EPOW - Ecology Picture of the Week

Explanation:  Found at high elevations of the Andes of southern Chile are these amazing relicts of ancient times: Monkey Puzzle Trees.  You may have seen these planted widely throughout the world as ornamentals, but here they are native, occurring as tall emergents over "lenga" southern beech trees (Nothofagus pumilio).  

Monkey Puzzle Trees are the most primitive living conifer.  It is the nearest living relative to species that existed in the Carboniferous period 300 million years ago that have long transformed to coal.   

The seeds are dispersed by many animals including Astral Parakeets (Enicognathus ferrugineus), Slender-billed Parakeets (E. leptorhynchus), a rodent called Darwin's Pericote (Phyllotis darwinii), and even livestock.  The seeds are gathered for food by the indigenous Pehuenche people. 

Monkey Puzzle Trees are fire-adapted and the seeds may need low-intensity fire to germinate.  Thus, the native range of the species, at least in the Andes, is in areas with periodic volcanic eruption and lightening.  However, massive fires in southern Chile in 2000-2001 destroyed 30,000 hectares (74,000 acres) of this species, including 71 percent of the araucaria forest in Malleco National Reserve in Chile.  Some of the trees lost were 2,000 years old.  

The overlapping leaves on the branches, 
and the round female cones that bear seeds.

In 1990, Ministerio de Agricultura in Chile declared this species a national monument and place it on the CITES (Convention on International Trade in Endangered Species) Appendix I list, which means that all trade of wild specimens is banned.  In May 2000, wild Monkey Puzzle Trees in Argentina were added to this list.  

In the Chilean Andes, a local plant guide notes that Monkey Puzzle Trees occur above 1000 m (3300 ft) elevation.  However, during a transect over the Andes that I conducted with the Canadian botanist Andy MacKinnnon, using a digital altimeter I recorded that Monkey Puzzle Trees occur on the wetter, west or Chilean side of the Andes down to 1050 m (3400 ft) elevation, and on the drier (rainshadow), east or Argentine side down to 860 m (2820 ft) in steppe forest edge, with straggler trees occurring down to 815 m (2670) elevation.  

Besides the populations in the Andes, there are two other populations of this tree found in the Pacific coastal mountain range of Chile called the Cordillera de Nahuelbuta.  These coastal populations are considered genetically distinct from the Andean form.  But the Andean forms themselves are diverse and seem to result from postglacial migration routes (Bekessy et al. 2002).

The related species called Bunya-bunya (Araucaria bidwillii) is found in coastal rainforests of southeast Queensland, Australia.  Occurrence of this genus in South America and Australia suggests a common, very ancient ancestor when both continents were joined as Gondwana.  This is one old family tree!

And the name "Monkey Puzzle" comes from the fact that branches are covered by stiff imbricate (overlapping) leaves that  would prevent a monkey from climbing the tree.  This is a double puzzle, as no monkey species occurs within the range of the species in southern South America, so why name the tree for something that doesn't even occur there? 

Information:
     Bekessy, S. A., T. R. Allnutt, A. C. Premoli, A. Lara, R. A. Ennos, M. A. Burgman, M. Cortes, and A. C. Newton.  2002.  Genetic variation in the vulnerable and endemic Monkey Puzzle tree, detected using RAPDs.  Heredity 88:243-249.