A month ago, as I was on the road heading southward through the heart of northwestern Argentina, I crossed through a very specific and fascinating sliver of jungle which runs along the slopes of the mountains of the geologic transition zone east of the Andes (see my entry of March 1: "ROLLING ACROSS NORTH CENTRAL ARGENTINA"). I knew it was a unique biogeographic region, but at the time I didn't know that this thin strip of terrain is actually considered to be an austral expression of the greater Amazon jungle region, which cuts southward through Bolivia, extending down into this part of Argentina.
The map to the right illustrates the two strips of this narrow biogeographic province, which cut down through the northwestern Argentine provinces of Jujuy and Salta, and then across Tucumán and into Catamarca provinces. The image came from the Argentine www.surdesur.com website.
On my drive south from Cafayate, in Salta Province, I cut through the southern end of the Valle Calchaquíes and over the top of the pass known as Abra del Infiernillo, on Ruta Provincial 307 to the picturesque town of Tafi del Valle, which lies in the valley of the same name. There is a reservoir below this town, and beyond the dam, one passes through the narrow defile known as La Angostura, which represents also the entrance into the Selva Las Yungas, which is our narrow strip of Argentine jungle. The road here narrows and winds as it conforms to the contours of the mountain canyon of the Río Los Sosa, and many of the sharp curves ahead are blind.
That's a glimpse of La Angostura to the left. Below that point Ruta Provincial 307 enters the compact and sinewy Reserva Natural Los Sosa, a stretch of some 18 km in length which parallels the road with an average width of 1 km with the idea to preserve and protect the diverse biosphere of this narrow stretch of territory that lies between the high plateaus to the north and the plains of Tucumán and the extension of the Chaco to the south and east. It was established in 1941.
The microclimate of this narrow band of jungle is wet and frequently clouded, but unlike its more tropical realms to the north in Brasil, there can be snow here in the winter. Since the zone occurs on the slopes of the mountains, the vegetation types change with the relative elevation. The most prominent of the many trees in the zone is the laurel, which is most common on the slopes between 500 and 1200 meters elevation, but also accompanied by a host of other species such as the horco molle, a diverse collection of cedros, plus nogal, mato and horco-mato. Three types of forests predominate at the upper elevations (pino del cerro, bosque de aliso and bosque de queñoa) and the lower realms are thick with a profound variety of trees, including palo blanco, palo amarillo, and especially tipa blanca, pacará and cebil colorado.
As for the fauna, the jungle is home to dozens of mammal species and at least 50 different types of birds.
This photo here shows a pair of memorial shrines, or "animitas" which are alongside Ruta 307 at an extermely sharp curve known as Fin del Mundo, which is about mid-way through the territory of the reserve. Currently, Tucumán Province has been studying a plan to improve the roadway here in this most treacherous stretch, where the via twists and turns around the countless bends in the mountain, often through thick fog and rain. There are parts here where the canyon walls are so steep and the jungle so thick that they say the sun never shines, but regardless of that, it is something special to experience. But there are obvious environmental issues concerning this narrow zone of jungle, and that is why these 18 kilometers were designated as a natural reserve many years ago. The government of Tucumán has published an extensive environmental impact statement which asserts that their highway improvement project will not impact adversly this relatively small and fragile biogeographic strip, but the truth has always been that Las Yungas has suffered through the years from human impact. Nonetheless, some improvement here is necessary, since this is the only route from Cafayate and Tafi del Valle connecting those communities with the main route to the cities of Tucumán and Catamarca. I do hope that the Argentines proceed with care in this endeavor.
When I drove through the Reserva Nacional Los Sosa, back on the last day of February the weather alternated between thick mist and true rain. I suppose I could have been disappointed that I could not see the canyon of the Río Los Sosa better, but actually, I think that the moist conditions are normal, along with the accompanying heat and humidity. Actually, once I had passed out of the mouth of the canyon and effected my linkup with the busy Ruta Nacional 38 running southward from Tucumán to Catamarca, the rains turned torrential, and remained so until just before I reached the latter city, where I managed to find a decent hotel to put up for the night.
In the coming weeks, when the spirit moves me, I hope to post more from my travels - details that just could not be covered adequately while on the road. So please do check back from time to time.
