Akiko Ogawa’s

EFB516 Ecosystems Notes

April 19, 2001 (Thu)

Disclaimer:

These notes are my personal notes. The course instructor or TAs have no responsibility for the contents or any discrepancies between the materials presented in the classroom and these notes. You cannot use or refer to these notes to support or defend your answers on your exams. I suggest you use these notes to complement your own notes, and not to solely rely on. I would appreciate your feedback on any part of these notes that I may be misunderstanding.


Announcements:

Ø      Make sure you read at least Olsen (Chap 21) and Brown (Chap 22) of Maximum Power.

Lecture topic:

Human-dominated Tropical Ecosystems (section 3)

Tropical Ecosystems (section 3)

Slides

·        A city in dry tropics, Bolivia:  Lots of people. There are more people in Mexico City than in entire Bolivia. How can be such a concentration of people? Ecological foot prints – what’s the area of the world that supports the cities? – Probably larger than you seen in the background.  People take far more room than the physical or cultural space they occupy in their dwellings in terms of land required for production of food, fuels, fiber, and assimilation of (?). What the tropics is in large part about is crowding, very intense industrialization, and pollution. People in higher mountains of Bolivia are moving down into the Amazon as part of government program because the soil is gone. They are practicing shifting cultivation in Bolivian Amazon.

·        Lake Titicaca: High elevation, relatively dry tropics in Bolivia.

·        Bolivia: soil is completely destroyed, especially in south. Used to be covered with trees in 1500s. Spaniard discovered gold and silver and cut down the forest. Spaniards put cows on this land.

·        Malaysia:  Most of tropics are poor. Kualarunpur is a well-developed city. What’s the secret? – gas and oil. Anna Calenina theory “Good marriages are all alike. Bad marriages are each wrong in a wrong way. Good economy requires resources, not too many people, and a government that works. Malaysia has resources.

·        Malaysia: enormous investments in public housing. The government is relatively benevolent. The government may not be corrupted as seen in many tropical countries. So the government can invest in the people.

·        Malaysia is also rich because they have chopped down their original Dipterocarp natural forest and made a very wise investment in oil pump.

·        Rivers tend to be silty.

·        Rubber tree plantation.

·        A shopping mall in Malaysia: inside is a lake, which was a tin mine, and are pontoon boats inside to move between shops.

 

 

Olsen’s paper about shrimp mariculture in Ecuador.

Is shrimp farming good or bad? Economically good? Comparative advantage. David Ricardo – a classical economist. Labor invested is what generates value. Comparative advantage says each region should specialize whatever produces. The opposite is self-sufficiency. According to Comparative Advantage, NYC gets its milk from Wisconsin, not upstate NY because whatever Wisconsin has, soil, climatically, ability to make milk cheap.  

What’s the obvious cost of shrimp farming?

(Discussion will be continued on next Tuesday)

Slides

Costa Rica

·        Genesis II: South Cortado(?), Costa Rica. Large quantity of water, wet thin soil, red thin soil, high diversity.

·        (Graph) Yield of crop (maize, rice, and wheat) vs. fertilizer use: Crop yield increases following saturation curve as fertilizer use increases.

·        Landscape: Now Costa Rica is mostly pastures, 2nd most agricultural, and then comes undisturbed forest. Land area is about the size West Virginia. 3.5 million people. Can Costa Rica sustain 3.5 mil. People? Can it sustain the people on interest rather than capital, and at what standard of living?

Sustainability is tougher to achieve than many people would think. When people use the word “sustainability”, they use it in different meanings.

1. For anthropologist and sociologist, it means sustainability of culture – indigenous, native American, Quakers, etc. Perspective of evil vast forces (?) against them.

2. To many people, sustainability of economy. Sustainability of growth in the economy is of paramount importance.

3. Sustainability of the environment - 1) resources that allow the other sustainability to happen, 2) protecting natural areas.

·        For most social scientist, the question, whether there are enough resources, is simply not an agenda. Although economics is treated as social science is focused on humans, cities are just as much an ecosystem. They are highly heterotrophic system, in that primary production doesn’t necessarily take place there. We can view human-dominated ecosystems as ecosystems we can use ecosystem science to address them.

·        Tropical agriculture is increasingly industrial agriculture = fertilizer use. Fertilizer is energy-intensive. With fertilizer, in general in tropics, you get 0.5 to 1 ton /ha/yr of yield of major grains.

- Fact #1: The curves indicate saturation, i.e., you add more fertilizer, you get less response per unit fertilizer.

- (Overhead) Fact #2: mostly in the tropics, the yields are very low. The yields of tropical countries are normally around 0.5 to 1.5 ton/ha/yr in almost all the tropics. In temperate region, yields are much higher. One reason is the night is never less than 11 hours, Poor soil may be another. These are average yields for tropical countries including those rich countries that use a lot of fertilizer. These are two biophysical facts.

These are two biophysical fats about the Tropics.

·        (Graph) Maize yield as a function of latitude.

·        (Graph) Energy inputs vs. Site Quality of crop land: You can get high yields either from a field of high site quality or by addition of energy (fertilizer). For example, Citrus County, Florida is only sand. They get high yield by adding fertilizer. Putting a lot of energy in fertilizer, irrigation, or pesticides, you can get high yield. Most agriculture is some combination of moderate site quality and moderate energy inputs. But over time, if started with a moderate site quality, any time you farm, you degrade the soil – exposing to the rain, washed it away, heavy tractors compacting the soil, etc. People put more and more energy. Yield may go up. But people don’t see the site quality is degrading. So as long as the energy is cheap, you can generate high energy. Agriculture everywhere depends upon continual input of fossil fuel. To feed each of us one calorie takes about 10 calories of oil, or for one day, 1 gallon of oil in agro-industrial systems. Basic fact of Costa Rica is that population has grown so much you cannot support them with non-industrial agriculture.

·         (Graph) Crude Oil and NPK fertilizer price: In 1973, the first oil price increase, price of fertilizer went to the roof. 2nd oil price increase, fertilizer increased again, or remained high. Costa Rica was more impacted by increase of oil price than in U.S. Costa Rica has become more energy-dependent than the U.S. Many tropical countries, the principal economic problem is that they haven’t recovered from the oil price increased in 1970s. They went into debt to pay for the agro-input, then they haven’t gotten out the debt since. Pope John Paul II is calling for canceling Third World debt.

·        Forest burning in Brazil.

·        Mahogany logging road.

·        Shifting cultivation: Slashing.

·        Drying the slash.

·        Burning.

·        Forest burned down to ash.

·        Crop field: good yield of corn, squash, beans (N-fixer). Only one or two years. Farmers move to next place. Nutrients are gone.

·        Patch of field in the forest: People cycle this cultivation method. These systems are solar-powered. This is sustainable as long as population is low.

·        Shifting cultivation in Costa Rica is rare.

·        Costa Rica’s agricultural landscape: they replaced the function of shifting cultivation with the addition of nutrients. This piece of tropical landscape is intimately connected with industrial world.

·        Coffee plantation: nutrients are gone, but they put fertilizer.

·        Crop field on a steep slope: People took the best (= flat) land. Small farmers have only steep mountainsides to cultivate.

·        Typical small farmers: Costa Rica has better democracy than the U.S., less corruption, higher standard of health care, people live longer, higher standard of literacy. But they are facing these problems.

·        Diverse landscape. Banana trees, coffee, pasture.

·        Human habitation: Started with one family, generation over generation, the valley was occupied with more people.

·        Pesticide applicators

·        Fertilizers

·        German agro-chemical firm: every types of -cides.

·        Typical pasture on drier area: no cows. No production at all.

·        Monte Verde: biological site.

·        New pasture in Atlantic side.

·        Cotton field: sprayed with DDT.

·        Edge of the deforestation going up the mountain.

·        Model of deforestation and simulation: modeled 1949, and simulated 1983.

·        Flow diagram of the system: to produce a dollar worth of banana, you’ve got to pay300 dollars for agro-chemicals. Pollution there is horrible.

·        About a quarter of the money they get from coffee and bananas go to the bank as interest. The estimate of the amount to for the input that allows export to occur.


Last modified: April 23, 2001.

Any comments? E-mail to akogawa@syr.edu