Ecosystem
If one examines the different life zones that exist in Costa Rica, it becomes apparent that it is one of the biologically wealthiest nation in the world. From the forested slopes of its volcanoes to the coral reefs on both coasts, Costa Rica possesses an almost unfathomable diversity of flora and fauna.
The greatest manifestation of Costa Rica's natural heritage is the diversity of its flora and fauna.
About 9,000 different kinds of flowering plants grow in the country, including more than 1,300 species of orchids. 
Nearly 850 species of birds have been identified here, which is more than are found in all of the United States, Canada and the northern half of Mexico combined. The country is also home for 209 species of mammals, 383 kinds of reptiles and amphibians, about 2,000 species of butterflies and at least 4,500 different types of moths. Though Costa Rica covers only 3.4% of the surface of the Earth, about five percent of the planet's plant and animal species are found here.
Copious rainfall has endowed Costa Rica with an abundance of rivers, but surprisingly, there are very few lakes. Nearly all the country's rivers begin in the mountains, where many are frothy white water routes perfect for rafting and kayaking.
The country's forests sometimes seem like the biological equivalent of a cathedral; those giant tropical trees have the appearance of columns, and the canopy they support holds a collection of epiphytic vegetation more complex than the paintings on the ceiling of the Sistine Chapel.
Mother Nature seems to work overtime in the tropics, and the consequent diversity of forests, has been classified by biologists into a dozen different life zones.
However, most of those forests can be lumped into three more general groups: rain, cloud and dry forests. Rain forests, with their massive trees, very high canopies and little growing on the dimly lit forest floor, can be found in the Atlantic lowlands and the southwest. The northwest contains some of the last remnants of the tropical dry forest, a less exuberant life zone that shares much of the diversity of the rain forests. Cloud forests, which cover the upper slopes of most mountains and volcanoes, are the most luxuriant of the tropical forests, with mosses and other small plants covering the trunks and branches of trees. They are all beautiful, and in many ways similar, but each one has plants and animals that won't be found in the rest.