impact Model (10/2010) Page 13

14 Factor 6. Managed and Protected Land. Gives value to managed and protected lands that are potential LEPC habitat including a 1.24 mi. buffer (Fig.7). (This buffer is based on the suggested buffer for wind turbines that may be erected on adjacent lands; see Factor 8.) Managed and protected lands within New Mexico include properties owned or managed by NM Dept. of Game and Fish, NM State Land Office, USDA Forest Service, US Fish and Wildlife Service, US Bureau of Land Management, The Nature Conservancy, and other private organizations. Figure 7. Managed and protected properties. NM LEPC Impact Model (10/2010) Page 14

15 Factor 7. Suitable Habitat. Gives value to suitable or potentially suitable habitat (Fig. 8). Suitable habitat was considered to be all vegetation types falling into the LEPC/habitat associations defined by PLJV (Playa Lakes Joint Venture, 2007): Shortgrass Mixedgrass Sandsage Shinnery These associations include vegetation types selected from the LANDFIRE existing vegetation type dataset (The National Map LANDFIRE, 2007): Western Great Plains shortgrass prairie Western Great Plains sand prairie Western Great Plains sandhill steppe Western Great Plains foothill and piedmont grassland Central mixedgrass prairie Inter-mountain basins semi-desert shrub steppe Chihuahuan gypsophilous grassland and steppe Quercus havardii shrubland alliance LANDFIRE vegetation map units are derived from a nationally consistent set of mid-scale ecological units (Comer, 2003). Existing vegetation is mapped through a predictive modeling approach using a combination of field reference information, Landsat imagery, and spatially explicit biophysical gradient data. This dataset is seamless across the model extent, and produces results similar to the procedure used in the OK model. Note that habitat which would be potentially suitable if managed for LEPC conservation (such as some agricultural land, mesquite shrubland, or introduced grasslands) was not included in the model. The primary purpose of the model at this point is to assess impacts of development on current LEPC habitat. However future efforts toward habitat rehabilitation and species restoration may wish to include these potentially suitable lands in the analysis, particularly those in close proximity to known LEPC occurrence. NM LEPC Impact Model (10/2010) Page 15

16 Figure 8.Suitable and potentially suitable LEPC habitat. NM LEPC Impact Model (10/2010) Page 16

17 Factor 8. Avoided Obstacles. Gives value to all land that is outside LEPC avoidance areas caused by fragmentation, vertical structures, or human activity (Fig. 9). Avoidance areas are buffers surrounding avoidance features as described in the OK model report, including features in Table 2. Table 2. List of avoidance features, associated buffers, and data sources Avoidance feature Buffer Data Source Major roads, railroads Electric transmission lines Active oil and gas wellheads Towers and other vertical structures >99 ft. high 1.5 mi. buffer applied to line location data 0.3 mi. buffer applied to line location data 0.35 mi. buffer applied to point location data 0.3 mi. buffer for towers and 1.24 mi. buffer for wind turbines applied to point location data New Mexico Resource Geographic Information System Program (RGIS; rgis.unm.edu) Ventyx, June 2010 NM Energy, Minerals, and Natural Resources Dept.; Oil Conservation Division (April, 2010). Texas Railroad Commission FAA Digital Obstacle File (June 2010) As seen in Figure 9, at the scale of these maps the dominant avoidance features in terms of total avoidance area are major roads (throughout the model extent) and oil and gas development (primarily in the southern portion of the model extent). Although not apparent at this scale many avoidance features become significant at a local or project scale, and should be closely examined at that scale. LEPC Impact Map Addition of the eight ranking factors yields the final development impact map, shown in Figure 10, with pixel values of 1 (least impact) to 8 (greatest impact) within the model extent. NM LEPC Impact Model (10/2010) Page 17

18 Figure 9. Area outside of LEPC avoidance feature buffers. NM LEPC Impact Model (10/2010) Page 18

19 Figure 10. NM LEPC impact model, ranking from least (1) to greatest (8) development impact. NM LEPC Impact Model (10/2010) Page 19

20 Applications of the model The primary goal of this study is to minimize negative impacts of development on LEPC habitat. Use of the model is intended to be beneficial for both developers and LEPC conservation efforts by reducing negative impacts and enhancing habitat protection (through identification of priority areas for acquisition and management). The LEPC is recognized as an indicator species for the health of grassland habitats, and much conservation effort is focused on this species. However, LEPC conservation alone does not reflect the status nor satisfy the needs of all species and habitats of concern in the region. Development activity must consider the impacts to this broader range of natural resources as well. In principle, any type of development activity that results in impacts to LEPC habitat in eastern New Mexico can benefit from use of this model. As examples, we focus on development of wind energy resources in the region. The area encompassed by the NM LEPC model has substantial wind energy resources, and includes a number of existing utility-scale wind energy projects with more in the planning stages or under consideration. Additional transmission lines will be necessary as well to support expanded wind energy development in this region. Figure 11 shows the wind power (50m) classification for eastern New Mexico (NREL, 2008), including the NM LEPC model extent. Much of the area within the model extent is estimated at wind power class 3 or greater, which is generally considered suitable for wind energy development. Existing wind energy projects (AWEA, 2010) and proposed new transmission lines (HPX, 2010) are also shown in Fig. 11. The challenge for both the renewable energy industry and the wildlife conservation community is to promote affordable development of this resource with the least impact on habitat for sensitive species such as the LEPC. We show two examples below of how the NM LEPC model can be used to assist in development of renewable energy resources by evaluating the impact of development in areas of concern, and in locating production and transmission facilities in areas of minimal impact. NM LEPC Impact Model (10/2010) Page 20

21 Figure 11. Wind power classification for eastern New Mexico. NM LEPC Impact Model (10/2010) Page 21

22 Application Example 1. Wind energy production Following the OK model, we have used the NM LEPC impact model along with the wind power classification to produce a spatial grid of areas within the model extent where: a) wind energy development potential is high (wind power class b) impact to LEPC habitat is low (LEPC impact rank 3), and c) contains enough contiguous low impact area to support wind energy development. The OK model assumes an LEPC impact buffer radius of 1.24 mi. for a wind turbine, and suggests contiguous low impact area of >5000 acres as suitable for wind energy development. Large utility-scale wind projects (>100 turbines) are likely to require contiguous low impact areas >20,000 acres, including the 1.24 mi. buffer. (Assumptions: 100 towers in a line x 0.15 mi. spacing x 2.5 mi. buffer width = 38 mi 2 = 24,000 acres. Turbine spacing is estimated from the average of existing NM wind farms.) Areas suitable for minimal impact wind energy development using the three criteria outlined above are shown in gray in Figure 12. Seven contiguous parcels between 5000 and 20,000 acres, suitable for small wind energy projects, and four very large contiguous parcels >20,000 acres, suitable for large wind energy projects, were identified within the model extent. Areas of high LEPC impact (impact rank >3), where wind energy development is undesirable, are also shown in Fig. 12. Areas in white within the model extent in New Mexico are either low wind energy class, where wind energy development is unlikely, or contain <5000 acres of contiguous low impact area. Approximately 48% of the model extent in New Mexico, a total of 7.8 million acres, satisfies the three criteria for low impact development, suggesting many opportunities for wind energy development in eastern New Mexico while at the same time minimizing impact on LEPC habitat. Existing wind energy projects in New Mexico shown in Fig.12 are within the minimum impact areas identified here. NM LEPC Impact Model (10/2010) Page 22

23 Figure 12. Contiguous areas >5000 acres with minimum impact on LEPC habitat (LEPC impact factor 3), and high wind energy development potential (wind power class 3). NM LEPC Impact Model (10/2010) Page 23

24 Application Example 2. Transmission line routing Distributed sources of renewable energy, such as wind energy, tend to be located in sparsely populated regions with inadequate transmission facilities. Gathering and bringing this energy to market will result in a major restructuring of our electric grid, including additional transmission lines in areas of renewable energy production. Transmission lines contribute to LEPC habitat fragmentation and routing is generally undesirable in areas of high LEPC impact ranking. Transmission lines are linear features with impact buffers that are small on the scale of the impact map shown in Fig. 10. However, transmission lines contribute to habitat fragmentation, and the impact of transmission line routing should be studied at a local scale. For example the section of proposed transmission line in northern Curry county (Fig. 11) traverses an area of high LEPC impact factor (impact rank = 4, 5 in Fig. 10). Figure 13 displays a map of this area at a local scale to examine impacts that should be considered in routing a new transmission line. (The red transmission line symbol is the width of the suggested transmission line buffer area; see table 2.) As seen in Figure 13, while much of the area is considered high impact, there are corridors of low impact, due to existing improved roads and/or transmission lines, which could be exploited for transmission line routing without increasing overall impact to LEPC habitat. Of course many other factors go into selecting a route for new transmission lines, such as availability of right-of-way, topography, and impacts on other landscape features or species of concern. Assigning impact value for LEPC habitat ensures that LEPC conservation is one of the factors in the route selection process. NM LEPC Impact Model (10/2010) Page 24

25 Figure 13. Detail of LEPC impact map and proposed transmission line route in northern Curry county. NM LEPC Impact Model (10/2010) Page 25

26 Limitations of the model All models are only as good as the assumptions upon which they are based, and the accuracy and completeness of the data that are used for evaluation. This model is not definitive in predicting or locating LEPC habitat or occurrence, or in quantitatively predicting potential effects of development. Many aspects of the model, particularly buffer distances, are based on expert opinion rather than rigorous observation, and do not reflect LEPC behavior associated with different activities (e.g. nesting vs. foraging). Other important aspects of LEPC conservation, such as population density and connectivity of suitable habitat are not included in the model. Many of these details were not considered either for lack of reliable data, or for the sake of model simplicity. Consequently this model and the associated data layers are intended as a general guide when exploring the potential effect of development on LEPC. The NM LEPC model is intended to be used to avoid, minimize or mitigate the potential effects to the most intact landscapes within the LEPC s historic range in New Mexico. A detailed assessment of model applications, limitations, and data accuracy is given in the OK model documentation, which is generally applicable to the NM LEPC model as well. Model Use and Application The NM LEPC model is intended as regional-level strategic planning and management tool. Although the model s data layers are delivered as 30-meter pixels, it should not be used at the individual pixel level or on small groups of pixels. The applicability of NM LEPC model to support land management planning on smaller areas will vary by location, and specific use. Further investigation by local and regional experts should be conducted to inform decisions regarding local applicability. However, it is the responsibility of the local user, using local knowledge, to determine if and/or how the NM LEPC model can be used for particular areas of interest. Managers and planners must evaluate the NM LEPC model data according to the scale and requirements specific to their needs. It is the responsibility of the user to be familiar with the values, assumptions, and limitations of the NM LEPC model. Industry professionals and consultants should always contact and seek recommendations from statutorily responsible state and federal natural resource agencies as soon as possible in the development planning process, prior to finalizing development and mitigation plans, since site-specific conditions may vary. Acknowledgements We would like to thank Megan McLachlan of Playa Lakes Joint Venture for making available the historic and current range and core and core buffer habitat data; Chris Hise of the Oklahoma Chapter of The Nature Conservancy for helpful comments and providing relevant OK and TX data; Tish McDaniel of the New Mexico Chapter of The Nature Conservancy and Grant Beauprez of the New Mexico Department of Game and Fish for reviewing this report; and Rayo McCollough of the Natural Heritage New Mexico Program for compiling lek data. NM LEPC Impact Model (10/2010) Page 26

27 References AWEA (American Wind Energy Assoc.) Wind Energy Projects New Mexico. (Accessed: April, 2010). Brennan, L.A., W.P. Kuvlesky, Jr. 2005, North American grassland birds: An unfolding conservation crisis. Journal of Wildlife Management 69 (1):1-13 Comer, P., D. Faber-Langendoen, R. Evans, S. Gawler, C. Josse, G. Kittel, S. Menard, M. Pyne, M. Reid, K. Schulz, K. Snow, and J. Teague Ecological Systems of the United States: A Working Classification of U.S. Terrestrial Systems. NatureServe, Arlington, VA. 75 p. Hagen, C. A., B. E. Jamison, K. M. Giesen, and T. Z. Riley Guidelines for managing lesser prairie-chicken populations and their habitats. Wildlife Society Bulletin 32 (1): Horton, R., L. Bell, C. M. O Meilia, M. McLachlan, C. Hise, D. Wolfe, D. Elmore and J.D. Strong A Spatially-Based Planning Tool Designed to Reduce Negative Effects of Development on the Lesser Prairie-Chicken (Tympanuchus pallidicinctus) in Oklahoma: A Multi-Entity Collaboration to Promote Lesser Prairie-Chicken Voluntary Habitat Conservation and Prioritized Management Actions. Oklahoma Department of Wildlife Conservation. Oklahoma City, Oklahoma. 79 pp. (Accessed: March, 2010) HPX (High Plains Express Transmission Project). January, 2010 base map. (Accessed: March, 2010.) Note that the routing of proposed transmission lines in this map is illustrative only. Detailed routing studies are underway at the time of this writing. Meinig, D.W The Shaping of America: A Geographical Perspective on 500 Years of History, Volume 2: Continental America, New Haven: Yale University Press. NREL (National Renewable Energy Laboratory) New Mexico 50m wind resource map. (Accessed: April, 2010) Playa Lakes Joint Venture Habitat Assessment Procedures Manual. Playas Lakes Joint Venture, Lafayette, CO. Sampson, F. B., and F. Knopf Prairie conservation in North America. BioScience 44: NM LEPC Impact Model (10/2010) Page 27

28 The National Map LANDFIRE LANDFIRE National Existing Vegetation Type layer. U.S. Department of Interior, Geological Survey. [Online]. Available: NM LEPC Impact Model (10/2010) Page 28