It is 7 pm and I am in my sleeping bag as it is already really cold. Today we walked from our temporary camp where we spent last night up to our main camp in ‘El Valle de Silencio’ at 2,500 m. At this altitude we are in oak forest where the trees are up to 50 m in height, festooned with epiphytes, lichens and mosses and with a groundstory dominated by bamboo.

Oak tree with Tom Simpson of Nature Live for scale

View of oak forest interior

It occurred to me as we were walking through the forest that a surprising number of the trees we were seeing would be familiar in a forest back home: oak (Quercus), alder (Alnus), holly (Ilex), buckthorn (Rhamnus) and Cherry (Prunus), not the same species of course, but the same genera.

Quercus costaricensis

Rhamnus sp.

As I sit huddled in my sleeping bag I realise that there is a certain affinity with the climate back home too and also a physical one as many of these species, or at least their ancestors would have come from North America at a time when there was a land-bridge between our Continent and North America. So presumably these high elevation forests were colonised by trees coming from North America rather than South America, a phenomenon documented already by several authors.