Current and predicted ranges for American beech trees under two climate change scenarios Adult frogs breed in the female s third year If Memorial Weekend May rafting continues three years in a row the populations crash Adult female longevity buys the population some resilience storage effect But rafting is turning these river reaches into populations sinks for these frogs Prediction based just on tree physiology Physiological Climate Envelopes discharge Spring Summer Fall 1 Immobile Susceptible 2 Mobile Resistant Population biology New northern limit with high food New northern limit with low food Where starvation presently affects bass population Demography study of how the vital rates of individuals birth death growth migration affect structure and dynamics of populations bass Current range Northern range expansion of small mouth bass and yellow perch predicted based on predicted climate warming scenarios The bottleneck for both fish is whether the young of the year can grow large enough to survive their first winter Population group of potentially interbreeding individuals same species co occur in time and space perch High food Low food Now 3 BIDE Equation for change in population size N density number of individuals per area or volume size structure age distribution sex ratio ratio 4 Dispersion pattern of distribution of individuals in space clumped even or random every site has an equal probability of being occupied by an individual independent of locations of other individuals N numbers in population Births Immigration Deaths Emigration 5 6 Intraspecific interactions between individuals of the same species vs Interspecific interactions between individuals of different species Parent Ganet Life and reproductive table summary of age or size specific rates of survival and fecundity progeny per individual chicks Constructed by following a cohort a group of individuals of the same age from birth until they all die or by other methods that approximate this ideal approach A peck apart 7 8 Of course long before you mature most of you will be eaten 9 10 11 12 Cohort life table for reproductives only ax number surviving to age x lx proportion original cohort alive at time age x mx fecundity of individual at age x lx mx number of progeny contributed per original individual of age x Basic Reproductive Rate Ro lx mx Ro is sum of progeny produced per original individual at the end of the cohort s life If Ro 1 population grows 13 Age structure of human population reflects age specific birth and death rates 14 Population growth Nt number of individuals at time t N Births Deaths population closed to migration N Births Immigration Deaths Emigration open pop N t rate of change dN dt rate of change over very small time interval b per capita birth rate number of births Nt 1time 1 time 1 if Nt 1000 and there were 34 births in a year b 0 034 year 1 d per capita death rate deaths Nt 1 time 1 time 1 if Nt 1000 and there were 16 deaths in a year d 0 016 year 1 15 dN dt b Nt d Nt b d Nt r Nt Nt Noert e 2 71828 base natural logarithm dN dt bNt dNt b d Nt r Nt closed population r b d per capita rate of population growth time 1 r 0 dN rN dt Density N r per capita rate of increase N numbers of individuals in population t time Nt Noert 17 r 0 r 0 Time 16 If r 0 population grows exponentially If r 0 population is in a stable equilibrium zero population growth although individuals turn over some die and are replaced by new births If r 0 population declines exponentially until it goes 18 extinct Elephants in Kruger National Park South Africa Billions of people 1650 0 5 1850 1 1930 2 1975 4 2000 6 19 20 Huge effect of age of first reproduction on population size in an expanding population B 3 N 4 9 B 8 N 4 8 Years B 2 N 4 16 A 1 A 2 A 4 B brood size N t population size at time t A age at 1st reproduction 21 22 Campbell Fig 52 13 density dependence in per capita birth and death rates due to intraspecific within species competition K carrying capacity of population in a given environment K depends on both the environment and the organism in question 23 mutually adverse interaction Per capita per individual birth or death rates Campbell Fig 52 11 24 Change in limiting factor Territoriality can produce this type of population growth overshoot e g speed limit versus regulation by enforcement of minimum and maximum speed N Density independent factors 25 Period of looser regulation Time 26 Demographic transition change from ZPG due to high death rate to ZPG due to low birth rate Analogy speed limit 60 mph regulated strictly 55 65 or loosely 40 80 Rapid population growth rate r steering Strong densitydependent feedbacks Distracted drivers Time lags in feedbacks Speeding Over N Time 27 r vs K selected life history traits r selected traits K selected traits Short life span Small size High predator vulnerability Weak competitor Good disperser Many small offspring Early reproduction Long life span Large size Low vulnerability to predators Strong competitor Slower disperser Fewer but better provisioned offspring Late reproduction 29 28
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