Question

For some, non-zero values of r and K, there is no equilibrium other than population extinction for any values of a and E; 17. (4 points) Which of the following are side effects of management for sustainable, optimal (as biomass, profit, or other measure) management of a single species (pick D) Species which prey on the managed species may decline; b. Species on which the single species feeds may increase; C. The competitive balance among various prey items of the species may shift; d. The total yield (biomass, gross revenue, profits) from all fisheries may decrease as other valuable species are affected by the single-species management; e. All the above; a 18. (7 points) The competitive exclusion principle states that: Two species cannot coexist if they overlap in resource use; b. Two species cannot coexist unless they have the same carrying capacity (the equilibrium value when only one species is present); Two species cannot coexist unless interspecific competition is less intense than intraspecific competition; d. Two species cannot coexist unless intraspecific competition is less intense than interspecific competition; Two species cannot coexist if they exhibit interspecific a. C orial behavior. 19. (7 points) The competitive exclusion principle is based on models of competitors in simple, constant environments. Which of the following mechanisms can allow coexistence in more complicated situations: a. Temporal variation in competitive abilities which alternately favor different species; b. Predators which preferentially prey on the competitively superior species; c. Spatial variability with different patches or parts of gradients favoring different species, with movement among areas; d. Periodic disturbances which destroy enough individuals to allow recolonization by competitively inferior species; All the above. e. 20. (5 points) Which of the following attributes of plant succession are usually true (pick 2); Across successional stages should be interpreted as from early to late stages: Total diversity across landscapes increases with range of successional habitats b. Species arriving early change soil and shade conditions to their own competitive disadvantage; c. Without human intervention, landscapes consist almost entirely of climax stages of vegetation; d. Within site productivity (per unit biomass of plants) increases consistently across successional stages; a. Endangered species are typically found in later successional stages; e.

Answer 1

17.during the sustainable management of one species may lead to side effects such as the existence of species which prey on managed species decreases and also the number of species wich eaten by the conserved species are decreases. The competitive balance is the existence of nature it also shifted .so that the total biomass or yield may decreases.

18.The competitive exclusion principle states that species with a same nitch ( resource ) cannot co exist together indefinitely. There intraspecific competition is less than that of inter specific competition.