Akiko Ogawa’s

EFB516 Ecosystems Notes

April 24, 2001 (Tue)

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      Read Collins “A New Urban Ecology” for next lecture (with priority).

Lecture topic:

Industrial/agro- ecosystems

Industrial/agro- Ecosystems

 

Olsen’s paper

·     Mangrove forest in Ecuador is destructed because of production of shrimp. Mangrove forests fringe the low energy environment of coasts of tropical world. Most aquaculture is extremely energy intensive – more than catching wildlife. Catching fish takes 10 to 20 calories of oil per a calorie of fish. Mangrove forest transformed to shrimp farm for export. This part of the process of globalization. Ecuador generates great amount of money. Exporters are a few relatively rich mestizoes. How do poor people traditionally make living? ­- Fishing.

·     How much of Ecuador coastal area was transformed to intensive shrimp farming? – About 50%. Where do they get shrimp larvae? – From natural estuaries. Shrimps take advantage of the bi-directional current of estuaries. Adult – ocean, eggs swept into estuaries, young stay for several months, and come back into the ocean. People catch larvae with A-frame nets at outgoing tide. No way to manufacture shrimp larvae at hatcheries. The more mangrove forests are transformed into fish ponds, the less the source of shrimp larvae. Shrimp farms are also have problems such as pollution and disease due to concentration of population – antibiotics.

·     What was Olsen’s problem? – He first tried to evaluate shrimp in terms of GNP. He was not capturing the important picture using conventional economics. He turned to emergy because emergy is more comprehensive.

·     If you try to figure out economic value of an ecosystem, is money appropriate? – It depends. Robert Costanza, Karin Limberg, and others wrote a paper in Nature in which they tried to put dollar values on ecosystem services. In Ecological Economics – a journal, society, and a way of thought. Can we put together Ecology and Economics – both came from the same word, “oikos” – together and have more powerful concept?

·     Externality – cost that’s not included in the price, e.g., external cost of producing MacDonald hamburgers = destruction of rain forest, to create the patch to create the cow, etc. Ecological economics try to internalize all the environmental cost becomes more expensive, e.g., you don’t pay the external cost of pollution which would include the hospital bills if somebody get hospitalized due to the pollution. The concept of ecological economics is they want to internalize externalities. If we do that, logical conclusion is that we have much more expensive price for everything we do. Neoclassical economics are keeping the price low. Protesters in Quebec recently are talking about a lot of externalities with the cheap products from the countries that don’t have strong labor or environmental laws.

·     Costanza says the value of ecosystem services around the world is greater than world’s GNP. But it seems absurd (to Dr. Hall) to put the value of ecosystem services into those kinds of units because 1) if we turn off the ecosystem services, we all die and it doesn’t make any difference, and 2) if you put value of loss of wildlife habitat into the price of something, it doesn’t make sense to say “the price of this hamburger is 0.037 grizzly bear habitat.”

·     Emergy – energy memory – really means energy quality. Not all the energy is the same. A calorie of sun light has much less ability to do work in the ecosystem than a calorie of a plant photosynthate, which has much less ability to do work than a calorie of high quality protein, which is still less value – detrital food chain is upgrading the nitrogen content. All of these are based on basic ecosystem way of thinking about how the world works.

·     There’s certainly controversy about what these quality factors should be. H.T. Odum believes they have to do with “how many steps it took in an ecosystem to upgrade them” – it’s one way.

·     Dr. Hall’s premises:

1) Money is not a sufficient index of measuring ecosystem health of well-being and contributions to human endeavors.

2) Energy makes a lot of sense because it’s a sort of universal currency of nature, and because we can use it to measure and understand many aspects of nature including things that contribute to fitness – fitness is what a biological game is all about. Your fitness is your ability to propel your genes to future.

3) Energy has different qualities as photosynthate has different qualities from protein’s.

·     However, Emergy analysis is controversial. Best way is to do any analysis is to do by several different techniques and see if you come up with similar answers. Dr. Hall did in his book emergy analysis, ecological foot print analysis, and comprehensive analysis, and came up with similar answers. What do you do with emergy – The most interesting example is in Mark Brown’s analysis.

 

Mark Brown’s paper

·     He compared the four systems – Thailand, Amazon, Sea of Cortez, and Papua New Guinea (PNG).

·     How can we characterize those four systems – different gradient of what? – Gradient of development. Thailand may be a little more developed.

·     What gives a country a comparative advantage in trade? Why PNG has a favorable trade balance? – It has large ratio of renewable, solar driven, free resources compared to fossil fuel-invested resources. Thus they don’t have to invest very much fossil energy in to getting a trade item – fish or tropical plant item. Because most of the energy provided to generate that product is done by nature. You don’t have to pay for nature’s services. T’fore PNG can generate product with high value (of emergy content) at relatively low cost. We choose product from PNG because it’s cheap.

·     An example – fish processing plant in Italy. These products go to Italian and mostly to US market. The fish are ? from South Africa, shrimp from Thailand, calamari squid from Malaysia. You can’t catch a squid in Mediterranean – natural subsidy is low. Malaysians often catch their fish or raise their shrimp with much less energy, thus at a favorable market price even after the shrimp production is shipped to Italy, packed there, and shipped back to the U.S. 

·     Basic point of Mark Brown’s is that if nature investment is high and then human investment is low then you can produce cheap price. But that is changing in Costa Rica? Why Costa Rica from high natural energy vs. fossil energy?

-         People are living in the best agricultural land.

-         Population growth.

·     Population growth is so great that you can no longer support the people with the land area. Land area is insufficient relative to the number of people. The ratio of number of people per ha of arable land is critical issue all around the world.

 

Science article, “Biospheric Primary Production During an ENSO Transition” by Behrenfeld et al.

Net primary productivity for the whole world for both water and the land was represented in the same unit for the first time (picture below, click to blow up and read the caption). We can see high productivity in Argentina and Chili in our winter, but nothing in the north hemisphere. Plume of NPP off Chili coast due to the cold upwelling bringing up the nutrients. The strong wind Dr. Hall experienced in Patagonia apparently is doing the same upwelling phenomena all the way across the South Atlantic Ocean. The tail of it can be observed coming off of Australia. Similar pattern can be seen off the east coast of the United States in summer.

 

Science article, “Energetic and Fitness costs of …“ by Thomas et al.

Blue tits (= Chickadee) are dependent on abundance of caterpillars that feed on new leaves of two oaks – Corsican and Continent. The authors compared the cost of metabolic effort as a function of how close they got to the peak of caterpillars. If blue tits arrive at the right time, the energy cost of raising a brood would only be three times higher than their normal budget. The closer they get to the peak of caterpillar abundance, the lower the cost and the larger the size of the brood. Bigger and more numerous offspring translates directly into fitness. This is a good example of how energetics is directly translated into fitness. 

Due to the climate change, the timing of new leaves has become earlier. Caterpillars can adjust their hatching time and fed on new leaves. But birds cannot arrive earlier, causing deficiency in fitness.

 

Costa Rica

In Costa Rica, Dr. Hall’s group applied the gradient space approach to try to understand better the economic circumstances of C. Rica. This is something called biophysical science. Most economics are done as social sciences.

(Chart of gradient space and geographical space of Luquillo Mountain in Puerto Rico) Every location in this geographical space has a corresponding position in gradient space of, for example, soil moisture. Each species has some optimal area where energetic costs and energetic gains will be optimized. They asked the same question if that is true for Costa Rica. The answer was basically yes.

Costa Rica coffee production is 2%.  (The geographical and gradient space chart of Costa Rica below) Black area – high coffee yields (1.5ton/ha), dark shade – moderately high (1ton/ha), light shade – at least 0.5ton/ha yields, and white – not much. When this is translated into gradient space, maximum production happens where the temperature is between 22 to 24 deg. C, and precipitation 1.4 to 3m/yr. In biophysical perspective, your opportunity of growing yield coffee of high net production and potential good economic return is in very restricted part of the country. Same with banana. First empirical evidence that the concept of gradient space works at least in domestic plants and the production, or net energy gain are high in these circumstances.

 

 

 

 

(Costa Rica rice production graphs in the left) Between 1968 to1973 the area of rice fields was reduced, and then between 1973 and 1975 greatly increased. In the same period, the amount of fertilizer/ha (second graph) generally increased – one indication of industrialization. Efficiency (at the bottom) (yield/ha) greatly increased from 1.3 to 2.8 in 1972 or so, and then dropped even though the fertilizer use increased. Why? – When you reduced the area in production, farmers went to use the best land. When the land area increased again, the yield/ha dropped down. This was found for all major crops except sugar cane. One of Ricardo’s economic principle – farmers use the best land first. With only so much land, you use the best first. When you expand beyond that, then your yield/efficiency declines.

What this means to the world of expanding population is that our efficiency is going to be decreasing more and more over time.

 

Costa Rica computer model demonstration

1943 undisturbed forests -> 1983 decreased over time. Up to 1990 the simulation just reflects the empirical data. The data shows that human population, #cows, agri land, fertilizer use increased. Yield /ha decreased. Yield/ha for cotton and grains increased enormously due to input of the input of imported fertilizers and other industrial chemicals. Amount of food required for this population is going to grow exponentially. Costa Rica is importing about 1/3 of its food calories. Food production is not keeping up with food requirement. Undisturbed forest is declining, CO2 is being released from deforestation. Cost of industrial inputs for just agriculture increased enormously, greater than all the gain from coffee – their most important crop – following the price increase in 1970s. This put C. Rica into debt. Costa Rica is still paralyzed by the debt they got from the oil price increases of the 1970s.  Economy of these developing countries, among which Costa Rica is relatively successful one, is still dependent upon the input of industrial inputs, and price of those input relative to the price of agriculture commodities. Coffee is the lowest price right now.

There’s nothing about protecting the environment. Food requirements go up, all the forests are gone, lots of CO2, all the lands are transformed into agriculture, urban area or pasture, or erosion, cost of agri input exceed the gain from coffee or banana – in other words, it doesn’t work. One reason they chose is Costa Rica was supposedly a model of sustainable development. But this study showed that it’s not really the case.

Reference:

Behrenfeld, Michael J., J.T. Randerson, C.R. Mcclain, G.C. Feldman, S. O. Los, C. J. Tucker, P.G. Falkowski, C.B. Field, R. Frouin, W.E. Esaias, D.D. Kolber, and N.H. Pollack. 2001. Biospheric Primary Production During an ENSO Transition. Science. 291(5513):2594-2597.

Thomas, Donald W., J. Blondel, P. Perret, M.M. Lambrechts, J.R. Speakman. 2001. Energetic and Fitness Costs of Mismatching Resource Supply and Demand in Seasonally Breeding Birds. Science. 291(5513):2598-2600.

 

Last modified: May 2, 2001.

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