Should we be concerned about invasive species?

Darwin and the theory of natural selection states that those organisms most fit for the environment survive. In the case of invasive species, this seems to be quite true, therefore, making them a cause of great concern for the humans as well as the environment.  Invasive species are introduced with the intention of providing benefit to the particular area. However, most of them end up causing more harm to the native environment than expected.

By the research that we did for determining the worst invasive species, we can say that these species have several advantages over the native species and most of these species have the ability to alter the environment in their favor, thus affecting or completely eliminating the native species. One of the advantages include the lack or less number of natural predators which help them flourish.  The high reproduction and dispersion rates, as well as the high economic damage done add up to the reasons that make the invasive species a cause for concern.

Determining the invasive species criteria:

The five criteria I chose for determining the worst invasive species are:

1.       High present population

2.       Dispersion rate

3.       Reproduction rate

4.       Economic damage

5.       Impact on biodiversity

I chose these because these are important characteristics regarding invasive species as well as these make the classification easier. I tried to find species that satisfy all the above criteria, along with having more information available about them that makes the classification distinct. The last three in my list which were- Bambusa vulgaris, Arundo donax and Sirex noctilio were easier to eliminate after comparing their characteristics regarding the above listed criteria. The other two species left were Eragrostis plana and Acacia longifoli. Both satisfied all the criteria but I chose Acacia longifolia because of its seemingly high and consistent presence over a wide area, as compared to the other.

The UN says to reduce meat consumption to curb global warming

“An American helps more in controlling global warming by going vegetarian than by switching their car to a hybrid Prius.”

By reading the article and by looking at the facts, I agree with the statement of the UN, that by reducing our consumption of meat, we would be able to contribute more towards controlling the climate change. Many people are aware of the various reasons contributing to environmental degradation like- overuse of fossil fuels, deforestation, and pollution by petrol and diesel run automobiles. But what most people do not know or fail to realize are the huge consequences that as trifling a habit as eating meat can have on the nature.

Like the fact that livestock farming generates 18% of the worldwide greenhouse emissions- in comparison with the lesser 13% accounted by the world's cars, planes and other vehicles. Rearing animals requires land which results in trees being cut down to make space for farmland to grow animal feed. In addition, it is estimated that some 70% of former forest cover has been converted into grazing areas- deforestation not only heats the planet as there is nothing to absorb the carbon dioxide, but it also deprives us of all the other benefits.  Even taking into consideration “grazing”, one can say that overgrazing is widespread, which eventually leads to soil erosion. Then there's manure — all the animal waste generates nitrous oxide, a greenhouse gas that has 296 times the warming effect of carbon dioxide.

Also, the continuous consumption of meat has resulted in increased demand, which has meant an increase in the need for animal feed- for which people from our own kind has had to suffer. Much more of the world's grain production is actually fed to livestock than to humans.

Apart from the motivation to help conserve environment, there are numerous other incentives that can be provided to an individual to cut down on meat eating. Like, the health risks one has to face can be seen in the increasing waistlines, especially in the US, as well as in the escalating threat of heart problems.

It can be argued that we can do or take up a lot of other things and activities to help the earth to not encounter its doomsday.  Yes, we can cut down our dependence on fossil fuels and switch to more eco-friendly or CNG run cars. Yes, we can make and pass legislations against deforestation and move towards utilizing renewable resources. But as we wait for these alterations to occur, we need some personal changes and a good example would be to shrink the amount of meat we eat. Rather than trying to stop eating meat at once, what people can do is focus on cutting the consumption down every day.

As responsible citizens of the world we should be asking ourselves that is it worth it to continue eating meat everyday at the expense of nature? Well, I asked myself and said NO.

Is the Indian Embassy field biologically diverse?

I think the Indian embassy field is biologically diverse. On adding up the data of all the biology classes, we found the number of different species to be 56 and the number of individuals of the species to be 193. I support my statement with taking into consideration the aspects of classifying something as diverse.

• I have found that the field species has richness( that there are multiple individuals of the species found) as well as  evenness( because largely, there are the same number of individuals every species, with some exceptions).
• The Simpson's Index points out that the field is diverse, as the probability comes out to be 0.095 which is closer to 0.
• The Simpson's Index of Diversity is 0.905, which is closer to 1 than to 0, indicating the probability that two individuals randomly selected from a given sample will be from different species.

Taking into consideration these factors, i can say that the Indian embassy field is considerably diverse.  

Measurements of my plant

I have found out the name of my plant: it's scientific name is "Agave attenuata" and it belongs to the family of "Agavaceae". It is commonly known by various names such as "fox tail agave", "lion's tail", "swan's neck", "elephant's trunk".
It is so called because of a feature of it. Each agave stem grows a flower spike, usually in about 10 years. The flower spike looks something like this:

Agave attenuata is native to the plateau of central Mexico(from Jalisco east to Mexico) and generally grow at elevations of 1900 to 2500 m.
Because of a good location of my plant in the campus, it receives an ample amount of sunlight, especially during midday.

In our last class, i did some measurements regarding my plant:

• I found the stem height to be 110 cm and the height of the plant including the stem and the leaves to be 182 cm.
• The diameter of the stem at breast height(DBH) is about 11.5 cm.
• I measured the canopy from two sides: if we visualize it, the part left of the stem is about 76 cm while the part right to the stem is 28 cm.
• We also had to measure the soil temperature by sticking in the thermometer, connected to a reading device, at various points in the soil surrounding the plant. However, in my case, the soil around my plant was quite hard, which made it difficult to push in the thermometer, so, i found out the soil temperature at only one point, which came out to be 20.9 degree Celsius.
• I also found out the light penetration through the leaf of the plant through the appratus set up out in the sun which included the light sensor and the reading device. I did it using the fresh leaf and the dry leaf:

 Fresh leaf: initial light when there was no leaf on the sensor=56930
              light passing through when the leaf was placed on top of the sensor=1392
Percent difference=56930-1392/56930
                           =0.9755*100
                           =97.6%(at the middle of the leaf)
Dry leaf: initial light when there was no leaf on the sensor=57449
              light passing through when the leaf was on the sensor=976 lux

Percent difference=57449-976/57449
                           =0.9830*100
                           =98.3%(at the middle of the leaf)


 pH  of the soil: additionally, i found the pH of the soil.

The pH( the "p" stands for "potenz" in German and the "H" stands for the "hydronium ions") is the measure of the acidity or basicity of an aqueous solution. It is measured on a scale from 0(very acidic) to 7(very basic), if the pH of a substance is 7 then it is classified as neutral, while if it is less than 7, it is acidic and if it is more than 7, it is termed basic. As we move farther away from 7, the acidity or basicity increases.
We can use a pH indicator to measure the pH of a solution. It is basically a chemical compound that is added in small amounts to the solution, which causes a colour change in the solution,depending on which the pH is determined. Below is a pH colour chart:

 

 

 Measuring the pH level of the soil is important before plantation because it intimates what type of plants can be grown. Plants grown in inappropriate pH will fail. In addition, the availability of nutrients changes with the pH. For example, if the pH of the soil is more than 5.5, then nitrogen is made available to the plants, while on the other hand, phosphorous is made available to plants when the pH is between 6 and 7. If the acidity level is high, then it can be corrected by adding lime and if the basic level is high, then it can be lowered by adding sulphur.

 I measured the pH of my soil sample by adding 20g it in water and letting it sit for about 20-25 minutes. After the particles settled down, i put an electrode into the water portion above the soil and determined the pH, which came out to be 6.52.

So, these are some of the aspects that i measured about plant.

What effect will these changes in population have on the environment and economy of Brazil?

I think the population change will surely have an impact on the environment as well as the economy.

As the population increases, there would be more demand for resources which will directly affect the environment such as more land would be required for housing. And that land will come from the existing vegetated area, thus decreasing the vegetation cover. The urban areas might increase as well with more urbanization. 

On the economic front, the standard of living might improve with the government investing more as the population increases. The government might have to spend more for the older population such as for retirement funds, considering that in the long term their size will increase. I think the working force will be the same, more or less.

Based on Brazil's current population age structure what do you expect in both the short term and long term to happen to Brazil's population?

Below is the population pyramid of Brazil for year 2010:

 We can see that the children(age group 5-19) and the working population(age group 20-54) is pretty high with the progressive decrease towards the older population.

I think that in the short term, the population will remain more or less the same or stable with not much substantial difference:

But in the long term, after around fifty years, Brazil's population pyramid is expected to change drastically with comparatively low birth rate and an even lower death rate. Which would mean that there would be a high population in the older age groups. This is evident from the expected population pyramid of 2050:

  


 

Why have i chosen IB Biology?

The IB program is an international program and so it is recognized by many countries. I am planning to go back to India after i graduate from high school and study the sciences there, so i think this is the most appropriate course for me to study.

Apart from this reason, i am interested in the sciences. This course includes a lot of important topics. This course is not only about theoretical knowledge but it also has a practical approach. That helps us in questioning and understanding the biological world.

So, this is why i have chosen IB Biology.

How is puzzle like science?

Science is about discovering the phenomena of the nature. The process of discovering can be called similar to solving a puzzle. There is always a problem to solve. As we begin looking for an answer, we find a lot of random information, which seems to make little sense to us. But step by step as we proceed, we see that all the pieces fit together to form a bigger picture or the information that seemed random to us at first points to a bigger fact.

The basic idea is that we have to relate and understand the order between various facts.