Laurel Forests of Southern Chile
As many folks have noticed by now, we’re passionate about growing temperate Chilean native plants. But why Chile, specifically? Besides reliving the fond memories of our travels in this coastal South American nation, we’re enamored by the biogeography of the region, which boasts a high rate of endemism and alludes to a long history of isolation. Similar to our home in the Pacific Northwest, the foothills of the southern Andes Mountains are dominated by temperate rainforests. These biomes experience high rainfall and mild temperatures and comprise of closed canopies with vibrant understories of shrubs, vines, ferns, and mosses. Temperate rainforests are relatively rare on our planet and today we’d like to shine a spotlight on the unique flora of the Valdivian Laurel Forests of southern Chile.
Where the Mountains Meet the Sea
Chile is renowned for its dramatic landscapes including rugged coastlines, impressive mountain ranges, harsh deserts, expansive matorral, endless forests, and an intricate network of lakes, rivers, and fjords. Chile has a rich mosaic of ecosystems due to its extreme topography and the sheer length of the country. In fact, Chile can be considered the world’s narrowest and longest country with an average width (west to east) of 110 miles and an average length (north to south) of 2,670 miles. The western length of Chile borders the Pacific Ocean and is low in elevation, whereas the eastern border follows the crest of the Andes, with an ultimate altitude of 22,615 feet above sea level. This extreme set of gradients results in a wide array of climatic conditions. An easy way to think about the latitudes of Chile is to compare it to the west coast of North America, wherein southernmost Chile would be comparable to Alaska, while northernmost Chile would be comparable to Baja California.
Exploring the Valdivian Laurel Forests
Laurel Forests, also known as laurisilva or laurophyll forests, are are an interesting form of vestigial forest comprising of broadleaf evergreen plants that share unique, convergent adaptations for rainforest conditions. The monikers for this ecosystem refer to the foliage characteristics of the Mediterranean Laurel, Laurus nobilis, whether or not plants described by such a forest are within Lauraceae. Laurophyll plants share analogous adaptations, which include glossy leaves that have a narrow and pointed oval shape with an apical mucro (a short, hard, pointed leaf tip) all which allow the leaves to shed water in a climate that is high in humidity and rainfall, allowing leaves to respirate.
Great plants think alike
Compare Chilean Laurel, Laureliopsis philippiana (top & right), and Wineberry, Aristotelia chilensis (bottom left). They’re not even remotely related!
So what? What’s so interesting about Laurel Forests? It just so happens that these forests tell a story that spans many millions of years, reminiscing of a time when our continents looked wildly different. The Valdivian Laurel Forest is a relict of the ancient supercontinent Gondwana, which comprised of what is now New Zealand, Australia, South America, Africa, Antarctica, and India. This ecosystem was once much more widespread but was incrementally displaced by the forces of plate tectonics that led to continental drift, mountain uplift, and ultimately desertification to the north and glacial advance to the south. Today, up to half of the plant species found in the Valdivian Laurel Forest are endemic and can be found nowhere else in the world and many of them are monotypic genera or even monotypic families with no close living relatives at all. These so-called “relict” species are like castaways, stranded in a small island of stability that prevented their extinction. We call such a safe-haven a “refugium”, and there are many examples of this phenomenon at middle-latitudes in both the northern and southern hemisphere.
Olivillo (Aextoxicon punctatum) is the only living member of the family Aextoxicaceae and is endemic to Southern Chile.
Keule (Gomortega keule) is the only living member of the family Gomortegaceae and is endemic to Southern Chile.
What fascinates us most about the Valdivian Laurel Forests is that for many of the native evergreen flowering plants, their closest relatives can be found on the other side of the world, almost as far away as possible. One example of these distant cousins is the genus Eucryphia, or the Leatherwoods as they are known in Tasmania. Eucryphia has just seven known species; two species are found in Southern Chile and five are found in Eastern Australia. Other notable examples include the families Winteraceae (including Winter’s Bark), Araucariaceae (represented in Chile by the Monkey Puzzle), Podocarpaceae, Atherospermataceae (the so-called southern sassafrases), Nothofagaceae (the southern beeches), Cunoniaceae (which may or may not include Eucryphia), and Lardizabalaceae (such as the Chilean Zabala).
A Living Fossil
The Monkey Puzzle Tree, Araucaria araucana, is one of the few living members of the Araucaraceae. These primitive conifers have broad, scaly leaves.
Monkey Puzzle Trees prefer the mountains where winter snowfall is common
Monkey Puzzle cones grow to 8 inches in diameter and individual seeds act like lawn darts
Life Below the Canopy
In addition to the unique diversity of evergreen angiosperms, the Valdivian Laurel Forests are home to a rich and complex understory of shrubs, vines, ferns, and mosses. Many of these can be found elsewhere in Southern Chile, such as in the drier Maulino Forests to the north and the colder Magellanic Subpolar Forests to the south. It may come as a surprise to some that Southern Chile is home to range of a bamboo species; with 10 or so species of Chusquea that vary from scandent shrubs to climbing lianas and towering canes. Fun fact: unlike Asiatic bamboos, Chusquea have canes that are solid all the way through.
When discussing the forest understory, we would be remiss if we didn’t talk about hummingbirds. With nine species of hummingbird present in Chile, these incredible birds are important pollinators that evolved alongside many Chilean native plants. For this reason alone Chile is home to an astounding number of plants with showy, tubular flowers that depend on these creatures for their reproduction. Just a few examples include species of Fuchsia, Lapageria & Philesia, Embothrium, Asteranthera, and many species in the family Gesneriaceae.
Lastly, we’d like to quickly mention some of our favorite quirky plants from the Valdivian Laurel Forest understory. These forests are home to the most southernly species of bromeliads in the world including Fascicularia, Ochagavia, and Greigia. While Greigia is a terrestrial plant, Fascicularia and Ochagavia are often epiphytic or lithophytic, gathering most of their nutrition and water through their leaves and growing roots primarily for anchoring their position. Sharing this niche are a number of ferns, which can be found both on the forest floor and within the canopy. One such interesting fern is the diminutive Austroblechnum penna-marina, which is a species that can be found in Chile, New Zealand, and Australia. In a future blog post we’d like to explore one of the most diverse plant families in Chile, the Myrtaceae (the myrtles).
