Oct 122010

Q. Mexico is one of the six most biologically diverse countries on the planet.  But which states in Mexico have the greatest biodiversity?

A. In general, the southern states (which receive the highest amounts of rainfall) have the greatest biodiversity: Chiapas, Oaxaca, and Veracruz.

The three most biodiverse states in Mexico

The three most biodiverse states in Mexico

To answer this question in more detail, it is useful to look at different types of plants and animals.

Mammal species are fairly well distributed throughout Mexico. Three of the wettest states lead in number of mammal species.  Chiapas has 205 different species followed by Oaxaca (194) and Veracruz (190). Interestingly, the next highest rated states are in central and northern Mexico: Jalisco (173), Michoacán (163), San Luis Potosí (152), Tamaulipas (145), Puebla (144), Durango (141) and Sonora (139). All states have over 70 mammal species, except for the relatively small states of Aguascalientes (40), Tlaxcala (50) and Guanajuato (65). Mexico as a whole has an impressive 901 mammal species; this figure places it ahead of all other countries.

Mexico is a bird watchers paradise. Veracruz and Oaxaca lead with 635 and 634 different bird species. Chiapas is third with 565 bird species followed by Sonora (445), Jalisco (438), San Luis Potosí (438), Tamaulipas (435) and Michoacán (429). Tlaxcala (86) and Aguascalientes (88) have the fewest number of bird species.

Mexico’s 808 different reptile species places it second, behind only Australia. Relative wet states lead in number of reptile species: Oaxaca (258), Chiapas (224), Veracruz (214) and Guerrero (158). However, the more arid states also have relatively large numbers of reptile species: Sonora (137), Chihuahua (118), Baja California (80) and Baja California Sur (68). Aguascalientes has only 17 reptile species.

Amphibians are very abundant in the wet southeastern states. Chiapas leads with117 amphibian species in followed by Veracruz (109), Oaxaca (106) and Hidalgo (66). Not surprisingly, there are very few amphibian species in desert states. Baja California Sur has only five species while Baja California has 12.

Mexico ranks fourth in the world in number of flowering plant species, behind only Brazil, Colombia and China. Veracruz is the clear leader with 4,907 species, followed by Chiapas (3,833), Oaxaca (3,388) and Jalisco (2,752). States with the fewest species are Aguascalientes (467), Tlaxcala (457) and Baja California Sur (484).

Mexico is also among the world leaders in number gymnosperm (nonflowering plants – mostly conifers and other evergreens) species.  Mexico has more species of pine trees than any other country. Veracruz leads with 31 species, followed closely by Nuevo León (30), Durango (29), Oaxaca (28), Hidalgo (27) and Chihuahua (26). Quintana Roo and Campeche have only one species while Colima and Yucatán have only two.

Ferns are also an important part of Mexico’s biodiversity. Chiapas leads with 693 fern species, followed by Oaxaca (669), Veracruz (534), Guerrero (374) and Puebla (297). States on the Yucatán Peninsula have relatively few fern species: Yucatán (25), Campeche (29) and Quintana Roo (39).

Source for the statistics in this post: Semarnat, El ambiente en números 2010, tabla 21: “Riqueza de grupos de species selecionadas, 2008” (CONABIO) (pdf document).

Several of our previous posts have discussed Mexico’s very wide range of climates, ecosystems and species diversity:

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!

Mexico’s mega-biodiversity

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Oct 122010

People from elsewhere generally think of Mexico as an arid country with lots of cacti. The general impression is that Mexico has relatively little biodiversity in comparison with equator-hugging tropical countries such as Brazil and Indonesia.

These impressions could not be farther from the truth.  While northern Mexico is indeed arid, many areas in southern Mexico receive over 2,000 mm (80 inches) of annual precipitation, almost entirely in the form of rainfall. The rainiest place in Mexico— Tenango, Oaxaca—receives 5,000 mm (16.4 feet) of rain annually.

Mexico's postage stamps regularly celebrate biodiveristy

Mexico's postage stamps regularly celebrate biodiveristy. Click to enlarge

Straddling the Tropic of Cancer, Mexico is a world leader in terms of climate and ecosystem diversity.  It is one of the only countries on earth with arid deserts, dry scrublands, temperate forests, high altitude alpine areas, subtropical forests, tropical rainforests and extensive coral reefs. The multitude of ecosystems in Mexico supports a very wide range of biodiversity.

  • Mexico’s vegetation zones. The link is to a pdf map (in color) of vegetation zones. The map (all rights reserved) is a color version of Figure 5.1 in Geo-Mexico.

Mexico’s Environmental Ministry (SEMARNAT) indicates that there are over 200,000 different species in Mexico.  This is about 10% – 12% of all the species on the planet. About half of all Mexico’s species are endemic; they exist only in Mexico. An unknown number of endemic species were forced to extinction by the intended and unintended importation of Old World species by the Spaniards.

The U.N. Environment Programme has identified 17 “megadiverse” countries.  The list includes Mexico, the USA, Australia, five South American countries, three African countries, and six Asian counties.  Actually, Mexico is among the upper third of this group along with Brazil, Colombia, China, Indonesia and DRC (Democratic Republic of the Congo). The other countries on the list are: the USA, Venezuela, Ecuador, Peru,  South Africa, Malagasy Republic, India, Malaysia, The Philippines,  Papua New Guinea, and Australia.

Chapter 4 of Geo-Mexico: the geography and dynamics of modern Mexico discusses Mexico’s diverse climates.  Chapter 5 focuses on ecosystems and biodiversity.  Chapter 30 analyzes environmental issues and trends including the impact of Old World species imported by the Spaniards, 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!

Sep 092010

In two previous posts, we examined the historical connections between Mexico and the Philippines.

A news story (on mb.com.ph) a few months ago alerted us to another, much more recent link between the two countries.

The Philippine Drug Enforcement Agency (PDEA) claims that a Mexican herb poses a significant public health risk. According to the PDEA, Salvia divinorum, which is hallucinogenic when sun-dried leaves are chewed, sniffed or smoked, has been found growing wild in the Teachers Village in Quezon City. The plant is a member of the mint family and has a distinctive square stem. It is not known how or when it was introduced into the Philippines.

It is endemic to the remote region of the Sierra Mazateca in the northern part of the state of Oaxaca, Mexico. The plant grows in the warm, damp tropical evergreen and cloud forests at elevations between 300 and 1800 meters (1000 to 6000 feet). Biologists remain uncertain whether the plant is a truly natural plant or whether it is actually a hybrid (a cross between two or more distinct plant species) or cultigen (a plant that has been deliberately altered or selected by humans). It is commonly known in Mexico as divine sage, and the local Mazatec indigenous group has a long tradition of employing the plant in spiritual healing ceremonies.

The active constituent of Salvia divinorum is known as salvinorin A. Wikipedia’s entry on divine sage claims that “By mass, salvinorin A is the most potent naturally-occurring psychoactive compound known.”

We are not sure why it is in the interests of the PDEA to offer helpful tips for anyone thinking of growing and using this particular plant, but a PDEA spokesperson did just that, describing the plant as being somewhat similar to cannabis (marijuana), but easier to grow, since it can be propagated via stem cuttings. In addition, “The addictive effect of the said plant will last long if the leaves of the plant will be spread on a person’s gums rather than sniffing or puffing it like a cigarette. They say it gives you an uncontrollable laugh trip because the user will see the people as if they were caricatures or cartoons.” At least the final part of that quote appears to be hearsay and probably not admissible if introduced into a courtroom!

Despite its known hallucinogenic qualities, the cultivation and possession of divine sage remain legal in almost every country around the world. In the USA, only certain states have criminalized the plant. Click here for a webpage which provides more details of divine sage’s legal situation in particular countries and US states.

In the Philippines, the PDEA is reported to be collecting further evidence prior to recommending whether or not owning the plant should be made illegal. Sounds like it could be a fun job if you can get it!

Divine sage is the latest link in the 450-year-long history of close connections between Mexico and the Philippines.

Mexico’s links with other countries are discussed in chapter 20 of Geo-Mexico: the geography and dynamics of modern Mexico. Ask your library to buy a copy of this handy reference guide to all aspects of Mexico’s geography today! Better yet, order your own copy…

Mexico’s first cooks and the origins of Mexican cuisine

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Jun 182010

Mexican cuisine has been one of the country’s most successful cultural exports over the past twenty years or so and most large towns in North America and Europe now boast at least one Mexican restaurant, even if the menu is not necessarily “authentic”. For those wanting to experiment, the basic ingredients for Mexican meals can now be bought virtually everywhere. The increasing popularity of Mexican food has been rivaled only by an extraordinary increase in the consumption of Mexican drinks, including Corona beer and tequila.

Ingredients for guacamole. Photo: Chef Daniel Wheeler. All rights reserved.

Archaeologists have also taken much more interest in Mexican food in recent years.

By 1970, studies carried out at various locations, ranging from Tamaulipas in the north of the country to Oaxaca in the south, had gradually led to the conclusion that the earliest plants to be domesticated in Meso-America were corn, beans and squash, and that all three had been domesticated between about 7000 and 10,000 years BP (Before Present, not British Petroleum…).

Further research subsequently led most archaeologists and palaeo-botanists to believe that squash was actually domesticated much earlier than corn. Re-evaluating cave samples, originally collected in the 1950s, using an improved carbon-14 dating technique, anthropologist Bruce Smith found that the squash seeds from one location were between 8,000 and 10,000 years old, while the oldest corn and bean seeds were much younger, less than 6,000 years old.

While Smith’s study does appears to confirm that squash was domesticated first, it does not necessarily mean that this squash was domesticated for its food value. Many experts think that early varieties of squash may have been domesticated primarily for their gourds, which could be used as ready-made drinking vessels and fishing floats.

The domestication of squash may have improved life, but it did not fundamentally change it. On the other hand, the eventual domestication of corn, about 7,000 years BP marked a true watershed in pre-Hispanic life, enabling the abandonment of a nomadic hunter-gathering existence in favor of settlement in semi-permanent villages. How important was this? In the words of renowned archaeologist Michael Coe, “it was the cultivation of maize, beans and squash that made possible all of the higher cultures of Mexico.”

With the passing of time, the ancient peoples of Mexico domesticated and cultivated many other native plants, including tomatoes, chiles, potatoes, avocados, amaranth, chayote (vegetable pear), cotton and tobacco.

The original article on MexConnect

If you enjoyed this post, you might also enjoy Geo-Mexico: the geography and dynamics of modern Mexico.

Las Tuxtlas Biosphere Reserve in Veracruz, Mexico

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Apr 172010

Scenically, the entire Tuxtlas region, in the south-eastern section of the  state of Veracruz, 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).

Click here for original article on MexConnect

Mexico’s varied climate zones are discussed in chapter 4 of  Geo-Mexico: the geography and dynamics of modern Mexico, while chapter 5 is devoted to Mexico’s ecosystems and biodiversity, including the nation’s many biosphere reserves.

Apr 122010

Many common garden flowers were developed from samples collected in Mexico by a German botanist financed by Britain’s Horticultural Society.

Karl Theodor Hartweg (1812-1871) came from a long line of gardeners and had gardening in his genes. Born in Karlsruhe, Germany, he worked in Paris, at the Jardin des Plantes, before moving to England to work in the U.K. Horticultural Society’s Chiswick gardens in London. Keen to travel even further afield, he was appointed an official plant hunter and sent to the Americas for the first time in 1836. What was originally intended to be a three-year project eventually became an expedition lasting seven years.

By Hartweg’s time, Europeans already knew that Mexico was a veritable botanical treasure trove, full of exciting new plants. For example, the humble dahlia, a Mexican native since elevated to the status of the nation’s official flower, had already become very prominent in Europe. Mexican cacti were also beginning to acquire popularity in Europe at this time.

The Horticultural Society saw both academic and financial potential in sponsoring Hartweg to explore remote areas of Mexico, and collect plants that might flourish in temperature climes such as north-west Europe.

Fuchsia fulgens

Fuchsia fulgens

Hartweg proved to be an especially determined traveler, who covered a vast territory in search of new plants. He collected representative samples and seeds of hundreds and hundreds of species, many of which had not previously been scientifically named or described. Orchids from the Americas were particularly popular in Hartweg’s day. According to Merle Reinkka, the author of A History of the Orchid, Hartweg amassed “the most variable and comprehensive collection of New World Orchids made by a single individual in the first half of the [19th] century”.

Shortly after arriving in Veracruz in 1836, Hartweg met a fellow botanist, Carl Sartorius (1796-1872), of German extraction, who had acquired the nearby hacienda of El Mirador a decade earlier. Sartorius collected plants for the Berlin Botanical Gardens. His hacienda, producing sugar-cane, set in the coastal, tropical lowlands, became the mecca of nineteenth century botanists visiting Mexico.

From 1836 to 1839, Hartweg explored Mexico, criss-crossing the country from Veracruz to León, Lagos de Moreno and Aguascalientes before entering the rugged landscapes around the mining town of Bolaños in early October 1837. In his own words, reaching Bolaños had involved “travelling over a mountain path of which I never saw the like before”, one “which became daily work by the continual heavy rains.” From Bolaños, Hartweg visited Zacatecas, San Luis Potosí (in February 1838) and Guadalajara, where he did not omit to include a detailed description of tequila making. From Guadalajara, he moved on to Morelia, Angangueo [then an important mining town, now the closest town of any size to the Monarch butterfly reserves], Real del Monte, and Mexico City, from where he sent a large consignment of plant material back to England. Hartweg then headed south to Oaxaca and Chiapas en route to Guatemala, Ecuador, Peru and Jamaica. He arrived back in Europe in 1843.

Hartweg visited Mexico again in 1845-46.  After arriving in Veracruz in November 1845, he traversed the country via Mexico City (early December) to Tepic, where he arrived on New Year’s Day 1846, to wait for news of a suitable vessel arriving in the nearby port of San Blas which could take him north to California. In the event he had to wait until May, so he occupied himself in the meantime with numerous botanical explorations in the vicinity, including trips to Ceboruco Volcano. From California, he sent further boxes of specimens back to England, including numerous plants which would subsequently become much prized garden ornamentals. During this trip, he also added several new conifers to the growing list found in Mexico. It is now known that Mexico has more of the world’s 90+ species of pine (Pinus) than any other country on earth. This has led botanists to suppose that it is the original birthplace of the entire genus.

It took several years for the boxes and boxes of material sent back to England by Hartweg to be properly examined, cataloged and described. Many of the samples from his early trip were first described formally by George Bentham in Plantae Hartwegianae, which appeared as a series of publications from 1839 to 1842. Among the exciting discoveries were new species of conifers, such as Pinus hartwegii, Pinus ayacahuite, P. moctezumae, P. patula, Cupressus macrocarpa, and Sequoia sempervirens. Hartweg’s collecting prowess is remembered today in the name given to a spectacular purple-flowering orchid, Hartwegia purpurea, which is native to southern Mexico.

Numerous garden plants derive directly from plants Hartweg sent back to Europe. These included Salvia patens (a blue flowering member of the mint family) which became the ancestor of modern bedding salvias, the red-flowering Fuchsia fulgens, ancestor of a very large number of Fuchsia cultivars, and the red-flowering Zauschneria californica, commonly known as California fuchsia.

Original article on MexConnect

The Irish may be everywhere, but mainly due to a Mexican water mold

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Mar 172010

During the Irish potato famine more than one million people died of starvation when their staple crop failed, and many of those who survived were forced to emigrate. This tide of emigration carried many Irish people to North America, particularly to the north-east of the USA.

How did the potato famine come about? The census of 1841 in Ireland recorded a population of about 8 million. This figure was a staggering 300% more than sixty years earlier. The staple Irish food at that time was the humble potato and Ireland’s rapid population growth during the early part of the nineteenth century was based on the so-called “potato economy”.  Ireland was bursting at the seams in 1841, but just a decade later, after the potato famine, the population had fallen to 6.5 million and by 1900 to around 4 million.

And where does a Mexican mold come in? The cause of famine was a water mold (Phytophthora infestans) that originated in Mexico. This fungus-like mold results in a disease called “late blight” in which entire fields of mature potato plants are destroyed within days. The name “late blight” is because the mold strikes late in the growing season, close to harvest time. Infected tubers are subject to soft-rot bacteria which render them useless as food. What is worse, the discarded rotting tubers can easily re-infect the succeeding year’s crop.

One kind of late blight mold, A1, crossed the Atlantic in the 1840s, reaching Europe in 1845 before rapidly spreading across the continent to reach Ireland. Although cultivated potatoes (Solanum tuberosum) originated in Peru, the late blight mold appears to have originated in the Toluca Valley of Mexico (adjacent to the western edge of Mexico City) where it is found in several related wild-growing Solanum tubers.

After the Irish potato famine, farmers learned to control the A1 mold through careful fungicide applications and by choosing varieties that had some resistance to late blight and planting only healthy tubers.

Since the 1980s, however, farmers are once again fighting late blight as the direct result of the escape of a second kind, A2, into the cultivated potato population. The problem stems from the fact that A1 and A2 can reproduce sexually, with the potential to have offspring that are strains with greater virulence or increased resistance to fungicides. Having two different kinds of late blight as parents greatly magnifies the genetic variability available for future generations of the mold .

The A2 mold first appeared outside Mexico in the 1970s and has already spread with serious economic consequences to the Middle East, Africa and North and South America. It seems almost certain that it will eventually also disrupt harvests in India and in China, the world’s largest potato producer. The A2 mold is considered the most important threat to potato cultivation worldwide. The current response of hitting it with higher and more lethal doses of fungicide is not in line with public demands for greener farming methods.

How did the A2 mold escape from Mexico? It was probably unintentionally carried by potatoes exported to Europe during the winter of 1976-77. Europe needed potatoes because a drought a year earlier had reduced its potato yields significantly. Unrecognized, the mold was then re-transported in seed potatoes throughout Europe and to the Middle East and Africa.

Scientists are studying wild potatoes in the Toluca Valley in an effort to try and identify precisely which gene or combination of genes provides these particular wild potatoes with some degree of defense against the worst ravages of the mold. Mexico’s main center for potato research is the Agricultural University at Chapingo, near Texcoco, on the eastern edge of Mexico City. The University is well worth a visit – if only to admire the magnificent Diego Rivera murals, including one of the world’s great nudes.

Happy St. Patrick’s Day, wherever you may be!

This is an edited version of an article originally published on MexConnect – Click here for the original article

Mexico’s innumerable links (economic, social, demographic and cultural) to the world are relevant to many chapters of Geo-Mexico: the geography and dynamics of modern Mexico.

Mar 142010

Rubber balls wouldn’t bounce very high at all if it wasn’t for some Mexican ingenuity. Think of the hours of pleasure that a simple rubber ball gave you as a child. Would you have had as much fun if it hadn’t bounced? I don’t think so… but what’s the secret ingredient?

It has long been known that the pre-Columbian peoples of Mexico had rubber objects, including balls. The basic ingredient was the sap or latex of the native Panama Rubber Tree (Castilla elastica).

A few years ago, Dorothy Hosler, an associate professor of archeology and ancient technology at the Massachusetts Institute of Technology, and two of her colleagues, chemist Sandra Burkett and undergraduate student Michael Tarkanian, realized that unprocessed pure latex is sticky and becomes brittle when dry. Put simply, balls made of pure latex don’t bounce, but shatter.

So, they then set out to tackle the mystery of what makes rubber balls bounce. In a landmark paper entitled, “Prehistoric Polymers: Rubber Processing in Ancient Mesoamerica,” published in the June 18, 1999, issue of Science, they revealed how a little Mexican ingenuity turned sticky, brittle latex into a stretchy elastic. Put simply, they revealed what made rubber balls bounce.

The magic ingredient is a little sap from the Morning Glory (Moonflower) vine! The addition of sap to latex begins complex chemical changes that provide a much improved material for tools, figurines and medicines, in a process akin to vulcanization, invented three thousand years later by Charles Goodrich. The addition of Morning Glory (Ipomoea alba) sap to otherwise brittle rubber also resulted in balls suitable for the development of Mexico’s ancient sport of Ulama.

Ipomoea alba, the tropical white-flowering morning glory (moonflower or moon vine).

How did Hosler’s team arrive at this startling conclusion? Documentary sources and ethnographic research suggested that Indians mixed natural latex with the juice of the morning glory vine, a plant prized for its curing properties. The researchers crushed some Morning Glory vines and squeezed the juice into a bucket containing the latex. After stirring for 15 minutes, the liquid latex solidified into a white mass, pliable enough to be formed by hand into a ball. The researchers made a ball about 3.7 inches (9.5 cm) in diameter and, lo and behold, it bounced!

When they used nuclear magnetic resonance scans to examine rubber balls dating back to 1600 B.C. that had been found in Veracruz and Chiapas, they were able to conclude that these had been made in a similar way.

Is it really surprising that pre-Columbian Indians discovered this chemical trick thousands of years ago? Well, perhaps not as surprising as you may think, since the two plants, Castilla elastica and Ipomoea alba often grow in close proximity. In fact, the Morning Glory vine often twines itself around the rubber tree, making it quite likely that a careless rubber tapper accidentally contaminated the latex being collected with a little (crushed) Morning Glory vine: an accident that turned out to have incredibly serendipitous results.

Whatever happened all those thousands of years ago, the mystery of why rubber balls bounce has finally been solved…

This is an edited version of an article originally published on MexConnect – Click here for the original article

Sports are not specifically discussed in Geo-Mexico, but the music, dance, language and cuisine of Mexico, together with cultural regions, are discussed in chapter18 of Geo-Mexico: the geography and dynamics of modern Mexico.