POPULATION CONCEPTS AND PRINCIPLES Flashcards
Individuals of SAME SPECIES residing in a particular area are referred to as _____________
population
Sustainability of the ecosystem is directly impacted by __________________.
population dynamics
A population consists of a group of interacting individuals of the same species that occupy a specific area at the same time. In mostnatural populations, individuals vary slightly in their genetic makeup; which is why they do not all look or behave exactly like a phenomenon called ______________.
genetic diversity
Speaks of a population’s birthrate, or the quantity of newmembers brought about via reproduction.Typically expressed as thenumber of live births per 1,000 individuals per year
Natality
Describes the death rate,or the total number ofpeople who pass awaywithin a population withina given time frame
Mortality
The ratio of men to women in a population is known as the ______________. It is frequently stated as the ratio of males to girls, or 100 to 1.
sex ratio
The proportion of individualsin each age group in apopulation
age structure
The number of individuals present in a subjectively designated geographic range
population size
population size is influenced by four factors which are
births, deaths, immigration, emigration
If the number of individuals added from births and immigration equals the number lost to deaths and immigration,then there is zero population growth.
yuh
The number of individuals of a population in a certain space at a given time.
Population density
In population density, for __________ ecosystems, it is usuallyexpressed as the number of individuals per unit _____ while for aquaticecosystems, it is usually expressed asthe number of individuals per unitvolume.
terrestrial, area
The SPATIAL PATTERN in which the members of a population are found in their habitat.
population dispersion
Individuals within populations are distributed in patterns that may be _____________, ____________, or _______________.
random, uniform, clumped
Patterns of dispersion can be produced by the ______________ within populations, by the _________________, or by acombination of the two.
social interactions, structure of physical environment.
_____________ in population ecology is a CHANGE IN THE NUMBER of members of a certain species in a particular location during a particular time period
Population growth
Populations vary in their capacity for growth, also known as the _______________ of the population
biotic potential
POPULATION GROWTH CURVE
The rate at which a population could grow if it had unlimited resources is the _________________ r.
It is expressed as the number of new individuals per existing individual per unit of time, such as the number of piglets per existing sow per year.
intrinsic rate of increase
POPULATION GROWTH CURVE
______________ consists ofall the factors acting jointly to limit the growth of a population. The population size of a species in a given place and time is determined by the interplay between its _______________ and __________________ .
Environmental resistance, biotic potential
What are some abiotic growth factors of a population?
favorable light
favorable temperature
favorable chemical environment
What are some biotic growth factors?
high reproductive rates
generalized niche
migrate
suitable habitat
Both biotic potential and environmental resistance determine the ________________, K, the number of individuals of a given speciesthat can be sustained INDEFINITELY in a given space.
carrying capacity
TYPES OF POPULATION GROWTH CURVE
____________________
shows the population grows faster with time starts out slowly and then proceeds faster and faster as the population increases. If the number of individuals is plotted against time, this sequence yields a J-shaped _____________ curve.
exponential growth
TYPES OF POPULATION GROWTH CURVE
It involves exponential population growth when the population is small and a STEADY DECREASE in population growth with time as the population approaches the carrying capacity.A plot of the number of individuals against time yields a sigmoid or S shaped logistic growth curve
Logistic growth
TYPES OF POPULAION GROWTH CURVE
____________ plot the numbers in _______ still alive at each age. A ______ refers to a group of individuals that share common characteristics or experiences within a defined time period or population (Setia, 2015).
survivor-ship curves, cohort 2x
SURVIVORSHIP CURVES
____________ is flat during early and middle life and drops suddenly as death rate increases among the elderly
Associated with species such ashumans and other largemammals that produce fewoffspring that are well caredfor
Type 1
survivorship curves
________ is intermediate, withmortality more constant overlife spans. This type is seen inHydra, gray squirrels, and birds
type II
survivor-ship curves
________ shows very high deathrates for the young, followedby lower death rates.This type is often associatedwith organisms, such as oysters, that produce very many offspring but provide little or no care. More examples are trees, marine invertebrates, and most fishes
type III
Species use different reproductive strategies to survive and adapt to their environments. These strategies fall into two maincategories: ___________ and __________
r - strategists, k-strategists
_________________
These species thrive in unstable,unpredictable focusing on environments by rapid reproduction.Their characteristics include:
R strategists
rapid reproduction
minimal parental care
high reproductive rates
These species are adapted to more stable environments, emphasizing SURVIVAL over REPRODUCTION. Their characteristics include:
late maturation, longer lifespans, significant parental care, stable populations
In population ecology, two key categories of factors influence population size: ______________ and __________ factors
density dependent, density independent
FACTORS INFLUENCING POPULATION SIZE
These factors become more pronounced as a population grows larger and denser.They are intrinsic to the interactions within the population and ecosystem
density - dependent factors
Density dependent factors result in
competition for resources
predation
disease
Density independent factors
natural disasters, environmental changes, climate extremes
Why is understanding population dynamics important?
- Human Impact
- Evolutionary Processes
- Economic Importance
- Ecological Interactions
- Understanding Ecosystem Health
- Conservation and Biodiversity
- Resource Management
- Predicting and Responding to changes
