How similar are Mexico’s two major deserts, the Sonoran Desert and the Chihuahuan Desert?

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May 292014
 

There are four desert areas in North America. Two of these areas (Great Basin and Mojave) are in the USA. The other two (the Sonoran Desert and the Chihuahuan Desert) are almost entirely in Mexico, but extend northwards across the border. The Sonoran Desert includes most of the Baja California Peninsula, together with the western part of the state of Sonora. The Chihuahuan desert is the northern section of the Central Plateau, including the northern parts of the states of Chihuahua.

The Chihuahuan Desert has been intensively studied by scientists interested in the possibility of life on Mars – see this New York Times article: Learning About Life on Mars, via a Detour to Mexico.

In a previous post – Why is northern Mexico a desert region? , we saw how the combination of the descending air of the Hadley Cell, which results in surface high pressure, and the effects of rain shadows resulting from neighboring mountain ranges contribute to the low annual rainfall total characteristic of both Mexico’s desert areas.

deserts-colorWhile these two deserts both experience an arid climate, they also have many differences.

Area

The Sonoran Desert has an area of about 311,000 square kilometers (120,000 sq mi). The Chihuahuan Desert has an area of about 362,000 square kilometers (139,769 sq mi).

Elevation

The Sonoran Desert is lower in elevation that the Chihuahuan Desert, with some parts (in the USA) lying below sea level. The Chihuahuan Desert varies in elevation from 600–1675 m (1969–5495 ft).

Summer temperatures

The Sonoran Desert tends to have higher summer temperatures than the Chihuahuan Desert, though even in the Chihuahuan Desert, daytime temperatures in summer are usually between 35 and 40̊C (95-104̊F).

Seasonal rainfall patterns

The ratio of winter to summer rainfall decreases from west to east. Most of the Sonoran Desert (to the west) has a bimodal rainfall regime with spring and summer peaks. On the other hand, most of the limited rain that falls in the Chihuahuan Desert comes in late summer.

The Chihuahuan Desert has a mean annual precipitation of 235 mm (9.3 in), though annual totals vary from 150 to 400 mm (6–16 in).

Vegetation, fauna and biodiversity

These seasonal rainfall differences result in significant differences in the vegetation of the two areas.

The bimodal precipitation in the Sonoran Desert provides two flowering seasons each year. Some plants bloom in spring, following winter rains, while others flower in late summer, following summer rains. Typical plants in the Sonoran Desert include columnar cacti (Cereus spp.) such as sahuaro, organ pipe, and cardon, as well as many other types of cacti, including barrels (Echinocereus), chollas (Opuntia spp.) and prickly pear (Opuntia spp.). Other succulent plants are also common.

More than 60 mammal species, 350 bird species, 20 amphibian species, 100 reptile species, 30 native fish species, 1000 native bee species, and 2000 native plant species have been recorded in the Sonoran Desert. The Sonoran Desert includes the Colorado River Delta, which was once an ecological hotspot within the desert, fueled by the fresh water brought by the river, though this flow has become negligible in recent years. See, for example, Will the mighty Colorado River ever reach its delta?

The vegetation of the Chihuahuan Desert is dominated by grasslands and shrubs, both evergreen and deciduous. Common species include tarbush (Flourensia ternua), whitethorn acacia (Acacia constrictor) and creosote bush (Larrea tridentata). The Chihuahuan desert has small cacti; succulent agaves (Agave spp.) and yuccas. Plants bloom in late summer, following the summer rains.

The Chihuahuan Desert is home to about 350 of the world’s 1500 known species of cactus, and includes the fascinating area of Cuatro Ciénegas, which has an unusually high number of endemic plant species and is one of the world’s richest hotspots for locally endemic cacti.

The Chihuahuan Desert is considered to be one of the three most biologically rich and diverse desert ecoregions in the world, rivaled only by the Great Sandy Tanmi Desert of Australia and the Namib-Karoo of southern Africa. However, settlements and grazing have heavily degraded the natural vegetation of some parts of the Chihuahuan Desert.

he Chihuahuan Desert has about 3500 plant species, including up to 1000 species (29%) that are endemic. The high rate of endemism (true for cacti, butterflies, spiders, scorpions, ants, lizards and snakes) is due to a combination of the isolating effects of the basin and range topography, climate changes over the past 10,000 years, and the colonization of seemingly inhospitable habitats by adaptive species. See here for more details of the flora and fauna of the Chihuahua Desert.

Landforms

This basin and range landscape of the Sonoran Desert trends north-northwest to south-south-east. Parallel faulted blocks are separated by alluvial bajadas (broad, debris-covered slopes), pediments and plains, which become wider approaching the coast. Despite being a desert area, this region exhibits many features that have resulted from water action, including wadis, salt flats, stream terraces and alluvial fans.

For a fuller description of the landforms of the Sonoran Desert, see this extract from A Natural History of the Sonoran Desert (edited by Steven J. Phillips and Patricia Wentworth Comus) published by the Arizona-Sonora Desert Museum.

The Sonoran Desert includes the subregion of the Sierra of Pinacate (part of El Pinacate and Gran Desierto de Altar Biosphere Reserve) with its distinctive volcanic cones, craters and lava flows. For more details, see The landforms of the El Pinacate and Gran Desierto de Altar Biosphere Reserve.

The landforms of the Chihuahuan Desert have been molded by tectonic uplift and erosion. Steep-sided but low hills are separated by wide bajadas from former lake beds and alluvial plains, occupying inland basins known as bolsons. Many parts form closed, interior basins with no external drainage. South of Ciudad Juárez, at Samalayuca, is one of Mexico’s most extensive areas of sand dunes. This is one of the most arid parts of the country, with high levels of salinization.

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Cosmic botanical garden in Toluca

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Mar 152014
 

The city of Toluca (population 1.8 million), the capital of the State of México, was in the news recently as the site for the tri-national meeting between the heads of state of Mexico, the USA and Canada to mark the 20th anniversary of NAFTA.

Nestled away inside the city, away from its burgeoning factories, is the former city market. The market closed in 1975. Plans to demolish it were forestalled when renowned Mexican artist Leopoldo Flores stepped up with a plan to restore the market building, which dated back to 1909, into an artistic gem housing a botanical garden.

Cosmovitral, Toluca

Used under Creative Commons Attribution-Share Alike attribution

The market’s original windows were replaced with large glass murals, comprised of half a million pieces of glass and covering a total area of more than 3,000 square meters. The revamped building, now known as the Cosmovitral, was reopened in 1980. In 2007, the Cosmovitral narrowly missed being named one of the 13 man-made wonders of Mexico.

The centerpiece of the Cosmovitral murals is the stunning image entitled Sun Man (Hombre Sol).

Possibly the world’s best decorated glasshouse, the Cosmovitral houses over 500 different plants from around the world and has become one of the city’s single most popular tourist attractions, though rarely visited by foreign tourists.

Where? The Cosmovitral is located in downtown Toluca at the intersection of Juárez and Lerdo de Tejada streets. Guided tours are available.

When? It is normally open Tuesday to Saturday, 10 a.m. to 6 p.m.; Sundays 10 a.m. to 3 p.m.

Admission? Tickets are 10 pesos (less than a dollar) for adults, 5 pesos for children. Guided tours, mostly to explain the Cosmovitral’s stained glass, are available. Art exhibitions are hosted regularly.

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May is a critical month in the 2012 wildfire season in Mexico

 Mexico's geography in the Press  Comments Off on May is a critical month in the 2012 wildfire season in Mexico
May 032012
 

This month is likely to be a critical month for wildfires. As we reported in an  earlier post – The geography of wildfires in Mexico: the disastrous wildfire season of 2011 – 2011 was Mexico’s worst year for wildfires for 30 years. The on-going drought in northern Mexico (the worst for 70 years) means that this year’s wildfire season is not likely to be any better.

May is the critical month because it marks the end of the dry season in most of Mexico, the time when the natural landscape looks parched. During the month of May, the landscape waits for the start of the rainy season, a season that is sometimes preceded by a spate of electrical storms. Electrical storms can trigger wildfires if they ignite the tinder-dry vegetation.

In the first four months of 2012, there have been some significant wildfires in several parts of Mexico, including one uncomfortably close to the Guadalajara Metropolitan Area, which has a population of almost 5 million.

Here is a brief round-up of the major wildfires in 2012 so far:

Durango

The largest single fire in the country so far in 2012 was in Potrerillos, in the municipality of Canatlán. It damaged 112 square kilometers (43 square miles). The 56 other wildfires experienced by Durango so far this year have all been small. The total area of the state damaged by wildfires this year currently stands at about 120 square miles.

Coahuila
Coahuila has experienced 30 fires so far this year, causing to more than 160 square kilometers. The latest three fires have been brought under control in the past few days. In the Sierra Salsipuedes (municipality of San Buenaventura) a wildfire destroyed 8 square kilometers of brush. Wildfires in the Sierra de la Madera (in the municipalities of Ocampo and Cuatrociénegas) damaged 37 square kilometers and 17 square kilometers respectively.

Sonora

So far in 2012, firefighters have fought 19 wildfires, affecting almost 40 square kilometers it total, mainly grassland and scrub, in the municipalities
of Yécora, Álamos, Rosario Tesopaco, Bacoachi, Quiriego, Nacori Chico and Cucurpe.

Jalisco

Some 1,000 firefighters battled for almost a week to bring a major wildfire in the Primavera Forest (Bosque de la Primavera) under control. The Primavera Forest is a partially-forested wilderness area with hot springs. It is set in a volcanic caldera on the western outskirts of Guadalajara, Mexico’s second largest city.

Location of Primavera Forest in relation to Guadalajara and Lake Chapala.

Location of Primavera Forest in relation to Guadalajara. Credit: Tony Burton; all rights reserved.

Initial reports say that the blaze began on 14 April when a garbage fire got out of control. By the time it was brought under control, the fire had damaged 85 square kilometers, about 35% of it forested, making it the worst fire in the area since 2005. That area damaged is about one-third of the total area of the Primavera Forest. Residents of Guadalajara were luckier than in 2005 because winds this time blew most of the smoke away from the city, so the city’s air quality was not seriously compromised. Even so, schools in some areas were closed briefly as a precaution.

The Primavera has a chequered history of protection. Most of the land is privately owned. It was declared a federally protected area in 1980, but ever since then real estate developers have nibbled away at the edges of the protected area, largely ignoring attempts by local officials to enforce zoning regulations.

Morelos
Several relatively small fires have damaged parts of this small state. The three most significant wildfires to date were in the municipalities of Tepoztlán, Tlalnepantla and Tlayacapan. They damaged 5 square kilometers of forest, but, because of the precipitous terrain, required the combined efforts over four days of more than 700 firefighters. The area, very close to Mexico City, is a popular weekend destination for city dwellers, and renowned for its ecotourism potential. Tepoztlán is one of Mexico’s Magic Towns.

Puebla
A small fire in Cerro del Palmar (in Liebres municipality) unfortunately resulted in two deaths, including that of a firefighter.

Oaxaca
More than 30 square kilometers have been damaged by wildfire this year in various parts of the state.

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Why is biomass density in Mexico relevant to climate change?

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Apr 282012
 

How can we measure the health of forests and other forms of natural vegetation? It has become commonplace to read about biodiversity and many conservation programs rightly stress its importance in the global scheme of things. In a previous post, we examined the biodiversity of Mexico and saw how it is one of the most biodiverse countries in the world.

Biodiversity may be a useful indicator of likely ecological resilience in the face of changing circumstances such as global climate change, but it does not tell the whole picture. In simple biodiversity measures, each species is counted and treated as being equally important. Species close to extinction are singled out for conservation efforts in an attempt to preserve a viable wild population of that species. If all else fails, specimens are transferred to botanical gardens or seeds are collected and stored in the hope that the species can be reintroduced and reestablished in a suitable location at some point in the future.

Biomass production in Mexico (Trees and bushes)

Biomass density in Mexico (trees and shrubs); from deJong et al, 2006.

But are all plant species equal? Should a giant redwood count the same as a dandelion? Certainly in terms of their ability to store carbon, larger plants are more valuable than smaller plants, though the total number of each species also matters. Storing carbon is important. When trees are cut down and burned (to clear the way for agriculture or settlement, for example) this stored carbon is released into the air and contributes to the processes causing global warming.

The term biomass is used to describe the total mass of living organic matter in a plant or in an area. The total biomass of a plant includes its bark, leaves and twigs. In a tropical forest, biomass includes every tree, shrub, sapling, vine, epiphyte and flower. About 50% of the biomass in most forests is carbon. The amount of biomass varies seasonally and is not necessarily stable over time, since plants increase their biomass as they grow. In a forest, the balance that matters in terms of sustainable forestry is the balance between the forest’s production of “new” biomass (through photosynthesis) and the consumption of some of its biomass by chopping, burning and natural decay. Clearly, human activity can directly impact this balance, but so too can natural events such as forest fires.

Bio-geographers have a great interest in assessing biomass since it provides a starting point for numerous models that attempt to estimate the effects of releasing some, or all, of this stored carbon on future global climates. Increasingly, their estimates from the use of remote sensing and satellite images are proving to be quite reliable when tested by comparing them to the biomass of the same area calculated from on-the-ground fieldwork.

The measure of biomass shown on the map is biomass density. Biomass density is the total amount of above ground living organic matter expressed as oven-dry metric tons per hectare. This map immediately reveals why conserving Mexico’s southern rainforests is so important. They are not only the most biodiverse areas of Mexico, their high biomass density values show that they also have far more than their fair share of Mexico’s total biomass. Conserving and managing these forests therefore needs to be a priority strategy in Mexico’s efforts to limit and mitigate climate change.

Sources:

The map comes from “Advances of Mexico in preparing for REDD” by Bernardus H.J. de Jong, Leonel Iglesias Gutiérrez and José Armando Alanís de la Rosa. Presentation given at the UNFCCC Workshop on Methodological Issues relating to Reducing Emissions from Deforestation and Forest Degradation in Developing Countries. Tokyo, Japan, 25 to 27 June 2008.

To read more about estimating biomass, see Estimating Biomass and Biomass Change of Tropical Forests: a Primer. (FAO Forestry Paper – 134) by Sandra Brown. FAO Forestry Paper 134. 1997.

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The geography of wildfires in Mexico: the disastrous wildfire season of 2011

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Jan 212012
 

In the past 20 years, wildfires have destroyed 47,000 square kilometers (18,000 sq. mi) in Mexico, equivalent to five times the area of all sections of Mexico City’s Chapultepec Park, the largest urban park in Latin America. The average fire in Mexico affects 32 hectares (80 acres); this figure has not changed significantly in recent years, even though the incidence of fires has increased somewhat due to a combination of climate change and an increase in the number of people living on the margins of forested areas. The National Forestry Commission (Conafor) says that 99% of Mexico’s forest fires are caused by human error, and only 1% are due to natural causes such as lightning strikes.

It generally takes about 30 years to rehabilitate forest areas ravaged by fire, with reforestation costing up to $2400/ha.

Wildfires are not entirely bad. For example, they help regenerate grassland areas, especially, with fresh young plants. On the other hand, in addition to protecting the existing vegetation, stopping wildfires when they occur helps to preserve soil structure and prevents additional emissions of CO2 from the burning of more plant material. At a national level, it is estimated that fires result in the erosion of 86 million metric tons of soil a year.

In a 2009 study, Conafor used 17 variables to identify the areas of the county with the highest risk of wildfires. Three broad areas accounted for the 900,000 square kilometers identified as having either a “medium” or “high risk” for wildfires:

  • i. Yucatán Peninsula, Chiapas, Oaxaca and Guerrero
  • ii. Central Mexico – Veracruz, Tlaxcala, Puebla, México, Michoacán, Jalisco and the Federal District. This area has more fires than any other because local populations often use fire to clear fields before planting.
  • iii. Baja California. This is the only area where the main fire season is in summer, from March to November. This is the rainy season in the remainder of Mexico, where the fire season corresponds with the winter dry season.

The first half of 2011 was an especially bad period for wildfires in Mexico, the worst for at least 30 years.

Coahuila wildfire, April 9, 2011 (Earth Observatory, Landsat-5)

Coahuila wildfire, April 9, 2011 (Earth Observatory, Landsat-5)

During the first half of 2011, serious wildfires devastated several areas of northern Mexico, with the states of Coahuila and Nuevo León being hardest hit. Other states badly affected included Durango, Chihuahua, Quintana Roo, Oaxaca, Puebla and Guerrero. More than 7,800 fires occurred, severely damaging a total area of 4100 square kilometers. 30 of Mexico’s 32 states were affected; only Tabasco and Baja California Sur escaped unscathed.

Conafor’s annual fire-fighting budget for the entire country is only 650 million pesos ($50 million dollars); the average annual area damaged by wildfires is only 2600 square kilometers, of which 500 square kilometers are forest. At the height of the 2011 fire season, more than 60 new fires were being reported each day, according to Conafor.

Coahuila

In the state of Coahuila, fires damaged 250 square kilometers in four weeks. It is believed that 50% of these fires were due to farmers losing control of deliberate burns. Farmers are supposed to have an adequate fire-suppression plan in place before setting a deliberate burn, but in practice this requirement is not enforced.

The main locations were La Sabina and El Bonito. Authorities were very slow to respond. Diana Doan-Crider, a wildlife biologist at Texas A&M University, has spent the past 25 years studying the Mexican black bear in the Serranía del Burro in Coahuila, an ecological corridor that runs parallel to the Eastern Sierra Madre. The area includes a large population of Mexican black bears. Doan-Crider claims that authorities completely ignored the first warnings and that their eventual response (two weeks after the first fires started) lacked adequate coordination. Many mother bears and their young cubs perished in the fires.

Firefighters in Coahuila had to cope with a spectacular but terrifying fire whorl or fire tornado

Nuevo León

In the neighboring state of Nuevo León, large swathes of ranching land were ravaged by fire. One rancher who lost more than 10,000 ha of cattleland was equally critical of the slow response time of firefighters who took more than two weeks to appear on the scene, by which time the fires had taken hold.

David Garza Lagüera had converted his 14,000 ha ranch into the Cumbres de Monterrey National Park, one of the key areas of bear habitat. The largest pines on his land were more than 150 years old. All were totally destroyed.

The worst damage was in Galeana, Montemorelos, Zaragoza, Aramberri and Mina. The area burned in Nuevo León in May 2011 was almost ten times the total area affected in the state for the whole of 2010.

Why was the 2011 fire season so bad?

To quote the Earth Observatory, “Lack of winter rain and frost left the plants dry and prone to fire. On top of that, the area has not burned for more than 20 years, during which time fuel built up. Thunderstorms and steady strong winds with gusts up to 110 km/h (70 mph) completed the formula for a dangerous, fast-moving wildfire.”

Ironically, the passage of Hurricane Alex in July 2010, which brought 1500 mm (60″) of rain to the Serranía del Burro, actually worsened the fire damage the following year. The rain from Hurricane Alex encouraged so much new growth in the final months of the rainy season that when it died back in the dry season, there was far more fuel available than usual for any wildfire that was sparked.

By the time the federal government declared a state of emergency, it was too late; the fires had already destroyed large areas of grassland, scrubland and forest. The emergency response when it finally arrived included help from the USA and Canada such as the specialist aerial Mars water-bombers stationed on Vancouver Island. The fires were only fully extinguished once the annual rainy season arrived.

As we now know, the disastrous fires of April-May 2011 were an early sign of Mexico’s worst drought for 70 years:

Aviation history as Mexico’s Aeroméxico uses biofuel for transatlantic passenger flight

 Mexico's geography in the Press  Comments Off on Aviation history as Mexico’s Aeroméxico uses biofuel for transatlantic passenger flight
Aug 132011
 

Aeroméxico, Mexico’s major international airline, made aviation history in July. Aeroméxico flight AM1, from Mexico City to Madrid, was the first ever commercial transatlantic passenger flight using bio-fuel. The Boeing 777 flew on a mixture of biofuel and regular jet fuel. Earlier this year, another Mexican airline, Interjet, began using renewable jatropha-based biofuel for flights between Mexico City and Tuxtla Gutierrez in the southern state of Chiapas. Jatropha is a genus of plants, mainly shrubs, that grow wild in several parts of Mexico, including Chiapas. Plantations of jatropha require four or five years of cultivation before the plant is sufficiently mature for commercial harvesting.

Jatropha-based biofuel is marketed as “green jet fuel” and is currently significantly more expensive than regular jet fuel. However, the price of biofuel is expected to fall rapidly as more of it is produced. The “life-time” emissions from using jatropha (including its growing period, processing and combustion) are estimated to be at least 60% less than using conventional jet fuel.

Sources of biodiesel.

Sources of biodiesel. Credit: Bayer CropScience

Mexico’s aviation sector will need 40 million liters of biofuel a year by 2015 in order to meet the national target of 1% of all airline fuel coming from renewable sources. The aviation industry’s long-term target is to halve its 2005 carbon footprint by 2050.

Despite Mexico’s recent adoption of jatropha-based biofuel, there is considerable controversy about the plant’s real value as a sustainable source of renewable energy. See, for example, the critique “Hailed as a miracle biofuel, jatropha falls short of hype” on Yale Environment 360, a publication of the Yale School of Forestry & Environmental Studies.

Mexico has forty UNESCO-designated biosphere reserves

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Jul 232011
 

A surprising percentage of Mexico’s land area is protected in one form or another. A very large number of sites of archaeological or historical importance are managed by the National Institute of Anthropology and History, more commonly known by its acronym INAH. In theory, all buildings more than 100 years old have some degree of protection (under INAH), but in practice this protection is often ignored by developers with other ideas.

Sites considered significant for their natural beauty are protected in a variety of ways, ranging from nature sanctuaries of local importance to protected areas, national parks and internationally recognized biosphere reserves. In total, more than 11.5% of Mexico’s land area is now protected. This percentage has risen steadily for more than a century.

The designation of biosphere reserve can only be made by UNESCO (U.N. Educational, Scientific and Cultural Organization), in a manner somewhat similar to the designation that some major historical sites enjoy as World Heritage Sites. One of the benefits of attaining Biosphere Reserve status is that it allows access to more sources of funding for conservation programs.

Mexico currently has 40 biosphere reserves. Only the USA (48), the Russian Federation (41) and Spain (41) have more. Worldwide, there are now (July 2011) 580 biosphere reserves in 114 countries. The guiding principle of biosphere reserves is that the local populace is not displaced, but actively involved in all aspects of management, research and monitoring.

Biosphere Reserve Zonation

Biosphere reserves have a research-intensive core area or areas at their heart, surrounded by a buffer zone, where sustainable development is fostered, before gradually transitioning into the surrounding region. Many reserves have innovative systems of governance designed to ensure that the views of local people are fully respected. The idea of biosphere reserves was first proposed in 1968 at the UNESCO “Biosphere Conference”, the first international attempt to reconcile the need for conservation with the use of natural resources for development.

No system is perfect. The challenges for biosphere reserves include strengthening the worldwide network by establishing new reserves in areas where few currently exist, as well as helping meet the on-going funding needs for all the reserves. One of the most significant future threats to biosphere reserves is likely to be the habitat changes wrought by global warming.

One of the more startling surprises in the existing network of reserves is the almost total lack of protection afforded to such an amazing part of Mexico as the Copper Canyon region, with its indigenous Tarahumara people and world-class scenery. But perhaps one day this region, too, will become part of Mexico’s extensive system of protected areas.

Mexico’s Biosphere Reserves, as of July 2011:

Baja California Peninsula:

  • El Vizcaíno (Baja California Sur): desert, mountain and coastal/marine ecosystems, petroglyphs, wall paintings, birds and Grey whales.
  • Sierra La Laguna (Baja California Sur): contrasting ecosystems, woodlands and scrub, with high degree of endemism.
  • Alto Golfo de California (Baja California and Sonora): extraordinary geological formations with volcanic craters, dunes, oasis and beaches, and a diversity of plant associations.
  • Islas del Golfo de California (Baja California Sur and Sonora): series of over 240 islands with high number of endemic species; ornithological paradise.

Northern Mexico:

  • Mapimí (Durango, Chihuahua and Coahuila): fragile warm desert and semi-desert ecosystems.
  • La Michilía (Durango): mountainous area of pine-oak forest; habitat for the now rare black bear (Ursus americanus) and wolf (Canis lupus).
  • El Cielo (Tamaulipas): one of the most ecologically rich and diverse parts of Mexico; numerous endangered animal species; ecotourism area.
  • Laguna Madre and Río Bravo Delta (Tamaulipas): a migratory bird haven on coastal wetlands.
  • Cumbres de Monterrey (Nuevo León): the landmark mountains that ensure the water supply for the state capital.
  • Maderas del Carmen (Coahuila): encompassing parts of the Chihuahuan Desert in Coahuila state adjacent to the U.S. biosphere reserve of Big Bend National Park.
  • Cuatrociénegas (Coahuila): an oasis with 500 pools that preserve species found only in the Coahuila state part of the Chihuahua desert.
  • Sierra de Alamos–Rio Cuchujaqui (Sonora): endangered tropical deciduous forest.

Central and Western Mexico:

  • Sierra de Manantlán (Jalisco and Colima): transition of the Nearctic and Neotropical biological realms; cloud forest and wild perennial corn (Zea diploperennis).
  • Chamela-Cuixmala (Jalisco): a Pacific Coast dry tropical forest harboring iguanas and crocodiles in lagoons and marshes.
  • Islas Marietas (Nayarit): a biodiverse archipelago of islands with a rich mix of marine species, corals and landforms.
  • La Primavera (Jalisco): pine and oak forest in a caldera close to Guadalajara, Mexico’s second city.
  • Sierra Gorda (Querétaro): ecologically diverse area with 14 vegetation types, historic missions and Huastec Indians.
  • Monarch butterfly migration sites (Michoacán and State of México): unique annual migration links Mexico to Canada and the U.S.
  • Sierra de Huautla (Morelos): woods full of endemic species.
  • Barranca de Metztitlán (Hidalgo): home of Otomí Indians and large variety of wildlife.
  • Los Volcanes (State of México/Puebla) is the volcanic landscape of significant aesthetic and touristic value that surrounds the twin volcanoes of Popocatépetl and Ixtaccíhuatl.
  • Islas Marías (Nayarit), a group of four islands, perhaps best known for its federal penitentiary, with considerable diversity of ecosystems and many
    endemic species.

Eastern Mexico:

  • Los Tuxtlas (Veracruz): a beautiful jungle-covered volcanic region, with vestiges of pre-Hispanic archeology.
  • Sistema Arrecifal Veracruzano (Veracruz): an archipelago off the Caribbean coast.
  • Pantanos de Centla (Tabasco): villages in coastal wetlands.

Southern Mexico:

  • Montes Azules (Chiapas): Lacandon tropical rainforest; 500 species of trees; several indigenous groups (including Tzeltal, Chol and Lacandon Maya).
  • Volcán Tacana (Chiapas): fragile ecosystems in Chiapas, adjacent to Guatamala.
  • El Triunfo (Chiapas): diverse evergreen cloud forest in rugged mountain terrain; a primary Pleistocene refuge for numerous endemic plants and animals; large mobile population.
  • La Encrucijada (Chiapas): shrimping lagoons on the Pacific Coast.
  • La Sepultura (Chiapas): ancestral lands of the Olmec and other pre-Hispanic cultures.
  • Selva El Ocote (Chiapas): rain forests, caves and reserves of underground water.
  • Huatulco (Oaxaca): coastal reserve protecting endangered sea turtles, dolphins and purple snails.
  • Lagunas de Montebello (Chiapas) series of beautiful lakes close to the border with Guatemala, set in upland, wooded terrain, with varied flora and fauna including orchids, butterflies, fish, reptiles, mammals and birds.
  • Naha-Metzabok (Chiapas) northern section of the Lacandon tropical forest, home to several members of the cat family and an important part of the Mayan forest biological corridor

Yucatán Peninsula

  • Ría Celestún (Yucatán and Campeche): coastal region including important wetlands and drowned river valley (ría) with diverse fauna and flora, including flamingos.
  • Región de Calakmul (Yucatán): diverse tropical rainforests; the largest forest reserve in Mexico, with important Maya sites; ecotourism project.
  • Ría Lagartos (Yucatán): coastal estuary with diverse birdlife including more than 18000 pink flamingos as well as some 30,000 migratory birds.
  • Arrecife Alacranes (Yucatán): the largest coral reef in the Gulf of Mexico, and the only one in Yucatán state.
  • Sian Ka’an (Quintana Roo): coastal limestone plain, and extensive barrier reef system on Caribbean coast, with numerous archaeological sites; more than 4,000 plant species.
  • Banco Chinchorro (Quintana Roo): mosaic of open water, sea grass beds, mangroves, sandy beaches and coral reefs; more than 95 species of coral.

Main source: UNESCO: Directory of the World Network of Biosphere Reserves

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How ecological is ecotourism in Mexico?

 Excerpts from Geo-Mexico  Comments Off on How ecological is ecotourism in Mexico?
Jun 162011
 

Ecotourism is often touted as one solution to many of the potential woes associated with conventional resort tourism. It should come as no surprise to find that Mexico has embraced ecotourism: Mexico’s biodiversity is phenomenal. It is one of the five most important countries in the world in terms of biodiversity:

To be ecologically successful, ecotourism probably has to be small-scale. Constructing the infrastructure necessary for large-scale coastal ecotourism projects often involves the destruction of highly productive (in ecological terms) wetlands, including tropical mangroves. These ecosystems play a vital role in helping preserve biodiversity and their destruction has serious long-term economic implications for fishing, port and marina access, coastline preservation and beach-based tourism.

Marine biodiversity

Mangroves (pictured on the right of the image) are especially vulnerable, with an undeserved reputation for being impenetrable thickets harboring noxious insects and reptiles. Mangroves sequester carbon and help reduce the organic content of water. Their roots bind unstable coasts, preventing erosion and acting as a natural barrier against hurricanes. They are important breeding, shelter and feeding places for fish, crustaceans and birds as well as being a source of charcoal, firewood, wood and roofing materials. They offer economic opportunities of fishing for shrimp, mollusk, fish and crustaceans.

In the year 2000, the total area of mangroves along Mexican coasts was estimated at 880,000 hectares (2.2 million acres), approximately two-thirds on the Atlantic and Caribbean coasts, and one-third on the Pacific. The annual loss of mangroves is estimated to be between 2.5% and 5% of this area. Even with the lower rate of loss, by 2025 mangroves will occupy only half of their 2000 area. In 2007 Mexico enacted federal legislation to protect existing mangroves.

The unique habitats of coral reefs are also at risk. Mexico has important zones of coral from the Baja California Peninsula and Sea of Cortés in the north to Cozumel Island and Chinchorro Bank in the south. The latter area is the northernmost extension of the Meso-American Barrier Reef system which is the world’s second largest reef system after Australia’s Barrier Reef. Marine pollution, overfishing and tourism have all hastened the decline of coral reefs,though many areas are now protected.

Even animal migrations are considered at risk. Some studies have shown that the number of tourists viewing the whale migrations off the coast of Baja California, for instance, is already having an adverse effect on the whales’ breeding habits.

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This is an excerpt from chapter 19 of Geo-Mexico: the geography and dynamics of modern Mexico. Buy your copy today, and learn more about Mexico’s fascinating geography. The more knowledge you acquire, the more pleasure you will derive from your next trip to Mexico!

Why Las Tuxtlas Biosphere Reserve is well worth a visit

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Jun 132011
 

In a recent post, we looked at an Enchanted Lake in southern Mexico, in the Sierra de las Tuxtlas, near Catemaco in the Gulf Coast state of Veracruz. In this post we take a look at the surrounding Las Tuxtlas Biosphere Reserve.

Tuxtlas biosphere reserve

Scenically, the entire Tuxtlas region is one of the most fabulously beautiful in all of Mexico. High temperatures combined with lots of rainfall result in luxuriant vegetation and boundless wildlife. Average monthly temperatures range from a pleasant 21 degrees C (70 degrees F) in January to a high of 28 degrees C (82 degrees F) in May, just before the rainy season kicks in. During the rainy season, from June to October, some 2000 mm (79 inches) of rain falls, often in late afternoon tropical deluges.

The jungle masking the lower slopes of the San Martín volcano gradually merges into tropical cloud forest at higher altitudes. Competing with the Silk Cotton (Kapok) and Ficus trees for light and sustenance are ground-hugging ferns. Overhead, the tangle of tree branches provides support for thousands of non-parasitic bromeliads (“air” plants) and orchids. More than 1300 species of flowering plants have been identified in this classic area for Neotropical ecology.

Bird-watchers are likely to spot the spectacular Keel-billed Toucan, or hear a Tody Motmot. Smaller birds include several species of hummingbird; look for the endemic Long-tailed Sabrewing. About half of all the bird species recorded in Mexico have been seen here, but birds are not the only wild animals inhabiting the jungle. Ocelots and tapirs are regularly seen and you may be lucky enough to see spider monkeys playing overhead in the canopy.

Clearance of the land for grazing and cultivation of the slopes to grow tobacco, bananas and sugar cane have reduced the original jungle to a relatively small number of isolated fragments. Fortuitously, this provides more varied habitats than the original vegetation, helping to enrich the area’s wildlife, further enhancing the region’s reputation as an ornithological and botanical paradise.

Fortunately an extensive area of this region was declared a Biosphere Reserve in 1998, ensuring that conservation programs now go hand-in-hand with human activities. The total area forming the Reserva de la Biósfera “Los Tuxtlas” is 155,122 hectares (380,000 acres).

Chapter 5 of Geo-Mexico: the geography and dynamics of modern Mexico focuses on Mexico’s ecosystems and biodiversity.  Chapter 30 analyzes environmental issues and trends including current environmental threats and efforts to protect the environment.  Buy your copy today to have a handy reference guide to all major aspects of Mexico’s geography!

The diversity of species (plants and animals) in Mexico

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Oct 152010
 

A previous post noted that Mexico’s very wide range of ecosystems make it one of the six most biodiverse countries on earth. We also looked at the states in Mexico with the greatest biodiversity.

Given its deserts, it is not surprising that Mexico ranks first in the world in cactus species and second in reptile species, behind only Australia. Mexico’s tallest cactus is the Pachycereus pringlei (cardón), a relative of the saguaro. It can grow to a height over 19 meters (60 feet) and 1 meter in diameter (39 inches). The largest reptile is the crocodile which can grow to 5 meters (16 feet) in length and weigh over 400 kilograms (880 pounds).  In recent years, several Mexicans have been killed by crocodile attacks.

Marine biodiversityLargely as a result of Mexico’s diverse tropical and subtropical forests, Mexico ranks fourth in the world with 30,000 different types of flowering plants, compared to only 18,000 in the USA and 12,000 in all of Europe. It also ranks fourth in number of amphibian species, which thrive in Mexico’s tropical rainforests. Mexico is also among the top ten in fern and butterfly species.

The temperate forests also harbor significant biodiversity.  Mexico has more species of pine trees and oak trees than any other country.  However, with deforestation, some of these species may be endangered.

Most people are very surprised to learn that Mexico is among the top three in mammal species, along with Indonesia and Brazil. Some of Mexico’s mammals are majestic like the jaguar, some are rather large like the tapir, but many are small and less impressive like bats, shrews, and rodents. Extinction of endemic Mexican mammals is a serious concern. The International Union for Conservation of Nature (IUCN) has listed 11 endemic Mexican mammals as “critically endangered”; 27 as “endangered”, and 14 as “vulnerable”.

Chapter 5 of Geo-Mexico: the geography and dynamics of modern Mexico focuses on Mexico’s ecosystems and biodiversity.  Chapter 30 analyzes environmental issues and trends including current environmental threats and efforts to protect the environment.  Buy your copy today to have a handy reference guide to all major aspects of Mexico’s geography!