Ch. 8 Lecture Flashcards Preview

Ecology > Ch. 8 Lecture > Flashcards

Flashcards in Ch. 8 Lecture Deck (29)
Loading flashcards...
1

individual

focus is on an individual

2

population

focus is on a single species

3

main question in population ecology

How does the environment affect the:

(GRADS)

-Growth

-Reproduction

-Abundance

-Distribution

-Survival

of a species?

4

Reasons for studying populations

-saving endangered and functionally important species

-controlling pest populations

-managing fish and game populations

-controlling disease epidemics and understanding their impacts

-human population growth

5

What does population ecology measure?

(DADA-RIBS)

-Distribution

-Age distribution

-Density

-Abundance

-Rate of growth

-Immigration/emigration

-Birth/death rate

-Spatial pattern

6

Characteristics of populations

-Distribution

-Abundance/Density

7

The distribution of species: Why isn't every species found everywhere?

-Evolved physiological, anatomical, and behavioral characteristics to compensate for environmental variation.

-metabolically costly, limiting distribution.

8

Distribution

describes a species SPATIAL LOCATION over the area that it occurs

-can change (i.e. seasonal)

9

Niche

-all the environmental factors that INFLUENCE GROWTH, SURVIVAL, and REPRODUCTION of a species.

-all the factors necessary for its existence.

-multidimensional (Predators v. Nutrients v. Temperature)

-fundamental and realized

10

Fundamental Niche

the TOTAL RANGE of physical environmental conditions that are suitable for existence, in the ABSENCE of COMPETITION and PREDATION

11

Realized Niche

describes the FRACTION of the fundamental niche that is ACTUALLY OCCUPIED by a species

-represents current distribution

12

difference between the fundamental niche and the realized niche is usually the result of:

biotic interactions

13

What controls the distribution of organisms at SMALL SCALES (within populations)?

Dispersion

14

3 basic patterns of Dispersion

-Random

-Regular

-Clumped

15

Random Distribution

EQUAL CHANCE of being anywhere

-RESOURCES distributed UNIFORMLY

-frequent, random pattern of disturbance SOLITARY animals with LARGE HOME RANGES

16

Regular Distribution

UNIFORMLY SPACED

-EXCLUSIVE use of areas

-individuals AVOID one another TERRITORIAL, NON-GROUP animals

17

Clumped Distribution

UNEQUAL CHANCE of being anywhere

-MUTUAL ATTRACTION between individuals

-patchy resource distribution, HABITAT HETEROGENEITY

SOCIAL animals

18

How are individuals distributed on a LARGER SCALE, across environmental variation?

most species show a CLUMPED DISTRIBUTION, whether they range over a large or small geographic area

19

Which factors influence species abundance and density?

niche characteristics

-Habitat Tolerance

Body size

20

Habitat Tolerance

conditions toward the EDGE of the RANGE may lead to PHYSIOLOGICAL STRESS, which could DECREASE reproductive FITNESS

21

Animals must ____ and this influences the distribution of the animal...

animals must EAT and whatever regulates the distribution of their FOOD will REGULATE the distribution of the ANIMAL

22

Abundance

the TOTAL NUMBER of individual of a species PRESENT in a SPECIFIED AREA

23

Density

# individuals/area

24

measuring abundance and density

Mark-Recapture Techniques

25

Mark-Recapture Technique

kr/Km1=nc2/Nx

(#recaptured)/(#marked 1st visit)=(#captured 2nd visit)/(#population)

26

discovered body size and density correlation

John Damuth, 1981

negative linear relationship

v body mass= ^ density

27

# species of herbivorous mammals

307

28

Lincoln-Peterson Index (Mark-Recapture)

N=(M*S)/R

N: population size estimate

M: marked individuals resleased (new marked)

S: size of 2nd sample

R: marked animals recaptured

highly effected by recapture rates

 

29

Schnabel Index (Mark-Recapture)

N=ΣMiCi/ΣRi

Mi: total previously marked in population

Ci: captured sample

Ri: recaptured in current sample

More accurate due to more samples taken and higher recapture rates