Poas Volcano National Park

This National Park was founded in January 25, 1971, and expanded to its present size of 6,506 Ha. in 1993. Poas Volcano receives the largest number of visitors to any park in the country. The spectacle of the main crater, Botos Lake, developed natural trails, and a great natural diversity make this park unique. Forests with a great quantity of epiphytes and tree ferns cover it, along with the poor man’s umbrella. The park is also an important energy source of hydroelectric and geothermal generation.


Hystorical Background
The Poas Volcano’s eruptions are known to have occurred as early as of 1747 when the Spanish governor Juan Gemir wrote about its activity. Other activity dates include 1834 when Andrés Oersted recorded underground explosions, and ash thrown from the volcano spread for up to 30 miles. One in 1910 is considered to be the largest eruption of mud, gases, pumice, and ash to be documented. From 1952/54, the last major period of activity with large clouds of ash and glowing rock accompanied by underground rumbling, formed the volcano’s present structure. In 1994 there was a smaller eruption that added some rocks to the 'beach' around the crater and significantly increased the production of sulphurous gas.

Flora and fauna
The Life Zones represented in the park are the Mountain Rain Forest and Very Humid Low Mountain Forest. There are four principal habitats. The Cloud Forest surrounds Botos Lake and the back part of the Potrero Grander; here the predominant species are wild papaya, pitch apple, oak, and two species of ttsta. Along the edges of the Caribbean side, the forest is taller and very wet, with numerous palms, tree ferns, and epiphytes. Elfin Forest is found along the Main Crater-Botos Lake trail; the main species are pitch apple, ardisia compressa, and Alzatea verticillata. The arrayanes are predominant near the point overlooking the crater and on the first stretch of the natural Botos Lake trail; in a few areas near the crater there is little vegetation except for a few tolerant colonists like bracken ferns. Although larger animals are scarce, the avifauna is diverse and abundant. A total of 79 species of birds have been identified, including various hummingbirds, Black Guan, Resplendent Quetzal, Rufous-collared Sparrow, Sooty Thrush, Emerald Toucanet, Large-footed Finch, and Yellow-thighed Finch. Few mammals are likely to be seen, though weasels, rabbits, squirrels, and coyotes are present, along with frogs, toads, salamanders, snakes, and insects.

Geology and climate
Poás is a volcano with a semiconical shape, with multiple calderas at its summit. At the bottom of the crater there is a lake that is full of sulphur and acids; as it gets dry sulfur emissions increase producing acid rain. North of the active crater, the Von Frantzius cone is the oldest eruptive center at the top of the massif. On the southeast side, lies another collapsed cone, filled by rainwater to form the Botos Lake. The Poas Volcano’s activity, although consistent, At the Poas Volcano the rainy season is from May thru November with minimal precipitation the rest of the year. Fog and mist are typical of the site, particularly in the afternoon. The average temperature is 12 degrees and rainfall is 3,500 mm.

Interest facts
Maximum height: 2,708 meters Main Crater: Diameter 1,320 meters; Depth: 300 meters; Botos Lake: Diameter 400 meters; Temperature 10-14 degrees C.

Regulations
-National Parks were created to preserve natural and cultural resources; the removal of any animal, plant, rock, or other item from the area is not permitted. - For your own safety stay on marked trails in the public use areas. - If you need help or information, ask the park’s personnel. They will be ready and willing to help you. - If you are near the Main Crater and feel any symptoms from exposure to the gases like coughing, nausea, or irritations in your eyes or respiratory tract, please leave the area as a precaution. - Help keep the park clean. Deposit trash in its respective bin (cans and glass, plastic, organic). - All living things, plants and animals share the planet with you. Let’s all protect them. - In case of an eruption, leave the area as soon as possible and follow the park rangers’ instructions. - The National Park has a set of regulations concerning public use. Respect them. – Don’t drink water without consulting the park’s personnel. - For your own safety, access to the crater and Botos Lake is prohibited. - Stay on the trails marked for public use.

The Costa Rica National Park System protects more than 25 % of Costa Rica