A study tour of Mexico’s endangered habitats and plants
By Paul Pollard
Ever since starting a career in horticulture in 1988, I have developed a great desire to study plants in habitat. In February 1997, Mr. Philip Brewster from Jardin Botanico Francisco Xavier Clavijero (J.B.C.), Xalapa, visited the R.B.G. Kew and gave an enthusiastic lecture on the diverse habitats and plants of Mexico. This lead me to pursue Mexico as an area of study. As a keen plantsman it was to be a good choice, as Mexico is a country of major bio-diversity and is home to between 10% and 12% of all living organisms on the planet (cf. Gomez-Pompa, et al 1994). Some authors (e.g. Mittermeier 1988) rank Mexico third in biological richness, after Brazil and Columbia.
During September 1998 I spent four weeks travelling the states Veracruz, Oaxaca Puebla and Morelos, along with Luke Hull (L.C.D., Tropical), who had been awarded a staff scholarship to the same destination.
After surviving the smog of Mexico City, we took a five hour coach trip to Xalapa, the state Capitol of Veracruz. Phil Brewster introduced Luke and myself to J.B.C. where he is Head of Garden Maintenance and Design. The garden is approximately 16 acres and is situated within a disturbed cloud forest environment at an altitude of 1,250 metres. Bordering both tropical and temperate climatic zones the garden provides the visitor with some interesting plant associations, e.g. temperate trees such as Platanus and Quercus dripping with tropical epiphytes such as orchids, cacti and bromeliads.
During the first week day trips were taken to various nearby habitats. One of my aims was to study the endemic cycad Dioon and to witness conservation programmes implemented to save these endangered plants. Therefore, our first visit was to a village called Monte Oscuro to see an initiative started in 1988 by Dr. Andrew Vovides (Curator, J.B.C.). After seeing huge quantities of cycad crowns being sold for ornament at local markets, Andrew managed to obtain funding to set up an in situ `cottage industry’, raising hundreds of plants from seed collected from nearby wild populations. Subsequent profits have enabled the expansion of the original nursery and the cultivation of other endemic plants such as Chamaedorea. The day was made complete with a worthwhile climb through jungle vegetation to see ancient, multi-headed specimens of Dioon edule, probably over 2,500 years old.
The second visit of the week was to one of the most beautiful natural features in Mexico — cloud forest. These habitats, which are often shrouded in mist and fog, contain predominately evergreen plants, with 50-metre trees covered in mosses, lichens, bromeliads and brilliantly coloured orchids. Unfortunately a great part of the original cloud forest has disappeared from its original zone of distribution, due to the cultivation of coffee.
After a day of rest, a journey of 250 kilometres took us to Punta Mancha on the east coast of Veracruz. Here we ventured (via boat!) through the stilt roots of the red mangrove, Rhizophora mangle and witnessed pelicans diving for fish in the Gulf of Mexico.
The second and third week encompassed a round trip of approximately 2,000 kilometres, covering the states of Veracruz, Oaxaca, Puebla and Morelos.Within the first couple of days I witnessed the tremendous diversity of a tropical rain forest, saw one of the last remaining sites of the endemic cycad Dioon spinulosum (which produces the largest cone of any gymnosperm), travelled along the precarious hair-pin roads across the Sierra de Juarez mountain range and looked in awe at the giant tree of El Tule, Taxodium mucronatum that, at 2,000 years old, has the largest trunk of any tree on earth, (14.04 metres/47 feet in diameter).
However, the highlight for me was travelling through the arid landscape of the Tehuacan Valley to see my favourite plants — CACTI!!! The Tehuacan Valley stretches between the states of Oaxaca and Puebla and we looked upon some stunning views of the surrounding mountains, which were dotted with columna cacti over 30 feet high. Here we took time to botanise the flora and saw huge specimens, notably Stenocereus webberi, Echinocactus platycanthus (the barrel cacti) and Cephalocereus columnotrahanii.
A trip up an active volcano (Popocatepetl, 5,465 metres) and visits to botanic gardens in Oaxaca, Puebla and Cuernavaca finished off a study tour that I shall never forget.