The tropical rain forests represent some of the most biologically diverse spots in the entire world. Though endangered by human overdevelopment, there are still areas whose tropical rainforests are presently thriving. The Philippines, an archipelago in Southeast Asia, is one of these regions. This blog will show the importance of the tropical rain forest ecosystem, as well how humans have impacted its health both positively and negatively. As a case study I will use the Palawan province, which boasts a rare combination of thriving forests, commercial growth and popularity, as well as adequate data and information for study.
To get started, here are a few maps of the region. The map to the left shows where the world’s tropical rain forests can be found. Note that they all have similar longitudes, which accounts for the similar climates in each of these widespread regions. Later we will see how mountain ranges and surrounding climates help to create these lush forests.
This map shows how deforestation has changed the structure of the world over time.
This is a map of the Philippines with an arrow denoting Palawan.
Finally, below is a map of Palawan. As you can see there is a mountain ridge in the center of the island, explaining the lush tropical forests in the region. About 52 percent of the island is covered by forests due to orographic precipitation. The hot climate near the ocean causes water to evaporate, creating clouds. When these clouds reach the mountain tops, they are squeezed over one region, creating a wet tropical rainforest ecosystem.
A Brief Geological History
About 18,000 to 12,000 years ago, Palawan and much of the Philippines was probably connected to the Asian mainland. At one point, there were four larger main islands in the Philippines, including Palawan, that were joined with the many smaller surrounding islands as a result of shallow sea water depths (Heaney et. al). The scattered structure seen in the present Philippines is due to relatively high sea levels which can be attributed to periodic shifts in development of continental ice sheets and global warming. Additionally, ages of tectonic shifting, volcanic activity, and continental uplift have led to mountain ranges within many of the Philippine islands (Heaney et. al). This scattering of islands combined with these newly formed mountains has resulted in isolated ecosystems that would not have been possible otherwise. The map below shows how much of the region that was once forest is now covered by ocean.
About Tropical Rain Forests
(facts from blueplanetbiomes.org)
(facts from blueplanetbiomes.org)
Interesting Facts
There are some general facts about the tropical rain forest that will be helpful in understanding why it is so useful to humans. The forests typically have year-round warmth as a result of their proximity to the equator, which receives direct rays from the sun. On average, 50 to 260 inches of rain falls per year, and the temperature stays between 68 and 93 degrees Fahrenheit. Though rain forests only cover a very limited amount of the Earth’s land surface, they produce nearly 40 percent of the planet’s oxygen, illustrating both its importance to the balance of all ecosystems, as well as the potential dangers in human destruction of rain forest ecosystems. Rain forests have very diverse species of plants, many of which humans use for medicines. In fact, about ¼ of all medicines used today have come from rainforest plants.
Layers of the Rain Forest
As many have probably learned in elementary school classes, the rainforest has distinct layers. One is the emergent layer, in which extremely tall, umbrella shaped trees tend to grow. These trees take up a lot of the sunlight, but are also exposed to winds which can dry up their leaves. This is why many of them tend to have small pointed leaves, and often lose them during dry monsoon seasons.
The upper canopy is below the emergent layer, and light as also readily available for these plants. This is where most of the animals live, because most of the food is available here. The upper canopy takes up most of the remaining light, blocking the lower levels from exposure.
The lower canopy, also known as the understory, has trees sixty feet or shorter, and consists mostly of shrubs and small trees. The humidity is very high here and it is in constant shade.
Finally, the forest floor is completely dark. A person could probably walk through a forest floor because without light, plants are unable to grow. Most of the life here consists of worms and fungi which decompose the litter from taller trees which falls to the forest floor. As a result of the physical stratification of the rain forests, there is no dominant species. Each plant or animal thrives on its own layer due to conditions that it finds favorable.
Plant Adaptations
There is so much rain per year, that plants have to adapt so that water does not weigh down their branches and break them. Many have oil-coated leaves to repel water. Taller trees tend to have darker colors with more leathery leaves so that they do not lose water in strong sunlight. Other smaller plants that need nourishment but do not have the advantage of size survive as epiphytes. That is, they attach to larger plants in the upper canopy so that they can gain nutrients and sunlight.
Animals
Rain forests have different animals depending on where you go. The tropical rain forests in Palawan in particular have animals that are endemic, such as the Palawan peacock. One common animal found in rain forests, however, are monkeys. This is because they are adapted to life in trees, with large hands and good hand-eye coordination.
Why do people come to Palawan? How do they impact it?
Forests have become increasingly threatened by humans. Rainforests once covered nearly 14 percent of the earth’s landmass. Now they only cover around 6 percent (www.philippines.hvu.nl). Industrial and developing countries are the biggest reason for this change. Timber is a highly valued commodity in almost all countries in the modern world. In the last two centuries technological innovations have led to industrial revolutions. More efficient means of extracting raw materials such as wood and oil have led to increased interest in formerly undiscovered areas. On a worldwide scale, forests have typically thrived in mainland areas (one exception is in the present day United States, where clear-cutting has been somewhat common), but have seen trouble on islands. The most glaring example of this is seen in Southeast Asian islands, where one can find the most endangered tropical forests in the world. Much of this can be attributed to human actions, specifically in the use of slash-and-burn agriculture in areas of excessive rainfall. Too much rain can create environments unfit for crop growing, especially since rain can wash away the nutrients necessary for certain crops. Many cultures have found it more profitable and convenient to resort to slash-and-burn techniques.
In Palawan in particular, reasons for human impact have been wide ranging. One is merely for raw materials and subsistence farming. The areas are fertile and livable, and have not been tapped of all of their timber and offshore oil. However, tourism has also taken a toll on the natural balance. Vacation spots, such as the resort at El Nido which offer snorkeling and kayaking have attracted attention worldwide.
Forests have become increasingly threatened by humans. Rainforests once covered nearly 14 percent of the earth’s landmass. Now they only cover around 6 percent (www.philippines.hvu.nl). Industrial and developing countries are the biggest reason for this change. Timber is a highly valued commodity in almost all countries in the modern world. In the last two centuries technological innovations have led to industrial revolutions. More efficient means of extracting raw materials such as wood and oil have led to increased interest in formerly undiscovered areas. On a worldwide scale, forests have typically thrived in mainland areas (one exception is in the present day United States, where clear-cutting has been somewhat common), but have seen trouble on islands. The most glaring example of this is seen in Southeast Asian islands, where one can find the most endangered tropical forests in the world. Much of this can be attributed to human actions, specifically in the use of slash-and-burn agriculture in areas of excessive rainfall. Too much rain can create environments unfit for crop growing, especially since rain can wash away the nutrients necessary for certain crops. Many cultures have found it more profitable and convenient to resort to slash-and-burn techniques.
In Palawan in particular, reasons for human impact have been wide ranging. One is merely for raw materials and subsistence farming. The areas are fertile and livable, and have not been tapped of all of their timber and offshore oil. However, tourism has also taken a toll on the natural balance. Vacation spots, such as the resort at El Nido which offer snorkeling and kayaking have attracted attention worldwide.
These are pictures of the El Nido resort. The the small green island is densely packed with plant life. This is probably what much of Palawan and most of the Philippines looked like thousands of years ago, including some of its landmass that is currently under water.
Data on Palawan
1992 | 2005 | |
Percent of Palawan’s area covered by forest | 52 | 46 |
Hectares of forest coverage | 738,886 | 667,386 |
Annual population growth rate | 3.5% | |
Conservation status | Critical/Endangered | |
Deforestation status (hectares claimed per year) in Philippines | From 1950 to 1978 – 204,000 | From 1989 to 1995 – 116,332 |
Endemic Animals? | Yes! For example, the black and green butterfly or the Palawan Peacock, Calamian deer, Palawan fruitbat, Palawan stink badger, the horseshoe bat | |
Data from Romeo B. Dorado. “The Real Score: Palawan’s Forest Remains the Largest.” Palawan Council for Sustainable Development and wwf.panda.org.
The Future of the Palawan Rain Forests
Future prospects for the Palawan forests are a mixed bag. Recently the Puerto Princesa River in Palawan was voted one of the seven wonders of the natural world. The publicity brought to the area will surely increase commercial attention and tourist attraction will increase. There was already a fast growing tourist industry. There is still continued logging and slash-and-burn farming. Other ecosystems, such as the coral reefs, are attracting tourists to waters and beaches. There are also oil deposits offshore. These factors all point toward future human interaction in the region, which typically ends in some form of exploitation of the plants and resources. There have also been multiple government reform programs involving conversion of public lands agrarian projects as a result of the rapidly growing population. There were even disastrous forest fires in 1998 that destroyed much of southern Palawan and much of its naturally existing forests.
However, there are more optimistic ways to analyze this data. Popularity of the region could also raise awareness and result in programs for the protection of its plant life. Though multiple studies were released that alleged that there was a rapid decline in forest cover in Palawan, today it remains the Philippines’ largest forest by far, representing 11.3 percent of the country’s total forests. In addition, in 1992 Palawan was cited as a national treasure and many measures were taken to reduce illegal mining and timber operations (etravelpilipinas.com)
Private companies are still attempting to submit private mining tenement applications which are estimated to cover about 50 percent of Palawan (Dorado). If this is allowed there will be no forests left in the region. However, many of these mining claims fall within restricted or protected zones, indicating that the government is at least partially doing its job in protecting the ecosystems. There is also the Palawan Council for Sustainable Development (PCSD) was formed to ensure sustainable development. It is a government agency, which means it has national funding giving it the clout to take substantive action against overdevelopment. There is also an Environmentally Critical Areas Network (ECAN) which guarantees protection of over 560,000 hectares of rain forest land (Dorado).
How can the situation be improved?
It is a good sign that deforestation has reduced significantly. Even so, the rain forest ecosystem in Palawan is still endangered, as are the endemic species. I still think a lot can be done to address the problems with the ecosystems. The government of the Philippines can fund alternate methods of agriculture to emphasize sustainable methods rather than slash-and-burn methods. The government can also create wildlife reserves and national parks as is done in the United States. With the annual population growth rate being 3.5 percent, it is likely that forests will be reduced even further to make room for more people. This is a worldwide problem of overpopulation, and there is no easy way to fix it. In developing countries such as the Philippines, education about replacement sized families can do a long way toward reducing population growth and protecting the remaining ecosystems.
It is a good sign that deforestation has reduced significantly. Even so, the rain forest ecosystem in Palawan is still endangered, as are the endemic species. I still think a lot can be done to address the problems with the ecosystems. The government of the Philippines can fund alternate methods of agriculture to emphasize sustainable methods rather than slash-and-burn methods. The government can also create wildlife reserves and national parks as is done in the United States. With the annual population growth rate being 3.5 percent, it is likely that forests will be reduced even further to make room for more people. This is a worldwide problem of overpopulation, and there is no easy way to fix it. In developing countries such as the Philippines, education about replacement sized families can do a long way toward reducing population growth and protecting the remaining ecosystems.
References
- Dorado, Romeo B. “The Real Score: Palawan’s Forest Remains the Largest.” Palawan Council for Sustainable Development. <http://www.pcsd.ph/news_updates/articles/NEWS%202011/The%20Real%20Score.pdf>
- Heaney, Walsh, Peterson. “The roles of geological history and colonization abilities in genetic differentiation between mammalian populations in the Philippine archipelago.” Journal of Biogeography. Volume 32, Issue 2, pages 229–247, February 2005 <http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2699.2004.01120.x/full>
- “Palawan.” The Philippines. The Utrecht Faculty of Education. <http://www.philippines.hvu.nl/palawan1.htm>
- "Palawan." Columbia Gazetteer of the World Online. 2011. Columbia University Press. 20 Nov. 2011. <http://www.columbiagazetteer.org/main/ViewPlace/105725>
- "Philippine Natural Environment, Natural Resources, Livelihood of the Philippine People | Etravel Pilipinas." Philippine Travel, Destination, Guide, Festivals, Events, Accomodation and News | Etravel Pilipinas. Web. 21 Nov. 2011. <http://www.etravelpilipinas.com/about_philippines/philippine_natural_resources.htm>
- "WWF - Palawan Moist Forests." WWF - WWF. Web. 21 Nov. 2011. <http://wwf.panda.org/about_our_earth/ecoregions/palawan_moist_forests.cfm>.
- http://www.enchantedlearning.com/subjects/rainforest/Where.shtml
- http://multimedia.wri.org/frontier_forest_maps/
- http://www.palawanmotorbiketours.comuf.com/contact.html
- http://photosvoyages.org/anglais/asie/philippines/palawan/map_palawan.htm
