1 Population growth rates and trends Topic 1 - Population Growth.
Population Ecology Characteristics of Populations Life History Traits Population Growth Models...
-
Upload
tracy-austin -
Category
Documents
-
view
221 -
download
2
Transcript of Population Ecology Characteristics of Populations Life History Traits Population Growth Models...
![Page 1: Population Ecology Characteristics of Populations Life History Traits Population Growth Models Regulation of Population Growth.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649f145503460f94c28336/html5/thumbnails/1.jpg)
Population Ecology
Characteristics of Populations
Life History Traits
Population Growth Models
Regulation of Population Growth
![Page 2: Population Ecology Characteristics of Populations Life History Traits Population Growth Models Regulation of Population Growth.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649f145503460f94c28336/html5/thumbnails/2.jpg)
Characteristics of Populations
Density-number/unit of area or volume
• Census• Estimate by indirect
indicators• Mark-recapture
method
Dispersal-spacing among individuals
• Clumped-humans• Uniform-penguin
rookery• Random-not common
in nature
![Page 3: Population Ecology Characteristics of Populations Life History Traits Population Growth Models Regulation of Population Growth.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649f145503460f94c28336/html5/thumbnails/3.jpg)
![Page 4: Population Ecology Characteristics of Populations Life History Traits Population Growth Models Regulation of Population Growth.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649f145503460f94c28336/html5/thumbnails/4.jpg)
Demography
• Study of vital statistics
• Age structure
• Birth rate (fecundity) and death rate
• Generation time
• Sex ratio
• Survivorship curves
![Page 5: Population Ecology Characteristics of Populations Life History Traits Population Growth Models Regulation of Population Growth.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649f145503460f94c28336/html5/thumbnails/5.jpg)
![Page 6: Population Ecology Characteristics of Populations Life History Traits Population Growth Models Regulation of Population Growth.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649f145503460f94c28336/html5/thumbnails/6.jpg)
Survivorship Curves
• Type I-little change during early and middle life (humans and large mammals)
• Type II-constant mortality over the life span, (squirrels)
• Type III-very high mortality for the young, but few after a certain age (oysters)
![Page 7: Population Ecology Characteristics of Populations Life History Traits Population Growth Models Regulation of Population Growth.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649f145503460f94c28336/html5/thumbnails/7.jpg)
![Page 8: Population Ecology Characteristics of Populations Life History Traits Population Growth Models Regulation of Population Growth.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649f145503460f94c28336/html5/thumbnails/8.jpg)
Life History
• An organism’s schedule of reproduction and death
• Includes:
1. Number of reproductive episodes/lifetime
2. Number of offspring/reproductive episode
3. Age at first reproduction
![Page 9: Population Ecology Characteristics of Populations Life History Traits Population Growth Models Regulation of Population Growth.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649f145503460f94c28336/html5/thumbnails/9.jpg)
Population Growth Models
• Exponential growth-describes an idealized population in an unlimited environment
• Logistic model-incorporates the concept of carrying capacity; assumes rate of growth slows as it approaches the carrying capacity (K)
• Two types of populations: K-selected (few offspring), r-selected (high reproductive rate)
![Page 10: Population Ecology Characteristics of Populations Life History Traits Population Growth Models Regulation of Population Growth.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649f145503460f94c28336/html5/thumbnails/10.jpg)
K-Selection
• Common in populations that live at densities close to the carrying capacity (K) of their environment
• Maturity and reproduction at a later age
• Production fo few, well-cared for young
![Page 11: Population Ecology Characteristics of Populations Life History Traits Population Growth Models Regulation of Population Growth.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649f145503460f94c28336/html5/thumbnails/11.jpg)
r-selection
• Populations that maximize (r), the intrinsic rate of increase
• Individuals mature early, produce large numbers of offspring at a time
• Maximize reproductive success in uncrowded, unpredictable environments
• Many insect and weed populations
![Page 12: Population Ecology Characteristics of Populations Life History Traits Population Growth Models Regulation of Population Growth.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649f145503460f94c28336/html5/thumbnails/12.jpg)
![Page 13: Population Ecology Characteristics of Populations Life History Traits Population Growth Models Regulation of Population Growth.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649f145503460f94c28336/html5/thumbnails/13.jpg)
![Page 14: Population Ecology Characteristics of Populations Life History Traits Population Growth Models Regulation of Population Growth.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649f145503460f94c28336/html5/thumbnails/14.jpg)
Population Limiting Factors
• Density-independent factors-unrelated to population size and affect the same percentage of individuals regardless of the size of the population (weather)
• Density-dependent factors-intensifies as population size increases (resource limitation)
![Page 15: Population Ecology Characteristics of Populations Life History Traits Population Growth Models Regulation of Population Growth.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649f145503460f94c28336/html5/thumbnails/15.jpg)
Boom or Bust Cycles
• Show a regular fluctuation in density
• Insects, small mammals (lemmings, snowshoe hares)
• May result from a time lag in the response to density-dependent factors
![Page 16: Population Ecology Characteristics of Populations Life History Traits Population Growth Models Regulation of Population Growth.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649f145503460f94c28336/html5/thumbnails/16.jpg)