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Providence College: Bio 220 Tropical BiologySpring 2012


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Conserving the Tropics
The future of our planet depends on our ability to conserve the biodiversity. Costa Rican rainforests face threats of massive deforestation, forest degrading and fragmentation due to logging and other human development, which causes a notable rift in the bio-diversity. Disturbances can upset the balance and flow of the forest’s sensitive ecological system. Environments need to be monitored, patterns need to be graphed and analyzed, and behaviors and interactions need to be understood. DeClerck et al. (2010) conveys that more extensive, longer-term, and smarter studies need to be done in the field of conservation. But they also allude to another obstacle to conservation: public opinion. DeClerck et al. suggests that it is difficult to make the people care about conservation of biodiversity when they are more concerned about human issues: poverty, tourism, etc.
Over the past decade conservationists have increased their initiatives to preserve and protect the diverse species that inhabit the rainforests of Costa Rica. A study done by Daily et al. on the mammalian conservation opportunities in agricultural landscapes of Costa Rica found that out of 26 native species found, 9 were isolated to living in the forest surrounding farmlands, 14 lived in both the forest and the farmlands and 3 made their homes mainly on the farmlands. This suggested that species richness decreased with the clearing of forests for agricultural purposes. Additionally, they discovered that the clearing of a region that had previously supported 60 different mammalian species caused 6 species to become locally extinct and many more of the larger carnivorous, herbivorous, and arboreal species to disappear from the region.


DeClerck, Fabrice A.J., Chazdon, Robin, Holl, Karen d., Milder, Jeffrey C., Finegan, Bryan, Martinez-Salinas Alejandra, Imbach, Pablo, Canet, Lindsay, and Zayra

Ramos, 2010. “Biodiversity conservation in human-modified landscapes of Mesoamerica: Past, present and future” Bioloigical Conservation, 143 (2010), 2301-2313.

Climatic influences on Conservation
La Nina or “little girl” is a period of time that sees lower water temperatures in the pacific coast of Central and Southern America. La Nina is associated with El Nino which consists of warmer than usual temperatures in the Pacific Ocean. The cold tongue at 10 N extends farther into the pacific characterizing La Nina. The temperatures in the Central Tropics may see a drop of 7 degrees during La Nina events. Rainfall in both the dry and wet season becomes distorted and varies greatly, once again stressing many plant and animal species that are not adapted for variability. These great disturbances by La Nina are due to her relationship with the low-level jet stream that is present in the Caribbean. These changes cause the low level jet stream to decrease its intensity as it comes from the Pacific and drives into the Caribbean. While this may not seem dramatic, the tropics and its productive coast are very sensitive to change. Changes can effect both terrestrial and marine life.
Effects of la Nina can be seen in terrestrial regions. There have been different observations of the effects of La Nina to terrestrial climate. Many agree that temperature usually drop. Precipitation amounts are often conflicted. Most agree that rain levels increase during La Nina while others find that rainfall decreases. Whether it is rainfall or temperature drops, terrestrial life is effected by La Nina. Bees have been found to decrease in numbers following a cycle of El Nino and La Nina events. This becomes a problem seeing as bees are important pollinators for much of the flora in Costa Rica. There have been global concerns and initiatives to help protect pollinators. Further study is needed to confirm the decline in bee community effect during pollination periods.
Costal coral and fisheries of the coast of Costa Rica are also effected by the change in weather. The decrease in temperature may see a decrease in the amount of fish nestled there. Reproduction often of fish communities often drop due to sensitivity from temperature changes. La Nina has also been considered recovery periods following El Nino events. Phytoplankton blooms often occur during this cooling trend.
As the temperature of the water rises, the symbiotic relationship between the algae and the coral becomes parasitic as the algae do not supply the coral with adequate nutrients. The coral responds by ejecting the algae. Both organisms have a high mortality rate outside the relationship. Loss of coral basically destroys the ecosystem, as it is a keystone species. Global warming also allows pathogens greater success. The fungus Batrachochytrium dendrobatidis is responsible for the extinction of an incredible 67% of Atelopus species, a frog endemic to Central America. Pathogenic success can decimate plant and animal populations, and tree frogs are especially vulnerable. The climate controls much of the species composition of any ecosystem. Species diversity is the best indicator of how an environment will respond to climatic change. Preservation of this diversity is instrumental to preserving ecosystems such as the tropical rainforest.

Amador et al. Dynamics of the Low-leveled Jet Stream over the Caribbean, http://ams.confex.com/ams/older/99annual/abstracts/1126.htm Gordan et al. Changing bee composition and frequency of flowering legume Andira Inerims during El Nino and La Nina Years (1997-1999) in Northwestern Costa Rica, Kansas Entomological Society 78(2):100-117. 2005
Guzman, Hector and Cortes, Jorge, Changes in Reef community structures after fifteen years of natural disturbances in the Eastern Pacific, Bulletin of Marine Science, Vol 69(1),2001, 133-149.
Peter W. Glynn, Coral reef bleaching in the 1980s and possible connections with global warming, Trends in Ecology & Evolution, Volume 6, Issue 6, June
Philander, George. El Nino, La Nina, and the Southern Oscillatio, San Diego, 1990, p85.
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Map of Costa Rica (created by Gabby Brum)

La Selva Biological Station
Scientists opened La Selva Biological Station to enhance species conservation, by protecting secondary forests and implementing public-educational programs. The La Selva Biological Station provides a place to observe and execute experiments to better understand the species that inhabit the forest as well as preserve the diversity of the tropical rain forest. They have established rules on recycling and interacting with species to protect and preserve the species living within the reservation. First, labeled receptacles are distributed throughout the station for throwing away different kinds of items (i.e. organic material, paper, plastic, and other). This system prevents people from littering as well as efficiently utilizes resources. Schwartzman et al pointed out that the people living in the forest are not the problem of conservation, but that they protect the land from being used in the wrong ways (Schwartzman 1353). Littering, for example, can be more strictly enforced if people who care are there to prevent it. Second, no one is allowed to conduct experiments other than observational in La Selva without a proper license to protect the animals, plants, and their environment from being used/altered by people who don’t know how to properly handle specimens. Chazdon et al (2009) explains that government policies can help influence the protection of forests through rules like these used at La Selva. La Selva successfully protects the forest, while still enabling people to experience the vast species diversity. As Chazdon and his fellow authors stated: “Involving local people in the management of forests increases the likelihood that secondary forests will persist” (Chazdon 1414).

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Stephan Schwartzman, Adriana Moreira, Rethinking Tropical Forest Conservation: Perils in Parks, Conservation Biology, Vol. 14 No. 5 pp 1351-1357, October 2000
Robin Chazdon, Carlos Peres, The Potential for Species Conservatiosn in Tropical Secondary Forests, Conservation Biology Vol. 23 No. 6 pp 1406-1417, 2009


A recent assessment of spatial and temporal factors influencing the diversity of animal communities in tropical secondary forests determined that the potential for the conservation of old-growth species in secondary forests is highest in regions where the ratio of secondary to old-growth forest area is relatively low, older secondary forests have persisted, there is small human disturbance, seed-dispersing agents are prevalent, and old-growth forests are close to abandoned areas. Moreover, this assessment suggested that both old-growth and secondary forests are important to the maintenance of forest species in human-modified landscapes. These findings attest to La Selva’s potential for species conservation, since the majority of La Selva’s area is old-growth forest, the reserve minimizes human disturbances, and the reserve has both old-growth and secondary forests growing in close proximity to each other.

Chazdon RL, Peres CA, Dent D, Sheil D, Lugo AE, Lamb D, Stork NE, Miller SE. 2009. The potential for species conservation in tropical secondary forests.
Conservation Biology 23(6):1406-1417.


Flora: The following flora were observed by individuals in Costa Rica.
Breadfruit Tree

Cocoa plant

Coffee Plant

Fungi

Heliconia Rostrata

Kapok Tree

Oil Bean Tree

Philodendron granpipes

Polaris Palm

Queen Aechmea

Strangler Fig

Trumpet Tree

Veiled Lady Fungi

The Walking Palm


Fauna: The following fauna were observed by individuals in Costa Rica.
Common Caiman

Golden Orb Weaver

Hoffman's Two-Toed Sloth

Iguana Iguana

Keel-Billed Toucan

Lobster Claw

Mantled Howler Monkey

Orange Kneed Tarantula

Passerini's Tanager

Red-eyed Tree Frog

Rufous-tailed hummingbird

Southern Stingray

Three-toed Sloth

Yellowtail Damselfish




In La Selva specifically has conservation initiatives for the following species: Great Green Macaw, peccaries, bats, and sloths.

Role of Diverse Bird Populations in Conservation

In La Selva Biological station there are over 100 species of birds living in the secondary and primary forests. Each bird species have specific environments to be found in and specific times of the day that they come out to forage. For example, understory birds like the Green Honeycreeper, Scarlet Tanager, Golden-Headed Tanager, and the Golden-Winged Warbler are seen frequently feeding off of the Miconia plants in secondary growth parts. There were also many upper-story birds that were seen on the edge of old growth and secondary growth forest, like the chestnut-mandible and keel-billed toucan and sometimes macaws can be spotted. In addition to frugivorous species we also saw many fish eating species along the riverbanks at La Selva. These included the Great Egret, Little Blue Heron and the Green Ibis. Species of birds are found on all levels of the forest from the floor to above the canopy all at different times of the day. The diet of these birds consists of a large variety of fruits, fish, insects, and for some, small mammals. Their role in secondary forests is vital for spreading plant species in developing forests and maintaining a stable population of their prey.
Conserving the old-growth habitats for these species is very important for seed dispersal and insect control for developing secondary forests. In Tropical Ecology by Kricher the presence and interaction of bird species has been investigated in Agroforests, which are plantations of usually coffee or cacao with canopy tree species. Ecological studies have been done in agrofrests because they are easy to manipulate to get a better understanding of interactions.
To understand the relationship between epiphytes and bird species, in one study they removed all the epiphytes in an agroforest to see how and what species of birds it will affect. They found that the Common Bush Tanager (Chlorospingus ophyhalmicus) population was negatively affected whereas the golden-crowned warbler (Basileuterus culicivorus) was not. It was concluded that epiphytes are essential nesting sites for many species of birds.
Another couple studies also done in agroforests investigated the bird and insect interactions. One wanted to understand how birds affect arthropod densities in the forest. They discovered that access by migrant birds help reduce these insect densities, thus reducing leaf damage. With a large diversity of birds that feed on arthropods they will help promote the health and survival of multiple tree species. A forest with more bird species will be able to consume a larger variety of arthropods that damage different plant species. The other insect study involved the consumption of Lepidoptera larvae consumption on coffee plants. This study was conducted on two agroforests, one that had many species of shading trees and another that only had one species. The found that the agroforest with higher tree diversity had more species of birds and a higher consumption rate of the larvae. They concluded that bird diversity might protect potential outbreaks of insects and maintain healthy stability of the forest.
With the help of agroforest studies we are able to understand the stability that birds bring to the forest and what plant growth they require for the survival. Encouraging more species of birds to live in the forest will help control a larger variety of problems resulting from destruction by insects, and help disperse seeds from more plant species.

Kricher, John. Tropical Ecology. First Edition. Princeton University Press 2011.


Great Green Macaw
Justin Morimoto, a bird expert, led bird walks where we were able to observe the Great Green Macaw at the La Selva station. The La Selva reserve has made a very conscious effort to provide a safe habitat for the Great Green Macaw. They have used this endangered species as a focus for their
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Great Green Macaw (by Justin Morimoto)
campaign to conserve a unique lowland Atlantic forest assemblage in Costa Rica (Chassot et al, 2002). La Selva reserve recognizes that these species require the high density of the Almendro (Dipteryx panamensis) and has been able to maintain these trees for these birds. These trees provide a nesting site as well as a primary food resource for the great green macaw. The reserve is well protected and therefore these birds have found refuge between the San Jaun River and the La Selva Biological Station (Chassot et al, 2002). There is only 10% remaining of the natural nesting habitat in Costa Rica for the Great Green Macaw. While these species face habitat loss, they also face the threat of poaching and capture for commerce (Guedes, 2004). For centuries they have been admired and desired because of their beautiful and unique feather coloration and now the unrestricted capture of these birds has become so great that populations are unable to recover fast enough. Once sold, many pet owners don’t understand the proper dietary restrictions of the birds. Their long life span causes them to outlive humans, leaving many abandoned or pre-maturely euthanized. La Selva is making a strong effort to protect and help re-populate the green macaw populations.

Chassot, Oliver, and Guissell M. Arias. "Great Green Macaw: Flagship Species of Costa Rica." Psitta Scene 53 (2002): 1-7. Print.
Guedes, Neiva M, R. "Management and Conservation of the Large Macaws in the Wild." The Neotropical Ornithological Society 15 (2004): 279-83. Print.
Loiselle, Bette A., and John G. Blake. "Population Variation in a Tropical Bird Community." BioScience 42.11 (1992): 838. Print.

Peccaries
The collared peccary is one of the most abundant mammals at the La Selva Biological Research Station. The ideal environment that the station provides for this species has allowed the peccaries the opportunity to grow and thrive. They have very few natural predators in the region, and are protected from hunters and other harmful anthropogenic disturbances. In addition, they are supplied ample sources of food by the tropical rainforest, have two substantial water supplies in the Puerto Viejo River and the Sarapiqui River, and have a large area of territory over which they can forage and burrow. The social nature of these animals means that they are no longer frightened away by the frequent researchers, conservationists, and tourists that visit the station. They have largely taken over as the dominant species of mammal in the area, and given their herd size and their effectiveness at foraging, they have outcompeted many other organisms for territory.
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Peccary at La Selva (by Chris Judge)

The peccaries found at La Selva are a testament to the benefits of tropical rainforest conservation. It also speaks volumes for the impact that humans can have on a tropical reserve, and speaks towards the notion that there are other alternatives to conserving habitats aside from removing the human presence (Schwartzman, 2000). Research shows, indeed, that this is not simply the beginning of an overpopulation of peccaries. It instead suggests that La Selva has restored a natural balance between predator and prey abundance similar to those found in undisturbed rainforests (Wilson, 1990). The abundance of these animals also provides numerous opportunities for research on mammal ecology, biological reproduction, and social behavior. Much of the previous literature on collared peccaries concerns their population size and response to hunting pressures (Bodmer, 1988; Ellisor, 1969; Bodmer, 1997), as they are a significant game species in the southwest U.S. and much of Central and South America. However, the conservation work being done at La Selva now enables that literature to expand to the biological aspect of the peccary, a much more recent area of study (Cooper, 2011; Mayor, 2010; Desbiez, 2009).

Bodmer, R.E. et al. (1988). Ungulate management and conservation in the Peruvian Amazon. Biol Cons 45: 303-310.
Bodmer, R.E. (1997). Hunting and the likelihood of extinction of Amazonian mammals. Conserv Biol 11: 460-466.
Cooper, J.D. et al. (2011). Is sexual monomorphism a predictor of polygynandry? Evidence from a social mammal, the collared peccary. Behavioral Ecology and Social Biology 65: 775-785.
Desbiez, ALJ et al. (2009). Niche Partitioning Among White-Lipped Peccaries (Tayassu pecari), Collared Peccaries (Pecari tajacu), and Feral Pigs (Sus Scrofa). Journal of Mammal 90:119-128.
Ellisor, J.E. and Harwell, W.F. (1969). Mobility and Home Range of Collared Peccary in Southern Texas. Journal of Wildlife Management 33: 425-427.
Mayor, P.G. et al (2010). Reproductive performance of the wild collared peccary (Pecari tajacu) female in the Peruvian Amazon. European Journal of Wildlife Research 56: 681-684.
Schwartzman, S. et al. (2000). Rethinking tropical forest conservation: Perils in parks. Conserv Biol 14: 1351-1357
Wilson, Don E. “Mammals of La Selva, Costa Rica.” Four Neotropical Rainforests. Ed. Alwyn Gentry. New Haven: Yale University, 1993. 275-278.

Bats
An example of biological researchers who are working to put conservation into the public spotlight by demonstrating that biodiversity has an impact on other aspects of life (economy, tourism, agriculture, etc.) are the folks at the Tirimbina Biological Reserve in La Virgen de Sarapiquí, Heredia, Costa Rica. At this location the Conservation Association of Monteverde (ACMCR – http://www.acmcr.org/) works to both research the abundance and diversity of bats as well as to educate people of all ages about bats. This group has made a similar observation to that of DeClerck et al.: it is hard to convince people to want to save bats. All people have ingrained opinions about bats, and most of them are negative. Society tends to think of bats as scary blood-suckers. Farmers in Costa Rica (and other Latin American nations) have the myth of El Chupacabra, a batlike creature that kills cows by sucking their blood. Though it is true that there are bats that suck blood to nourish themselves, not all bats do this and the bats that do never could suck enough to kill a cow directly. The reputation of bats has been blown out of proportions. And because of these misconceptions, all species of bats are targeted and killed by farmers as pests.
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Little black myotis, Myotis nigricans


Though it is hard to change the image of the bat, the ACMCR is optimistic that through education it will be possible. The target audience of their program is young children, because they believe it will be easier to form a realistic idea about bats in the minds of individuals who have maybe never or at least for a shorter time thought badly of bats. They believe that the youth will then teach their parents what they have learned, and in this way a whole society will be altered.

The ACMCR group teaches that bats are mammals, with fur and mammary glands. Bats are also one of the most common species of mammals in the world with 1116 species total (21% of the total mammal species). Though they have wings, bats still maintain five fingers. This is one piece of evidence that humans and bats are still pretty closely related evolutionarily. They want the public to see that bats are
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Central American yellow bat, Rhogeessa tumida
similar to humans, and therefore humans should be sympathetic to these animals.

Bats have a unique way of navigating and “seeing” the world: echolocation. Although bats are colorblind and have poor vision, they can see. Bats instead rely on echolocation, an ability quite like sonar. They emit high frequency calls and then listen to the echoes in order to locate objects around them (such as their prey). Some bats use their mouths to transmit the sounds, while others use a unique body part called the nose leaf. Most bats have large ears to help them receive the sounds that are bouncing back. Bats can form 100 images per minute using this echolocation.

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Central American yellow bat, Rhogeessa tumida

These fascinating animals have a great deal of benefits on human beings and their surrounding environment. One is that bats eat insects that humans consider pests. A 10 gram bat can eat 1000 mosquitoes per hour. As long as we conserve bats, people can save money on pesticides and not get bitten as often. Bats also aid in seed dispersal for some species of plants. For example, A 20 gram short-tailed bat eats Cecropia seeds and disperses 24,000 seedlings per night. Bats are well known for helping regenerate forest due to their seed dispersal. Additionally bats are important pollinators, including for plants that we use in agriculture like the agave plant. The agave plant is used to make tequila, which is exported and enjoyed globally. By showing people that bats play a crucial role in the environment and our lives, the ACMCR group can help show why conservation should be a priority that is equally as important as the economy and the problem of poverty.




Sloths

523787_3708675761731_1420684924_33509429_427081442_n.jpgThe sloth sanctuary exemplifies some of the current mammalian conservation efforts. 580395_3708675521725_1420684924_33509428_692180143_n.jpgAlthough these quiet animals are masters of camouflage, they still face threats of extinction. Sloths are indigenous to Central and South America. These arboreal creatures were not built for speed or endurance and therefore find the most refuge hidden amongst the trees, far out of harms way. Starvation, hypothermia, or tiredness increases their vulnerability of falling out of trees.


Humans as well as the harpy eagle and jaguars are the biggest threats to the sloth species. Unfortunately, sloths cannot differentiate tree branches from human made structures that invade their habitats, and consequently fall victim to deforestation and human development. At the sloth center some of the sloths that experienced electrical burns from powers lines and others that had major cuts and other lacerations from barbed wire fences. The sanctuary attempts to preserve the sloth species by assisting them through their recovery and releasing them back into the wild once they seem able to sustain life on their own.
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Daily, Gretchen C., Gerardo Ceballos, Jesús Pacheco, Gerardo Suzán, and Arturo Sánchez-Azofeifa. "Countryside Biogeography of Neotropical Mammals:
Conservation Opportunities in Agricultural Landscapes of Costa Rica." Conservation Biology 17.6 (2003): 1814-826. Print.


In addition to initiatives to conserve animal species, we observed several ecological and environmental conservation initiatives taking place in Costa Rica.

Coffee Plantations
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Coffee is the number one exported crop in Costa Rica. 529740_3708663201417_1420684924_33509386_824494382_n.jpgCoffee plantations can possibly have a great impact on conservation, particularly of bird species. One study showed that a variety of bird species will regularly forage in coffee plantations if native fruit bearing plant species are incorporated. The incidence of bird foraging increased with
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the amount of fruit availability. This is an intuitive find, but it proves that if more native plant species are incorporated into coffee plantations it can help increase the bird presence and perhaps population. Another study demonstrated the value of coffee plantations to migratory birds. This study showed that coffee plantations had the second highest presence of migratory birds, behind acacia groves. The importance increases greatly in the dry season when the numbers of migratory birds present double. This could be important to species during the mating process.

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Carlo, Tomaes A., Jaime A. Collazo, and Martha J. Groom. "Influences of Fruit Diversity and Abundance on Bird Use of Two Shaded Coffee Plantations." Biotropica 36.4 (2004): 602-14. JSTOR. Web. 29 Apr. 2012.
Greenberg, Russell, Peter Bichier, and John Sterling. "Bird Populations in Rustic and Planted Shade Coffee Plantations of Eastern Chiapas, Mexico." Biotropica 29.4 (1997): 501-14. JSTOR. Web. 29 Apr. 2012.

Cahuita
Cahuita is located in the Talamanca Canton of Limon Province, just north of Panama and in the southeast region of Costa Rica. It is a tourist city in the, and consequently the lifestyle and culture is not completely oriented towards preserving the species. Tourism can lead to pollution and water disturbance, leading to severe damage to marine as well as freshwater life.

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Camille observing marine life (photographed by Chris Judge)


Coral Reefs
Like rainforests, coral reefs are in serious danger worldwide. Coral reefs are the exclusive home to hundreds of fish and invertebrate species, and therefore, it is critical to preserve these species’ habitats. Coral reefs develop over the course of millions of years and are not well adapted to acute stresses. Under optimum conditions, they grow horizontally only up to 3 cm a year and vertically between 1-25 cm per year.
Natural as well as anthropogenic stresses currently harm the reef at Manzanillo National Park in Costa Rica. The reef is polluted with runoff from the Rio Estrella. Toxic substances from pesticides and sewage runoff can cause metabolic problems in coral, decrease growth rates, and inhibit reproduction. Sediment accumulation on the coral heads prevents growth or kills the coral entirely. Fertilizer runoff and organic matter from sewage can cause an increase in nutrient contents that favor benthic algae growth, which can outcompete coral and cause coral death.COral_1.jpg
The reef at Manzanillo also suffered an earthquake in 1991. The earthquake caused sections of the reef to drop, which prevents it from obtaining enough sunlight, and ultimately causes portions to die. Other segments of the reef are uplifted to the surface, where they cannot survive. The sheer physical destruction wrought by natural disasters is devastating to the fragile coral organisms as well. Earthquakes cause sedimentation, depositing fatal amounts of debris on the coral heads. Coral reefs fringe islands with a high degree of volcanic activity. Costa Rica is a seismic hotspot with frequent tremors and countless volcanoes, which means that even the world aside from humans provides a constant threat to the coral ecosystem.
A physical manifestation of the reef’s distress is coral bleaching, which occurs when environmental disruptions kill endocellular symbiotic organisms called zooxanthellae. The resulting pigment loss causes the corals to appear white. Elevated temperatures and intense solar irradiation cause coral bleaching. Coral bleaching leads to coral mortality, and studies have shown up to 60% reduction in species richness one year after a bleaching event. Finely branched, soft corals are the most susceptible to death by bleaching. As global temperatures continue to increase, the incidence of bleaching will increase concurrently, and reefs around the world will suffer for it and continue to dwindle.

Dubinsky, Zvy, Stambler, Noga. Marine pollution and coral reefs. (1996) Global Change Biology 2(6): 511-526
Pastorok, R.A, Bilyard, G.R. Effect of sewage pollution on coral reef communities. (1985) Marine Ecology 21: 175-189
Brown, B.E. The fate of coral reefs in the Andaman sea, eastern Indian Ocean following the Sumatran earthquake and tsunami, 26 December 2004. (2005) The
Geographical Journal 171(4): 372-374
Brown, B.E. Coral bleaching: causes and consequences. (1997) Coral Reefs 16(5): S129-S138
Loya, Sakai, Yamazato, Nakano, Sambali, Van Woesik. Coral bleaching: The winners and the losers. (2001) Ecology letters 4(2): 122-131

Mangrove Forests
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Experts report that, “at least 35% of the area of mangrove forests has been lost in the past two decades, losses that exceed those for tropical rainforests and coral reefs…” (Valiela, 807).
Although mangrove forests are continuing to decrease in area, they are receiving less publicity than tropical rainforests and coral reefs. The destruction of mangrove forests is occurring globally, mostly due to anthropogenic causes. Humans are removing, destroying, and damaging the forests for profitable and industrial purposes. For example, mangrove forests are being carved out and replaced with dikes and ponds that are used to support the cultivation of shrimp. Mangrove forests are also being removed in order to create “salt flats” for salt collection and production. These actions are eliminating the energy that mangrove forests provide to other ecosystems. In doing so, humans are decreasing biodiversity within the mangrove habitats and the offshore ecosystems that the mangrove forests support. Along with providing habitats to multiple organisms, mangroves also possess many other ecological purposes. For example, mangrove forests provide stability to the land they are rooted in, and help prevent erosion. The elimination of mangroves decreases land stability.
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This being said, conservationists are raising awareness and developing restoration projects. As technology advances (i.e. satellite imaging), it has become easier to see the changes in the mangrove ecosystems. Satellite imaging illustrates the mangrove forests’ importance to the stabilization of coastal zones, and how human interaction is causing the land to diminish. Even the most untouched forests are losing species. It is believed that as mangrove forest sites are rehabilitated, the organisms that usually reside in the mangrove root systems and sediment will also regenerate and the ecosystem will gradually be restored. In order for these restoration projects to continue to be successful, researchers need to continue to collect applicable ecological information and legislatures need to develop policies and management plans.
Mangrove forests in Costa Rica are supposed to be protected by law; however, there is nobody who can consistently enforce the law. Therefore, pollution and evidence of human effects are still present within the mangrove forests. Furthermore, many issues have risen between real-estate companies and conservation societies. These real-estate companies believe that the mangrove forests decrease the value of surrounding properties as the dark mangrove sediment causes the waterfront locations to become less appealing. However, the ecological importance of the mangroves overpowers the economical desires.

Alongi, Daniel M. "Present State and Future of the World’s Mangrove Forests." Environmental Conservation 29.3 (2002): 331-49. Print. Mangrove Forests: One of the
World's Threatened Major Tropical Environments
Kricher, John. Tropical Ecology. Princeton: Princeton University Press, 2011. Ebook Library. Web. 02 Mar. 2012
Valiela, Ivan. "Mangrove Forests: One of the World's Threatened Major Tropical Environments." Bioscience 51.10 (2001): 807-15. Print.

San Jose
San Jose is a highly populated city in Costa Rica. As one travels over the mountainous terrain to San Jose, the plant and animal biodiversity decreases. The pollution and deforestation caused by humans and agricultural production decreases biodiversity. In the future, hopefully conservationists continue to research and establish animal and ecological conservation initiatives, while politicians continue to moderate human environmental interactions, to ultimately promote the preservation of the tropical species.


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Aerial view of the agricultural regions.

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Mountainous region in Costa Rica.





















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Aerial view of the city landscape as we fly into San Jose.