What is an Ecosystem?
Practice/feedback
09-02-99/09-04-99
Note: multiple answers possible
1. Cows severely deprived of phosphorus have been known to eat bones, rabbits and birds. But, cows are ruminants and eat herbaceous matter, i.e., plants (ignore the deprivation story). Cows are called: (a) decomposers (b) omnivores (c) carnivores (a) herbivores
2. Gross productivity (PG) eventually is respired insitu, or it is channeled either through a decomposer (microbes, fungi) or a grazer (a cow, an elk or a tortuose) (a) true(b) false
3. The amount of energy stored at the 2nd trophic level is about 80 % to 90 % of that found at the 1st trophic level. (a) true (b) false
Less than 10% is stored in the second trophic level; 80 to 90% is lost as heat
4. All matter is eventually oxidized to CO2 and H2O and the energy released is dissipated back to the atmosphere as heat. (a) true (b) false
Given enough time; of course, mineral are recycled.
5. Consumer (Animal) respiration includes both the heat lost in supporting standing biomass and the inefficiency of growth and reproduction (a) true (b) false
6. In ecological terms respiration is heat lost because of the inefficiency of energy transformation. (a) true (b) false
7. Digestibility is the percentage of ingested feed absorbed from the gut. (a) true (b) false
8. The digestion coefficient has no units, i.e., it is a decimal fraction. (a) true (b) false
9. The true digestibility of the energy consumed by a ruminant herbivore was 60%. That means 40% of the consumed energy was excreted in the feces. (a) true (b) false
10. Productivity is an attribute of plants and has units of mass, area and time (a) true (b) false
11. For many animals the energy contained in feces and urine cannot be measured separately, e.g., birds. The ecologists subtract the combined fecal and urine energy from ingested energy and call it assimilated energy. That is similar to what animal scientists or food scientists call (a) metabolizable energy.
12. Response of rangeland environments to human or natural inputs is always uncertain. (a) yes (b) no
13. Most secondary producers are herbivores. (a) true (b) false
Of course, secondary producers are also heterotrophs
14. The conceptual boundaries of an ecosystem are defined by the issue to be addressed. (a) true (b) false
15. Heterotrophs include all consumers. (a) true (b) false
16. A trophic level is a conceptual level of energy or dry matter storage in the ecosystem. (a) true (b) false
17. Nutrient cycling can not happen without herbivory. (a) true (b) false
Matter is ultimately decomposed vis-a-vis decomposers and nutrients are recycled. The herbivore may be
an intermediate step.
18. Rangeland plants have many mechanisms to cope with defoliation, such as fire and herbivory. (a) true (b) true
19. (a) The lithosphere is the surface few millimeters to meters of the earth’s crust which supports life and anchors plants. (b) The hydrosphere is the surface of the earth’s crust which supports life and anchors plants. (c) The film talked about environment as a general set of circumstances/habitat characteristic of a specific organism (d) Cultural traditions are learned behaviors (e) The words grassland and biome are congruous; it is okay to talk about grassland biomes.
20. An attribute of plants is their peak standing crop. (a) true (b) false
21. Biomass is characterized by volume.. (a) true (b) false
Biomass is characterized by mass
22 According to the film, environment is characterized and named by the kinds of plants and animals found there, e.g., a desert environment or a semi-arid environment.(a) true (b) false
23. The lithosphere is the interface between land and water. (a) true (b) false
I suppose the interface between land and water might be called a riparian area
24. An example(s) of a tertiary producer and secondary consumer that has a wide range of environmental tolerance might be (a) an elk (b) a moose (c) a coyote (d) cougar (e) a pronghorn
25. The units of productivity must include mass, area and time. (a) true (b) false