Ch 40: Ecology

Question 1

Ecology

Answer 1

Study of interactions between organisms and the environment, Including Biotic (Living) and Abiotic (nonliving)

Question 2

Biotic factors

Answer 2

plants, animals, dead trees, may include behaviors as well as interactions with other species

Question 3

Abiotic Factors

Answer 3

Nonliving, chemical, and physical components, E.x air, water, soil, sunlight, temperature, and climate

Question 4

Climate

Answer 4

the weather in some locations averaged over some long period of time.

Question 5

2 Scales of climate

Answer 5

Macroclimate patterns, Microclimate

Question 6

Macroclimate patterns

Answer 6

global, regional, local levels the changing angle of the sun over the year, bodies of water, and mountains exert seasonal, regional, and local effects on macroclimates

Question 7

Microclimate

Answer 7

the small fine-scale variation, for example under a log or on a riverbank shaded by vegetation

Question 8

Biomes

3 things

Answer 8

Major types of ecosystems that occupy very broad geographic regions

• The layering of vegetation in all biomes provides diverse habitats for animals
• Biomes are dynamic and usually exhibit extensive patchiness
• Similar characteristics can arise in distant biomes through convergent evolution

Question 9

Two main types of Biomes

Answer 9

Aquatic and Terrestrial.

Question 10

General Features of Terrestrial Biomes(3)

Answer 10

1. named for major physical or climatic factors and for vegetation
2. No sharp boundaries
3. Vertical layering is an important feature of terrestrial biomes, and in a forest, it might consist of an upper canopy, low-tree layer, shrub understory, ground layer of herbaceous plants, forest floor, and root layer
4. ecotone - area of intergraation

Question 11

Disturbance and Terrestrial Biomes

Answer 11

• A disturbance is an event such as a storm, fire, or human activity that changes a community
• Fire suppression has changed the vegetation of the Great Plains

Question 12

Aquatic Biomes(3)

Answer 12

1- The largest part of the biosphere (planet) – covers 75% of the surface
2- Two types – Freshwater and Marine
3- All Aquatic Biomes have Vertical stratification which forms unique layers

Question 13

Photic Zone(aquatic)

Answer 13

enough light for photosynthesis to occur a (Aphotic –almost no light)

Question 14

Benthic Zone(aquatic)

Answer 14

the bottom layer, composed of sand, inorganic matter, organic sediments called
detritus (dead)

Question 15

Thermocline(aquatic)

Answer 15

As you go from top to bottom you have multiple layers of fast temperature changes

Question 16

thermocline(aquatic)

Answer 16

separates the warm upper layer from the cold deeper water, in oceans and most lakes, a temperature boundary

Question 17

turnover(aquatic)

Answer 17

Many lakes undergo a semiannual mixing of their waters, mixing oxygenated water from the surface with nutrient-rich water from the bottom

Question 18

Two types standing bodies (lakes), and running bodies (rivers)(Freshwater Biomes)

Answer 18

Littoral Zone and Limnetic zone

Question 19

Oligotrophic lakes(Freshwater Biomes)

Answer 19

deep lakes that are nutrient-poor and oxygen-rich contain little phytoplankton

Question 20

Eutrophic lakes(Freshwater Biomes)

Answer 20

shallower, high nutrient content and lower oxygen levels high concentration of phytoplankton

Question 21

current(Freshwater Biomes)

Answer 21

the unique physical features of Streams and rivers

Question 22

What do flowing bodies of water have?(Freshwater Biomes)

Answer 22

Flowing bodies of water have vertical divisions from the headwaters to the mouth, If unpolluted they can be very productive

Question 23

Estuaries (Freshwater Biomes)

Answer 23

where freshwater streams or rivers merge with the ocean

Question 24

Intertidal zone(Marine Biomes)

Answer 24

where land meets the water, submerged and exposed by the twice-daily tides.

Question 25

Neritic zone(Marine Biomes)

Answer 25

past intertidal zone shallow water over continental shelves

Question 26

Pelagic biome(Marine Biomes)

Answer 26

the vast realm of open water

Question 27

Coral reef(Marine Biomes)

Answer 27

created by cnidarians and their hard calcium carbonate shells. Support other corals, sponges, and algae. Among the most productive ecosystems on Earth.

Question 28

Must define a population

Answer 28

a group of individuals of a single species living in the same general area

Question 29

Population Ecology

Answer 29

Study of how biotic and abiotic factors influence a populations

Question 30

4 factors that influence populations

Answer 30

1. **Density** 2. **Distribution** 3. **Size** 4. **Age**

Question 31

Density

Answer 31

number of individuals per area (the unit of area can change), births→ immigration increases, deaths→emigration increases

Question 32

Dispersion

Answer 32

a pattern of spacing among individuals within the boundaries of the populations.

Question 33

3 types of dispersion

Answer 33

Clumped, Uniform, and Random

Question 34

Demography

Answer 34

the study of vital statistics of a population and how they change over time.  Birth and Death rates especially using survivorship curves

Question 35

life table

Answer 35

age-specific summary of the survival pattern of a population, made by following cohorts

Question 36

cohort

Answer 36

a group of individuals of the same age

Question 37

survivorship curve

Answer 37

is a graphic way of representing the data in a life table, The survivorship curve for Belding’s ground squirrels shows a relatively constant death rate

Question 38

Survivorship curves can be classified into three general types(name and define)

Answer 38

1. **Type I: low death rates during early and middle life and an increase in death rates among older age groups** 2. **Type II: a constant death rate over the organism’s life span** 3. **Type III: high death rates for the young and a lower death rate for survivors**

Question 39

reproductive table

Answer 39

or fertility schedule is an age-specific summary of the reproductive rates in a population, It describes the reproductive patterns of a population

Question 40

The Exponential Model of Population Growth

Answer 40

- **It is useful to study population growth in an idealized situation** - **Idealized situations help us understand the capacity of species to increase and the conditions that may facilitate this growth** - **Any species, regardless of its life history. Is capable of exponential growth if resources are abundant.**

Question 41

Exponential population growth(4)

Answer 41

is population increase under idealized conditions - **Under these conditions, the rate of increase is at its maximum, denoted as *r*max** - **The equation of exponential population growth is** - **Exponential population growth results in a J-shaped curve** - **The J-shaped curve of exponential growth characterizes some rebounding populations**

Question 42

The Logistic Model of Population Growth

Answer 42

- **Exponential growth cannot be sustained for long in any population** - **A more realistic population model limits growth by incorporating carrying capacity** - **Carrying capacity (*K*) is the maximum population size the environment can support without habitat degradation** - **Carrying capacity varies with the abundance of limiting resources**

Question 43

Life History

Answer 43

- **Traits that affect an organism’s schedule of reproduction and survival.** - **Three Variables** - **How early in life does reproduction begin?** - **How often does the organism reproduce?** - **Some have one event (big-bang reproduction(semelparity)** - **Some produce offspring in repeated events (iteroparity)** - **How many offspring per reproductive event** - **These traits are evolutionary outcomes, not conscious decisions by organisms**

Question 44

K-selection

Answer 44

life-history traits that are sensitive to population density and carrying capacity. (logistic model), Populations living close to the density imposed by the carrying capacity

Question 45

r-selection

Answer 45

life-history traits maximize reproductive success (exponential model)

Question 46

density-independent populations

Answer 46

birth rate and death rate do not change with population density

Question 47

density-dependent populations

Answer 47

birth rates fall and death rates rise with population density

Question 48

Competition

Answer 48

as the density of a population increases the competition for resources intensifies. Organisms compete for food, space, or essential nutrients

Question 49

Territoriality

Answer 49

Available space for territories or nesting may be limited thus controlling the population

Question 50

Disease

Answer 50

increasing densities allow for easier transmission of diseases.

Question 51

Predation

Answer 51

As prey populations increase, predators may find the prey more easily