Oaks in Chiapas, Mexico

Driving up and up, Leaving the tropical forest of the lowlands, tufted Pines start to appear alongside the road, as well as fog. I was never meant to be here, but oh-so excited to see such a forest so close to the equator. I am in the Pine/ Oak cloud forest of Chiapas state, Mexico. A stronghold of otherwise temperate climate tree species that keep a foothold high up in the mountains. The pines are largely void of perching plants (epiphytes), but as soon as broad leaved trees start to appear with big lower branches things are getting interesting; these trees are absolutely covered in epiphytes. However, I have to focus on the road. Not only do I have to overtake ageing Volkswagen beetles, but also keep a keen eye out for overloaded trucks, that have no issue with overtaking each other on blind corners. The next time I encounter the oaks (Quercus spp.) is in a more tranquil setting; we are parked near a cemetery, situated under the crowns of gnarly large leaved oaks. The graves are colourfully painted, and with Día de los Muertos (day of the dead) approaching, a family has gathered to tidy up some graves, give them a fresh lick of paint, sing and drink and celebrate their loved ones. It’s overcast and foggy, quite a serene setting.

A cemetery under a canopy of Oaks, Mexico

The oak’s lower branches are covered in an array of ferns, mosses, orchids, succulents and bromeliads. It is a stand with other familiar northern hemisphere trees such as Cupressus, Arbutus, Magnolia, Prunus, Cornus, Juniperus and of course Pinus.

I live in Gisborne, and as a tree guy I am truly blessed having two world class tree collections on my doorstep. They are Eastwoodhill and Hackfalls arboretum. During my stay in Mexico I especially felt connected with Hackfalls as this is home to the largest collection of oaks in the southern hemisphere. The arboretum was founded by Bob Berry and he was an avid tree collector. During the 80’s he made several seed collecting trips to Mexico. Hence the collection of Mexican oaks at Hackfalls is very extensive. A search of the Hackfalls catalogue reveals that he also visited Chiapas state, the area I had the privilege of visiting. I have found three entries:

Quercus crassifolia Humb. & Bonpl. Grid location. I6-74/87. Wild seed from Campo Santiago, Chiapas, Mexico. This large-leaved, shorter leaf stalked southern form was originally named Q. brachystachys?,  perhaps it should still be regarded as a separate species, or at least a variety. [Bob originally listed this as Quercus crassifolia (Q. brachystachys)

Quercus crispipilis Trel. Central America. Grid location: H5-25/93. Wild seed from North of Comitan, Chiapas, Mexico.

Quercus crispipilis Trel. [Originally recirded by Bob as "Quercus crispipilis var. pannosifolia? C.H. Mull. (Q. skutchii?)", both names are now synonyms of Q. crispipilis]. Grid location: H6-71/25. Wild seed from San Cristobal de Las Casas Botanical Gardens, Chiapas, Mexico from a heap of seed on  the ground (collected elsewhere?). Thierry Lamant correction from material that I sent to him.

Globally, there are about 600 different oak species known. Mexico is home to the greatest number of different species of oak in the world. With about 160 species present and 109 species endemic to Mexico (Wikipedia) the remainder ranging into central America and Southern United States. However, according to the International oak Society’s website oaknames.org there are 204 different oak species and taxa present in Mexico. I am in Chiapas state in the very south of Mexico, not far from the border with Guatemala. According to my local tree guide (Árboles y arbustos de los bosques de montaña en Chiapas, 2010), there are 13 species of oak present in Chiapas state. Even with the species down to 13 I’m having a hard time identifying them as the guide is in Spanish and I’m very poor at that. My wife speaks it fluently, but the jargon used in the tree guide, she finds very confusing. Which is fair enough, ask any highly educated friend that is not a plants person about what glabrous means (without hair).  To confuse things even more is that oaknames.org has 38 accepted different species listed for Chiapas! What further complicates identification is how oaks readily hybridize. In such cases the hybridized tree shares the characters of two species, complicating identification significantly. Furthermore, the hybrid offspring is fertile, and so the succession of casual plant sex continues, creating whole hybridized populations. Mexico is one of those hotspots where this freely occurs, with such high diversity within the species. A quick search for oaks on theplantlist.org reveals numerous species classified as “illigimate, invalid or unplaced”. Suggesting that botanists still have lots to classify.

We go to Huitepec, a reserve not far from San Cristóbal de las Casas. It follows a slope to almost to the top of an extinct volcano with the same name. It has a 2-kilometre track through it, with fading information panels and dilapidated shelters.

 Sign at Huitepec reserve, note the local Mayan name below Latin name.

At the lower reaches of this cloud forest remnant nearly all the oaks are coppiced at about 3 to 4 metres above ground level. Old pockets of decay at the lower part of these trees make it evident that these trees have long been the subject of this practice. When the branches are routinely cut to just above the old wounds, the tree reacts by sending multiple straight branches upwards; ideal as building material and fence posts, etc. The lower, old parts of these trees are covered in a plethora of epiphytes.

A Coppiced Oaks covered in epiphytes, Huitepec reserve.

An Oak with its crown full of epiphytes

Bob Berry’s catalogue reveals that he actually collected acorns in San Cristóbal de las Casas at a Botanical garden. Since there are no Botanical gardens advertised on the internet, a more in-depth research revealed that there is one at a local University (Ecosur, which published the above tree guide). After parking the rental car, I explain my reason for being there to the guards. My communication in broken Spanish pays dividends; one of the friendly guards escorted me to a greenhouse. Inside I meet José; he sits behind an old desk and is surrounded by trays of acorns, each with a handwritten note of what species they are. I explain him why I’m there: to learn more about the oaks of Chiapas state. Before long, it becomes clear that we are both passionate plantsmen with a common language: Latin. The garden is not a botanical garden as we know, rather a collection of trees planted wherever the space allows, actually quite unlikely that Bob was here as the trees are way too young. He shows me around going from oak to oak. Also a few of the other trees, Magnolia, Taxodium, Platanus etc. Ten different oaks are present at the University, some of them look quite similar (see pictures below). My head is spinning with the information overload. The thing is that the difference between the leaves are minute, look at the two leaves in the picture at bottom left. To me they look distinctly different, number nine being oblong (rounded leaf base and leaf tip) whereas number ten is lanceolate (pointed leaf base and leaf tip). However, José is adamant that they are both Q. disophylla. Oh, and number seven might be Q. acutifolia instead of Q. ocotefolia. Hey, who am I to dispute local knowledge!

Samples collected at Ecosur university, numbered from top left

Hugging the Guatemalan border, National park Lagunas de Montebello is a collection of lakes surrounded by Pine / Oak forest. It is quite touristy but I enjoy the short walks to viewpoints to several of the lakes. Here pines tower over a sub canopy of deciduous trees. The canopies of the Oaks also contain an abundance of epiphytes. There are even bromeliads growing on powerlines, how they get a foothold here is anyone’s guess. Here I say goodbye to the cool climate, and head downhill to the humid and hot lowlands.

Quercus polymorpha

So, what was it like for Bob, 40-50 years ago? Today the main roads are relatively well kept. Once we had to bribe our way through what was once a military checkpoint, highjacked by locals. Chiapas state has the highest density of indigenous people (Mayan) in Mexico. In remote rural areas the hierarchy of pre-Spanish times are still largely intact. Chiapas is the stronghold for the Zapatista movement. It came to existence roundabout the time of Bob’s visits, and it pursuits autonomy in the region. It does not recognise federal government and it even came to an armed uprising in 1994. Whole villages and regions exist with their own economic, medical and schooling system. There have been no clashes in recent years. San Cristóbal de las Casas is a tourist town these days and with that comes relative safety. But I’m sure that Bob had a rocky ride getting there as roads would have been very poor. It must have been quite the adventure getting there.