Quiz 1

Question 1

what is a Reynolds number tell

Answer 1

relative importance of viscous and inertial forces

Question 2

what is the Reynolds number proportional to

Answer 2

body size and velocity

Question 3

is water viscous or non-viscous

Answer 3

viscous (sticky)

Question 4

what implications does water density have on organisms

Answer 4

less need for structural elements (ex jelly fish)

organisms differ less in density, thuscan float more easily

Question 5

does water have a high or low specific heat

Answer 5

high specific heat (energy needed to change temperature)

Question 6

how does water affect temperature of ecosystem

Answer 6

buffers temperature change

Question 7

how does water affect light

Answer 7

it attenuates (diminishes) it

Question 8

what makes water tea coloured

Answer 8

dissolving organic matter

Question 9

what are the hypotheses for the differences between aquatic and terrestrial ecosystems

Answer 9

Aquatic habitats are depositional ecosystems – since water flows downhill so lots of detritus

> Nutrient limitation – aquatic systems are generally limited by phosphorus, while terrestrial
ecosystems are generally limited by nitrogen

> aquatic plants are smaller – more edible, more nutrient rich than terrestrial systems, more turnover

> strength of herbivory – herbivores consume 3x greater proportion of primary production in aquatic than terrestrial food webs

> trophic cascades are mostly wet

> aquatic systems are more strongly saturated – big eats small

> transmission of information – use of chemical, visual, and auditory cues differ in aquatic vs terrestrial ecosystems

> aquatic systems are more patchier

> light limitation – less water underwater

Question 10

are life spans generally shorter or longer in aquatic systems

Answer 10

shorter – so dynamics are easier to observe rapidly

Question 11

what is intertidal

Answer 11

zone between high and low tide component

Question 12

what causes the variety in tidal ranges

Answer 12

shape of ocean basin and how they determine the response of the water to the gravitational pull of the moon

Question 13

what do intertidal organisms need to deal with

Answer 13

desiccation stress (removal of water)

variable salinity

Question 14

why was rocky intertidal where a lot of ecology took place

Answer 14

strong gradient of environmental conditions

accessible

many organisms are : easy to count, slow, lack emotional appeal (societally okay to experiment on) , population changes happen rapidly

Question 15

what is a sessile organism

Answer 15

fixed in one place

and are arranged in horizontal bands as a function of tidal height

Question 16

what is a fundamental niche

Answer 16

conditions where a species could inhabit

Question 17

what is a realized niche

Answer 17

conditions where a species does inhabit in presence of competition and predation

Question 18

what determine upper limits of niche

Answer 18

tolerance and physical factors such as desiccation

Question 19

what set lower limits of niche

Answer 19

set by biological factors such as predation and competition

Question 20

what do the distributions of sessile organisms tell us

Answer 20

they define realized niche of a species and are a signal of strong gradients in stress and species interactions

Question 21

what can species interactions define

Answer 21

physical niche of species

ex: space competition. defines lower boundary of some species

Question 22

how do ecosystem engineers affect diversity

Answer 22

increase

Question 23

what level of diversity has the highest diversity

Answer 23

intermediate

dynamic state is between competitive domination and nothing

Question 24

how do burrowing animals affect intertidal sediments

Answer 24

mix it, which aerates it

Question 25

what are the different depths of intertidal sediment

Answer 25

biogenetic mixing depth - where critters like to live anaerobic (low oxygen depth) - critters = :(((

Question 26

what is an ecosystem engineer

Answer 26

species that create, modify, or maintain physical habitat for themselves and other species

Question 27

what are the types of ecosystem engineer

Answer 27

allogenic - organisms that form habitat by transforming materials from one state to another (ex: beavers) autogenic- organisms that form habitat with their own physical structure (ex: trees)

Question 28

what are autogenic ecosystem engineers referred to when they are abundant

Answer 28

foundation species

Question 29

what does the presence of foundation species define

Answer 29

the structure and abiotic conditions of the ecosystem

Question 30

what are the impacts of foundation species

Answer 30

increase habitat complexity change water flow patterns recruitment rates sediment erosion and deposition nutrient cycling primary productivity

Question 31

examples of foundation species

Answer 31

``` kelp forests glass sponge reefs mollusc - beds eel grass coral ```

Question 32

what are foundation species linked to

Answer 32

alternative stable states presence/lack of foundation species can shift identify of ecosystem

Question 33

what is a subsidy

Answer 33

movement of resources or material that boost the productivity of the recipient ecosystem

Question 34

does the donor ecosystem or the recipient ecosystem control subsidy

Answer 34

usually donor - controlled

Question 35

what are scavenger communities in subtidal ecosystems often driven by

Answer 35

resource subsidies

Question 36

why might subsides have complicated impacts on the food web dynamics

Answer 36

``` interference competition exploitative competition scramble competition facilitation subsidized predation ```

Question 37

what determines the dynamics of lakes

Answer 37

interactions between physical, chemical, and biological components of the lake

Question 38

explain relationship between temperature and density

Answer 38

<0 degrees : water freezes (low density), it floats between 0 and 4 degrees : water is less dense at cooler temperatures above 4 degrees : warmer water floats

Question 39

how do salts and dissolved substances affect density

Answer 39

make water heavier

Question 40

what is stratification

Answer 40

when there is a relationship between water, temperature, and depth usually warmer at top layer

Question 41

what is reverse stratification

Answer 41

when there is ice, water is coldest at top layer

Question 42

what sets the stage for the seasonal dynamics of lakes

Answer 42

stratification turnover

Question 43

what is turnover

Answer 43

when lakes go from stratification in the summer to unstratified often occurs during fall and is driven by cooling temperatures (decreasing density differences) and wind

Question 44

what does water do to light

Answer 44

it attenuates (reduces it) it light is absorbed by water and scattered by particulate matter dissolved in it

Question 45

how does algae affect light

Answer 45

the more algae in the water, the less light can penetrate it

Question 46

what is respiration

Answer 46

uses o2 and breaks down sugars to release energy

Question 47

does respiration need light

Answer 47

no

Question 48

what determines rates of photosynthesis and respiration

Answer 48

nutrients (phosphorus and nitrogen) light (photosynthesis only) temperature

Question 49

what is lake trophic status

Answer 49

useful classification of lakes based on their nutrients, o2, production, and light

Question 50

what are the categories of lake trophic status

Answer 50

oligotrophic - clear, low nutrients, low photosynthesis, low respiration mesotrophic -- intermediate clarity and nutrients eutrophic -- high nutrients, which leads to high production at the surface, which shades out lower regions causing low photosynthesis and high respiration rates (low o2)

Question 51

what are the different layers of thermal stratification

Answer 51

epilimnion - surface, warm layer metaliminion - middle, mixed layer hypolimnion - cool, bottom layer

Question 52

what were the key findings of Soule 2004

Answer 52

species extinction is generally expected. to reduce bioturbation, but the magnitude of reduction depends on the functional traits of individual species , risk of extinction, and order in which species are lost - extinction and order in which species go extinct govern the ecosystem - level consequences of biodiversity loss

Question 53

what were the key findings of Bertness, Callaway

Answer 53

The whole ecosystem is determined by one species (or group of species). These species often have positive impacts on biodiversity (Bertness and Callaway reading) and can profoundly influence many important ecosystem processes.

Question 54

what were the key findings in Carpenter

Answer 54

food chain structure (number of trophic levels) can cascade down the food web to control primary productivity