The Next 50 Years: Opportunities for Diversifying the Ecological Representation of the National Wilderness Preservation System within the Contiguous United States

25 The US National Wilderness Preservation System (NWPS) is the world’s largest wilderness 26 protection network, yet within the contiguous US (CONUS) it does not encompass the diversity 27 nor is it fully representative of ecological systems on federal lands. To potentially increase 28 NWPS diversity and representation, we simulated adding potentially eligible lands within 29 CONUS, in the following sequence, to assess changes in ecological systems: National Park 30 Lands not currently designated wilderness; non-NWPS lands currently managed to not degrade 31 wilderness character; US Forest Service Inventoried Roadless Areas; and Bureau of Land 32 Management roadless lands. Inclusion of these categories would increase the NWPS area from 33 12.8% to 48.3% of federal lands, increase diversity by adding 46 ecological systems, and nearly 34 triple the number of ecological systems on federal lands with >20% representation. Our analysis 35 identifies opportunities to increase diversity and representation of ecological systems within the 36 NWPS. 37 Management and Policy Implications 38 Over 50 years ago, the Wilderness Act (1964) established a process for adding lands to the 39 National Wilderness Preservation System (NWPS). If the goal of wilderness management and 40 policy is to provide the best possible representation of ecological systems within the NWPS, then 41 adding lands to the NWPS will be vital for preserving the diversity of species and habitats found 42 throughout the contiguous US (CONUS). Adding lands to the NWPS will also provide the most 43 robust wilderness protection network for adapting to future land-use and climate change. We 44 demonstrated which land designation categories among National Park lands not currently 45 designated wilderness; non-NWPS lands currently managed to not degrade wilderness character; 46 US Forest Service Inventoried Roadless Areas; and Bureau of Land Management roadless lands 47 provide the greatest opportunities for diversifying and increasing representation of ecological 48 systems. This information can inform future management and policy of the NWPS. All 4 land 49 designation categories provide important opportunities for increasing ecological systems 50 representation. However, even if all land designation categories were added to the NWPS, 64 51 ecological systems on federal lands (12%) would remain unrepresented. There is, nonetheless, 52 substantial opportunity to diversify the NWPS and increase levels of representation of ecological 53 systems. 54 Introduction 55 Noss and Cooperrider (1994; p. 89) stated that a first principle of conservation planning 56 is to “represent, in a system of protected areas, all native ecosystem types...across their natural 57 range of variation.” Expanding the representation of ecological systems (i.e., native ecosystem 58 types) within a protected area network (i.e., a network of lands having permanent protection from 59 conversion of natural land cover and a mandated management plan to maintain a natural state; USGS60 GAP 2012), has 3 primary benefits. First, maximizing the diversity of ecological systems 61 represented in protected areas will likely protect greater numbers of species and their habitat. For 62 example, Pouzols et al. (2014) showed that protected area expansion, if strategically 63 implemented, could triple the average protection of vertebrate species ranges. Second, greater 64 diversity of ecological systems represented in a protected area network may enhance the 65 resilience of species and habitats to global changes (Shaffer and Stein 2000). Third, greater 66 representation of ecological systems in areas protected from human-caused disturbance can serve 67 as reference areas for comparison to more highly-managed or human-impacted areas (Belote et 68 al. in press). Leopold (1949, p. 196) recognized the benefit of an ecologically representative 69 protected area network by stating that “each biotic province needs its own land for comparative 70 studies of used and unused land.” 71 The value of an ecologically representative system has long been recognized, even 72 though few existing protected areas were established explicitly to protect representative 73 examples of ecological systems. Over the last few decades, additions to the global protected area 74 network have not commensurately increased ecological representation, but rather have 75 maintained the bias towards high altitude and low productivity areas (Aycrigg et al. 2013, 76 Watson et al. 2014). This is consistent with the lack of complete ecological system representation 77 found within the protected area network of the United States (US) and, more specifically, within 78 the National Wilderness Preservation System (NWPS; Aycrigg et al. 2013, Dietz et al. 2015). 79 Over the past 50 years, the NWPS has protected numerous large unfragmented areas, but has yet 80 to achieve the full representation of ecological systems found on federal lands (Dietz et al. 2015). 81 In 1964, the US Congress established the most protective of protected area networks, the 82 NWPS, to preserve “natural conditions” and “ecological, geological, or other features of 83 scientific...value” (The Wilderness Act (WA) 1964, section 2c). Examining the ecological 84 diversity and representation in the NWPS as a distinct protected areas network is important for 2 85 reasons. First, the NWPS, which comprises 12.8% of the total federal lands, 13.6% of the 86 protected area network, and approximately 2.6% of the contiguous US (CONUS), is functionally 87 and legally distinct from other protected areas within the US because the system has a high level 88 of protection and prohibits many human activities, such as road-building, logging, energy 89 development (i.e., oil and gas drilling), off-road motor vehicles, developed tourism facilities, and 90 permanent structures (WA 1964, section 4c). Second, WA provides for the expansion of the 91 NWPS in a systematic way (WA 1964, section 3). For example, all 4 federal land management 92 agencies (i.e., National Park Service (NPS), Bureau of Land Management (BLM), US Fish and 93 Wildlife Service (FWS), and US Forest Service (USFS)) are legally required to evaluate the need 94 for new wilderness areas during their land and resource management planning process. In 95 addition, roadless areas possessing wilderness characteristics, which are among potentially 96 suitable federal lands, are eligible for wilderness designation. 97 Areas outside the NWPS, but with wilderness character, are becoming rare because of 98 pressures from land-use changes, such as demands for energy development and urban expansion 99 surrounding these areas (Martinuzzi et al. 2015). Consequently, these areas are becoming a more 100 important component of a comprehensive strategy to protect biodiversity. Even though there are 101 many types of protected areas (on federal, state, local, and private lands) that contribute to 102 biodiversity conservation throughout the US, the NWPS serves a unique role and it could better 103 conserve biodiversity if its resilience could be strengthened by identifying the most ecologically104 important areas to diversify its ecological representation on federal land. 105 Dietz et al. (2015) found that while the total area of the NWPS within CONUS has 106 increased steadily over last 50 years, the number of ecological systems represented in wilderness 107 reached an asymptote approximately 30 years ago. The number of ecological systems 108 represented was below the total number of ecological systems that occur on federal land and 109 therefore could potentially be included in the NWPS. 110 We extended the analysis of Dietz et al. (2015) to simulate the potential for increasing the 111 diversity and representation of ecological systems by sequential and cumulative additions to the 112 NWPS. We identified 4 spatially distinct and mutually exclusive land designation categories that 113 could be included in the NWPS. First, we included National Park lands that are not designated as 114 wilderness, but are eligible for wilderness designation (WA 1964, section 3c). We excluded 115 portions of National Parks that were already designated wilderness, National Parks that were 116 established principally for cultural resources or as scenic roadways, and National Parks <5,000 117 acres, which is, with some exceptions, the minimum size for wilderness areas (WA 1964, section 118 2c). Second, we included congressionally or administratively recommended wilderness areas 119 including USFS and BLM Wilderness Study Areas (WSA) and areas recommended for 120 wilderness by USFS, BLM, and FWS. These lands are currently managed so as not to degrade 121 their wilderness character. This category excludes any areas that are within National Parks to 122 keep it distinct from our first category (from here forward we refer to this category as ‘lands 123 managed so as not to degrade their wilderness character’). Third, we included USFS Inventoried 124 Roadless Areas (IRAs) that are not included in the second category. Fourth, we included BLM 125 roadless areas that are not included in the second category. We chose these land designation 126 categories and this sequence because they represent our estimate of the current level of 127 protection already afforded these lands and the likelihood of securing sufficient public support 128 for their addition to the NWPS under the process established by WA (1964). We wanted to 129 compare our results to the results of Dietz et al. (2015); therefore we used CONUS as the spatial 130 extent for our analysis. Our objectives are to evaluate the change in ecological system diversity 131 (i.e., how many ecological systems) and representation (i.e., what proportion of an ecological 132 system) by simulating the addition of each of 4 land designation categories to the NWPS (Table 133 1). As in Dietz et al. (2015), we used 20% as a convenient threshold