To ensure CEPF investments are channeled toward the species and locations of the highest priority, the ecosystem profile adopts conservation outcomes-targets against which the success of investments can be measured-as the scientific underpinning for determining CEPF's geographic and thematic focus. These conservation outcomes were defined in cooperation with scientists from CI's Center for Applied Biodiversity Science, and represent the full set of quantitative targets that must be achieved in order to prevent biodiversity loss. The expectation is that CEPF grantees will work in partnership with other donors and key actors to ensure that investments are working toward preventing biodiversity loss and that performance toward measurable goals will be monitored and evaluated. Outcomes, therefore, do not represent those targets to be achieved exclusively through CEPF funds, but rather through partnerships with other conservation organizations, government, communities and donors.
The conservation outcomes presented in this ecosystem profile span a hierarchical continuum of three ecological scales:
- Species - avoid the extinction of globally threatened species;
- Sites - areas containing species of global importance; and
- Corridors - landscapes that maintain ecological processes.
These three levels are connected geographically through the presence of species that are located in several sites, and beyond, at sites housed within larger landscapes. An ecological connection also exists. If species are to be conserved, then the sites where they reside must be protected and sustainably managed; landscapes must maintain the ecological services on which the sites and the species depend. At the landscape level, the team defined biodiversity conservation corridors (within which sites are nested) to target investments at increasing the amount of habitat with ecological and biodiversity value within these corridors. Given the threats to biodiversity at each of the three levels, the ecosystem profile team set quantifiable targets in terms of extinctions avoided, sites protected and corridors consolidated.
Outcome definition is a fluid process and as data become available, species-level outcomes need to be expanded to include other taxonomic groups that previously had not been assessed. Avoiding extinctions means conserving globally threatened species to make sure that their IUCN Red List status improves or at least stabilizes. This in turn means that data are needed on population trends. For most of the threatened species, however, no such data is currently available.
In determining species outcomes, CEPF aims to stabilize and improve the conservation status of species in order to achieve the ultimate goal of avoiding the extinction of globally threatened species. Thus, in preparing the ecosystem profile, CI determined that the obvious targets for conservation in Northern Mesoamerica are globally threatened species that have a high probability of extinction in the medium term. Species outcomes were therefore based on the conservation status of individual species, as compiled in the 2002 IUCN Red List, which provides quantitative, globally applicable criteria under which the probability of extinction is estimated for each species. At the time of this profile's preparation, IUCN had identified 470 species as Critically Endangered (CR), Endangered (EN) and Vulnerable (VU) for Mesoamerica (Table 3). Preventing the extinction of these species forms the first level of quantitative conservation outcomes.
Globally threatened species in Northern Mesoamerica are dominated largely by plants due to the fact that this taxonomic group contains many more species than other taxa, and also by amphibians based on the disproportionate threat that amphibians face in the region. Of these 470 species, 106 species are considered to be Critically Endangered, defined as those species that face an extremely high risk of extinction in the wild. Mesoamerica's Critically Endangered species are listed in Appendix 1.
Site outcomes aim to identify, document and protect areas that are critical for the conservation of global biodiversity. Most species are best conserved through the protection of sites that they inhabit. Thus, the next level of analysis for the ecosystem profile sought to identify particular site outcomes, also called key biodiversity areas, for each target species. The objective of defining individual sites was to identify areas where investments could be made to create protected areas or special conservation regimes, expand existing protected areas and improve protected area management, all of which help to prevent species extinctions. For the analysis, key biodiversity areas were identified based on two major criteria: vulnerability (contain globally threatened species) and irreplaceability (contain globally important congregations of species). Furthermore, the team defined individual sites as those areas that could be managed as a single unit.
To identify site-level outcomes, the team analyzed the distribution of globally threatened species and mapped out the location. Several sources of data were used. In Mexico, the team used Important Bird Areas (IBAs) as determined by the International Council on the Preservation of Birds (CIPAMEX) and BirdLife International. In Belize and Guatemala, the analysis was based on BirdLife International's Key Areas for Threatened Birds in the Neotropics, which are the precursors of the IBAs. In addition, the analysis included existing protected areas where globally threatened species occur, as well as important habitat for threatened species that currently are not protected but could be managed as a single unit. Several additional factors were considered: habitat for endemic species; sites with large congregations of waterfowl and fish; distribution of amphibian species; and analysis of the geo-referenced localities database contributed by the National Commission for the Knowledge and Use of Biodiversity (CONABIO) in Mexico.
Based on this methodology, the team initially identified 24 key biodiversity areas covering approximately 14.3 million hectares (see Appendix 2 for a detailed list of the globally threatened species in each key biodiversity area). These are the highest priority sites for conservation, based on both vulnerability and irreplaceability.
To ensure that CEPF invests in those areas of the highest priority for global conservation, the team prioritized the 24 key biodiversity areas further. The areas were ranked based on two considerations: their importance for the protection of endemic and globally and nationally threatened species and on their potential to conserve habitat of wide-ranging, higher trophic level species (Table 4). Because CEPF is a global initiative, the team gave more weight in the analysis to considerations related to ranking in Critically Endangered species. Therefore, while the conservation potential ranking was considered an important element, the final prioritization reflected more the species-based ranking that emphasizes globally threatened species.
The prioritization exercises showed similar rankings for both parameters, with areas that demonstrated high importance for species protection also indicating excellent potential for maintaining habitat (Appendix 3). Based on the analysis, the following eight key biodiversity areas, which harbor 176 Vulnerable, Endangered and Critically Endangered species, were identified as the highest priorities for conservation in Northern Mesoamerica:
- Selva Zoque, Mexico
- Reserva de Biosfera Sierra de las Minas, Motagua, Bocas del Polochic, Guatemala
- Sierra Madre de Chiapas, Mexico
- Los Cuchumatanes, Guatemala
- Selva Lacandona y Sierra del Lacandon, Mexico and Guatemala
- Parque Nacional Laguna del Tigre, Guatemala
- El Gran Peten, Mexico and Guatemala
- Chiquibul/Montañas Mayas, Guatemala and Belize
Identification of corridor outcomes, which represent the highest level of analysis for the profile, aimed to define conservation priorities at the landscape level. The need for identifying such corridors rests on the understanding that existing protected areas and sites are often too small and isolated to maintain ecosystem functions and evolutionary processes. The focus must therefore be on linking major sites and protected areas in a network, or so-called biodiversity conservation corridors, across wide geographic areas in order to maintain these large-scale processes. In addition, corridors are necessary for wide-ranging species and for ecological processes on which key biodiversity areas depend.
Corridors within the Northern Mesoamerica region were identified and delineated based on the following criteria: coverage of key biodiversity areas, existence of large-scale intact biota assemblages, needs of wide-ranging landscape species, connectivity of habitats, and opportunities for maintaining ecological and evolutionary processes. Based on the results, two corridors were identified for CEPF investment: 1) the Selva Maya and 2) the Selva Zoque and Chiapas/Guatemala Highlands corridors. These corridors encompass the majority of site and species outcomes for Northern Mesoamerica. They are large enough to maintain ecosystem processes essential for sustaining biological diversity, while also being anchored by key biodiversity areas that have been determined to be of the highest priority for conserving globally threatened species. These corridor outcomes aim to consolidate the areas that function as corridors for biodiversity, including the conservation of areas that provide connectivity to maintain ecological processes. The two corridors and eight key biodiversity areas are described below in brief, including significant biological features and threatened species and habitats.
The Selva Maya contains the second most extensive mass of continuous tropical rainforest in the Americas after the Amazon Forest. It extends throughout the southeast of Mexico (the states of Chiapas, Tabasco, Campeche, Yucatan and Quintana Roo), over the province of Petén in Guatemala and throughout Belize. The Selva Maya is covered with tropical montane rain forest (Selva Lacandona in Chiapas, and Chiquibul and the Mayan Mountains in southern Belize) as well as tropical lowland rain forest (Marqués de Comillas in Chiapas, Yucatan Peninsula, Peten in Guatemala, northern Belize). The Selva Maya includes the middle and lower parts of the Usumacinta river basin, which, together with the Grijalva river basin, is one of the most important river systems in Mesoamerica. The endemic species of the Selva Maya comprise 11 mammals, including the Yucatan brown brocket deer, 20 birds including the ocellated turkey, 39 reptiles and 11 amphibians. At least 19 species of endemic fishes have also been reported.
Lacandona, Laguna del Tigre and the Gran Peten key biodiversity areas
Lacandona, Laguna del Tigre and the Gran Peten are linked as three of the most important key biodiversity areas in the Selva Maya corridor. Lacandona supports the mammals Tylomys bullaris (CR) and T. Tumbalensis (CR), along with four species of Endangered insects and four species of Endangered plants. The Gran Peten supports two other species of Endangered plants and two species of Endangered reptiles. These key biodiversity areas are also important because of the presence of the northernmost populations of many Neotropical species, such as Baird's tapir (EN), jaguar, ocelot, white-lipped peccary, howler monkey, spider monkey, scarlet macaw, harpy eagle and the Moreleti crocodile.
Chiquibul/Montañas Mayas key biodiversity area
The Chiquibul/Montañas Mayas of Belize and east-central Petén is the fourth key biodiversity area in the Selva Maya corridor. The Montañas Mayas contain several peaks that exceed 1,000 meters, the windward side of which is covered with wet forest and contains a herpetological assemblage with many similarities to that of the adjacent lowlands and the southern portion of the Petén. Broadleaf forest, including riparian forest, occurs in the lowlands. The leeward side of these mountains tends to be much drier and is covered with what has been referred to as pine parkland or palm, and pine savanna. The Upper Raspaculo River shows particularly high dynamism due to regular extreme disturbance from flooding. This damage, along with that from three hurricanes that have passed through the area since 1961, has created a large area of secondary forest in the upper basin. The Montañas Mayas support two globally threatened amphibian species, and riparian areas appear to support a high density of Baird's tapir (EN). While few endemics occur, at least one frog, Rana julian, is limited to these mountains.
The Selva Zoque and Chiapas/Guatemala Highlands corridor includes the key biodiversity areas of the Selva Zoque in Oaxaca; Chiapas and Veracruz; the Sierra Madre of Chiapas; and Cuchumatanes and the Sierra de las Minas in Guatemala. The corridor is best known for its ecosystem diversity and its high endemism. For example, six endemics are concentrated in a small patch of cloud forest in El Pozo, Chiapas: the salamander Ixalotriton niger
(CR), the frog Eleutherodactylus pozo
(CR), the lizards Anolis parvicirculatus
and Sceloporus internasalis
and the rats Ototylomys
sp. nov. and Tylomys bullaris
Selva Zoque key biodiversity area
In addition to its expansive wet tropical forest, the Selva Zoque contains large areas of montane mesophilous forest and pine-oak forests that mingle with tropical montane forests and other communities, thus giving rise to landscapes with a very elevated diversity of flora and fauna. The importance of the Selva Zoque region is outstanding at the bioregional level. Zoque and its immediate surroundings represent the northern or western limit of Central American species such as highland guan, quetzal and the horned guan (EN). Several new species of plants and animals have also been reported as endemic to the area. Zoque also maintains extensive populations of large mammals such as jaguar, river otter, Baird's tapir (EN) and spider monkey, and large birds such as harpy eagle, scarlet macaw and great curassow. The Selva Zoque is considered to be one of the largest areas containing tapir habitat and is currently the northwestern limit of its distribution. Although the Selva Zoque is Mexico's second largest forest, it has no officially protected areas.
Sierra Madre of Southern Chiapas key biodiversity area
The Sierra Madre of southern Chiapas includes a chain of mountains of extraordinary biodiversity. This species diversity is a result of the area's proximity to the Pacific coastline and its altitudinal diversity. The region connects both with Selva Zoque and the Guatemala mountain chain in the south, and covers the greatest expanse of mesophilous montane forest or cloud forest in all of Northern Mesoamerica. This region constitutes the principal habitat in the world for species such as the quetzal and the endemic horned guan (EN). The El Triunfo Biosphere Reserve is perhaps the most important representative of this entire region, including important ecosystems, species, endemic taxa and ecological services. El Triunfo supports one of Mexico's largest fragments of mesophilous montane forest, a vegetation type that constitutes less than one percent of Mexico's territory.
Cuchumatanes key biodiversity area
The Cuchumatanes highlands encompass most of northwestern Guatemala. The Sierra de los Cuchumatanes is the most extensive highland region in Mesoamerica with 1,500 km² lying above 3,000 m elevation. Most of Cuchumatanes is covered with pine-oak lower montane and montane humid forest. However, on windswept higher slopes and peaks lower montane wet forest is present and in the extreme northern portion a subtropical pluvial forest covers the Sierra de los Cuchumatanes. The Sierra receives over 6,000 mm of rainfall annually. Cuchumatanes shares much of its fauna with the Chimaltenangan, Cuilcan and Minan areas and supports six endemic amphibians: the salamanders Bolitoglossa jacksoni (CR), Dendrotriton cuchumatanus (CR) and Bradytriton silus (CR), the frogs Hyla dendrophantasma (CR), Plectrohyla tecunumani (CR) and Hyla perkinsi (CR).
Sierra de las Minas-Motagua-Bocas del Polochic key biodiversity area
The different altitudes and orientation of the Sierra de las Minas have a profound influence on the climate and ecological conditions in the 242,642-hectare biosphere reserve. Rainfall varies significantly within short distances. Some areas of the upper reaches of the Polochic receive more than 4,000 mm of rainfall annually, while in the Motagua valley annual precipitation is less than 500 mm. The geographical isolation of Sierra de las Minas and its altitudinal variability have given rise to a great diversity of habitats for flora and fauna, which have functioned as islands of genetic evolution. Cloud forest covers 1,300 km² of the reserve, which probably represents the largest expanse of this ecosystem in Mesoamerica. The biosphere reserve alone is home to 885 species of mammals, birds and reptiles, which represent 70 percent of all species of Belize and Guatemala. Among the plant species, Persea schiedeana (VU), Quercus purulhana (VU), Cornus disciflora (VU) and Parathesis vulgate (EN) risk extinction and 56 species are endemic. Sierra de las Minas supports 21 species of regionally endemic birds, such as horned guan (EN), along with quetzal and probably harpy eagle.
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