Flashcards in Lecture 37 - Our Global Environment/Ecology/Biosphere I Deck (43):
What is ecology?
scientific study of interactions between organisms + the environment
What are the 6 levels of ecology?
What is the biosphere?
-sum of all the planet's ecosystems
What is global ecology?
-examines influence of energy + materials on organisms across the biosphere
What is a landscape?
-mosaic of connected ecosystems
What is landscape?
-mosaic of connected ecosystems
What is landscape ecology?
-focuses on exchanges of energy, materials + organisms across multiple ecosystems
What is an ecosystem?
-community of organisms in an area + physical features they interact with
What is ecosystem ecology?
-emphasizes energy flow + chemical cycling among various biotic + abiotic components
What is a community?
group of populations of different species in an area
What is community ecology?
-examines effect of interspecific interactions on community structure and organization
What is a population?
-group of individuals of same species living in an area
What is population ecology?
-focuses on factors affecting population size over time
What is organismal ecology?
-studies how an organism's structure, physiology + behavior meet environmental challenges
What are abiotic factors?
-temperature, light, water, nutrients
What are biotic factors?
-other organisms that are part of an individual's environment
What are biomes? What are they characterized by?
-major life zones
-characterized by vegetation type (terrestrial) or physical environment (aquatic)
What are 2 types of climate?
What is dispersal?
-movement of individuals or gametes away from centers of high population density or area of origin
The ability for a species to disperse or transplant often depends upon _____
What are 5 biotic factors that affect distribution of organisms?
similar characteristics can arise in distant biomes through _______
EX: cacti in N. America and euphorbs in African deserts
Population growth is ____ under ____ conditions
What is r
Why is exponential population growth unrealistic?
-population will reach carrying capacity (K)
What is carrying capacity? (K)
maximum amount the environment can support
6 factors that are affected by density
1. competition for resources
6. toxic wastes
As population becomes more ______ this leads to movement out or _____
What are metapopulations
-groups of populations linked by immigration and emigration
What are 3 main variables of life history?
1. age at which reproduction begins
2. how often the organism reproduces
3. how many offspring are produced per reproductive episode
What is semelparity?
-reproduce once and die
What is iteroparity?
-produce offspring repeatedly
Which kind of environments favor semelparity?
Which environments favor iteroparity?
What is k-selection?
-density dependent selection
-selects for life history traits that are sensitive to population density
What is r-selection?
-selects for life history traits that maximize reproduction
When did human population start growing exponentially?
When did growth of the human population slow?
Different populations in the world go through _____ at different times
What is demographic transition?
high birth/death rate to low birth/death rate
What is a major factor associated with demographic transition?
-improved healthcare/education for women
What figure can you use to tell what stage of the demographic transition that a country is in?
age structure pyramids