echology chap 6 defintiions Flashcards
geology
study of origin, history, structure of earth
topography
physical configuration or features of region
weather
short term changes in temperature, wind, humidity, rain, clouds etc at given place and time
climate
physical properties of large area (preciptitation /temperature) as measured over long period of time
limiting factor
a shortage (me: excess) or absence of key factor that restricts the success of specieis in a given area (Limiting factors can be either biotic or abiotic and are different in different areas)
endemic species
a species that is restricted to specific conditions or a specifc region
habitat
place or region where organism lives
niche
physical or biological conditions that an organism needs to live and reproduce; also defined as the role an organism plays in a area - including how it interacts with living and non-living elements requried by the organism
ecological footprint
amount of biological productive land &water needed to supply a population with the renewable resources it uses & to absorb or dispose of the wastes from such resource use. Measure of AVG ENV impact population in different countries and areas (see per capita footprint)
demography
factors describe size and structure of population - see demographic factors [camera zooms out]
demographic factors
age structure, sex ratio, life tables, density, dispersion
age structure
number individuals in population of a specific age
life tables
table of data summarizing mortality [death] in a population: a) # individs surviving to each age group; shows distribution of mortlity with age b) fertility: # offspring per femaile c) lifespan
population dispersion
distribution of organisms in population over given area (clumped, random, uniform)
population density
number individuals in Population in a given area
population
group individuals of same species that live in same area at the same time
exponential growth
rate of population growth over time (with no limits). If plot individuals against time gives J curve
logistic growth
rate population growth over time (limited by carry capacity of environment) - S curve (level off)
K, carrying capacity
maximum stable population size particular environment can support (this is characteristic of environment)
r, rate of increase
rate of increase of pouplation (characteristic of the species)