Tropical Forest Fragmentation and Its Impact on MicroclimateBy Ashley Chastain
I.Introduction

Tropical forest fragmentation is a topic that has been debated by scientists for a long time. Most debates focus on the fact that as we strip our planet of these forests are we impacting our own climate by the results of global warming. But that’s a topic for them to debate, this article plans on focusing how the fragmentation impacts the forests own microclimate. Whether it’s humans chopping down the forests or starting a fire all the way to natural fires the plan is to examine just how much change can occur due to these events. I intend to look at several forces that cause this fragmentation and will then look at the damage this process leaves in its path.

II.Background

II-A. Forest Fragmentation

For a long time now the population of humans has increased and so has the pressure on these humans to find new places to live. With little regard to what has come before us, we have turned to deforestation as a way to clear land for us to call home. Even though tropical forests make up a small portion of this deforestation the results are devastating. When we are destroying these forests we don’t look at the bigger picture. Not only do approximately half of the planets species live in these forests but also deforestation results in climate change.
With deforestation we are impacting researchers the change to discover possibly lifesaving medications but also species the likes which no one has studied. There are many pharmaceutical products that come from species of plants, for example digoxin used to treat heart failure which is isolated from the foxglove plant. Destroying these regions reduces the chances that we are able to effectively study and possibly experience incredible results.

But forest fragmentation also occurs naturally through fire. This process helps turnover nutrients and helping to enrich the soil. So in a way these fires help the forest, but at the same time they provide an easy way for humans to inhabit the area destroyed. It then becomes a double edged sword for the forest. Also when forest fires occur humans are quick to react and try to extinguish the flames in order to reduce the destruction. But since these fires are a process of creation in a forest they also impact the turnover of new nutrients that the forests require.

II-B. Edge Effect

The edge effect is the distinct changes that a forest experiences when it becomes the exposed outer region to another habitat. This effect then causes changes to the microclimate in that area and can impact up to 100 meters into the forest. Not only will the climate of these regions experience changes but often times new wildlife will inhabit the new area and impact the edge as well. As you can see this effect is magnified when deforestation or fires occur as there is a new edge effect created. The edge effect doesn't just affect the edge but will also disturb sections of the environment that are within close proximity to the edge. It's almost like a domino affect in that the edge that is being exposed to new conditions then adapts or is destroyed and the next part of the rain forest becomes the edge. It can promote a process of destruction and greatly impact an entire rain forest.

edge effect.jpg
edge effect.jpg

(Photo courtesy of atbc2008.org)

II-C. Microclimates

Microclimate is the word used to describe an area of a larger area that experiences a different climate. For example the edge of a rain forest experiences drastically different conditions then say the center point of a rain forest. While they may not be very far apart in terms of distance, the animals and plants could vary vastly genetically and physically. This is one of the few reasons why a rain forest is home to such a large array of species. Because no section of the rain forest is identical to another section. It creates great biodiversity and also helps the process of natural selection and evolution amongst species. A microclimate and its inhabitants are very sensitive to the slightest changes in the environment. This sensitivity is what encourages the vast changes between sections of a rain forest. When one section is then disrupted its neighboring section will feel the changes. It's a chain reaction of events that alters more than just the immediately affected microclimate.

III.Fragmentation and Its Impact

Fragmentation affects many things inside of a tropical forest. From the plants and animals to even the temperature that the area experiences. When fragmentation occurs it brings about a great change to the environment. Through history we know that it takes generations for species to adapt to specific conditions, so we know instantly exposing a part of a forest to new conditions will have remarkable consequences on the species that lived there before.

The new area being exposed to its new microclimate often times fails to adapt quickly enough to its new surroundings. The plants and animals will either die or try to migrate to an area with more favorable conditions. So the edge effect then causes the tropical forest edge to possible die out and then in turn expose more of the internal forest to the same harsh conditions. It’s a possible cycle of events that can destroy more of the tropical forest than was originally intended.

For example there is a video that will follow this paragraph that NASA used their satellites in order to capture images of the Amazon rain forest from the time period of 1975 up until 2010. As you can see from the video in just a few short years each time some sort of deforestation occurs that the edge of that area expands over the next several years. By the end of the video you can see the results of fragmentation and see just how devastating fragmentation is to a tropical forest. This destruction has reduced the size of the Amazon forest by around 20 percent in just 30 years. There are prediction numbers out there in scientific studies that estimate that the forest will be reduced to little more than 15 percent of its original size by 2070.



IV.Varying Temperatures and Their Result

As most are aware of the Earth’s surface temperatures have been increasing at an alarming rate over the past few decades. This can have drastic impact on animal and plant life and most have experienced these results. But for a tropical forest and its microclimate the results are much more intimate. Temperature plays in important role in establishing living conditions for plants and animals. Just like humans are accustomed to temperatures in the range of 68-77 degrees Fahrenheit, each species has an optimal temperature it prefers to ensure its survival.

Temperature is an important part of a tropical forests structure. It determines the plants that are able to thrive and provide for the animals that live there as well. It also determines the species of animals that will settle and raise their offspring. When a forest experience fragmentation often the climate that is then exposed is different from its previous climate. This can cause plants to die and animals to migrate deeper to an area with a climate they prefer for their daily lifestyle.

The plants experience temperate changes from the resulting sun exposure and ground temperatures that are releasing heat. These plants are often use to the sun coverage and other foliage that lowers the temperature under the canopy layer of the rain forest. Even slight jumps in temperature can cause havoc in a plants function and survivability. Just by losing sun coverage the heat from the sun can destroy plants who are used to little more than minutes of sun during a day.

V.Animal and Plant Life

The species that reside in these environments depends on their stability in order to survive. Something humans take for granted is the fact that we live in controlled environments with air conditioning and air filters. These species require specific temperatures, amounts of sunlight, and even exposure to other species themselves. When any of these things are altered the species future is vastly modified.

Certain species of plants rely on a really specific amount of sunlight in order to grow and be healthy. A plant that relies on little sunlight has no chance when its microclimate is morphed into an area where sunlight is beating down for hours at a time. This in time will destroy the plant and prevent its reproduction and future as a species. Since most of the species are obscure to mankind we could be killing off potentially valuable resources to both medicine and other forms of science.
Animals also rely on the plants to produce fruits or places for them to inhabit. When the plants they rely on for food or shelter becoming extinct they have nowhere to live. It can devastate a population of animals and submit them to much harsher conditions for which they can call home. Some species may never adapt to new conditions and become extinct.
File:Aglaucus3.JPG
File:Aglaucus3.JPG

(Digital recreation of a Glaucous Macaw photo courtesy of wikimedia commons)

VI.Greenhouse Gases

Tropical forests are of vast importance to the human race because of the vast amount of carbon dioxide they are able to harvest. As we know carbon dioxide is a greenhouse gas that is currently wreaking havoc on our ozone layer. Plants are the opposite of animals when it comes to how and which gas we require for life. Animals use the oxygen that plants produce from the carbon dioxide that animals create in a cycle of gas exchange. Now that we are using mass amounts of carbon based fuels our carbon dioxide levels are rising at an alarming rate. Deforestation is one of the main causes because of the large amounts of carbon dioxide a forest can store and then use to continue the cycle.

By eliminating the tropical forests as we currently are, we will in turn create more unused carbon dioxide further leading to the demise of the ozone layer. While people may debate the true cause of global warming, I think we can all agree that a hotter planet is not a more desirable planet. So we should in turn respect the tropical forests and understand that they are responsible for far more than just pretty photos. The tropical forests are major players in the usage and turnover of carbon dioxide in our atmosphere. Further damaging these forests will only increase the carbon dioxide that is crippling our plants atmosphere.

VII.Conclusion

In conclusion, tropical forest fragmentation has many negative results and there are many things we can do to stop the alarming rate of tropical forest deforestation. Scientists agree that the untapped potential of the tropical rainforest is something we need to spend more time in protecting. The species of plants and animals could contribute to scientific breakthroughs if we could spend the time researching and developing these research opportunities. And it won’t just benefit the scientific community but tropical forests also reduce the amount of carbon dioxide that is currently in our atmosphere. We need to be more respectful and allow the rain forests ecosystem to continue to thrive and produce these wonderful species and benefits.


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Works Cited

Ewers, R. M., & Banks-Leite, C. (2013). Fragmentation Impairs the Microclimate Buffering Effect of Tropical Forests. Plos ONE, 8(3), 1-7. doi:10.1371/journal.pone.0058093
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Liptzin, D., Silver, W., & Detto, M. (2011). Temporal Dynamics in Soil Oxygen and Greenhouse Gases in Two Humid Tropical Forests.Ecosystems, 14(2), 171-182. doi:10.1007/s10021-010-9402-x
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Wood, T. E., Cavaleri, M. A., & Reed, S. C. (2012). Tropical forest carbon balance in a warmer world: a critical review spanning microbial- to ecosystem-scale processes. Biological Reviews, 87(4), 912-927. doi:10.1111/j.1469-185X.2012.00232.x