Biodiversity manifests in unbelievably varied facetings, and in certain areas we find “biodiversity hotspots” one at each other’s side. The valleys that run from the snowy top of the Andes down to the Pacific Ocean, starting in Columbia and ending in the Land of Fire are one of these half-undiscovered jewels of biodiversity.
“A violet by a mossy stone / Half hidden from the eye! Fair as a star, when only one / is shining in the sky”
After a poetic intro, let’s try to catch the essence of the question in a more down-to-earth way. I guess many of us played Pokémon –either with Gameboy Color or now with Nintendo Switch-. I had the luck to play the latest versions (Sword and Shield). In that period, I had just finished reading the Pulitzer Prize-winning Half-Earth by E.O. Wilson. It is a highly approachable educational essay explaining what biodiversity is, how much it is now endangered, and proposing as a solution to institute around the globe natural reserves corresponding to half of the land surface of the planet to protect it. Well, living my dream as a Pokémon trainer, I was struck by how similar their specific distribution on the map is with the actual distribution of real animals in the various ecosystem; e.g. you may find Rattata (the mouse) almost everywhere, but to catch a more rare type you will have to reach a single grass spot and search for it either during daytime or nighttime and with a certain weather condition. I wanted to use this unorthodox but accessible example to describe how sometimes incredibly rich biodiversity niches composed of exquisitely endemic species do thrive in the most circumscribed areas.
Gocta Cataracts, Peru by Omri D. Cohen on Unsplash
The Andean forest valleys Many small rivers originate in the summits of the Coastal Range and run until the Pacific ocean, forming the Andean forest valleys. In south-central Chile, the Coastal Range records a wet-temperate climate, with strong oceanic influence. Furthermore, due to the westerly winds and the polar front, the coastal environments present heavy precipitations -around 6000 mm per year. We are lucky enough to live in a world packed with wonders. In the span of 100 kilometers, the panorama stretches from the ocean to lowland tropical forests to higher cloud forests to the snow-capped peaks of a geographical and biological ascent. This, and so much more, constitutes the Andean forest valleys on the Pacific side. In this regard, an article by N. Myers in Nature -2000- consecrated the Tropical Andes as one of the 25 biodiversity hotspots on earth, and actually the most remarkable one according to the CEPF (Critical Ecosystem Partnership Fund). This is due to their exceptionally high level of endemism, i.e. the number of species native and circumscribed to the area. As of 2000, research showed how Tropical Andes had about 45,000 plant species – while the next closest hotspots were recorded to have 25,000-, meaning that a sixth of all plant species in the world can thrive in the Tropical Andes. Moreover, out of these 45,000 total plants, 20,000 are endemic - while the next hotspot contains just 15,000 endemic species. As for animals, for the temperate forests of southern South America as a whole, endemism at the species level is 53% for hemiparasites and 45% for vertebrates. It must be said, also, that there still remain areas along the Andean forests where both plants and animals are not properly recorded yet, like beads of biodiversity concealing themselves in untrodden niches.
Alas, the bad news is that these areas have now ended up quite “fractured” because of human activity. I do not want to stress upon the atrocities of deforestation in these pages, but certain macro areas of these Andean forests have been extensively cleared to establish cultures and so on. This means that the corridors that used to connect from north to south the fragments of coastal forest are gradually being either cleared or impoverished. In Chile, the last remains of temperate forests are restricted to the upper elevations in the Andean mountains and to the southern section of the Coastal Range, where there are still, mercifully, some continuous forests.
Yet, here we are, neither in Australia nor in Madagascar: so how come there is such a high level of endemism? The reason is that the biota (animal and plant life) of southern temperate forests evolved in almost total isolation from other forests nearby since at least the early Quaternary (about 2.5 million years ago).
Araucaria trees. Conguillío National Park, Chile by LBM1948
Three major forest varieties
Even though we of weMori currently concentrate our efforts mostly in Borneo and Kenya, I think that for knowledge sake we should have a closer look to the luxuriant variety of these Andean forests, simply because we ought to know as much as possible about what is important and precious to us: “Because how can we understand the deep principles of sustainability of a forest or river if we still do not know even the identity of most of the insects, nematodes, and other small animals that run the finely tuned engines of the energy and material cycles?”.
The numerous Andean forests can be divided into three major types:
1. The deciduous Maulino forest: Characterized by dry summers (January–March), these forests represent the northern limit of the temperate rainforests, with abundant precipitation all year round and contain a particularly high floristic species richness and endemism.
2. The Nahuelbuta forest: This forest is rich in a specific range of endemic species and, most importantly, may represent a centre of paleo-endemism, suggesting that this area was an important glacial refuge for temperate forest species.
3. The Valdivian evergreen forests: Luckily, this forest extends almost uninterrupted along the western slopes of the Coastal Range. Even though human activities impoverished the original green mantle, significant areas of old-growth forests still remain. An example of the richness of the local biodiversity is shown by a survey of terrestrial mollusks in the Valdivian Coastal Range that recorded 14 species of native mollusks.
The most hidden beads We know that there are thousands and thousands of still undiscovered species on earth: animals, plants, fungi, and so on. As the very last example, I would like to leave you today with what I consider a crown jewel for zoology and natural history: the discovery of the olinguito (Bassaricyon neblina) a few years ago.
Olinguito in the wild at Tandayapa Bird Lodge, Ecuador by Mark Gurney
The summits of the Northern areas of the Andes are shrouded by so-called cloud forests: a little explored, dreamlike environment - completely different from lowland forests - that most of the time is soaked with the humidity of the clouds forming from the vapor that rises from lower altitudes. There, in 2013, this small and oh-so-cute carnivore mammal (length: 35cm, weight: 1kg), was discovered – having distinct anatomy from its “cousin” the olingo and officially registered in 2014. The exceptionality of this discovery resides in the fact that so recent years we found a brand new species of carnivore mammal, which is a new “family branch” on its own and consists of four subspecies.
Even though such a glamorous discovery may not happen ever again, it still shows us how much wonder is to be found, if we carefully gaze at this tapestry packed with marvels that is the nature of our planet.
So, we must PROTECT AND RESTORE!
C. Smith-Ramirez, 2004, The Chilean coastal range: a vanishing center of biodiversity and endemism in South American temperate rainforests, Biodiversity and Conservation 13: 373–393, Kluwer Academic Publishers
N. Myers, R. A. Mittermeier, C. G. Mittermeier, G. A. B. da Fonseca & J. Kent, 24 February 2000 Biodiversity hotspots for conservation priorities, Nature
Endemism | Definition of Endemism by Oxford Dictionary, https://www.lexico.com/definition/endemism
Scientists Discover A New Mammal - The Olinguito https://www.youtube.com/watch?v=xZzay8mmkGw
E. O. Wilson, 2016, Half-Earth, p.103, Liverlight Publishing Corporation
J. Stromberg, 14 August 2013, For the First Time in 35 Years, A New Carnivorous Mammal Species is Discovered in the Americas, Smithsonian Magazine, https://www.smithsonianmag.com/science-nature/for-the-first-time-in-35-years-a-new-carnivorous-mammal-species-is-discovered-in-the-americas-48047/
Cover photo by Timur Kozmenko from Pexels