Cycle 11 - Ecology in Anthropocene Flashcards
What is population ecology?
study of how and why populations of organisms grow and decline
What is population size?
the number of individuals making up the population at a specific time
What is population density?
the number of individuals per unit area/volume of habitat
How does population density compare with body size?
large body size = population density decline
What is an age structure?
statistical description of the relative numbers of individuals in each age class
How are individuals categorized by age?
pre reproductive or post reproductive
Why is the percent of reproducing individuals in a population important?
to see how fast the population will grow in the future
What is generation time? How is it important for population growth?
average time between the birth of an organism and birth of its offspring
- short in species with small body size = faster population growth
When do exponential models or logistic models apply for population growth?
exponential - populations experience unlimited growth
logistic - population growth in limited due to resources
When do exponential models or logistic models apply for population growth?
exponential - populations experience unlimited growth
logistic - population growth in limited due to resources
What are the four changes to population that must be considered for demographic change?
- # of births
- # of deaths
- immigrants to a population
- emigrants from a population
How can you calculate the change in population size?
∆N/∆t = B - D
What is births per capita (b)? deaths per capita (d)?
b = B/N
c = D/N
What is the equation for per capita growth rate (r)?
b-d = r
What is the equation for exponential model of population growth?
dN/dt = (b-d)N = rN
What is zero population growth in terms of the equation?
b=d so r = 0
What is the intrinsic rate of increase?
maximum possible per capita population growth rate in a population living under ideal conditions
rmax x N
What is the carrying capacity?
maximum number of individuals that an environment can support indefinitely (K)
What is the logistic model of population growth?
population growth slows as the population size approaches K
What is the equation of logistic model of population growth?
dN/dt = (rmax x N)(K-N/K)
What happens when K = N?
zero population growth
What happens when K = N?
zero population growth
Why is the logistic population growth model necessary?
realistically shows intraspecific competition - dependence of two or more individuals in a population on the same non-infinite resources
What does it mean when r<0 and r>0 in either model?
r<0 increasing population and r>0 decreasing population
What are density dependent variables? Examples for regulating plant and animal populations?
factors that increase or decrease with population density
ex. predation, parasitism, disease
What are density independent variables?
reduce population size regardless of density?
What is co-evolution?
evolution of genetically based, reciprocal adaptations in two or more species that interact in the same ecological setting
What the is effect on interacting populations in PREDATION?
+/- predators gain nutrients and energy, prey are killed or injured
What the is effect on interacting populations in PARASITISM?
+/- predators gain nutrients and energy, hosts are killed or injured
What the is effect on interacting populations in HERBIVORY?
+/- Herbivores gain nutrients and energy, plants are killed or injured
What the is effect on interacting populations in Competition?
-/- both competing populations lose access to some resources
What the is effect on interacting populations in COMMENSALISM?
-/0 one population benefits, other is unaffected
What the is effect on interacting populations in MUTUTALISM?
+/+ both benefits
What are endoparasites?
live within a host
What are ectoparasites?
feed on the exterior of the host
What are some plant defence mechanisms?
- spines and thorns
- poisonous chemicals
How do species avoid detection?
camouflage
What are aposematic species?
species that are poisonous that have bright patterns to advertise potential predators
What is mimicry?
same pattern as aposematic species but are not actually poisonous
What is the Anthropocene?
500-70 years ago - extinction of species and declined species due to human activity creating long-lasting geological mark and potential 6th mass extinction
What is habitat fragmentation?
remaining areas of intact habitat are reduced to small isolated patches
What is the edge effect in a forest?
removal of natural vegetation disrupts the local physical environment, exposing the borders of the remaining habitat to additional sunlight, wind, and rainfall
What are extirpations? Where do their result from?
local population extinction
results from overexploitation (excessive harvesting of an animal or plant species
What are the major threats to biodiversity due to humans?
- Habitat destruction
- overexploitation
- climate change
- invasive species and disease
- pollution
Why was there a significant increase of population after the Black Death plague?
industrial revolution and improving healthcare
Can the carrying capacity change?
yes! vary by habitat and season
How does crowding affect reproduction?
plants at higher density produce fewer seeds = density dependant factor
How is parasitism a density dependent factor?
its transmission is facilitated by increasing population density
How is predation a density dependent factor?
more prey density = easy predator access
Which type of density factor is infraspecific competition?
resources are limited so density dependent factor
What type of density factor is weather/temperature?
density independent factor
Can density independent and dependent factors work simultaneously?
Yes! ex. heat weakens immune system (independent) more disease (dependent)
What is fecundity?
potential reproductive output
How can humans purposefully impacted other species population growth?
- biological control by introducing a species to control another
- conservation management by moving, culling, or facilitating reproduction
How can bacteria in the human body change our behaviour?
increases appetite, stress response
How is host-parasite and example of co-evolution/evolutionary arms race?
infections cause anti influenza responses for protection with antibodies
selection for viruses to escape antibodies through mutations
new antigenic cluster causing infections
Which type of species interaction will not result in coevolution?
commensalism – neutral species will not evolve
What are some new approaches to better Anthropocene?
fecal transplants to restore a healthy gut ecosystem
one heath concept - well being of people animals and environment
