Population Ecology Flashcards
define ecology
the study of interactions among ORGANISMS and BETWEEN organisms and their environments
define habitat
specific environment where an organism lives (including living and no living elements: ROCKS, SOIL, PLANTS)
define niche
the functional role of a species in a community (FEEDING, FLOW OF ENERGY & MATTER, INTERACTIONS W OFHER ORGANISMS ETC)
define specialist
a species that can survive ONLY in a NARROW RANGE of habitats or depends on very specific resources
define generalist
a species that can survive across a WIDE ARRAY of habitats or use a wide array of resources.
define population
group of individuals of a SPECIES that live in a particular area
what population features help predict dynamics?
- population size
- population DENSITY
- population DISTRIBUTION
- age structure
- sex ratio
describe population size
number of individuals present at a given time
describe population DISTRIBUTION
the spatial arrangement of individuals
- random
- uniform
- clumped
types of pop distributions?
- random
- uniform
- clumped
describe age structure
number of individuals of each age or age class in a POPULATION
young = growing; old = declining
what is the most common sex ratio in pops?
50/50
what is population growth determined by?
- births
- deaths
- immigration
- emigration
what is the equation for growth rate?
(B-D) + (I-E)
——————
100
describe an exponential growth graph
“J curve” r = growth rate/slope
what limiting factors restrain growth?
- water
- space
- food
- predators
- disease
define carrying capacity
the MAX pop. size of a given species an ENVIRONMENT can sustain
define logistic growth
INITIAL EXPONENTIAL GROWTH, sssssssslowing, & stabilizing & carrying capacity. (S CURVE GRAPH)
what shape does a logistic graph have?
S curve shape (k = carrying capacity; N= pop size
what accounts for logistic growth curves in environments?
density dependent factors (DISEASE, PREDATION ETC)
what are density independent factors?
occur REGARDLESS OF DENSITY such as catastrophic weather events
size = ?
N
carrying capacity = ?
k
define high biotic potential
species with MANY OFFSPRING (insects, fish, frogs, plants)
define low biotic potential
species w FEW YOUNNG (mammals, birds, etc)
insects have what type of biotic potential?
HIGH
mammals have what type of biotic potential?
LOW
describe type 1 survivorship curve
HIGH SURVIVAL YOUNG, declining old
describe type 2 survivorship curve
mediate survival of all ages \
describe type 3 survivorship curve
LOW SURVIVAL YOUNG, greater^^ survival OLD
describe a k strategist species
- few offspring
- SLOW growing
- parental care
(LIKE HUMANS)
describe an r strategist species
- many offspring
- FAST growing
- NO parental care
populations tend to stabilize near what?
K (carrying capacity)
