Nahá–Metzabok Biosphere Reserve is a biosphere reserve in southeastern Mexico. It is located in the state of
Chiapas
Chiapas (; Tzotzil language, Tzotzil and Tzeltal language, Tzeltal: ''Chyapas'' ), officially the Free and Sovereign State of Chiapas ( es, Estado Libre y Soberano de Chiapas), is one of the states that make up the Political divisions of Mexico, ...
, on the northeastern flank of the Chiapas Highlands. The reserve protects montane rain forests, pine and oak forests, and natural lakes.
Geography
The reserve encompasses two separate flora and fauna protection areas, Metzabok and Nahá, and a buffer zone around them. Metzabok Flora and Fauna Protection Area has an area of 33.68 km2.UNEP-WCMC (2021). Protected Area Profile for Metzabok from the World Database of Protected Areas. Accessed 26 September 2021 /ref>
Nahá Flora and Fauna Protection Area is located to the southeast of Metzabok, and has an area of 38.47 km2.UNEP-WCMC (2021). Protected Area Profile for Nahá from the World Database of Protected Areas. Accessed 26 September 2021 /ref>
The reserve has a rugged topography, composed of parallel folded ranges of hills extending from northwest to southeast. The underlying geology is principally limestone. There are
karst
Karst is a topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathering-resistant ro ...
ic plateaus atop the ridges, and narrow valleys and ravines separate the ridges. Elevations range from 840 to 1,280 meters above sea level.UNESCO (2018). "Naha-Metzabok Biosphere Reserve, Mexico". UNESCO, December 2018. Accessed 26 September 2021 /ref>
Water has dissolved the porous limestone, creating caverns, sinkholes, and sinkhole lakes (cenotes). Some of the lakes are isolated, while others have underground connections with each other and/or surface rivers and streams. The Nahá and Metzabok lake systems are connected to each other, and together form a endorheic basin, closed basin.Bücker, Matthias & Flores Orozco, Adrián & Gallistl, Jakob & Steiner, Matthias & Aigner, Lukas & Hoppenbrock, Johannes & Glebe, Ruth & Barrera, Wendy & Carlos, Pita & García, César & Pérez, José & Buckel, Johannes & Hördt, Andreas & Schwalb, Antje & Pérez, Liseth. (2021). Integrated land and water-borne geophysical surveys shed light on the sudden drying of large karst lakes in southern Mexico. Solid Earth. 12. 439-461. 10.5194/se-12-439-2021.
Lake Nahá (also known as Lake Naja) is located in the Nahá reserve, at 16°59'27.6"N and 91°35'29.6"W. The lake is approximately 1 km in diameter and 30 m deep. It is a karstic lake in a mountain basin, with the lake surface at approximately 830 meters elevation surrounded by mountains up to 1200 meters elevation. The Nahá River drains northwards from Lake Nahá towards the Metzabok lakes.Domínguez-Vázquez, Gabriela and Gerald Alexander Islebe (2008). "Protracted drought during the late Holocene in the Lacandon rain forest, Mexico". ''Vegetation History and Archaeobotany'' Vol. 17, No. 3 (May, 2008), pp. 327-333 /ref>
Metzabok's lake system includes 21 lakes of different sizes, most of which are interconnected when the water level is high. The largest lakes are Lake Tzibaná (1.24 km2 and 70 m maximum depth) and Lake Metzabok (0.83 km2 and 25 m maximum depth). They are located at 17º6'30" to 17º8'30" N and 91º36'30" to 91º38'50" W, and the lake level is approximately 550 meters elevation. The Nahá River is the principal surface tributary, although the lakes may have additional subsurface inflows. There is no known surface or sub-surface outflow, and the Nahá and Metzabok lakes are considered a closed system. Lake levels typically fluctuate by about 10 meters annually with seasonal rainfall patterns. During a drought from March to August 2019, Lake Metzabok dried up completely and the water level in Lake Tzibaná dropped by 15 meters.
The reserve is in the transition between the foothill
Lacandon rainforest
The Lacandon Jungle (Spanish language, Spanish: ''Selva Lacandona'') is an area of rainforest which stretches from Chiapas, Mexico, into Guatemala. The heart of this rainforest is located in the Montes Azules Biosphere Reserve in Chiapas near the ...
The reserve has a tropical rain forest climate. Mean annual temperature is above 22º C. Average annual rainfall is 2500 mm, which falls mostly between May and October.
Flora and fauna
Flora in reserve ranges from pine–oak forest to montane evergreen
cloud forest
A cloud forest, also called a water forest, primas forest, or tropical montane cloud forest (TMCF), is a generally tropical or subtropical, evergreen, montane, moist forest characterized by a persistent, frequent or seasonal low-level cloud c ...
, foothill rain forest, and wetlands.
Lower montane rain forest grows between 400 and 800 meters elevation, including around Lake Nahá. Characteristic trees include ''
Brosimum alicastrum
''Brosimum alicastrum'', commonly known as the breadnut or ramon, is a tree species in the family Moraceae of flowering plants, whose other genera include Ficus, figs and mulberry, mulberries. The plant is known by a range of names in Mesoamer ...
Hirtella americana
''Hirtella'' is a genus of 110 species of woody trees in family Chrysobalanaceae. It was first described as a genus by Linnaeus in 1753. ''Hirtella'' naturally occurs in tropical forests throughout Latin America, the West Indies, southeast Af ...
Spondias radlkoferi
''Spondias radlkoferi'' is a species of flowering plant in the cashew family, Anacardiaceae. It is found from southern Mexico to north-western Venezuela in riparian borders and secondary growth forests. Several species of Neotropical bats in the ...
Guarea
''Guarea'' is a genus of evergreen trees or shrubs in the family Meliaceae, native to tropical Africa and Central and South America. At their largest, they are large trees 20–45 m tall, with a trunk over 1 m diameter, often buttressed at the ba ...
'' spp.
Pine-oak forest grows on the ridges, characterized by species of pine (''Pinus'') and oak (''Quercus''), with ''
Carpinus tropicalis
''Carpinus tropicalis'' is a species of tree native to central and southern Mexico, Guatemala, El Salvador, Honduras, and Nicaragua.
Description
''Carpinus tropicalis'' is small to medium-sized tree which grows up to 30 meters tall, with a tr ...
,
Myrica cerifera
''Myrica cerifera'' is a small evergreen tree or large shrub native to North and Central America and the Caribbean. Its common names include southern wax myrtle, southern bayberry, candleberry, bayberry tree, and tallow shrub. It sees uses both i ...
,
Styrax argenteus
''Styrax'' (common names storax or snowbell) is a genus of about 130 species of large shrubs or small trees in the family Styracaceae, mostly native to warm temperate to tropical regions of the Northern Hemisphere, with the majority in easter ...
'', and species of alder (''Alnus'') and walnut ('' Juglans'').
40,000 plant and animal species live in the reserve. These include 48% of the Mexico's bird species, 33% of bats, 11% of reptiles, and 25% of the mammals in only 0.4% of the country's land area.
The karstic sinkholes and lakes create distinctive wetland habitats, which is recognized by the reserve's Ramsar designation.
Conservation
Nahá and Metzabok flora and fauna protection areas were designed in 1998. The Nahá and Metzabok flora and fauna protection areas were designated a
Ramsar site
A Ramsar site is a wetland site designated to be of international importance under the Ramsar Convention,8 ha (O)
*** Permanent 8 ha (P)
*** Seasonal Intermittent < 8 ha(Ts)
**
Tzeltal Tzeltal may refer to:
* Tzeltal people, an ethnic group of Mexico
* Tzeltal language
Tzeltal or Tseltal () is a Mayan language spoken in the Mexican state of Chiapas, mostly in the municipalities of Ocosingo, Altamirano, Huixtán, Tenejapa, ...
Maya peoples
The Maya peoples () are an ethnolinguistic group of Indigenous peoples of the Americas, indigenous peoples of Mesoamerica. The ancient Maya civilization was formed by members of this group, and today's Maya are generally descended from people ...
live in the reserve. Communal land tenure within the reserve's core zone is recognized by the Mexican Government. Land tenure in the buffer zone is principally ejidos.
Threats to the reserve include water pollution from pesticide runoff,
habitat fragmentation
Habitat fragmentation describes the emergence of discontinuities (fragmentation) in an organism's preferred environment (habitat), causing population fragmentation and ecosystem decay. Causes of habitat fragmentation include geological processes ...
from forest clearance for timber and agriculture, and increased fire risk.