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Keywords:

  • biodiversity;
  • gap analysis;
  • habitat loss;
  • mediterranean ecosystems;
  • protected areas
  • análisis de disparidad;
  • áreas protegidas;
  • biodiversidad;
  • ecosistemas Mediterráneos;
  • pérdida de hábitat

Abstract

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Beyond Mountains and Shrublands
  7. Discussion
  8. Acknowledgments
  9. Literature Cited
  10. Supporting Information

Abstract: Global goals established by the Convention on Biological Diversity stipulate that 10% of the world's ecological regions must be effectively conserved by 2010. To meet that goal for the mediterranean biome, at least 5% more land must be formally protected over the next few years. Although global assessments identify the mediterranean biome as a priority, without biologically meaningful analysis units, finer-resolution data, and corresponding prioritization analysis, future conservation investments could lead to more area being protected without increasing the representation of unique mediterranean ecosystems. We used standardized analysis units and six potential natural vegetation types stratified by 3 elevation zones in a global gap analysis that systematically explored conservation priorities across the mediterranean biome. The highest levels of protection were in Australia, South Africa, and California-Baja California (from 9–11%), and the lowest levels of protection were in Chile and the mediterranean Basin (<1%). Protection was skewed to montane elevations in three out of five regions. Across the biome only one of the six vegetation types—mediterranean shrubland—exceeded 10% protection. The remaining vegetation types—grassland, scrub, succulent dominated, woodland, and forest—each had <3% protection. To guard against biases in future protection efforts and ensure the protection of species characteristic of the mediterranean biome, we identified biodiversity assemblages with <10% protection and subject to >30% conversion and suggest that these assemblages be elevated to high-priority status in future conservation efforts.

Resumen: Las metas globales establecidas por la Convención sobre Diversidad Biológica estipulan que 10% de las regiones ecológicas del mundo deberán estar conservadas efectivamente en 2010. Para alcanzar esa meta en el bioma mediterráneo, por lo menos 5% más de superficie debe estar protegida formalmente en los próximos años. Aunque las evaluaciones globales identifican al bioma mediterráneo como una prioridad, sin unidades de análisis biológicamente significativas, datos de resolución más fina y los correspondientes análisis de priorización, las inversiones futuras en conservación pudieran conducir a la protección de más superficie sin incrementar la representación de los ecosistemas mediterráneos únicos. Utilizamos unidades de análisis estandarizadas y seis tipos potenciales de vegetación natural estratificados en tres zonas de elevación en un análisis global de disparidad que exploró sistemáticamente las prioridades de conservación en el bioma mediterráneo. Los niveles de protección más altos se localizaron en Australia, África del Sur y California-Baja California (de 9–11%) y los niveles de protección más bajos se localizaron en Chile y la Cuenca del mediterráneo (<1%). La protección estaba sesgada hacia elevaciones altas en tres de las cinco regiones. En todo el bioma, solo uno de los seis tipos de vegetación—matorral mediterráneo—excedió 10% de protección. Los tipos de vegetación restantes—pastizal, matorral, dominio de suculentas, y bosques—tenían <3% de protección cada uno. Para evitar sesgos en futuros esfuerzos de protección y asegurar la protección de especies características del bioma mediterráneo, identificamos ensambles de biodiversidad con <10% de protección y sujetos a >30% de conversión y sugerimos que estos ensambles sean elevados a un estatus de alta prioridad en esfuerzos de conservación en el futuro.


Introduction

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Beyond Mountains and Shrublands
  7. Discussion
  8. Acknowledgments
  9. Literature Cited
  10. Supporting Information

The world's diverse ecological systems are rapidly being converted to urban areas, croplands, and commercial forests (Sala et al. 2000; Hoekstra et al. 2005). Out of concern for the natural world, humans have set aside networks of natural areas and protected them from destructive uses. Protective areas are unevenly distributed; thus, some ecotypes are virtually absent from the world's protected areas, whereas others are overrepresented (Pressey 1994; Pressey et al. 1996; Rouget et al. 2003).

We focused on the five regions on Earth within the mediterranean biome: California (U.S.A.)-Baja California (Mexico), Chile, South Africa, southern Australia, and the mediterranean Basin. The biome covers <5% of the Earth's surface but harbors more than 48,000 (20%) of the world's vascular plant species—a high proportion of which are rare and locally endemic (Cowling et al. 1996; Médail & Quézel 1997). The mediterranean biome also has one of the world's most skeletal protected-area networks, encompassing only 5% of the biome (IUCN categories I-VI) (Hoekstra et al. 2005). The biome is under extremely intense development pressure; its characteristic dry, warm summers and wet, mild winters have long attracted urbanization, tourism, and agriculture, (Di Castri 1981; Rundel 1998; Bunn et al. 2005). Previous studies indicate conversion exceeds protection in the biome by a factor of 8:2, which surpasses conversion of all other biomes except temperate grasslands, savannas, and shrublands (Hoekstra et al. 2005).

The Convention on Biological Diversity's Global Targets for 2010 calls for the effective conservation of “at least 10% of each of the world's ecological regions” (United Nations Environment Programme 2002). Meeting this goal will be particularly challenging in the mediterranean biome, where an additional 5% protection is needed. Without targeted and strategic planning, efforts to meet the convention's numerical goal could be satisfied but still fail to protect the biodiversity representative of the mediterranean biome. For example, if montane elevations continue to be overrepresented, characteristic mediterranean-climate species, such as the valley oak (Quercus lobata) in California (U.S.A.) and the ruil (Nothofagus alessandri) forests in Chile, may be lost. Existing global priority-setting efforts, however, such as the biodiversity hotspots (Myers et al. 2000) or Global 200 ecoregions (Olson & Dinerstein 2002), provide little strategic guidance for implementation of the 2010 goal because their coarseness fails to reflect patterns of biodiversity characteristic of the biome. Conversely, although there have been numerous conservation assessments at the country and local levels (e.g., South Africa's Cape Floristic Region), they are of limited use for identifying global, biome-wide conservation priorities because the methodology, criteria, and data vary greatly. A new global prioritization is needed to assure future conservation investments will increase the amount of area protected and enhance representation of mediterranean biodiversity within the protected-areas network.

To identify areas of high conservation importance within the terrestrial mediterranean biome, we used biodiversity assemblages defined by potential natural vegetation type and elevation zone to conduct a global gap analysis (Scott 1993; Jennings 2000). In contrast to other units, such as country or ecoregion, which have previously been used for global prioritization analyses, these units are consistently defined across all five regions, which permits appropriate comparisons and can provide differentiation within otherwise very large areas. We assessed patterns of protection and land conversion across the biome and identified priority biodiversity assemblages for future conservation. Finally, we conducted a sensitivity analysis to compare what would be protected with these assemblages with that protected with coarser units, such as country or ecoregion. Our findings can help ensure that future conservation investments facilitate adequate representation of mediterranean biodiversity and thereby increase the pace and scale of much needed conservation in the biome.

Methods

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Beyond Mountains and Shrublands
  7. Discussion
  8. Acknowledgments
  9. Literature Cited
  10. Supporting Information

Units of Analyses

We used the 39 terrestrial ecoregions identified by the World Wildlife Fund (WWF) in the Mediterranean Forests, Woodland and Scrub biome (Olson et al. 2001) to define the spatial extent of the mediterranean biome (total area of 3,222,000 km2). For the five geographic regions, we assembled country- and regional-scale data on potential natural vegetation (PNV) (Table 1). To allow systematic comparisons across the regions, we assigned PNV classes to six global vegetation types with assistance from regional experts: grassland, scrub, shrubland, succulent dominated, woodland, and forest (Table 2). Each vegetation type was also stratified into three elevation zones: lowland (<300 m), foothill (300–1000 m), and montane (>1000 m) with a 90-m, digital elevation model (NASA National Geospatial-Intelligence Agency 2002). These thresholds, derived from the literature on a number of the regions (Barbour & Major 1988; Davis et al. 1998; Burgess et al. 2004), reflect climatic and topographic variation and were selected so we could capture patterns of biodiversity—hereafter referred to as Mediterranean Biodiversity Assemblages (MBAs).

Table 1.  Sources of data on potential natural vegetation, land cover, and protection for the mediterranean biome.
Region*Name/description/publication dateSource/Author
  1. *Region codes: Cal, California (U.S.A.); Mex, Mexico; Chl, Chile; SA, South Africa; Aus, Australia; MedB, Mediterranean Basin.

Potential natural vegetation
  AusEstimated pre-1750 major vegetation groups—NVIS Stage 1, v. 3.0 (2006)Australian Government Department of the Environment and Heritage
  CalKuchler map of potential vegetation (1996)U.S. Bureau of Reclamation, Mid-Pacific Region, MPGIS Service
  MexBiotic communities of the Southwest (1979)Brown, D., and C. Lowe, Map digitized by The Nature Conservancy (Arizona)
  ChlSinopsis bioclimatica y vegetacional de Chile (2005)F. Luebert and P. Pliscoff
  MedBMajor forest types in the Mediterranean (2001)Guidotti, G., P. Regata, S. Jimenez-Caballero, World Wildlife Fund Mediterranean Programme Office
  SAVegetation map of South Africa, Lesotho and Swaziland (2004)L. Mucina and M.C. Rutherford, editors
Current land cover
  AusIntegrated vegetation cover (2003)Bureau of Rural Sciences—Australia Department of Agriculture, Fisheries and Forestry
  CalMulti-source land cover data, v2 (2002)California Department of Forestry and Fire Protection
  ChlCatastro de la vegetación nativa de Chile (1997)Corporación Nacional Forestal, Comisión Nacional del Medio Ambiente
  MedBPan-European land use and land cover monitoring (2000)Environment & Climate Programme of the Fourth Framework
  MedBCorine land cover changes (2005)European Topic Centre on Terrestrial Environment, Corine land cover changes (1990–2000)
  MedBGeoCover-LC raster scene without MMU for southern & eastern MedBasin (2005)MDA Federal Inc.
  MexGeoCover-LC raster scene without MMU (2005)MDA Federal Inc.
  SASouth African national landcover database (1997)Council for Scientific and Industrial Research
Protected areas
  AusCollaborative Australian protected areas database (2004)Australian Government Dept. of the Environment and Heritage
  CalTNC property title interests in California (2005)The Nature Conservancy, California
  CalPublic conservation and trust lands (2006)California Resources Agency Legacy Project, updated by The Nature Conservancy, California
  ChlProtected areas for Chile (2006)Center for Advanced Studies in Ecology and Biodiversity; Departamento de Ecología Pontificia Universidad Católica de Chile
  MedBWorld database on protected areas (2006)IUCN and UNEP-WCMC
  MexPrivate reserves in Mexico (2000)Centro Pronatura de Información para la Conservación. Pronatura A.C. Noroeste
  SAProtected areas of South Africa, Lesotho, Swaziland (2005)South African National Biodiversity Institute
Table 2.  Description of global vegetation types used to assign vegetation and land cover classes to permit comparison among the five regions of the mediterranean biome.
Vegetation typeVegetation descriptionExample from California, U.S.A.
Foresttree dominated, generally >60% canopy cover; tree layer dominated by a mixture of evergreen, sclerophyllous, winter deciduous, and conifer speciestypical tree species: Quercus agrifolia, Q. chrysolepis, Q. kelloggii, Lithocarpus densiflorus, Umbellularia californica, Pseudotsuga menziesi and associated species forming dense forests in coastal mountains and in foothills on mesic, north-facing slopes
Woodlandtree-dominated vegetation with canopy closure generally <60%; tree layer dominated by evergreen, sclerophyllous species, and/or winter-deciduous speciesoak woodlands dominated by Quercus agrifolia, Q. douglasii and/or Q. lobata on lowlands, found on broad ridgelines and gentle to moderate slopes of foothills
Shrublanddominated by evergreen, sclerophyllous, woody shrubs, generally >1.5 m, open stands transitional to woodlandsdense stands of chamise chaparral dominated by Adenostoma fasciculatum
Succulent dominatedvegetation with a dominant succulent layer (distinguished only in South Africa and the Mediterranean Basin)not defined due to mapping resolution
Scrubmostly low, often semiwoody vegetation generally <1.5 m in height, many species drought-deciduous, often more open than shrubland; herbaceous layer varies from well developed to absent depending on soils, fire history, precipitation, land use and other factorscoastal sage scrub or sage scrub, typical species include Eriogonum fasciculatum, Artemisia californica, Salvia spp. and Encelia spp.
Grasslandherbaceous community dominated by grasses and herbsannual grasslands dominated by non-native species, including Bromus spp., Avena spp., Erodium cicutarium, and scattered native herbs such as Lupinus spp., Eschscholzia spp., Nasella spp.

Protected and Converted Areas

To assess the amount of formal protection in the mediterranean biome, we used country- and state- (for California, U.S.A.) scale data for four of the regions and the World Database on Protected Areas (WDPA) (2006) for the Mediterranean Basin (due to the lack of comparable data across 22 countries in Europe, the Near East, and North Africa). Protection levels were assessed with IUCN categories I-IV, which reflect areas specifically designated for biodiversity protection (IUCN 1994). The protection categories in the protected area databases for Australia, Chile, and Mexico had been converted to IUCN categories by within-country organizations. For California and South Africa respectively, we considered gap status 1 and 2 areas (Davis et al. 1998) and type 1 areas (Rouget et al. 2005) as meeting IUCN I-IV protection status. For the Mediterranean Basin, we used WDPA polygons (categories I-IV) if available and buffered point locations by the area recorded in the database for the remaining protected areas. We combined overlapping buffers and omitted all points without coordinates. Protection information is reported as the percent protection of the total spatial area of the region, elevation zone, six vegetation types, or MBA.

To calculate the conversion of natural areas, we acquired recent country- and regional-scale land-cover data and extracted urban and high-intensity agriculture classes (e.g., plantations) (Table 1). Areas classified as converted were subtracted from the spatial extent of the potential natural vegetation data. All spatial data were converted to a raster format and integrated in a geographic information system geodatabase (ArcMap, version 9.1, ESRI, Redlands, California).

Analyses

Differences in percent protection were compared with nonparametric analysis of variance (ANOVA) (JMPIn, version 5.1, SAS Institute, Cary, North Carolina). We conducted a log-likelihood chi-square analysis (Manly et al. 1993) to compare the current distribution of protected areas with that expected if the total amount of protection had been allocated to ensure equal representation of each unit (region, elevation, vegetation type, and combinations of these). This resource-selection approach compares the observed protection of each unit as a proportion of the total across all units, with the amount of protection expected given the spatial area of that unit. If, for example, observed protection is greater than expected, then the unit is considered disproportionately protected. We also calculated the conversion-to-protection ratio of the different units with the conservation risk index (Hoekstra et al. 2005).

To identify priorities for future conservation, we placed our global MBAs (e.g., montane forests) into a prioritization framework with two axes, percent converted and percent protected, divided into four quadrants. These quadrants had thresholds of 10% protection (goal stipulated in the Convention on Biological Diversity) and 30% conversion (total area converted in the mediterranean biome). We associated these quadrants with the conservation investment needed to adequately represent mediterranean biodiversity by 2010. Urgent priority MBAs were those that had <10% protection and relatively high level of conversion (>30%). High-priority assemblages also had <10% protection, but they had a relatively low level of conversion (<30%). We considered the two MBAs that already met the 10% protection threshold medium priorities and appropriate for later focus. Finally, a sensitivity analysis was conducted to compare priorities identified from MBAs with priorities identified from country and ecoregions, illustrating that areas of high conservation need are missed when coarser units of analysis are relied on.

Results

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Beyond Mountains and Shrublands
  7. Discussion
  8. Acknowledgments
  9. Literature Cited
  10. Supporting Information

Patterns of Protection and Conversion in Mediterranean Regions

At the global scale, 4.3% (139,415 km2) of the mediterranean biome was within protected areas specifically designated for biodiversity protection (IUCN categories I-IV). Percent protection was similar in three mediterranean regions: 11% in Australia and South Africa and 9% in California-Baja California, with Chile and the Mediterranean Basin each with <1% protection. Across the biome protection of lowland areas, at 6.3%, exceeded protection of foothill and montane areas (2.9% and 3.2% respectively) (Supporting Information). The greater protection of lowlands was a result of the extensive system of reserve lands in Australia, where low elevations dominated owing to the absence of montane areas. With Australia removed, lowland protection decreased to 1.7%. The distribution of protected areas across elevational zones was significantly different than expected when the total amount of protection was allocated according to the spatial extent of each of these classes (lowlands χ2= 61838.67, df = 4, p < 0.0001; foothills χ2= 42846.80, df = 4, p < 0.0001; and montane χ2= 17662.35, df = 3, p < 0.0001). Lowlands in Australia were almost twice as likely to be protected than lowlands in the other four regions (Supporting Information). Protection of foothill and montane elevations in California-Baja California and South Africa was disproportionately greater than expected, whereas protection of these elevations in the Mediterranean Basin and Chile was less than expected.

Across the entire mediterranean biome shrubland had the highest protection (11.8%), whereas the five other vegetation types—grassland, scrub, succulent dominated, woodland, and forest—each had <3% protection. Protection of these vegetation types was significantly different than expected given their spatial area (χ2= 72310.23, df = 5, p < 0.0001). Shrubland was four times more likely to be protected than any other vegetation type and the only type with more protection than expected given its extent, particularly in South Africa, Australia, and California-Baja California (Supporting Information). Woodland vegetation types had the greatest disparity in the area protected among the five regions. The Mediterranean Basin had only one-third the protection expected for this vegetation type compared with Australia, which had approximately three times the protection expected. Forest in California-Baja California and in Australia had disproportionately high levels of protection compared with the expected amount (Supporting Information).

Conversion to urban or high-intensity agriculture affected 30.8% (993,605 km2) of the mediterranean biome and differed significantly among the five mediterranean regions. Highest conversion was in Australia (37%) and the Mediterranean Basin (30%); South Africa and Chile had 25% and 24% conversion respectively, and California-Baja California had the least conversion (17%). By region, land conversion exceeded protection by a factor of 22 in Chile and the Mediterranean Basin, compared with a factor of three in Australia, South Africa, and California-Baja California.

Levels of conversion were significantly different among the three elevational zones. Land conversion in low elevation regions was highest at 41.8%, followed by 29.7% in foothills and 8.7% in montane areas. Ratios of conversion to protection by elevation varied greatly by region: lowlands in Chile and lowlands and foothills in the Mediterranean Basin had 32–40 times the amount of conversion to protection. At the other extreme, the conversion to protection ratio was almost zero for montane regions in California-Baja California. At the global scale by vegetation type, the highest conversion occurred in woodland (39%) and shrubland (35%). Forest (28%), scrub (18%), grassland (9%), and succulent dominated (3%) vegetation types were less converted, although these differences were not significant.

Beyond Mountains and Shrublands

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Beyond Mountains and Shrublands
  7. Discussion
  8. Acknowledgments
  9. Literature Cited
  10. Supporting Information

Across the biome protected areas were disproportionately concentrated in shrubland vegetation and montane elevations (Australia was excluded because it harbors only minimal areas of montane elevations). When we used the prioritization framework to place MBAs into urgent, high, and medium priority quadrants, we found that approximately half (1.5 million km2) the mediterranean biome was in urgent need of conservation investment (i.e., areas where efforts could ameliorate conservation risk sensu Hoekstra et al. 2005). These included lowland and foothill assemblages, particularly woodland and forest, across all five regions (e.g., California's lowland forests) (Fig. 1, quadrant 1). In contrast, when investments were allocated on the basis of conversion and protection characteristics of each country, all investments were channeled to the Mediterranean Basin (Fig. 2, quadrant 1).

image

Figure 1. General conservation prioritization framework by Mediterranean Biodiversity Assemblage (vegetation type stratified by elevation) within each region on the basis of integration of percent protection and percent conversion (Q, quadrant [1, 2, 3, 4]; L, lowland; F, foothill; M, montane). The horizontal line indicates 10% land protection and the vertical line 30% land conversion (the total amount of conversion in the mediterranean biome). The inset (graph in quadrant 4) is an enlargement of the area within the red square in the lower-left corner and shows assemblages with <10% protection and <30% conversion.

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image

Figure 2. General conservation prioritization framework by country on the basis of integration of percent protection and percent conversion. The horizontal line indicates 10% land protection and the vertical line 30% land conversion (the total amount of conversion in the mediterranean biome). Symbols and Q are defined inFig. 1. Country codes are as follows: AUS, Australia; MEX, Mexico; U.S.A., United States; CHL, Chile; ALB, Albania; BGR, Bulgaria; BIH, Bosnia & Herzegovina; CYP, Cyprus; DZA, Algeria; EGY, Egypt; ESH, Western Sahara; ESP, Spain; FRA, France; GIB, Gibraltar; GRC, Greece; HRV, Croatia; IRQ, Iraq; ITA, Italy; JOR, Jordan; LEB, Lebanon; LBY, Libya; MAR, Morocco; MCO, Monaco; MKD, Macedonia; MLT, Malta; PRT, Portugal; PSE, Gaza Strip; SCG, Serbia & Montenegro; SMR, San Marino; SYN, Slovenia; SYR, Syria; TUN, Tunisia; TUR, Turkey; and ZAF, South Africa.

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High priorities for conservation investment (i.e., opportunities to protect contiguous and large natural landscapes) accounted for 39% (1.2 million km2) of the biome (35 of the 67 MBAs). These high priority areas included all units in the Mediterranean Basin and Chile not considered urgent, lowland and foothill scrub in Australia, all elevation woodland in California-Baja California, and lowland and foothill scrub, shrubland, and woodland assemblages, among others, in South Africa (Fig. 1, quadrant 2). With the country filter, 20 countries, including Mexico and Chile, were high priority (Fig. 2, quadrant 2). The country filter, however, excludes South Africa and the U.S.A., even though they contain high priority areas, such as South Africa's Albany thickets (Fig. 3, quadrant 2).

image

Figure 3. General conservation prioritization framework by ecoregion on the basis of integration of percent protection and percent conversion. The horizontal line indicates 10% land protection and the vertical line 30% land conversion (the total amount of conversion in the mediterranean biome). Symbols and Q are defined in Fig. 1 .

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Only 12 MBAs, 11% (350,000 km2) of the spatial area of the biome, were of medium priority because they already met the 10% protection goal. These MBAs included numerous montane assemblages in California-Baja California (scrub, shrubland, forest, and grassland), foothill forest and shrubland in South Africa, and lowland shrubland in Australia (Fig. 1, quadrants 3 and 4). In contrast, prioritization conducted with the country filter relegated all mediterranean biodiversity of Australia, South Africa, and California to medium status (Fig. 2, quadrants 3 and 4).

Discussion

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Beyond Mountains and Shrublands
  7. Discussion
  8. Acknowledgments
  9. Literature Cited
  10. Supporting Information

Habitat conversion across the mediterranean biome, especially in lowland elevations (i.e., <300 m) is alarming. Lowland forest and woodland in Chile, for example, have been 74% and 64% converted respectively to pasture and plantations (Aronson et al. 1998). Similarly, lowland scrub in South Africa has been 72% converted, primarily through agricultural clearing of resnostereld with high soil fertility (Low & Rebelo 1996). Conversion of lowlands in the Mediterranean Basin, by contrast, reflects the high density of human settlement, urbanization, and tourism development. Lowland population density is over two times that of foothill and 4 times that of montane elevations (CIESIN et al. 2005). In California-Baja California mediterranean scrub ranked as the third-most converted (66%) vegetation of any of the five mediterranean regions. Levels of conversion, however, were starkly different across the border: 75% conversion in California (U.S.A.) and 23% in Baja California, Mexico.

Patterns of protection also varied with elevation and vegetation: shrubland was overrepresented and, in the majority of regions, protection was skewed to montane elevations. These findings are consistent with the results from other studies that show protection is concentrated on less economically valuable land, in sparsely populated areas, and at higher elevations (Pressey 1994; Pressey et al. 1996; Rouget et al. 2003). In South Africa, for example, there was 4 times as much protected land in montane areas as in lowlands (21% vs 5%)—a reflection of the historic preservation of upper watersheds to protect water catchments (Rouget et al. 2003). Similarly, in California-Baja California, montane elevations had 17% protection and foothill and lowland elevations had 9% and 6% protection respectively because of large swaths of montane areas captured within U.S. national forest lands. The consequence of this pattern is that characteristic mediterranean species from lower elevations may be lost, such as the endemic Torrey pine (Pinus torreyana) in California's southern coast or the Iberian lynx (Lynx pardinus) in lowland woodlands of the Mediterranean Basin (Supporting Information).

The Convention on Biological Diversity's goal of achieving 10% effective conservation of the world's ecological regions provides an ambitious target for conservation in the mediterranean biome. Even so, some have questioned the adequacy of such goals (Svancara et al. 2005), particularly for a biome characterized by pronounced local endemism and high beta diversity. Using consistently defined biodiversity assemblages, we found four-fifths of assemblages had not achieved 10% representation in protected areas. We suggest that those with <10% protection and >30% conversion be considered urgent priorities for conservation investment. These priorities are as follows: in California-Baja California, lowland and foothill scrub and lowland forest and grassland; in South Africa, lowland scrub and lowland shrubland; in Australia, lowland forest and woodland and foothill woodland, shrubland, and grassland; in Chile, lowland and foothill forest and woodland; and in the Mediterranean Basin, lowland and foothill shrubland and woodland, and lowland forest.

The sensitivity analysis highlighted how conservation investment priorities shifted depending on the analysis unit used. For Chile's biodiversity, for example, urgent conservation investment priorities (<10% protection and >30% conversion) identified with country units resulted in Chile, along with Australia, South Africa, and California-Baja California, receiving no attention at all (Fig. 2). Alternatively, when ecoregions were used to identify investment priorities, 41% of mediterranean Australia, 34% of South Africa, and 29% of California-Baja California emerged as priorities. Yet even with the use of ecoregions, none of Chile's biodiversity was identified as in urgent need of protection (Fig. 3). It was not until we used the biodiversity assemblages that over one-third of the Chilean matorral (lowland and foothill woodland and forest) ranked as urgent (Fig. 1). In short, the use of units that reflect biodiversity patterns across the biome permits global conservation organizations and their partners to identify gaps in representation and to tailor conservation strategies to different biodiversity assemblages. This provides the foundation for finer-resolution stratification among assemblages within each quadrant on the basis of local endemism, beta diversity, ecological processes, threats, and with stakeholder involvement, as illustrated in many regional conservation assessments (e.g., The Nature Conservancy of California's central coast ecoregional plan).

Although the mediterranean biome currently has only a skeletal network of protected areas, there are mechanisms that can help conservationists reach global conservation goals and, ultimately, sustain this cradle of outstanding biodiversity and civilization. For example, in European Union countries, the Natura 2000 aims to maintain and restore endangered habitats and species (Torkler 2006), in Chile the government has embraced the Convention on Biological Diversity's goal and adopted a set of biodiversity sites it intends to protect, whereas in California (U.S.A.) regulatory mechanisms such as the Endangered Species Act offer biodiversity protection. Our results provide a meaningful template for determining where to invest globally fungible, but limited, funds to increase and evenly distribute protected areas across a threatened biome. As such, our work joins a growing body of literature that can help conservation practitioners greatly enhance returns on biodiversity conservation investments.

Acknowledgments

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Beyond Mountains and Shrublands
  7. Discussion
  8. Acknowledgments
  9. Literature Cited
  10. Supporting Information

We thank our many colleagues from the five mediterranean regions who were so generous with their data and expertise, especially: N. Helme, P. Pliscoff, P. Regata, G. Wardell-Johnson, P. Rundel, F. Antonelli, P. Lombardi, and B. Reyers. We are grateful to R. Klinger, J. Quinn, M. Reynolds, and V. Russell for valuable discussions and P. Kareiva and S. Solie for comments on an earlier version of the manuscript. This research was funded by The Nature Conservancy and the Rodney Johnson/Katherine Ordway Stewardship Endowment.

Literature Cited

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Beyond Mountains and Shrublands
  7. Discussion
  8. Acknowledgments
  9. Literature Cited
  10. Supporting Information
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Supporting Information

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Beyond Mountains and Shrublands
  7. Discussion
  8. Acknowledgments
  9. Literature Cited
  10. Supporting Information

Estimate of the area, percentage of land protection and percent land conversion by Mediterranean Biodiversity Assemblage (Appendix S1); occurrence of protected areas by mediterranean region and elevation (Appendix S2); occurrence of protected areas by vegetation type (Appendix S3); occurrence of protected areas by region and vegetation type (Appendix S4); and characteristic species of Mediterranean Biodiversity Assemblages (Appendix S5) are available as part of the on-line article. The author is responsible for the content and functionality of these materials. Queries (other than absence of the material) should be directed to the corresponding author.

Please note: Wiley-Blackwell are not responsible for the content or functionality of any supporting materials supplied by the authors. Any queries (other than missing material) should be directed to the corresponding author for the article.

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Please note: Wiley Blackwell is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.