Madrean Pine-Oak Woodlands

Patricia Koleff²⁴, Jorge Soberón²⁴ and Andrew Smith¹¹

Biodiversity
Flagship Species
Threats
Conservation

The Madrean Pine-Oak Woodlands Hotspot as defined here includes the main mountain chains of Mexico, namely the Sierra Madre Occidental (including the Madrean Sky Islands of southern Arizona and New Mexico), the Sierra Madre Oriental, the Trans-Mexican Volcanic Belt, the Sierra Madre del Sur, and the Sierra Norte de Oaxaca, as well as isolated mountaintop islands in Baja California (particularly around the Sierra de la Laguna). Excluded are the more mesic pine-oak formations of the Altos and Sierra Madre de Chiapas, lying to the east of the Isthmus of Tehuantepec, which are included within the Mesoamerica Hotspot. Thus, most of this hotspot lies within Mexico, with isolated patches occurring further north, in the southern United States. Many of the pine-oak woodlands have an insular-type distribution by virtue of being surrounded by more extensive floristic provinces, generally tropical or arid. This feature is particularly noticeable in the northern Mexican Highlands and the Madrean Sky Island Archipelago. In total, the original extent of this hotspot covered 461 265 km².

The Madrean Pine-Oak Woodlands Hotspot consists of rugged mountainous terrain, high relief, and deep canyons, evidence of its complex geological history. The Sierra Madre Occidental, which runs from Jalisco north through Sonora and Chihuahua to the Madrean Sky Islands, is mostly composed of volcanic rocks from the Cretaceous and early Tertiary, covered by other Early-Middle Tertiary materials. Its origin seems to be related to the subduction of the Farallón Plate beneath the North American and Caribbean Plates. The Madrean Sky Islands, a series of about 40 mountain tops, lie between the Mogollon Rim and the Sierra Madre Occidental. About half of the mountains occur in the United States, including the tallest sky island, Mt. Graham (at 3 300 m), while the remainder occur in northern Mexico. The Sierra Madre Oriental of eastern Mexico and southwestern Texas is composed of sedimentary marine rocks from the Jurassic and Cretaceous that folded up into complex shapes. The tallest peaks are Potosí (3 625 m) and Peña Nevada (3 480 m).

The Trans-Mexican Volcanic Belt, which runs from west to east across central Mexico and serves as a bridge connecting the Sierra Madre Occidental and Sierra Madre Oriental, is the tallest mountain chain in the country, including the peaks of Pico de Orizaba (5 747 m) and the Popocatépetl (5 452 m). As its name suggests, this chain is volcanic in origin, and is composed primarily of igneous rock. The Sierra Madre del Sur, which runs parallel to the Pacific Coast of Guerrero, is the most geologically complex, with pre-Cambrian units, volcanoes from the Mesozoic, and formations from the Middle Tertiary related to the Sierra Madre Occidental. Finally, there is the Sierra Norte de Oaxaca in northern Oaxaca State, with the tallest peak being Zempoaltépetl (3 400 m).

Most pine-oak forests in Mexico are found in areas with a temperate climate, characterized by average annual temperatures between 5°C and 18°C. Annual precipitation of temperate zones in Mexico is typically between 500 mm and 2 500 mm, with lows of 300 mm (P. cembroides forests) and highs of 3 000mm (Gonzalez-Medrano 2004). Humidity varies according to altitude and slope. In the Sierra Madre Orien-tal, for example, the climate is more humid on the northeastern slope, and subhumid on the western slope and in the highest portions of the mountain range. However, the wettest portions are home to cloud forests that represent the northernmost reaches of this vegetation in Mexico. Likewise, in the Sierra Madre Occidental, the western sides generally receive more rainfall and have a milder winter, although as a whole, the entire mountain range is considered to have mild winters and wet summers (Brown 1994), with mean annual rainfall around 550 mm (mostly falling in August). In the Sierra Madre Oriental, average annual rainfall ranges from 250–300 mm in the north and from 900–1 500 mm in the southern parts near Nuevo León, Mexico. In the Sierra Madre del Sur, annual precipitation is between 800 and 1 600 mm (Rzedowski 1978). Snow is common on the tallest peaks of mountain ranges, particularly in the Trans-Mexican Volcanic belt.

As a result of the different climates, aspect and orientation of slopes, type and depth of soil layers, and the complex geological history of the region, the hotspot features distinct biotic communities. These characteristics, along with its significant north-south latitudinal reach, make it difficult to treat any one portion of the hotspot as representative of the whole. There are, however, clear affinities of flora and fauna among its subregions. For example, half of the characteristic species in the Madrean flora found in northern Mexico and the southern United States extend as far south as Durango, and one-fifth of these typical species range into southern Mexico (McLaughlin 1994). These observations, along with the consistent canopy habitat provided by pines and oaks, attest to the cohesiveness of the hotspot.

As the name of this hotspot denotes, pine and oak forests are the characteristic vegetation type. At one extreme, these forests may contain monospecific stands of either pines (Pinus sp.) or firs (Abies sp.); at the other extreme, they are represented by almost pure stands of oak (Quercus sp.). Mexico is considered an important center of diversity for both Pinus and Quercus, and has the highest diversity of pine species of any country in the world, with 44 of the 110 recognized species of pine occurring there (Farjon and Page 1999). The country also has 135–150 species of oak, representing more than 30% of the world's species of the genus Quercus; of these, 86 are endemic to Mexico (Nixon 1993).

Across the hotspot, different regions have varying combinations of species, with some more dominant than others. On the Sierra Madre Occidental, pine-oak forests grow on elevations between approximately 1 500 and 3 300 m. The dominant species on the east slopes is Pinus lumholtzii (15–20 m tall, growing at 1 900–2 400 m), while in the Madrean Sky Islands the dominant species are P. leiophylla (15–25 m), P. cembroides (6–12 m), P. ponderosa (23–30 m), Quercus hypoleucoides, Q. arizonica, Q. emoryi, and Q. rugosa (Valero et al. 2001a). The Sierra Madre Oriental is dominated by pine-oak forests growing at altitudes between 1 000 and 3 500 m, particularly Pinus nelsonii (6–7 m), P. cembroides, P. pseudostrobus (15–25 m), P. ponderosa, and P. greggii (10–25 m, with a restricted distribution at 1 200–2 700 m), as well as the oaks Q. castanea and Q. affinis (Valero et al. 2001b). In the Trans-Volcanic Belt, pine forests grow at elevations of 2 275–2 600 m, pine-oak at 2 470–2 600 m, and pine-cedar at more than 2 700 m. The dominant species in the western reaches include Q. resinosa, Q. magnolifolia, Q. conspersa, and Q. peduncularis (and Q. rugosa and Q. laurina grow at over 2 400 m); the eastern reaches are composed of Q. mexicana, Q. crassifolia, Q. laeta, and Q. deserticola. Pine forests comprise mainly P. montezumae (20–30 m), P. pseudostrobus, P. hartwegii (15–30 m), and P. teocote (10–20 m). Below 2 000 m, P. oocarpa (12–20 m), P. michoacana (20–30 m), P. herrerae (30–35 m), P. pringlei (20–25 m), and P. leiophylla are common, while above 3 000 m, the forests are a combination of P. hartwegii and Abies religiosa (35–45 m, and up to 50–60 m) at 3 000 m (Valero et al. 2001c).

In the Sierra Madre del Sur, oak forests grow at 1 900–2 500 m, cloud forests at 2 300 m, and pine-oak and pine forests at elevations between 2 400 and 2 500 m. Dominant species in oak forest formations include Q. magnolifolia and Q. castanea, while in pine forests the most common species are P. herrerae, P. pseudostrobus, P. pringlei (15–20 m), and P. ayacahuite (more than 20 m, up to 45 m), and the endemic P. rzedowskii (15–30 m) (Farjon and Styles 1997; Valero et al. 2001d). Finally, in the Sierra Norte de Oaxaca, pine forests with P. ayacahuite, P. lawsonii (25–30 m), P. chiapensis (30–40 m), P. devoniana (20–30 m), and P. pseudostrobus grow at 1 600–2 600 m, and pine-oak forests characterized by P. hartwegii, P. devoniana, P. lawsonii, P. montezumae, Q. laurina, and Q. rugosa grow from 2 000–2 800 m. P. hartwegii, P. ayacahuite, and P. patula (35–40 m) occur at higher elevations, sometimes in association with cloud forests. Oak forests are typical between 2 000 and 2 500 m, and include species such as Q. crassifolia, Q. castanea, Q. crassipes, Q. rugosa, and Q. laurina. As one approaches the Isthmus, some regions become more humid and the presence of epiphytes increases (Valero et al. 2001e).

The Madrean Pine-Oak Woodlands Hotspot is also an important center of cultural and ethnic diversity. In Mexico, the natural resources of over half of the national territory are under the control and use of indigenous communities (Toledo et al. 2002). Indigenous communities are also commonly established within the country's natural protected areas, and thus have to be taken into consideration in all plans for management and protection (CONANP 2002). Among the ethnic groups characteristic of the region are the Chinantec, Cora, Cuicatec, Mazatec, Mixe, Mixtec, Náhuatl, Popoluca, P'urhepecha, Tarahumara, and Zapotec (Robles-Gil 1995).

Biodiversity

Flowering plant species richness in the Madrean Pine-Oak Woodlands Hotspot has been estimated at approximately 5 300 species (24% of the Mexican flora; Rzedowski 1993; González-Medrano, pers. comm.), although a compilation of total vascular plant diversity for the Mexican pine-oak community using herbaria databases held at the Comisión Nacional para el Conocimiento y Uso de la Biodiversidad (CONABIO) suggests that it may contain as many as an astonishing 6 700 species. The total native flora of the Madrean Sky Islands includes nearly 2 000 species (McLaughlin 1994), although surveys of many such islands are incomplete.

It is more difficult to estimate level of endemism within the pine-oak woodlands, particularly because of the incompleteness of inventories, but it is clear that the percentage is quite high. Rzedowski (1993) estimates that a remarkable 75% of the pine-oak flora of Mexico and the pine-oak regions in the Madrean Sky Island Archipelago is endemic, although it is unclear whether this includes pine-oak forests lying east of the Isthmus of Tehuantepec. While this figure is undoubtedly an overestimate, it is the best available; we, therefore, use a figure of 3 975 endemic vascular plant species based on this percentage.

Examples of endemic genera in the hotspot include: Arnicastrum, Pionocarpus, Pippenalia, Stenocarpha, and Trichoryne (Sierra Madre Occidental); Greenmaniella, Loxothysanus, and Mathiasella (Sierra Madre Oriental); and Achaenipodium, Microspermum, Hintonella, Omiltemia, Peyritschia, and Silvia (Trans-Volcanic Belt and Sierra Madre del Sur) (Rzedowski 1978). The ten most diverse families are: Asteraceae, Poaceae, Leguminosae, Orchidaceae, Cactaceae (the pine-oak forests harbor between 189 and 213 cacti species, of which as many as 44% are thought to be endemic; B. Goettsch, pers. comm.), Cyperaceae, Euphorbiaceae, Acanthaceae, Fagaceae, and Agavaceae.

Around 525 bird species are known to occur regularly in the hotspot, of which 23 are strict endemics. Most endemics occur in the middle Sierra Madre Occidental, the Trans-Mexican Volcanic Belt, and the southern Sierra Madre Oriental. Three bird genera are endemic to Mexican pine-oak woodlands, two of which are monotypic: Euptilotis, represented by the eared quetzal (E. neoxenus);Xenospiza, with a single species, the Sierra Madre sparrow (X. baileyi, EN); and Rhynchopsitta, with two species, the thick-billed parrot (R. pachyrhyncha, EN) and the maroon-fronted parrot (R. terrisi, VU).

Another perspective on avian endemism in this hotspot is its coincidence with BirdLife International's Endemic Bird Areas (EBAs) (Stattersfield et al. 1998). Four EBAS overlap with this hotspot as we have defined it: the Sierra Madre Occidental and Trans-Mexican Range EBA supports seven range-restricted species, including the thick-billed parrot, the Sierra Madre sparrow, and the imperial woodpecker (Campephilus imperialis, CR). The Sierra Madre del Sur EBA contains four threatened, range-restricted species – the shortcrested coquette (Lophornis brachylopha, CR), the white-tailed hummingbird (Eupherusa poliocerca, VU), the Oaxaca hummingbird (E. cyanophrys, EN), and the white-throated jay (Cyanolyca mirabilis, VU)–, as well as the white-fronted swift (Cypseloides storeri). The Northern Sierra Madre Oriental EBA has two restricted-range species, including the maroon-fronted parrot, while the Southern Sierra Madre Oriental EBA has four species confined to it, including two threatened species: the bearded wood-partridge (Dendrortyx barbatus, VU) and the dwarf jay (Cyanolyca nana, VU).

A remarkable 218 amphibian species have been recorded from this hotspot, with an estimated 50 species endemic. Frogs of the genera Hyla and Eleutherodactylus are the most speciose, with 35 and 36 species, and nine and eight endemics, respectively. Although salamanders are mostly restricted to northern temperate zone habitats, the families Plethodontidae, with 63 species (25 endemic), and Ambystomatidae, with 14 species (five endemic), are well represented in the hotspot. Salamanders of the genera Pseudoeurycea (25 species present, 13 endemic), Thorius (17 species, nine endemic), and Chiropterotriton (11 species, two endemic) are particularly well represented.

In terms of reptile diversity, there 384 species known from the hotspot, and an estimated 37 species are endemic. One reptile genus is endemic, Rhadinophanes, with a single species, the graceful mountain snake (R. monticola). Among lizards, the genus Sceloporus is represented by 50 species, of which six are endemic; in addition, 14 species have been recorded from the genus Anolis, two of which are endemic. Among snakes, the Colubridae are particularly well represented, with 147 species (17 endemic), including 14 species of Geophis (seven endemic), 11 species of Rhadinea (three endemic), and 16 species of Tantilla (five endemic).

There are 328 species of mammals thought to be present in the hotspot, only six of which are strictly endemic. Remarkably, there are also two endemic genera, both monotypic: Zygogeomys, represented by the Michoacán pocket gopher (Z. trichopus, EN), and Romerolagus, with its single species, the zacatuche or volcano rabbit (R. diazi, EN), endemic to the Trans-Mexican Volcanic Belt.

Given that the pine-oak woodlands have a general “sky islands” character that would not be expected to be concordant with fish distributions, it is perhaps surprising that the hotspot includes 84 fish species and that 18 of them are endemic. This reflects the fact that Mexico's total fish fauna is remarkably diverse, even at high elevations and in semiarid regions. A major component of diversity consists of species in the minnow family Cyprinidae that form a biogeographic track along the axis of the Sierra Madre Occidental (Miller and Smith 1986). This group includes twenty montane species in genera that enter Mexico primarily from the western United States, although the hotspot's only endemic genus, Codoma, is also included. In central Mexico, diversity is associated with lake-adapted fishes in the high-elevation lakes that were created by tectonism and volcanism. These lacustrine species include several live-bearing fishes in the family Goodeidae, and a number of silversides in the endemic Mexican genus Chirostoma.

Among invertebrates, the pine-oak woodlands harbor approximately 160–200 butterfly species, of which 45 are endemic to the hotspot (J. de la Maza, pers. comm.). Perhaps the most noteworthy butterfly in the pine-oak woodlands is the monarch (Danaus plexippus), whose spectacular annual migration of up to 4 000 km from the north culminates in masses of butterflies in the forests of Michoacán (Brower et al. 2002).

Flagship Species

Not surprisingly, a number of the pine and oak species from which this hotspot derives its name have exceptional value for conservation. For example, the Sierra Madre Occidental is home to at least two endemic species of oak, Quercus carmenensis and Q. deliquescens (Nixon 1993), while forests in the Baja California Peninsula hold an important diversity of pine trees, among them Pinus lambertiana, one of the largest pine trees in Mexico, reaching 70 m in height and with cones of 70 cm in length.

The most charismatic species in this hotspot is the endemic zacatuche or volcano rabbit, one of the smallest and most unusual of rabbits. It sports small, round ears and – unlike other rabbits – utters high-pitched, penetrating vocalizations. The zacatón bunchgrasses are essential to the zacatuche– the rabbit constructs the entrance to its burrow at the base of a clump of bunchgrass, and prunes the plants so that they form a dense roof for protection and cover (Cervantes et al. 1990; Romero and Velazquez 1994; Velazquez et al. 1996). The zacatuche lives only in the Trans-Mexican Volcanic Belt surrounding Mexico City. It currently occurs on the slopes of the Iztaccíhuatl Volcano and the Popocatépetl Volcano, and in 16 small fragments of habitat on the slopes of the Pelado Volcano and the Tláloc Volcano in the mountain complex south of Mexico City. Frequent burning of the zacatón grasses to increase the production of palatable forage for livestock, clearing of zacatón for thatch (used in brooms and other products), unsustainable forestry, and ever-increasing encroachment of settlements from the expansion of Mexico City have all negatively impacted the zacatuche (Portales et al. 1997; Velazquez et al. 1996). Efforts to save the zacatuche from extinction will benefit the entire habitat and all the species occupying the Trans-Mexican Volcanic Belt of the Madrean Pine-Oak Woodlands Hotspot, and for this reason it has been proposed as a symbol for conservation in Mexico (Velazquez 2001).

This hotspot is also home to one of the world's most famous wildlife spectacles, the overwintering mass of monarch butterflies (Danaus plexippus) in the pine forests of Michoacán. Each fall, about 100–500 million monarchs migrate south from eastern North America to form giant clusters on the boughs and trunks of trees in the oyamel fir (Abies religiosa) dominated ecosystem (Brower et al. 2002). There are only about 30 of these overwintering sites covering 10–25 ha each. It has been estimated that the spring and summer range of the monarch is a million times more extensive than their overwintering habitat (Brower et al. 2002). This scientific and aesthetic wonder attracts over 200 000 visitors annually and represents a seasonal economic boon to the communal landholders that manage the main butterfly sanctuaries in the Monarch Butterfly Biosphere Reserve.

During January of 2002, however, disaster struck, and as many as 250 million dead monarchs littered the ground in a carpet 20 cm deep in places. In some colonies, over 80% of all butterflies died (Brower et al., in press). The immediate cause of this tragic loss was a severe winter storm that swept across Mexico, but deforestation has increased the susceptibility of monarchs to such storms. The forests provide substantial protection, but with increasing fragmentation of these forests, the vulnerability of the butterflies to cold and wet conditions intensifies. Despite recent legislation to prevent logging, the practice continues, and the miracle of the monarchs is in jeopardy.

Farther north, in Cave Creek Canyon in the Chiricahua Mountains of southeastern Arizona, birders flock to see the elegant trogon (Trogon elegans). This species' distributional range closely maps onto that of the Madrean Pine-Oak Woodlands Hotspot, and it reaches its most northern extension in the sky islands. It is not alone, as the southeastern mountains in Arizona harbor more species of hummingbird than any part of the United States, as well as a host of other flora and fauna that link this sky island to the pine-oak woodlands to the south. The uniqueness of the biota in these sky islands has given rise to an expanding ecotourism industry and, indeed, ecotourism, primarily based around bird watching, is the main economic driver in this part of Arizona.

Threats

Pines (and, to a lesser extent, oaks) are very important for the Mexican logging industry and their exploitation for timber has increased, in some areas becoming indiscriminate. Illegal logging is on the rise in many areas (Challenger 1998). Additionally, many non-timber forest products are being used unsustainably within the hotspot, although these fail to register in any formal economic accounting. Examples are: a common vascular epiphytic plant (despite the fact that pine forests usually do not have epiphytics) that seems like a lichen (Tillandsia usneoides), which is extracted for Christmas ornamental purposes in Mexico; and a large variety of mushrooms in pine-oak forests such as Amanita spp., Leccinum spp., Russula spp., and Boletus spp., among others, that are extracted for culinary use (Challenger 1998). Habitat alteration, generally through fire, influences the understory and impacts both flora and fauna. Fires are partly a natural process in this ecosystem, but intentional burning has increased greatly to foster regeneration of fresh sprouts for livestock grazing, and also for other agricultural purposes. In southern Arizona, fire has been excluded for almost a century, primarily due to suppression by federal and state agencies, and modification of fuels by grazing and other causes. The apparent result of 90 years of suppression and fuel modification has, at higher elevations, led to conifer forests changing from open-grown ponderosa pine (P. ponderosa) to dense stands of mixed conifers (Allen 1994).

In most areas of the Madrean Pine-Oak Woodland Hotspot, local experts highlight the massive disruption of the ecosystem. In the mountain region to the south of the Cuenca de México, Romero et al. (1999) plea for reforestation programs, and patrolling actions to reduce wildlife poaching, illegal timber harvest, plant collection, and soil and rock extractions. In the forests of Michoacán that are home to overwintering populations of monarch butterflies, illegal deforestation proceeds on a grand scale. Stattersfield et al. (1998) comment on the threats occurring within each of the region's EBAs as follows: In the Northern Sierra Madre Oriental, “the mixed conifer forests... are being destroyed by fire, logging and clearance for agriculture.” In the Sierra Madre Occidental and Trans-Mexican Range EBA there has been “almost complete destruction of old-growth pine forest,” which seriously threatens the survival of the thick-billed parrot and may have led to the extinction of the imperial woodpecker (currently listed as CR). And in the Southern Sierra Madre Oriental, “the majority of the forests…have already been lost or degraded, and this destruction continues through logging, agricultural expansion, firewood-gathering, road and associated tourist developments, sheep ranching and overgrazing, as well as intensive urbanization.” The consistency of these reports across the landscape of the Madrean Pine-Oak Woodlands Hotspot paints a grim picture for its remarkable biodiversity.

Due to the fragmented nature of the Madrean Pine-Oak Woodlands Hotspot, arriving at a precise estimate of the amount of original vegetation remaining intact is not easy. Originally, pine-oak forests covered around 21% of Mexico (Rzedowski 1978), and it is estimated that about 50%-67% of this has been lost and that the remaining forest covers no more than 8% of the country (Rzedowski 1993). However, these figures do not take into account those remaining stands that have been impacted by fire, overgrazing, and other factors. In total, we estimate that no more than 20% of the remaining vegetation can be considered pristine. Other estimates stating that less than 1% of the original vegetation of the Sierra Madre Occidental remains intact (Lammertink et al. 1997) refer to pristine, old-growth forests with no history of human intervention, but nonpristine pine-oak forests are capable of retaining a very significant portion of the original diversity.

Conservation

Despite the biodiversity value of the Madrean Pine-Oak Woodlands Hotspot, the region's protected area coverage is poor. Less than 6% of the hotspot is under some form of official protection, and only 1.9% is in protected areas that fall within IUCN categories I to IV. Most terrestrial vertebrate species endemic to Mexico that are unrepresented in the country's protected area system are located on the southern slopes of the Sierra Madre del Sur and, to a lesser extent, on the western slopes of the Sierra Madre Occidental and the eastern slopes of the Sierra Madre Oriental, highlighting the immediate need for improved protection in this hotspot.

Among the more important protected areas in the hotspot is the famous Reserva de la Biosfera Mariposa Monarca (563 km²), the Monarch Butterfly Biosphere Reserve, in Michoacán, which was decreed in 1986 and conserves different types of vegetation such as pine, pine-oak, Abies, and Juniperus forests. One of the larger protected areas is the Sierra de Manantlán Biosphere Reserve (1 396 km²) in Jalisco (and also in the Trans-Mexican Volcanic Belt); pine-oak forests are very diverse in this reserve, with some 33 species of Quercus. Close to this reserve is the La Primavera Forest Reserve (305 km²), while further to the east are the following National Parks: Nevado de Colima (96 km²), Nevado de Toluca (468 km²), and Iztaccíhuatl-Popocatépetl (903 km²), as well as the Cofre de Perote (117 km²) and Pico de Orizaba National Parks (197 km²) in Veracruz. The largest protected area in the Sierra Madre Oriental, and one of the largest in Mexico is the Cumbres de Monterrey National Park (1 774 km²), while further north, on the American side of this hotspot, is the Big Bend National Park in Texas, covering 3 245 km².

In the Sierra Madre Occidental, parks conserving notable stands of pine-oak formations include the Cumbres de Majalca National Park (48 km²), the Cascada de Basaseachic National Park (58 km²), and the La Michilía Biosphere Reserve (93 km²). Further north, in the Madrean Sky Islands of the United States, most of the pine-oak woodland is “protected,” but the majority is in U.S. Forest Service land. However, a variety of much smaller, highly protected reserves occur, some in private ownership (such as The Nature Conservancy), although most are U.S. National Monuments, or designated as U.S. Wilderness Areas. These include Coronado National Memorial (19 km²), Chiricahua National Monument (42 km²), Chiricahua Wilderness (355 km²), Miller Peak Wilderness (82 km²), and Pajarita Wilderness (31 km²). Finally, in Baja California, the Sierra de la Laguna Biosphere Reserve (1 124 km²) was established as a protected area in 1994 primarily to protect this island of intact pine-oak vegetation.

A number of conservation NGOs are working in the region. The Fondo Mexicano para la Conservación de la Naturaleza is working to enhance social participation so as to prevent fires in protected areas and a number of strategic regions, among them pine-oak forests in the Sierra de Manantlán and the monarch butterfly sanctuary. PRONATURA/PRONATURA NORESTE is an NGO established in 1997 that aims to conserve and promote the sustainable use of natural resources in northeast Mexico. The organization has programs under way in the Sierra Madre Occidental (the Thickbilled Parrot Sanctuary in Madera, Chihuahua) and Sierra Madre Oriental, where it is contributing to the government program of reforestation and soil restoration in areas affected by forest fires in the villages of Laguna de Sánchez and Mesa de las Tablas at the Sierra de Arteaga in the states of Nuevo León and Coahuila, respectively.

The Sierra Madre Alliance is a support network of Mexican and international partners pursuing conservation priorities in the Sierra Madre Occidental in Chihuahua. The Alliance aims to preserve biodiversity and restore the functioning of the forested ecosystems of the Sierra Madre through local participation, including: protection of remnant old-growth pine-oak forests, and the establishment of a Tarahumara-managed forest reserve in Pino Gordo. Finally, in the United States, the Sky Island Alliance is dedicated to preserving this globally important region. Formed in 1992, it has worked with agencies in Mexico to produce a Sky Islands Wildlands Network Conservation Plan designed to take into account the needs and concerns of all stakeholders in the region (within the U.S., including the U.S. Forest Service, existing Nature Conservancy and Audubon Society reserves, private ranges, etc.) to formulate a framework for conservation of the unique biota in the region.

Another very positive development has been the work of CEMEX to protect Maderas del Carmen in the northern part of Coahuila. Since 1999, the company has purchased and effectively protected what is now a total of 70 000 ha of land, including several new pieces that bring El Carmen right up to the U.S. border and make it contiguous with the Big Bend National Park in Texas. Now that the Mexican and American pieces have been connected, the result is a 2 000 000-ha conservation mega-corridor that has enormous significance for conservation. Indeed, it includes both some of the most important remaining tracts of the Chihuahuan Desert wilderness and significant portions of this newly-recognized Madrean Pine-Oak Woodland Hotspot. Furthermore, the vision of CEMEX is to expand protection on the Mexican side even more, making this area a real model for private sector conservation.

Nevertheless, it will take a ground swell of approaches, from the NGO, government, and private sectors, to arrest the decline of the Madrean Pine-Oak Woodlands Hotspot across its full extent. So perhaps it is best to conclude with a remarkable story of one village that has looked for solutions to meet the demands for both economic development and biodiversity conservation and, in doing so, has preserved its own future.

The village of San Nicolás Totolapan is perched on a mountain just south of Mexico City. The rapid urbanization of Mexico City has encroached upon the village; indeed, most of its young people worked dead-end jobs in the city and had no connection to the land of their ancestors. For generations, this small community had coexisted with nature through livelihoods based on the sustainability of natural resources. The village's traditions and unique environment were in jeopardy. In response, they looked toward a solution that would protect their local land (ejido) while preserving their cultural heritage. The result has been a remarkably successful ecotourism park – the San Nicolás Totolapan Park – providing a unique experience with nature in an environmentally sensitive manner. There are 150 km of bike and hiking trails, photographic routes, a nursery for native plants (for reforestation), as well as permits for camping and fishing. Through ecotourism the community is ensuring the survival of a biodiverse ecosystem, as well as providing environmental awareness programs. In addition to the environmental benefits that the park provides for the region, it has also had a positive impact on the daily lives of the local people, for example, through increased employment. This example shows how protecting the Madrean Pine-Oak Woodlands Hotspot can be a win-win situation.

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