Sunday, March 13, 2016

Cuerici - a hidden jewel in the clouds

Cuerici is a private reserve that includes fragile high-elevation habitats including primary oak forest, a canyon that shelters an endangered species of palm, and some areas of secondary growth forest as well.  It is tucked in a valley on the Pacific slopes of the Talamanca mountain range in Costa Rica.  The reserve is owned by a small association on conservation-minded individuals, one of whom is named Don Carlos.  The association purchased the land from his grandfather, some of which used to be cattle pasture but most of that land was primary oak forest.  Now Don Carlos looks after and maintains the forest and small biological station, as well as his own trout farm on the side of the mountain.  The water for the trout farm runs down the mountain, flows through the trout ponds, and then is collected into a filtering basin where the waste sediments from the fish are allowed to deposit and decompose into a rich fertilizer for the garden and making sure that the water that flows out of the farm is not heavily contaminated.
We only stayed at this station for five days, but there was a lot packed into that short time.  Don Carlos led us on a walk through the different parts of the forest.  The first part went through fast-growing alder trees, which have moved into various patches of abandoned cow pasture during the last 20-60 years.  However, we soon entered an area of primary growth, meaning forest that has never been clear cut or heavily harvested, in a narrow canyon.  The canyon is sheltered from the stronger wind experienced by the surrounding oak forest, making it a distinct microhabitat, full of lush green ferns and tree ferns, and a few small palms, which look mildly out-of-place high in these chilly mountains.  Actually, there used to be a lot more palms in this forest, but many were cut to harvest heart-of-palm, a tasty and popular food in Costa Rica.  Don Carlos found just one remaining palm in the reserve, but he has been working on a replanting project, using seeds from other sources to start saplings back on his farm and then transplanting them into the canyon so that they have a head start and are less likely to be choked out by other plants.
Once we climbed up out of the canyon, we entered yet another type of vegetation.  Large oak trees dominated this area of forest above 2,500 meters, with moss dangling from their branches and bryophytes clinging to their trunks.  Orchid flowers bloomed high up in the canopy or on rotting logs.  The understory was relatively open compared to in the canyon, but with dense patches of bamboo.  The wind roared in the canopies of the oaks constantly.
Don Carlos explained various aspects of the forests biology and conservation as we walked, and I was amazed at the complexity of all the dynamics that affect the forests health and composition.  For instance, wind has a huge effect on all the plants in the forest, increasing evapotranspiration and thus causing plants to dry out, or even knocking over trees and other plants if it is strong enough.  Don Carlos emphasized the importance of the oak trees, which block most of the wind from entering the interior of the forest, and the danger of removing even a few of the trees.  Once there is a gap in the canopy, the wind is free to enter and can widen the gap by knocking over trees around it.  This effect is worsened by the fact that the oak roots interlace with their neighbors, and when one is removed and the roots die this extra support is lost.  In addition, the moss hanging from their branches collects moisture from the fog and clouds, which then drips down onto the base of the oak trees, and when the wind is too strong it blows the moss off the trees and farther down the slope. 
Another interesting dynamic has to do with the bamboo, which is unusual in its flowering habits.  Each individual bamboo only flowers once and then dies, and the bamboo in a particular forest time their flowering to occur together.  It varies from place to place, but bamboo can go 10, 20, or even more years between flowerings.  However, when it does, it is an event that totally alters the forest ecosystem; migratory birds come in great numbers to feed on the seeds, and when the bamboo dies it makes new space for other plants like the oak seedlings to get a foothold.  Oak trees grow very slowly, and this dying off of the bamboo might be the only opportunity for new seedlings to germinate and survive, meaning that when oak trees are cut, it might take hundreds of years for the oak forest to recover, if it ever does at all. 
It was inspiring to see the dedication with which Don Carlos has tried to integrate small-scale sustainable farming with preservation of a fragile ecosystem.  It was also interesting to see a private effort at conservation, which appears to have been very successful at preserving the area but has also struggled with some financial difficulties.  I am excited to see how this method of conservation compares with that used at Palo Verde National Park, the next site we visit and the first one that is publicly owned.
Sequoia Grettenberg

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