Question: Many Scientists consider humans as the most invasive species, as humans can greatly change an environment and impact living things that reside there. Are we being stewards of the world? Tale a look at an issue in which human intervention has positively or negatively affected the biodiversity of our ecosystem.
Humans are indeed considered invasive species of the world that can change an ecosystem to an extent where no other living things can survive in the ecosystem. This is mainly because of our increased consumption of natural resources that destroy every other living thing in that ecosystem. I remember watching Matrix reloaded where smith (evil guy) said that humans are similar to a virus, simply because they never try to co-exist with an ecosystem. Instead they consume and deplete resources in one ecosystem and then move on to the next. This is exactly how a virus would behave. In this blog, I will talk about the Amazon forest and how human intervention has affected its habitants and the entire ecosystem.
The Amazonia (Amazon rainforest) is situated in South America and covers over half of Brazil. This forest is one of the world’s greatest natural resources due to the continuous cycle of carbon-dioxide to oxygen. Amazonia is also called the “Lungs of our Planet”, because around 20% of the Earth’s oxygen is recycled by this rainforest. This magnificent forest harvests over 500 mammals, 175 lizards and over 300 other reptile species. Yet despite this paradise, 20% of the forest had been deforested to a point of no re-growth. Between 1991 and 2000, the total area lost in Amazon rose from 415 000 to 587 000 km2. All this deforestation, has largely affected the species living in that ecosystem and it would have affected the entire world. Much of this deforestation is active through Cattle ranches, small-scale (subsistence) agriculture, Large-scale (commercial) agriculture and lastly urbanization. With more than 30 percent of the world’s species found in the Amazon, we cannot afford to lose this vital area.
here is a video on biodiversity in the Amazon:
What are we loosing?
- The Amazon forest recycles over 20% of oxygen in the world. Making it a vital source for survival on Earth. Without this, global warming would be accelerated, making the blue planet an inhabitable wasteland.
- Scientist estimates that we are losing 137 plant and insect species every day, due to rainforest deforestation.
- Over 121 prescription drugs are sold worldwide that come from plant-derived sources. The problem is that while 25% of western medicine is derived from these tropical trees and plants, less than one percent of trees and plants are tested by scientists.
- There were estimated 10 million Indians living in the Amazonian Forest 500 years ago. Now, there are less than 200 000. Many of these tribes have shamans and medicine men that have researched the effects of medicinal plants and herbs. When these people die without passing their knowledge, thousands of years of knowledge about medical plants have been lost.
- There are at least 3000 fruits found in rainforests where only 200 are used around the world. The natives use over 2000. Fruits are an important part of our diet. The fruits that we don’t use might give us vital nutrients that can prevent many diseases.
- And many, many more... (refer to http://www.rain-tree.com/facts.htm for more information)
Impacts on species and environment due to the deforestation in Amazon
Rainforests holds much species because the climate within that ecosystem is suitable for a diverse range of plants and animals to survive. The warm, moist climate with lots of sunlight and water enables plants and animals to grow without limits. Now tropical forests only cover about 7 percent of the 14% the earth once had. This continuous deforestation has affected Amazonian species in too many ways. Deforestation wipes out animals living in that area, reducing their numbers. Many species cannot survive the rapid change in climate and they just die off. If you think about this with the statistics, 587 000km2 of animals die due to human deforestation. If that is considered murder, just think about how many charges we would get.
(deforested land)
Although rainforest appears to have a fertile soil, it is just the contrary. Soil in the Amazonia has very poor nutrients in their soil. This nutrient loss is due to the high precipitation which causes minerals to leach. 99% of all nutrients of the Amazonia are found on the decomposing litter found above the soil. When an area is completely deforested for farming, the farmer typically burns the vegetation to create a fertilizing layer of ash. But, due to leaching this nutrient reservoir is lost. This leads unto high rates of erosion and flooding. Without trees to hold the soil, much of the deforested ted land can easily be turned into a dessert.
Affect on regional and global climate regulation: Large scale deforestation in the Amazon shows a considerable reduction in the evapotranspiration (process of evaporation and transpiration from plants). This deforestation will impact the global climates of the whole world, changing the North Atlantic and European storm tracks and cooling of southern Europe. It will also warm up parts of Asia in the winter.
Effect on Carbon storage: The Amazon accounts for nearly 10% of the world biomass. The Amazon rainforest is a vital piece in storing the organic biomass, and thus keeps the greenhouse gasses from the atmosphere. Due to continues forest reduction, stored carbon is released to the atmosphere, speeding up the effects of global warming.
Benefits of Deforestation to Humans
BRAZIL ECONOMY: Brazil’s economy is evidently depended on the Amazonian deforestation. The decline of deforestation in 1988-1991 marked the economic slowdown of Brazil. Similarly, the rocketing rate of deforestation from 1993 – 1998 matched the economic boost of Brazilian economy. The main causes of Brazilian deforestations are cattle ranching, small and large scale agriculture, and logging. Through these statistics, it is clear that humans benefit from the exploitations of nature’s natural gifts. We, humans need this much exploitations to become successful in our lives and lead a well maintained life. The only problem is that we don’t realize how much is sacrificed to achieve this goal.
In our religion classes, we have learned that humans are called to be the caretakers of this world and not its destroyers. God gave us dominance over all species and animals to take care of them using our brain. Yet, what’s happening now is contrary to what God has created us for. We basically survive from the continuous destructions of nature. An example would be from the Brazilian economy. Still, destruction is not all that we can do. We have realized many of our mistakes and have taken steps to fix them. Brazil’s new policy has bought down deforestation rates. We humans are capable of co-existing with nature’s species. The only problem is that we don’t realize the problems until we face them. We could have prevented all this if we had thought of the consequences beforehand. Our existence does not depend from invading ecosystems but it depends solely on the co-existence with nature’s most prized creations.
SOURCES:
http://www.blueplanetbiomes.org/amazon.htm
http://www.mongabay.com/brazil.html
http://rainforests.mongabay.com/amazon/amazon_wildlife.html
http://www.nicholas.duke.edu/thegreengrok/amazonbiodiversity
http://earthobservatory.nasa.gov/Features/Deforestation/
