Ecology Study Questions: History, Lead, Mercury, Soil, pH and Nutrients
IES Winter 2003
History of Ecology
1) According to ecosystem ecologists what are the three dominant patterns of ecosystems? Briefly describe each one. Check a dictionary of ecology or ecology text, like Odum, if you are unsure.
2) Describe the contribution of two early ecologists.
3) What is the Green Revolution?
What is its relationship to Rachel Carson’s, Silent Spring?
4) Do you think humans are part of nature? Why or why not?
Jude VanBuren
Lead (Pb)
1) If the lead level in blood exceeds 10 ug/dL it is considered poisoning. What is 10 ug/dL in ppm? ppb? Show your work.
2) Why are children less than 6 years old most at risk for lead poisoning? Hint: there are physiological as well as environmental reasons. Why are pregnant women at risk?
3) What are the symptoms of lead poisoning? Can children have a high lead level but lack symptoms?
4) What kinds of nutrients can mitigate prevent absorption of Pb?
5) Since the year1750 there has been an exponential rise in Pb in the environment. What are the major sources of exposure to Pb at present?
6) Explain why did various ag groups lobbied to include a clause that land in pear and apple orchards from the 1940s should not be planted to root and tuber crops in land transfer contracts.
7) What ion does Pb mimic in the mammalian body? What are the route of Pb movement and the half time of ingested lead in various parts of the body? Why is it transferred to the fetus?
8) If the effects of Pb were known to the Greeks, why did it take so long to ban it? When did lead use as a pesticide begin in the US and when did it end?
9) Why do a higher % of Hispanic children in the “high risk” area of the Yakima valley have elevated Pb levels in comparison with the state average? Two reasons.
10) How does globalization/free trade as it is currently practiced contribute to increase of Pb in the US environment?
Mercury (Hg)
1) What form of mercury is most toxic? What organisms can take elemental mercury and change its chemical state? Where are they found?
2) Describe the mercury cycle. What are the natural sources of Hg in the environment? The presence of Hg in the environment has been estimated to increase five times over the background. What are the anthropogenic sources of Hg in the environment?
3) What are the main three routes of exposure to Hg for adults and which is most important?
4) Where is mercury stored in the body? What are the health effects of Hg for adults? For fetuses in the womb and children?
5) What is a fish advisory? What Washington lakes have advisories for Hg? Do the number of fish advisories reflect the amount of contamination in Washington State?
6) How many cans of tuna/week can you safely eat according to the fish advisory for tuna?
7) How does the Mercury Bill that has been introduced in the Washington legislation propose to reduce the sources of mercury in the environment? Which sources does it not propose to regulate?
8) Extra credit: Why does the seafood industry lobbyist oppose this Mercury bill on the basis that China is the source of the pollution? (This is truly the lobbyist’s point of view and it would be useful to know if there is data to back this up.)
Soil
1) What is the difference between soil structure and soil texture?
2) What are the 4 components of soil and why are they important with respect to a plant?
3) What is a soil profile? What are the 4 common horizons and their characteristics?
4) What is soil organic matter and what is its role in the soil?
5) What is the parent material of soil in the south Puget Sound area? How does it affect gardening and farming?
6) What are the four soil orders found in Washington and what are their characteristics?
Soil pH and Nutrients
1) Only 5% of the plant’s atoms that are not C, H or O and are called plant “nutrients”. The nutrients in greatest concentration are called “macronutrients”. Which nutrients are macronutrients, and what are their cationic and/or anionic forms?
2) What are the micronutrients and what are their cationic and/or anionic forms? What is their general role?
3) How much elemental N, P and K does a 12(N)-24(P)-12(K) fertilizer contain? Show your work.
4) What are the four ways that nutrients (or heavy metals) are held in soils? Which hold nutrients in a more available form?
7) Define pH. What is an acid? A base? Why is soil pH called a master variable?
5) At what pH are most of the nutrients plants need available? Which nutrients are most available at a low pH? At a high pH?
6) What are the natural and human causes of soil acidity?
7) What is the role of nitrogen in the plant (animals too)? How does a root absorb nitrogen? Why is the symptom of nitrogen deficiency in plants chlorosis (yellowing) of leaves?
8) What is biological nitrogen fixation of legumes? Why is it important?
9) What is the role of phosphorus in the plant? How does the root absorb it (two ways)?
What are common P deficiency symptoms?
10) What is the role of potassium in the plant? How does the root absorb it? What are
common K deficiency symptoms?
11) When purchasing a fertilizer, but trying to avoid heavy metals and other hazardous compounds, what steps might you take?
12) What fertilizer may contain naturally occurring but high levels of which heavy metal?
13) Check yourself on the nutrient deficiency symptoms. Answers are in the “notes” mode of viewing the screen (so you can see the screen and a note pad below).
Duff Wilson’s Talk
1) What is the “fertilizer loophole” in regulations?