Climate, Biomes, & Populations Cont. Flashcards
Tropical forest biome
Occurs in equatorial and sub equatorial regions; very rainy, hot and high biodiversity
Climate:
-in tropical rain forests, rainfall is relatively constant, while in tropical dry forests precipitation is highly seasonal
-temp. is high year round w/ little seasonal variation
Biodiversity:
-vegetation is vertically layered w/ intense competition for light, high primary productivity
-biodiversity is very high, covers only 5% of land and yet harbors 70% of terrestrial animal and plant species
Temperate broadleaf forest biome
Found mainly at mid-latitudes in the Northern Hemisphere; rainy, seasonal, moderate biodiversity
Climate:
-significant amounts of precipitation during all seasons
-winters are cool, summers are hot and humid
Biodiversity:
-vertical layers include trees, shrubs, and herbs, moderate primary productivity
-moderate biodiversity
Tundra biome
Covers extensive areas of the Arctic; alpine tundra exists on high mountaintops at all latitudes; dry, cold, low biodiversity
Climate:
-precipitation is low in arctic tundra and higher in alpine tundra
-winters are very cold, summers are cool
-has permafrost
Biodiversity;
-vegetation is herbaceous (mosses, grasses, dwarf shrubs and trees, and lichen); low primary productivity
-low biodiversity
Permafrost
Permanently frozen layer of soil
Chaparral biome
Occurs in mid-latitude coastal regions in several continents; dry, seasonal, low biodiversity
Climate:
-precipitation is low and highly seasonal, w/ rainy winters and dry summers
-summers are hot, winters are cool
Biodiversity:
-dominated by shrubs, small trees, grasses, and herbs; low primary productivity
-low but variable biodiversity-many endemic plants
-many plants are adapted to fire and drought (disturbance)
Population ecology
Explores how biotic and abiotic factors influence the abundance, dispersion, and age structure of populations
Population
A group of individuals of a single species living in the same general area
Immigration
Influx of new individuals from other areas
Emigration
Movement of individuals out of a population
What are the four key properties of populations?
Size, density, dispersion, and rate of change in size over time
What are the techniques used to estimate densities and total population sizes?
Counting in subplots, using an indicator of population size, or using the mark-recapture method
Counting in subplots
Count the # of individuals in randomly locate plots, calculate density in plots and extend to entire area; ex: counting 12 ducks in one plot, there’s 4 plots total so 12 x 4 = 48 ducks in pond or 0.48 ducks per m^2 (12/25)
Measuring indicator traits
Use a proxy measure to estimate population size or density, such as # of nests, burrows, tracks, or fecal droppings
Using the mark-recapture method
Capture, tag and release a random sample of individuals in a population. Marked individuals are given time to mix back into population. Capture second sample of individuals, and note how many of them are marked.
N = population size
n1 = # captured and marked
n2 = # captured in second sample
m = # recaptured
For two different species, you capture and make 100 individuals. When you return, you capture 50 unmarked and 50 marked individuals of species A and 99 unmarked and 1 marked individuals of species B. Which species has the biggest population?
Species B
