Entries Tagged 'Natural Tragedies' ↓

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Pollution is the introduction of contaminants to an environment, according to wikipedia. Pollutants are not necessarily toxic chemicals that poisons the air we breathe, soil we stand on, and water we drink. Even chemicals seen as beneficial like fertilizers, which in reasonable amounts can boost crop production, becomes a poison when used in quantities that can’t be degraded by nature.

Pollution plays an important role in the loss of biodiversity. In our previous post on biodiversity, we learned that each species has role in an ecosystem and a balance must be maintained. Most ecosystems can withstand some abuse and regenerate as long as most species involved are still present. For instance, if we cut down half of a forest, the other half will soon cover the denuded area in 50 to a hundred years.

Pollution, however, has a more pervasive effect than simply cutting down a tree. Ultimately, it kills delicate species that might have a crucial role in the survival of another. Lets take a look at the 4 common pollution issues we are aware of today: (1) air, (2) water, (3) soil, and (4) species.

1. Air pollution as a threat to biodiversity.

Plants need sunlight to produce food via photosynthesis and smog prevents them from doing so. This affects both the plants (they die off) and the animals that depends on them for food. Fortunately, smog is geographically confined, usually in the vicinity of large cities where there are not much biodiversity anyway.

Another example would be acid rain, a product of the burning of “dirty” fossil fuel like coal. Lichens, fungi, and air plants are sensitive to acid rain and its impact can go far beyond where sulfur is being pumped into the atmosphere since they are incorporated into clouds and swept by the winds. A study in 1983 revealed that half of the Black Forest (in Germany, not the cake) was damaged by pollution, notably acid rain.

2. Water pollution as a threat to biodiversity.

The world’s oceans are our biggest garbage dumps. Everything we dump into streams or flush down the drain or throw out on land and gets swept away by rains goes into the oceans, where currents whirl them around for good measure. Toxins directly and adversely affect larvae, eggs, and other organism that lives near the surface or bottom, where toxins usually accumulate.

Larger fishes or mammals may not be directly affected but they store the toxins within themselves as they feed on the lower life forms. The beluga or white whale of the St. Lawrence river have high concentrations of toxins in their bodies.

3. Soil pollution as a threat to biodiversity.

Soil pollution is the build-up of toxic substances in the soil over time. Soil contaminants not only kill beneficial microorganism, they are also taken up by the plants. If we grow corn on polluted soil, we’d be eating those toxins too.

For biodiversity, the immediate threat is the eradication or killing-off of those species belonging to the primary link in the food chain.

4. Species pollution.

This may be a strange concept, a foreign species contaminating an ecosystem and changing the species landscape, but it is real. That’s what happened to the American Walnut. It was the dominant tree species in the Eastern United States, providing both a beautiful wood and food for humans and a host of wildlife.

Then, in 1904, some Chinese chestnuts were brought into New York’s Zoological Society’s Bronx park, carriers of a deadly parasitic fungus. The American chestnut was wiped out in most of its natural range by the 1950s. The space left by the chestnuts were taken over by oaks.

Other examples of introduced species that became pests in their new habitat include cane toads (from South America to Australia), Golden Apple Snail (US to Vietnam and the Philippines), Wild European Rabbits (Europe to Australia), and Kudzu (Japan to US).

Why is Darfur in the news? Darfur–loosely translated as land of the Fur, the dominant tribe in this western region of Sudan– has been the scene of another ethnic cleansing in Africa reminiscent of the Rwandan Genocide. This time, it’s the Sudan government and a nomadic arab tribe, the Janjaweed, against a ragtag collection of rebel groups from three ethnic tribes in the Darfur region.

Darfur is not a religious conflict, the battle lines were drawn across ethnicity. But is it really about a group of people unable to accept the color and creed of another? The Janjaweed and the Furs have existed peacefully in symbiosis for centuries. What really is behind the Darfur killings aside from the Sudan government using the Jajanweed to eliminate a threat to their regime?

Previously, we made a post on the 10 effects of global warming. Number 10 on the list is the threat on global security brought about by competition for dwindling resources. During one of our web wandering moments, we stumbled into this report titled The Real Roots of Darfur. It tells the story of Alex de Waal, an anthropologist who studied the social impact of the drought gripping the Darfur region even before the war  broke out, and an old Arab sheik.

The old, bed ridden Arab said he feared the future because “the way the world was set-up since time immemorial was being disturbed and it was bewildering, repressing, and the consequences were terrible.” And that was back in the mid-80’s. The old timer has never been out of his beloved desert and he doesn’t know, nor care, about things like greenhouse gases, global warming, and climate change.

His fears were based simply on the following observations in his twilight years:

1. Sand blew into fertile lands.

2. The ever rarer rains washed away the remaining fertile soil.

3. Farmers who once welcomed his tribe and their camels are now blocking their migration because the land could no longer support both people.

4. Many of his tribesmen has already lost their stock and scratched at millet farming on marginal plots, often the last resort for survival by a proud Arab people.

Now, the terrible consequences the wise sheik spoke of is happening. His fears were brought into reality by a person close to his heart,  Musa Hilal, his son and leader of the Jajanweed.

Originally, the environment’s degradation and the subsequent sufferings were blamed on the region’s inhabitants until scientists pinpointed another: global warming…

But by the time of the Darfur conflict four years ago, scientists had identified another cause. Climate scientists fed historical sea-surface temperatures into a variety of computer models of atmospheric change. Given the particular pattern of ocean-temperature changes worldwide, the models strongly predicted a disruption in African monsoons. “This was not caused by people cutting trees or overgrazing,” says Columbia University’s Alessandra Giannini, who led one of the analyses. The roots of the drying of Darfur, she and her colleagues had found, lay in changes to the global climate.

Are the events in Darfur a glimpse of what will happen in the future on a grander scale once disruptions caused by climate change makes unavailable the natural resources we are enjoying today? Will our generation or those coming after us be able to answer that question in the affirmative?

Looks like not only these 7 artic species are threatened by Global Warming, even Homo sapiens sapiens is at risk, especially those living in and around the Sahara, as detailed in this article entitled How to Prevent the Next Darfur by Time. This book by Stephen Faris, called Forecast: The Consequences of Climate Change, who wrote it after he learned in Darfur that the root to the conflict is related to climate change might give us  clues to the answer.

Tragedies are not limited to Shakespeare, botanical history is also littered with them. Such is the story of the American Chestnut Tree.

Before the 1990’s, the American Chestnut was the dominant tree species (approximately 40%) in the forest of the Eastern United States. The American Chestnut was highly priced for its beautiful and durable wood, its aesthetic qualities, and, of course, its nuts. The chestnuts provide wildlife with ample food and were also gathered by humans.

In 1904, a forester noticed that some trees in New York Zoological Society’s Bronx park were dying. The problem was traced to a parasitic fungus, Cryphonectria parasitica, common on Chinese and Japanese Chestnuts but never before known in the Americas. The parasite was unwittingly brought into the park together with some Chinese Chestnut specimens.

The Chinese species have enough natural resistance to the parasite not to be severely damaged when infected. However, the American Chestnut does not have such a resistance. The parasite started to spread everywhere the American species was found and all efforts to curve it proved futile.

From 1904 until the 50’s the disease left dead trunks over the American Chestnut’s entire natural range from Maine to Alabama. The space left by the dead trees were quickly taken over by oaks and other species so Americans aren’t aware of the loss today. Have they survived to this day, the American Chestnuts would be supporting a multi-billion timber industry and wildlife should have been much more abundant.

The roots of the many dead trees continued to live and send up sapling but they were continuously beaten back by the blight until the root stocks, exhausted after more than 50 years, died too. Today, out of the estimated 3.5 billion trees originally in the natural range, fewer than 100 are producing nuts. The huge trees seen today in Oregon were planted as much of Western North America is still free of the parasite.

A lot of time, money, and effort was spent to bring the American Chestnut back to its natural range with only limited success. A hybrid with mostly American genes was planted on the the White House lawn in 2005. It is doing well up to the present, a symbol of humanity’s attempt to atone for what is considered as the greatest botanical disaster in history.