Por: Álvaro Cogollo – Director Herbario Jardín Botánico Medellín
Biological Refuge theories suggest that significant alterations in forest coverage and species distribution occurred during the Pleistocene Period.
These transformations were due to severe climate changes that took place during pleni and interglacial periods, changes that can be traced back to
the Miocene period, and which had a profound effect on the speciation and diversification of the planet’
s life forms. Areas associated with specific
biomes contracted significantly and alternately, according to prevailing climatic conditions (dry or humid).
According to Hernández et Al. (1992) pleistocene refuge theory and evolutionary histories reflected in discrete biogeographic units have been key
criteria in the delimitation of endemic hotspots throughout Colombia. These
“hotspots
”
or endemic centers are the result of fragmentation
processes that have periodically separated species contained in these regions, creating isolated “
pockets
”
of biodiversity. Along the entire country,
over 58 of these endemic
“
pockets
” have been identified. These sites are immensely valuable in terms of biodiversity conservation.
Rio Claro
’
s watershed forms part of one of these centers, named after its principal rivers: the Nechi-Nare Region. According to scientific studies
developed during the last three decades, this zone is of special importance due to its unique geological, biological, and biogeographical conditions.
The region presents rare geological and geomorphological qualities -such as its karstic limestone formations-
, the result of hundreds of millions of
years of geological processes, including six million years of erosion as part of the central andean cordillera. Such special geological characteristics
have led to the existence and development of similarly unique biological habitats. Many species of plants discovered over the last decades present
an elevated degree of endemism, directly related to the remarkable soil characteristics.
The Nechí-Nare is a region of great biogeographic importance as it is historically considered a biotic interchange zone in which species from
different geographic origins came into contact with each other. This is how we come to find floristic elements from Chocó, Guyana, the Amazon
Forest, Central and North America. In addition to this remarkable phenomenon, we can find many intercontinental disjunctions, as is the case with
the genus Caryodaphnopsis from the Lauraceae family, of which Río Claro holds two endemic species (Cogollo, 2013).
The Rio Claro Nature Reserve is one of the principal refuges and repositories of endemic species in the region. It has also become an international
example of in-situ ecosystem conservation. Current deforestation practices throughout the entire region have eradicated over 95% of forest
coverage, which leaves Rio Claro as one of the last remaining germoplasma reserves from which to repopulate the entire region.
The following is a list of new species described in the Río Claro Region:
Adelobotrys antioquensis
Adelobotrys hoyosii
Aiphanes parvifolia
Allomaietta pancurana
Aphelandra tetroicia
Astrocaryum triandrum
Caryodaphnopsis cogolloi
Caryodaphnopsis sp. nov. 2
Chamaedorea ricardoi
Compsoneura claroensis
Cuphea fluviatilis
Cybianthus cogolloi
Dieffenbachia cardenasii
Dieffenbachia magdalensis
Duguetia colombiana
Epidendrum mutisii
Geonoma chlamydostachys
Heliconia santae-theresae
Magnolia silvioi
Matisia serpicostata
Melicoccus antioquensis
Mouriri colombiana
Pitcairnia fluvialis
Pseudolmalmea boyacana
Pseudoxandra sclerocarpa
Pterandra colombiana
Rhodostemonodaphne antioquensis
Simira hirsuta
Unonopsis sessilicarpa
Zanthoxylum lenticulare