Santa Marta montane forests


The Santa Marta montane forests is an ecoregion in the Sierra Nevada de Santa Marta, a massif on the Caribbean coast of northern Colombia.
The ecoregion covers altitudes from near sea level up to around, where it gives way to Santa Marta páramo.
The isolation of the massif and the range of elevations and climates has resulted in a wide variety of species including many endemics.
The lower levels contained tropical rainforest, which has largely been cleared.
Higher up, this gives way to cloud forest.
Much of this has also been cleared for coffee plantations, pasture for sheep and cattle, and farming.

Geography

Location

The ecoregion covers the slopes of the Sierra Nevada de Santa Marta in the north of Colombia, with an area of.
The range rises to snow-covered peaks only from the Caribbean sea.
The ecoregion is almost entirely surrounded by the Sinú Valley dry forests ecoregion.
To the northeast and northwest it transitions directly into Guajira-Barranquilla xeric scrub.
In the higher elevations of the mountains the ecoregion gives way to Santa Marta páramo.

Terrain

The triangular Sierra Nevada de Santa Marta massif covers and rises to an elevation of, with peaks that are permanently capped in snow.
The northern edge is parallel to the Caribbean coast.
The southwestern edge descends to the dry and warm Magdalena River alluvial plain and the Ciénaga Grande de Santa Marta marshes.
The southeastern edge adjoins the valleys of the Cesar River and Ranchería River.
Volcanic rocks from the Mesozoic and Tertiary eras include batholiths of granite, diorite and quartz monzonite, and there are areas of sedimentary rocks.
The massif was pushed up to its present height in the Miocene and Late Pleistocene.
Glacial lakes at elevations over are the sources of the main rivers that originate in the massif.

Climate

Average air temperatures range from in the plains to or less in the peaks.
Rain is carried by the northeast trade winds, with wet seasons from September to December and from May to July.
The north side receives the most precipitation, up to annually at above sea level, with less rain higher up and to the south of the massif.
At a sample location at the Köppen climate classification is Cwb: warm temperate, winter dry, warm summer.
Mean temperatures range from in January to in June.
Total annual precipitation is about.
Monthly precipitation at the sample location ranges from in February to in October.

Ecology

The ecoregion is in the neotropical realm, in the tropical and subtropical moist broadleaf forests biome.
The isolated location surrounded by dry forests has allowed many endemic species of flora and fauna to develop.
It is seen as a biological and geographic island, distinct from the Andes.
However, there are similarities to the Serranía del Perijá, to the east, which is normally included in the Cordillera Oriental montane forests.
76% of bird species in Perijá are shared with the Sierra Nevada de Santa Marta. 80% of Perijá's butterflies in the Ithomiinae and Heliconiinae families is shared with the Sierra Nevada, but only 40% with the eastern slope of the Cordillera Oriental further to the south.
The ecoregion is part of the Northern Andean Montane Forests global ecoregion, which includes the Magdalena Valley montane forests, Venezuelan Andes montane forests, Northwestern Andean montane forests, Cauca Valley montane forests, Cordillera Oriental montane forests, Santa Marta montane forests and Eastern Cordillera Real montane forests terrestrial ecoregions.

Flora

There are warm, wet forests on the north of the massif and part of the west, isolated from similar forests elsewhere.
These tropical rain forests at altitudes up to have trees that may reach in height depending on rainfall.
The understory contains tree ferns and grasses with large leaves.
There are some endemic species, but relatively low diversity compared to other neotropical ecoregions.
These forests are considered to be a Pleistocene refuge.
There are few species in common with the cloud forests higher up, but there are similarities to wet forests elsewhere in Colombia, in Panama and Venezuela, and at a family level to forests in the Amazon.

On the drier western side forests at elevations from above sea level have large trees including Poulsenia armata, red ucuuba, Pterygota colombiana, muskwood, Panama rubber tree, Ficus macrosyce, avocado and Andean royal palm.
Above the trees and palms are smaller, and include Zygia longifolia, forest acai, Súrtuba and spiny treefern.
The forests include vascular epiphytes such as Vriesea elata and droophead tufted airplant, understory plants with large leaves such as Rattlesnake Plant and dumb cane, and mosses and liverworts such as Octoblepharum albidum and Leucomium strumosum.
There are cloud forests above, with vegetation related to the forests of the tropical Andes and the higher elevations in the Caribbean, which contain many endemic species.
In some areas the cloud forest dips down to lower levels.
The trees at elevations up to of altitude form a canopy of in height.
The flowering plant families with the largest numbers of genera are Asteraceae, Orchidaceae, Fabaceae and Rubiaceae.
The genera Monochaetum and Tillandsia each have five endemic species.
The family Melastomataceae has 13 endemic species.
Andean royal palms emerge from the cloud forest canopy, and dominate wet and sloping areas.
They are common from, and the wax palm is common from.
Other cloud forest tree species include palo azul, Cavendishia callista, Graffenrieda santamartensis, Gustavia speciosa and Tovomita weddelliana.
The understory includes tree ferns, palms, prop-root plants, vascular epiphytes and woody lianas.
There are many Bryophytes such as the thallose liverwort Dumortiera hirsuta and the moss Phyllogonium fulgens.
Cloud forests from high are found in areas with heavy fog and mist between elevations of, although there is less rainfall than on the lower slopes.
Typical tree species are wax palm, Chaetolepis santamartensis, Chusquea tuberculosa, Hesperomeles ferruginea, Monochaetum uberrimum, Myrcianthes myrsinoides, Myrsine coriacea, Paragynoxys undatifolia, Pino de Pasto and Weinmannia pinnata.
Bryophytes and lichens include Anastrophyllum auritum, Musgo, bonfire moss and Hypotrachyna gigas''.

Fauna

Mammal species include the Central American agouti, jaguar, lowland paca. neotropical otter, ocelot, South American tapir, Venezuelan red howler and white-lipped peccary.
Endemic mammals include the red-tailed squirrel, Tomes's rice rat and unicolored Oldfield mouse.
Endangered mammals include the red-crested tree-rat.
Bird species include bay-headed tanager, black-chested jay, blue-billed curassow, coppery emerald, crested guan, keel-billed toucan, Santa Marta blossomcrown, scarlet-fronted parakeet and white-tipped quetzal.
Birds with restricted ranges include black-backed thornbill, green-bearded helmetcrest, montane woodcreeper, mountain velvetbreast, Santa Marta parakeet, strong-billed woodcreeper, white-tipped quetzal and yellow-crowned whitestart.
Endemic birds include the Santa Marta parakeet and white-tailed starfrontlet.
Endangered birds include the black-and-chestnut eagle, black-backed thornbill, blue-billed curassow, Santa Marta bush tyrant, Santa Marta parakeet, Santa Marta sabrewing and Santa Marta wren.
There are many species of reptiles and amphibians.
Endemic sauria include the Colombian Clawed Gecko, Ptychoglossus romaleos, Proctoporus specularis and Santa Marta Anole,
Amphibians include several Pristimantis species, mostly at the higher elevations, including Cebolleta Robber Frog, Cristina's Robber Frog, Ruthven's Robber Frog and Santa Marta robber frog.
The only endemic amphibian genus of the Sierra Nevada includes Walker's Sierra frog.
Endangered amphibians include Atelopus arsyecue, Guajira stubfoot toad, Harlequin frog, Nahumae stubfoot toad, Walker's stubfoot toad, Santa Marta poison arrow frog, Boulenger's backpack frog, Walker's sierra frog, Ground robber frog and Ruthven's robber frog.

Status

The World Wide Fund for Nature gives the region the status of "Vulnerable".
The massif was settled in the Pre-Columbian era, and traces of these communities remain.
Areas of the ecoregion have been sporadically occupied since the end of the 19th century.
From 70% to 80% of the original forest has been cleared in the last 50 years.
The wet forest of the lower levels has been reduced to thinned-out fragments by settlements, marijuana and coca cultivation, logging, extraction of firewood and conversion to pasture.
Deforestation causes erosion, mud slides in the rainy seasons and silting of the rivers.
In the late 19th century large belts of forest at the middle levels were converted to coffee cultivation.
Large areas of forest have also been cleared to create pasture, kept clear by annual burns.
Higher up, the Ancho and Frío river basins and other parts of the cloud forest have been modified to make space for sheep and cattle rearing, farming of potatoes and fruit, and extraction of wood.
Forests clearance has threatened the populations of large animals, which are also hunted for food, for their skins, or as perceived threats to cattle.
Roads opened to the higher areas have led to looting of pre-Columbian sites, hunting and extraction of firewood.
A 2006 book reported that of the Santa Marta montane forests 33.4% had been transformed by human activity.
Parts of the ecoregion are theoretically protected by the Sierra Nevada de Santa Marta National Park, Tayrona National Natural Park and Sierra Nevada de Santa Marta Biosphere Reserve, but these areas were still being cleared in 1998.
The indigenous reserves of the Cogui, Arsario and Arhuaco people overlap the Sierra Nevada de Santa Marta National Park.