Lab 10

Question 1

….: two or more individuals use the same resource

Answer 1

competition

Question 2

competitive interaction among members of the same species is called …
competitive interaction among members of different species is called …

Answer 2

intraspecific competition; interspecific competition

Question 3

plants growing in the same environment compete for …, …, and …

Answer 3

sunlight; water; soil nutrients

Question 4

in plants, the … is an indicator of the success of a population, but … of individuals is important as well

Answer 4

number of individuals; size

Question 5

a better measure of competitive outcomes in plants is … accumulation over time

Answer 5

biomass

Question 6

to measure biomass, ecologists harvest all plants from a sampled area, separate the harvest by species, … the plant material, and .. the samples to determine which species has amassed more grams of tissue per unit area over the time of the study

Answer 6

dry; weigh

Question 7

C.T. de Wit developed a method for comparing effects of intra and interspecific competition in plants. his experimental design, called a …, begins with seeds of two species planted in a series of pots. they start with equal number of seeds, but the proportions of the two species vary from all species A to combos of A and B to all species B

Answer 7

replacement series

Question 8

The straight line connecting the 100% A biomass and the 100% B biomass represents a …: that the total yield at each frequency along the replacement series is predicted by the proportions of A and B planted in that pot. This is what we would expect if competition between species is exactly as intense as competition within the species

Answer 8

null hypothesis;

Question 9

The actual biomass totals can be compared with the… to determine how interspecific competition compares with intraspecific competition

Answer 9

null model

Question 10

If the two plants produce a higher combined biomass in mixed planting than in pure stands, then the total biomass line curves above the straight line predicted by the null model. This would be expected if the two plants are extracting … from the soil, or are in other ways exploiting different …

Answer 10

different nutrients; niches

Question 11

If one species interferes with growth of the others, as expected in allelopathic plants that release chemicals which inhibit the growth of other species, then the combined biomass line … the straight line of the null model.

Answer 11

sags below

Question 12

For ecologists, the de Wit method can give insights into the extent of…between two competing plant species

Answer 12

niche overlap