It is becoming increasingly difficult to manage and expand statutory conservation areas (i.e., parks and formally protected areas). Therefore, alternative opportunities for land conservation merit closer attention. This paper examines the extent to which privately owned conservation areas contribute to biodiversity representation. Gap analyses were performed for a large semi-arid region in South Africa with a comprehensive database of private conservation areas. The distribution of private conservation areas was compared to statutory conservation areas using several landscape characteristics: biome and vegetation variant, elevation class, ecological process area, total area, and threat status (endangerment). Conservation target achievement for the vegetation variants was also assessed, as was the degree to which private conservation areas complemented statutory conservation areas by representing different landscape characteristics. The number of targets achieved nearly tripled if private conservation areas were considered in addition to statutory conservation areas. Further, private conservation areas significantly complemented statutory conservation areas in the types of biomes, elevation classes, and threat status classes conserved. Private conservation areas were especially important in conserving lower elevation habitat, and by association, endangered vegetation. This particular relationship is expected to be common worldwide. Our results indicate that private lands conservation deserves an increased allocation of resources for both research and implementation.
The use of statutory conservation areas (SCAs) has been the cornerstone of biodiversity conservation strategies in most countries of the world. Unfortunately, the global protected areas network is far from reaching its goal of comprehensively conserving biodiversity (Brooks et al., 2004; Rodrigues et al., 2004b). In a global gap analysis, only 26% of the 11,633
vertebrates were represented to target levels in protected areas (Rodrigues et al., 2004a). Even though the global net work of SCAs covers a respectable 11.5% of the World’s land surface (Chape et al., 2003), this area is strongly biased to wards certain types of geographies, and hence, habitats. Pro tected areas are usually located in the least productive portions of the landscape, where the costs to society of con servation are lowest (for example, in rugged, scenic and infer tile landscapes) (Pressey, 1994; Norton, 2000; Scott et al., 2001; Rouget et al., 2003). Meanwhile, habitat conversion outpaces conservation at alarming rates (Knight, 1999), for example at a rate exceeding 8:1 in temperate grassland and Mediterra nean scrub biomes (Hoekstra et al., 2005). Additionally, man agement of existing parks is chronically under-funded. The mean operating budget for parks in developing countries covers only 30% of their budgetary needs (James et al., 1999). It is increasingly clear that the global network of statutory reserves alone is not going to be adequate for con serving biodiversity (Morton et al., 1995; Norton, 2000). One response to these problems would be for the developed world to help pay the $4 billion annual budget required for the maintenance and creation of new protected areas in develop ing countries (Bruner et al., 2004). But indications are that society is not ready to pay the cost of conserving biodiversity in reserves (e.g. James et al., 2001; Pearce, 2007).
In response to the problems at hand we examine an emerging strategy: strengthening the network of private con servation areas (PCAs) (Hale and Lamb, 1997; Knight, 1999; Langholz and Lassoie, 2001; Langholz and Krug, 2004). One study found that if PCAs were used in conjunction with SCAs for conserving biodiversity, then the state would save 80% in acquisition costs (Pence et al., 2003). PCAs are sometimes termed private protected areas, and for this study meet four characteristics: (i) owned by freehold or long-term leasehold by a private investor(s) or syndicate; (ii) funded and/or run by a private investor or syndicate; (iii) managed for biodiver sity and possibly for nature tourism, game-based ventures or leisure; and (iv) owned with the intent of preserving the land in a predominantly undeveloped state (Pasquini, 2007). For the most part, PCAs have been left out of conservation statistics, national conservation–planning frameworks, and until recently, generally out of academic research. However, the few studies performed show that thousands of PCA own ers have demonstrated a willingness and capacity to conserve several million hectares of land (Langholz, 1996; Thackway and Olsson, 1999; Langholz and Lassoie, 2001; Chacon, 2005; Figgis et al., 2005; Jones et al., 2005; Mitchell, 2005; Sims-Cast ley et al., 2005; Pasquini, 2007). Conserving land is important, but not the end goal; the question remains, how well are PCAs conserving biodiversity itself (Langholz
and Krug, 2004; Merenlender et al., 2004; Mitchell, 2005)? Wallace et al. (2008) made a typology of 18 po tential benefits of PCAs, and found that the most commonly observed benefits in a US county were conservation of ripar ian areas, contiguity with other PCAs, protection of big-game concentration areas, and buffering of public protected lands. Fitzsimons and Wescott (2008) found that PCAs enhanced
PCAs and SCAs, and found several vegetation types that were represented only in PCAs.
Here we provide a comprehensive picture of how PCAs contribute to biodiversity representation and target achieve ment within a region, as well as test the complementarity of PCAs to SCAs. We use a data-rich region of South Africa as a case study and examine several elements of biodiversity: vegetation types, elevation classes, threatened ecosystems, and areas important for ecological processes. While the re sults are specific to this region, we feel that the causal rela tionships that emerge are applicable worldwide. We find that PCAs play a vital role in biodiversity conservation, espe cially in the productive lowlands. We conclude that this role deserves increased attention from conservation, research, and funding institutions.