Ecosystem Ecology

Question 1

Evolution

Answer 1

the change in the characteristics of a species over several generations and relies on the process of natural selection.

Question 2

Natural Selection

Answer 2

process whereby organisms better adapted to their environment tend to survive and produce more offspring.

Question 3

Mutation

Answer 3

when a DNA gene is damaged or changed in such a way as to alter the genetic message carried by that gene.

Question 4

population

Answer 4

a group of individuals of the same species living and interbreeding within a given area.

Question 5

Population Density

Answer 5

a number of organisms/area

Question 6

birth rate

Answer 6

The ratio of live births in an area to the population of that area

expressed per 1000 population per year

Question 7

Death rate

Answer 7

The ratio of deaths in an area to the population of that area; expressed per 1000 per year

Question 8

Growth rate

Answer 8

The rate, or speed, at which the number of organisms in a population increases.

Question 9

Immigration

Answer 9

when new organisms join a population, changing allele frequencies.

Question 10

Emigration

Answer 10

Emigration is when members of a population leave, taking with them their genes.

Question 11

Biotic Potential

Answer 11

the maximum reproductive capacity of an organism under optimum environmental conditions

Question 12

Exponential Growth

Answer 12

Exponential growth requires specific ideal conditions.

A population can grow exponentially when it has access to unlimited resources and no competition.

begins at a slow rate then speeds up when the population rises

Question 13

Logistic Growth

Answer 13

population increase - growth rate starts slowly, as there are few individuals, then increases in speed as numbers increase, but then

competition increases and resources become increasingly scarce, populations reach the carrying capacity (K) of their environment, causing their growth rate to slow nearly to zero

Question 14

Carrying Capacity

Answer 14

the number of people, other living organisms, or crops that a region can support without environmental degradation.

Question 15

Limiting Factor

Answer 15

anything that constrains a population’s size and slows or stops it from growing

can be biotic - food

or abiotic - logging

Question 16

Density Dependent Factors

Answer 16

regulating factor - any force that affects the size of a population of living things in response to the density of the population (the number of individuals per unit area). usually biotic forces

disease

food access

Question 17

Density Independent Factors

Answer 17

a limiting factor that affects the size of a population of living things regardless of the density of the population

flooding - wildfire - disasters

Question 18

Boom and Bust Cycle

Answer 18

long periods of almost exponential growth (boom) and a subsequent population crash due to competition (bust)

boom-bust dynamics, can allow for the evolution of much larger amounts of diversity than would be expected with stable equilibrium dynamics.

Question 19

R strategist

Answer 19

production of numerous small offspring followed by exponential population growth. They require short gestation periods, mature quickly (and thus require little or no parental care), and possess short life spans

reproduce at a relatively young age; however, many offspring die before they reach reproductive age.

initially opportunistic - flourish in temporary environments and unpredicatble events - roaches - rats -weeds then replaced by competition over time

Question 20

K strategist

Answer 20

stable populations and tend to produce relatively low numbers of large offspring

long gestation periods lasting several months

slow maturation (and thus extended parental care), and long life spans

inhabit relatively stable biological communities

elephants

humans

Question 21

survivorship Type 1, 11, 111

Answer 21

type I - high probability to survive early and middles life but rapid decline in late life

type II - roughly constant mortality rate

type III greatest mortality is early in life

Question 22

Metapopulation

Answer 22

“population of populations” distributed in discrete habitat patches

meta-population approach tracks the occupancy of habitat patches through time

useful when discussing species in disturbed habitats

Question 23

Source habitat

Answer 23

high quality habitats that produce and export population

considered better than sink habitat, but when natural disaster destroys source habitat, sometimes sink habitat is last place for a species.

Question 24

sink habitats

Answer 24

habitats in which populations cannot survive when they are isolated from other populations

(sometimes are last place of species when source habitat is destroyed)

Question 25

Climate

Answer 25

atmospheric conditions in an area, such as temperature and rainfall

Question 26

Biome

Answer 26

a large naturally occurring community of flora and fauna occupying a major habitat

Question 27

tundra

Answer 27

treeless regions found in the Arctic and on the tops of mountains

Tundra is the coldest and driest of all the biomes. Tundra comes from the Finnish word tunturia, meaning treeless plain

Question 28

Permafrost

Answer 28

permanently frozen layer below Earth’s surface

consists of soil, gravel, and sand, usually bound together by ice

earth remains frozen for at least two consecutive years

Question 29

Boreal Forest/Conifer

Answer 29

northern boreal forest, is found in 50° to 60°N latitudes.

evergreen—they bear needles all year long. These adaptations help conifers survive in areas that are very cold or dry.

Question 30

Boreal Forest/Taiga

Answer 30

russian word = forest

Snow forest - subarctic region variety of trees species. coldest forest

coniferous species - cone shape helps snow fall off branches - canopy

deciduous trees- white birch, trembling aspen and balsam poplar.

thin layer of soil - short growing season - dry - russia siberia - finland

Question 31

Temperate Rain Forest

Answer 31

coniferous or broadleaf forests

mild climates or temperatures

two seasons.

(winter) is quite long and wet
(summer) is short, dry and foggy.

tall trees, mosses ferns, broad sarray of wildlife

from alaska to california - mild weather conditions are maintained by moisture-laden air blown in off the Pacific Ocean and hemmed in by the coastal mountains

Question 32

Tropical Rain Forest

Answer 32

wet warm hot humid climate consistent all year round

thin soil shallow roots

ground layer

shrub

undercanopy

main canopy

emergents

Question 33

Temperate Deciduous

Answer 33

eastern part of the United States and Canada, most of Europe and parts of China and Japan.

biome that is changing.

four distinct seasons: winter, spring, summer and fall.

Winters are cold and summers are warm.

Question 34

Grasslands: Temperate

Answer 34

having short grasses as the dominant vegetation. plants with long, extensive roots that dig deep into soft, nutrient-rich soil.

Precipitation in the temperate grasslands usually occurs in the late spring and early summer

inland

massive root structure creates a dense net that develops a sod layer anchor - reduces erosion retains water

taken over in 1800s for crops - mismanaged

north america

eurasian steppe

Question 35

Grasslands: Savanna

Answer 35

grassland with scattered individual trees

half the surface of Africa

found in warm or hot climates

dry and a rainy season

rainfall is concentrated in six or eight months of the year, followed by a long period of drought

Annual fires then maintain the area as a savanna.

Question 36

Grasslands: Chaparral

Answer 36

Spanish word “chaparro” which means scrub oak

coastal regions, varied vegetation, (not the same as desert scrub which is a transitional zone between deserts and grasslands.)

cool, moist air from the ocean hits dry, warm land masses, typically along the west coast, forming this semi-arid mediterranean climate. The chaparral covers somewhere between 2-5% of terrestrial earth and is found on multiple continents

climate here is considered semi-arid and summer and winter are quite distinct

mild year round, there is a drastic change between daytime and nighttime temperatures

only 5% of planet but 20% of vascular plants - poor soil - easily eroded rocky

precipitation is generally unpredictable, but always very low in summer

Question 37

Desert

Answer 37

20% of the Earth. less than 50cm of rainfall per year

• little rainfall (less than 50 centimeters per year)
• temperatures vary greatly between day and night
• high evaporation rates
• coarse-textured soils
• drought-resistant vegetation

4 types:

hot and dry - hot, dry deserts that occur at low latitudes

semiarid - long, dry summers and cool winters

coastal - western edges of continents

cold - low temperatures and long winters