10-5 POPULATION PATTERNS
1. POPULATION PROPERTIES Size (often hard to measure) Density– amount of population per unit of area (population crowding) # of individuals = population density area (units 2 ) Dispersion – spatial organization of the population
1. POPULATION PROPERTIES Dispersion – spatial organization of the population
1. POPULATION PROPERTIES Dispersion – spatial organization of the population Clumped – population is clustered together, usually around resources or from social behavior ex/ school of fish
clumped
1. POPULATION PROPERTIES Dispersion – spatial organization of the population Uniform – the population is evenly dispersed from each other usually from social interactions ex/ bird nesting sites or solitary predators
uniform
1. POPULATION PROPERTIES Dispersion – spatial organization of the population Random – the population is randomly scattered throughout the area EX: Dandelions from random wind dispersion of seeds
random
2. POPULATION DYNAMICS Age Structure i.the number of individuals of different ages within the population
2. POPULATION DYNAMICS Age Structure i.the number of individuals of different ages within the population ii.different age groups may have different abilities such as birth/death rates
2. POPULATION DYNAMICS Survivorship Curve probability of individuals surviving to a certain age
2. POPULATION DYNAMICS Survivorship Curve probability of individuals surviving to a certain age I – Low birth rate, low infant mortality, survives to old age (Humans & large mammals)
2. POPULATION DYNAMICS Survivorship Curve probability of individuals surviving to a certain age I – Low birth rate, low infant mortality, survives to old age (Humans & large mammals)
2. POPULATION DYNAMICS II – Survivorship rate equal at all ages (Birds & reptiles & rats) 2
2. POPULATION DYNAMICS II – Survivorship rate equal at all ages (Birds & reptiles & rats) 2
2. POPULATION DYNAMICS III – High birth rate, high infant mortality rate (Fish, Insects, Plants)
2. POPULATION DYNAMICS III – High birth rate, high infant mortality rate (Fish, Insects, Plants)
10-5: POPULATION GROWTH CHAPTER 19
1. MODELS OF GROWTH Exponential a)birth and death rates are constant (b > d)
1. MODELS OF GROWTH Exponential a)birth and death rates are constant (b > d) a)the rate increases as the population gets larger b)limited by density-independent factors
DRAW THIS GRAPH AND A LINE SHOWING WHAT EXPONENTIAL GROWTH WOULD LOOK LIKE
works well for bacteria growth but not for most organisms
1. MODELS OF GROWTH Logistic a)starts off as b> d b)levels off as it reaches carrying capacity (K)
1. MODELS OF GROWTH Logistic a)starts off as b> d b)levels off as it reaches carrying capacity (K) (K): the number of individuals the environment can support over time.
1. MODELS OF GROWTH Logistic a)starts off as b> d b)levels off as it reaches carrying capacity (K) (K): the number of individuals the environment can support over time. c)This is when b rates = d rates (zero population growth) d)limited by density-dependent factors
DRAW THIS GRAPH AND A LINE SHOWING WHAT A LOGISTIC GROWTH WOULD LOOK LIKE Label carrying capacity with a K
Most organisms such as seals, and whales follow this model
2. REGULATING POPULATION GROWTH Limiting factors: restrains population growth
2. REGULATING POPULATION GROWTH Density-independent factors: No regard for population density limits Exponential Growth EX. Weather, seasons, natural disasters
2. REGULATING POPULATION GROWTH Density-dependent factors: increase or become more prominent when the population density increases Limits Logistic growth EX. predation, pollution, food shortage