Archive for » April, 2011 «

Saturday, April 23rd, 2011 | Author:

Biodiversity-

As this graph shows, human population and extinction rates have been rising at the same amount, in the same time frame. These increasingly high extinction rates result in a loss of biodiversity on a global scale. As the graph suggests, human actions have led to the large growth in extinction. (Note: extinctions are a natural occurrence when a specie is unable to adapt to a changing environment….but our current levels of extinction are not natural)  Why should we care? According to this MSNBC article, we still have time to stop or slow down the Earth’s 6th Mass Extinction. However, in order to know how to stop or slow down a mass extinction, first we need to know what causes it in the first place. As Dr. S taught in class, there are 5 main human-caused extinctions:

1. Excessive Predation: hunting, raising wild animals as pets

2. Habitat Destruction: deforestation, housing developments, growth of cities

3. Destruction of Keystone Species: species that play a crucial role in their ecosystem–> without it the ecosystem could collapse.

4. Introduction of Exotic Species: competitors overthrow native species, unnatural predators disrupt the food chain, diseases spread especially among plants.

5. Pollution and Contamination: BP oil spill, water pollution, air pollution, climate change

It is important that we all do our part in trying to stop the 6th mass extinction, but it also goes further than just an individual level. It needs to be an international level. We need to get governments from across the globe to recognize the serious problem on our hands. However, that starts with community efforts (like our campus for instance). Communities can appeal to their government representatives and let them know that this issue is important to us. Let’s all do our part in trying to stop excessive predation (give up hunting as a hobby, or do it less, or make sure the species you’re hunting is not endangered), habitat destruction (deforestation), destruction of keystone species, introduction of exotic species, and pollution and contamination (recycle, throw trash in trash cans, etc).

Final Thoughts-


Over the semester I have learned so much from this class, and honestly i’m going to miss it so much in my upcoming semesters! I am now more knowledgeable about global problems, but also specific case studies of these problems (domestically and internationally). I have learned different solutions to these problems…there is hope that we can fix them! These global problems are the issues that I hope to help solve someday, and maybe that’s why they mean so much to me. Whether there will be one solution, I don’t know. I think it is more likely that a number of solutions, creative ideas, technological advances, and a more thorough understanding of nature will help us solve these problems. I think it is important to note the global trends that Dr. S lectured: rise in population, rise in water demand, decline in natural resource supply, rise of ecosystem services suffering, decrease in crop yields, decrease in biodiversity, and an increase in climate change.

Let’s spread the word by appreciating and respecting the true value of nature!

Fun Earth Day Activities:


On Friday, I stopped by the Underground to celebrate Earth Day! I was happy to see that there was a good turnout (even though it was raining!), because that means that we have an active community who cares about our environment! There were many fun activities such as tie dye, decorating reusable cups (I made mine with a sun, earth, and an ocean!), making t-shirts, and many more. While this was a fun, lighthearted celebration, I did keep in mind what Earth Day is truly about: respecting our Earth and our environment.

-Kristen Callahan

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Friday, April 08th, 2011 | Author:

(Demonstrators protesting to protect coral reefs in Belize.)

Coral reefs, “the rainforests of the seas”, are very beneficial for humans and are necessary for the survival of marine life. So why are we (whether directly or indirectly) destroying them? And what can we do to stop harming these coral reefs? These are some of the thoughts that first pop into my mind when thinking about threatened coral reefs. On this wonderful website about coral reefs I found some answers to my questions.

First, I think it is important to discuss why we should care about coral reefs. According to NOAA, coral reef tourism, jobs, and food amounts to about $375 billion per year. Since coral reefs need specific living conditions to thrive (shallow depth, warm water, specific salinity), they tend to grow around tropical islands, many of whose economies rely heavily on tourism revenue. What will happen to these countries economies if all of a sudden their coral reefs (a major source of tourism profits) have died? Will less people take vacations to those countries? Those affected countries could lose billions of dollars a year as a result.

Besides coral reefs important economic value, we should also care because they are an intricate part of the marine food web. About 25% of fish take shelter in coral reefs, along with up to 2 million other species. Therefore, if most of the coral reefs in the ocean die, 2 million species would become displaced, and perhaps die. This would have a devastating effect on the food web. In turn, that would effect our fisheries (which we also discussed in class). We are already overfishing 75% of wild fish. If these wild fish (our food source) lose their food source (smaller fish, microorganisms, etc) because the coral reefs supporting those species have died, then the populations of wild fish we eat will take a sharp decline. (Which will be bad because they’re already in danger/overfished!)

In addition, coral reefs also protect shorelines by lessening the impact of storms and waves. While I could go on and on discussing more about coral reefs, I think the two points I made about why we should care about coral reefs are possibly the most important. Especially because it explains why coral reefs are important to us, therefore, governments and people can realize that it is in our best interests to preserve them!

-Kristen Callahan

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Friday, April 01st, 2011 | Author:

On March 19th I went to the Environmental Film Festival in DC to see the film “America’s Lost Landscape: The Tallgrass Prairie”.The first thing I want to note is that the theatre was packed! I was surprised because I figured that a film about the prairies wouldn’t exactly be the most popular of the films. This film focused mostly on how the tallgrass prairie, a “national treasure”, had been lost to white farmers and settlers after the War of 1812. One statistic that struck me was that if the pre-settler prairie was a thousand piece puzzle, only about one piece is left. The beginning of the film explained how the prairie has hot, dry summers and cold, wet winters. Since the climate is too dry for trees, the Big Blue Stem (about 5-10ft tall) grass is the major plant of the prairie. The prairie had biodiversity with a hundred species of birds, bison, elk, coyotes, and badgers, in addition to many different types of grasses and plants. About 30 Indian tribes lived on the tallgrass prairie. After the War of 1812 when the Indians were pushed out of the prairie, the white settlers flooded onto the land. Louis and Clark had discovered that the prairie soil was very fertile, and the settlers cleared the land for extensive farming. By the 1880s all of the bison had vanished from the prairie (keep in mind this is only about 70 years since the settlers arrived0. By 1900, there was no prairie left…it had all been converted into farm land. This devastation of the tallgrass prairie is so shocking because it happened within the lifetime of one person.

The last part of the film focused on a man named Aldo Leopold and his efforts to conserve the prairie lands. His books helped redefine the environmental movement and the way that people viewed their land. By the 1960s, the prairie conservation had taken hold and some of the tallgrasses began to return. Today, prairie conservationists focus on doing roadside restoration projects. While the tallgrass prairie is an important place for agriculture, I think it is important that we try and save a portion of it (like establishing national parks). We can’t expect to change the ecosystem of the tallgrass prairie, and the soil would be more productive if we worked with it, instead of against it. I really enjoyed watching this film and learning about the tallgrass prairie, especially since it is a topic that I have never really studied before. I hope that after reading this blog you can respect the tallgrass prairie and realize that conservation efforts are important.

-Kristen Callahan

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