Providence College

Bio 220 Tropical Biology

Spring 2010

Biodiversity in the Tropical Rain Forest:

The Rain Forest covers 5-6% of the Earth's surface and is believed to be home to nearly half of all land animals and plants and trees. The biodiversity in the Tropical Rain Forest is immense with an abundance of vegetation, birds, insects, reptiles, mammals and amphibians. In fact, it is estimated that one single hectare (roughly 2.5 acres) contains 900 tons of living plants, 750 species of trees and 1500 other plants. The biological richness of the Rain Forest is currently severely threatened. By 2020, scientists believe nearly 80-90% of the world's rain forest ecosystems will be destroyed. Deforestation by logging, clearing for agricultural land, cattle grazing, and subsistence farming is the main driving force behind rising species extinction rates.

The rain forest can also be described as "the lungs of our planet" because they provide to humanity in two very important as well as universally recognized services. First and foremost they regulate our global climate patterns as well as helping to moderate the negative attributes of climate change in particularly global warming. It can be understood that favorable climatic conditions can determine the existence of rain forests in a particular location, for example tropical rain forests only exist in geographical areas that have an endless amount of rainfall as well as sunshine, and these areas can generally be found around the equator. Another beneficial is that rain forests can affect the global climatic conditions by acting as pollution filters, which helps in the reduction of the amount of carbon dioxide released. This process is completed by a manner known as photosynthesis, were rain forest trees absorb carbon dioxide and in turn release oxygen back into the atmosphere typically producing around 20% of the world's oxygen as well preventing the cause of global warming.

Secondly, rain forests serve as storages for global diversity, which can be seen in a wide array of diversity among plants and animals. These two essential factors have aided in countless arguments for upholding the protection of the rain forest from continuous destruction caused sadly by the human population. The reason it is so important to preserve biodiversity as much as possible is because if we slowly continue to lose biodiversity then we will also begin losing out on potential discoveries of new medicines, raw materials and food. For example, rubber was one of the most prominent products of the rain forest, which in turn provided in the construction of perhaps one of most famous applications, rubber tires on bicycles and cars, which are widely used for transportation. Thus, it is extremely important to promote rain forest conservation to protect the richness of biodiversity and the other essential benefits.


Although the diversity of fauna in the tropics may not be immediately visible to the impatient sight-seer, the depths of the rain forest teem with an array of mammals, birds, fish, amphibians, reptiles, and insects. In Costa Rica, you may not encounter any jaguars but you will probably stumble across some howling monkeys, poisonous frogs, colorful birds and intimidating insects, at the very least. As secondary growth forests become intertwined within the old-growth primary forests, there are thousands of species that await their taxonomic fate - as of yet, there are over 35,000 species of insects, 160 species of amphibians, 220 species of reptiles, 850 species of birds, and 205 species of mammals inhabiting the diverse ecological niches and ecosystems of Costa Rica.[1] Within La Selva Biological Station in the Braulio Carillo National Park, about 108 species of mammals have been identified with many more to be discovered. Of these species at La Selva, 72 are bats and there are a total of 113 bat species throughout Costa Rica. Furthermore, more than 400 species of resident and migratory birds (nearly half of the total bird species which inhabit Costa Rica) have been observed at La Selva.[2] Although about 25% of the country constitutes protected land, an increase in deforestation and the subsequent destruction of habitats threatens the enchanting diversity of fauna that populate Costa Rica.

1. "Costa Rica Flora and Fauna." [Online] Available <>.
2. "La Selva Biological Station." [Online] Available <>.

Brown Throated three-toed sloth
Bullet Ant
Collared Peccary
Golden Orb-Web Spider
Green Great Macaw
Hourglass Treefrog
Keel-billed Toucan
Mantled Howler Monkey
Pharomachrus mocinno
Plumed Basilisk
Silver Argiope Spider
Strawberry Poision Dart Frog
Two-Toed Sloth
White-Faced Capuchin
White-nosed Coati


Costa Rica has more than 9,000 species of higher plants. Colors are bright, heights are variable, and their primary divisions could be divided into primary and secondary growth. Some of the plants emit fragrances in order to attract pollinators to allow them to continue their lineages. The most abundant flora are ferns, and the national plant of Costa Rica is the orchid, which is most diverse in the cloud forests.[1]

In tropical rain forests, it may appear as though there is not much diversity at all when it comes to plant life. Besides buttressed trees, palms, lianas, and maybe some epiphytes, the forest may look the same to the untrained eye. However, there are many species of plants, but most simply have very similar plant anatomy. Plants that grow well in rainforests tend to look very similar because many have evolved to have very similar morphology that works well in rainforests. There are so many different niches in the forest, so plants can grow to many different heights, support many different species, create even more microhabitats, and continue to contribute to the immense biodiversity of the tropical rain forest.[2]

1. "Ecosystems." [Online] Available <>.
2.Terborgh, John. Diversity and the Tropical Rain Forest. New York: Scientific American Library, 1992. Print.

Apple Guava Tree
Balsa Tree
Chocolate Plant
Dutchman's Pipe
Florida Strangler Fig
Oil Bean Tree
Peace Lily
Rainbow Heliconia
Red Passionflower
Tree Fern
Trumpet Tree

Tropical Biology Class Snorkeling in Cahuita, Costa Rica

Tropical Biology Class at La Selva