jueves, 21 de octubre de 2010

FARMS!!!!!!! :)

Farming and Food Production

Subsistencevariety of mixed cropsextensive use of human labor, low input for fossil fuelschemicals and capital.
Commercial- single cropmaximum yieldhigh levels of technology.

There are different classifications of farming:

Energy budget farming

Examine inputs, outputs, flows and storages in order to determine this.
Consider marketable product, which is only % of total output




lunes, 18 de octubre de 2010

MEDC vs. LEDC (food supply and distribution)

MEDC and LEDC have very different characteristics regarding food production and distribution, like the following: 


jueves, 14 de octubre de 2010

Food, crops, yields, techniques, revolutions, and so

5. What three systems provide the most of the world’s food?
  • wheat
  • corn
  • rice

6. Distinguish among  polyculture and slash-and-burn-agriculture.
  • Polyculture- type of interplanting in which many different plants are planted together.
  • Slash-and-burn agriculture- when farmers grow as many as 20 different crops together on small cleared plots. In this type of interplanting, crops mature at different times, provide food throughout the year and keep the soul covered to reduce erosion.

7. What is a green revolution? What limits could these have?
Green revolution is a process that has increased the 88% of the increase in global food production by increased yields per unit of area of cropland. The first stage began in 1950, in MEDC and its mainly caused by technological advances, population changes, and evolution of ecological and social ideologies.
It involves 3 steps:
  1. develop and plant monocultures of selectively bred or genetically engineered high-yield varieties of key crops like rice, wheat and corn.
  2. produce high-yield by using large inputs of fertilizer, pesticides and water
  3. increase in the number of crops grown per year on a plot of land

The limits that this revolutions has rely mainly in lack of water, high cost for small farmers, and physical limits to increasing crop yields.

miércoles, 13 de octubre de 2010

Unbalanced Food Supply...?

The issues involved in the unbalanced global food supply are: 


miércoles, 6 de octubre de 2010

Pyramids of population

Population pyramids are graphic representation of population and are used to:
  • Population distribution
  • Population change, for upper levels (because the majority of lower level
  • Identify ratios male:female




Stage 1: EXPANDING
High CBR, rapid fall in each upward age group due to high CDR, short life expectancy

Stage 2: EXPANDING
High CBR, fall in CDR as more individuals live to middle age, slightly longer life expectancy

Stage 3: STATIONARY
Declining CBR, low CDR, more individuals live to old age.

Stage 4:CONTRACTING
Low CBR, low CDR, higher dependency ratio (those that cannot work), longer life expectancy



*LEDCs tend to be stage 1 or 2
*MEDCs tend to be stage 3 or 4

Two different points of view about population growth :)

Two important theories that contrast a lot about population growth and food shortages are:


Thomas Malthus's theory:

  • That the power of population is indefinitely greater than the power in the earth to produce subsistence for man.
  • Population growth will outpace agricultural production.
  • According to Malthus, disease, food shortage and death due to starvation, were nature's way to control population.
  • He thinks the control of birth will prevent these problems.
  • It assumes population grows exponentially and agricultural production grows in a linear manner.
  • It doesn’t recognizes human capacity to increase food supply.





Ester Bosercup's theory:
She was a Danish economist and writer who worked for the UN, she wrote about population growth and agricultural development from a technocentric perspective.

  •   Humans will create technology to increase the food supply and create a sustainable society.
  • Necessity is the mother of invention.
  • Too optimistic

Formulas and ratios to measure the changes

There are 4 main factors affecting population change:
  • Birthds
  • Deaths
  • Immigration
  • Emigration 

And to measure changes in those, we use:

MEDC & LEDC ... not only a label

Human development index is the measure of the "well-being" of a country. It is based in factors like:
  • Life expectancy
  • Life quality
  • Education
  • GDP per capita

How do populations behave?

There are variables that affect how do populations change over time (growing or decreasing), and these are called limiting factors. These keep populations in check and can be classified into:
  • Density dependent factors
  • Density independent factors
Density dependent factors are those that, as its name implies, depend on population density. This means that the impact these factors have depends on how many individuals there are. These are usually biotic factors, such as biomass, predation, competition.

Density independent factors are those that affect a population regardless of its size. These are usually abiotic factors. Some examples are pH, temperature, salinity, and also natural disasters such as tornadoes, earthquakes, volcanic explosions.



The "profit" in an ecosystem (sustainable yield)

If the ecosystem was to be a business there would be a "profit", called sustainable yield. SY is more clearly defined as the resources you can take from nature, without harming it or affecting its balance. 



·      Sustainable yield can also be seen as the increase of natural capital. The natural income that can be exploited each year without depleting the original stick or its potential for replenishment.
o   Carrying capacity
o   Population size
o   Total biomass
o   Rates of change of population/biomass/energy

EIAs :O

EIA's stands for Environmental Impact Assessments, and they are used and followed to obtain data, analyze it, and conclude what should be made with it to lower negative impact.




Environmental Impact assessments must:
  •       include a section that identifies the impact.
  • ·    Try to predict or to estimate the value or reach of this impact.
  • ·    Assess or limit an impact.


Economy & Systems & Capital & Resources & so on...

The different economic systems around the world have several similarities, the main one is that they produce and distribute goods and services by using natural, human and manufactured resources to satisfy people's needs and wants in the must effective and efficient way. 

martes, 5 de octubre de 2010

If every one in the world would live like me...

This entrance is about my ecological footprint in the world, and it consists in a calculation (that takes in account my life style, how much I travel, what do I eat, what do I buy, etc) that gives at the end how many worlds would the human population need (in means of natural resources) if everyone lived like I do.  

sustainability.....Where can I eat that?

Sustainability is recently one of the most common topics of conversation, investigation and specialization around the world, but what exactly does it mean?