ECOLOGY FINAL

larger ecosystems should have longer food chains because their greater habitat heterogeneity provides more ecological niches for a diversity of species

Ecosystem size hypothesis

____ ecosystems typically have more ( often 5) trophic levels than _____ ecosystems (usually 3-4) due to differences in ecological efficiencies.

aquatic, terrestrial

Assimilated energy/ consumed energy =

assimilation efficiency

In aquatic ecosystems, _____ show a much greater response to nutrient supplementation than _____

autotrophs, heterotrophs

Given that the bottom of the ocean is anaerobic, what process in the nitrogen cycle is likely to be occurring in this location? a. nitrification b. denitrification c. mineralization d. assimilation

b. denitrification

The substantial increase in anthropogenic noise has had a dramatic impact upon many different species. What is this an example of? a. Ecosystem instrumental value b. Ecosystem change c. Ecosystem service d. Ecosystem interconnectedness

b. ecosystem change

When an animal eats fruit with hard seeds that cannot be digested and are excreted whole as a waste product, the seeds constitute _____ energy. a. assimilated b. egested c. respired d. kinetic

b. egested

The conversion of organic matter into inorganic nutrients is known as: a. Denitrification b. Mineralization c. Nutrientization d. Weathering e. Eutrophication

b. mineralization

The rate of nitrogen influx into terrestrial ecosystems by human activity is leading terrestrial systems to be considered a: a. Nutrient source b. Nutrient sink c. Nutrient flux d. Nutrient efflux e. Nutrient spirals

b. nutrient sink

At high nutrient levels, aquatic producers are typically larger macroalgae that have much longer lifespans and ______ _________ ______

bigger standing crops

The general patterns of global biodiversity show that: a. for most taxa there are many more species at low longitudes b. regional biodiversity is uniform across the globe c. equatorial regions harbor the greatest biodiversity d. islands are the most diverse regions of the globe e. migration across biotic regions generates most biodiversity

c. equatorial regions harbor the greatest biodiversity

What is the largest pool of phosphorous in the global phosphorous cycle? a. the atmosphere b. terrestrial biomass c. deep ocean waters and marine sediments d. terrestrial rocks e. aquatic biomass

c. deep ocean waters and marine sediments

Where does most decomposition occur in aquatic systems? a. surface waters b. equally throughout the water levels c. sediements d. stream and river banks

c. sediments

Where sunlight is not available, (ex: deep ocean thermal vents) producers rely on _____ as their source of energy

chemosynthesis

(In)- the percentage of energy or biomass in a trophic level that is consumed by the next higher trophic level.

consumption efficiency

consumed energy/ net production energy of the next lower trophic level =

consumption efficiency

nitrogen fixation occurs in some species of ______, _______ and ______

cyanobacteria, free-living species of bacteria, bacteria that form mutualisms with plants

What accounts for the pyramid shape of the diagram that represents energy in trophic groups in an ecosystem? a. Energy produced by consumers is greater than energy stored by producers. b. Energy stored by consumers is greater than energy stored by producers. c. Energy is gained as it moves from one trophic level to the next. d. Energy is lost as it moves from one trophic level to the next.

d. Energy is lost as it moves from one trophic level to the next.

primary consumers tend to have ____ efficiencies than secondary consumers because prey tissues are more digestible than plant tissues

lower

net production energy/ assimilated energy=

net production efficiency

energy for growth and reproduction is __ ___ ___

net secondary productivity

terrestrial trophic pyramids are typically "_____" while aquatic trophic pyramids can be "_________"

"upright" "inverted"

for active homeothermic animals that spend energy to maintain body temp, move, circulate blood, and osmoregulate, net production efficiency can be as low as _____ % For sedentary poikilothermic animals, net production efficiency can be as high as ____&

1 75

ecological efficiency incorporates: 1. 2. 3.

1. consumption 2. assimiliation 3. net production

techniques to measure CO2 uptake and release include: 1. 2. 3.

1. light-dark bottle experiments 2. place a leaf in a sealed container with added CO2 that contains trace amounts of a rare carbon isotope 3. using towers that sample CO2 concentrations at different heights above the ground

Aquatic ecosystems are limited by: 1. 2. 3. 4.

1. temperature 2. precipitation 3. nutrients 4. light

Mean annual precipitation is positively related with NPP until ___ m of annual precipitation is reached. Ecosystems that receive more that this experience a decline in NPP because ______

3 nutrients leach from the soil

consumers typically have a partial15N that is ____% higher than their prey

3.4

because energy is lost at each step, ecological efficiency is usually low, ranging from ___-____%

5-20%

the portion of energy that a consumer digests and absorbs; analogous to GPP for producers.

Assimilated energy

break down detritus into simpler elements that can be recycled.

Decomposers

In general, NPP is positively correlated with _____ _____

annual temperature

When a leaf is concealed in the dark, only ____ ____ occurs. We can then measure the GPP as =

CO2 respiration, NPP + Respiration

In ____ systems, measuring CO2 doesn't provide a good estimate of NPP because CO2 is rapidly converted into bicarbonate ions

aquatic

The sum of NPP and respiration = ____

GPP

the rate at which energy is captured and assimilated by producers in an area.

Gross Primary Productivity (GPP)

the nitrogen cycle involves the transformation of nitrogen from forms that are not useful (____) to forms that are biologically available (____)

N2 NO3

The energy plants send to mycorrhizal fungi is included in total ____

NPP

____ can be measured as the change in producer biomass over time Substantial amounts of herbivory or tissue mortality will lead to an underestimation of this

NPP

the rate of energy that is assimilated by producers and converted into producer biomass in an area; includes all energy that is not respired:

Net Primary Productivity (NPP)

the percentage of assimilated energy that is used for growth and reproduction; the percentage of assimilated energy that remains after respiration.

Net Production Efficiency (Pn)

the rate of consumer biomass accumulation in a given area; analogous to NPP for producers.

Net Secondary Productivity

the final process in the nitrogen cycle, which converts ammonium to nitrite, and then from nitrite to nitrate.

Nitrification

the process of converting atmospheric nitrogen (N2) into forms producers can use, including ammonia (NH3) which is rapidly converted into ammonium (NH4+), and nitrate (NO3-).

Nitrogen fixation

the cyclical movement of nutrients within and between ecosystems

Nutrient cycling

producers release ___ during photosynthesis and take up ___ during respiration so we can estimate NPP and GPP by measuring changes in concentrations of this

O2, O2

the rate at which solar or chemical energy is captured and converted into chemical bonds by photosynthesis or chemosynthesis.

Primary Productivity

The FCL is limited by an ecosystem's production-less productive ecosystems will have shorter FCLs

Resourse availability or energy supply hypothesis

the biomass of producers present in a given area of an ecosystem at a particular moment in time.

Standing Crop

a chart composed of stacked rectangles representing the amount of energy (i.e., pyramid of energy) or biomass (i.e., pyramid of biomass) in each trophic group.

Trophic pyramid

The Virginia Opossum is the one marsupial found in North America, which of the following is the most likely explanation for how the Virginia Opossum colonized North America? a. Opossums dispersed into North America after the Panama land bridge formed connecting North and South America b. Opossums dispersed into North America from Asia while the Bering land bridge was still above water c. Opossums dispersed into North America while North America was a part of Gondwanaland d. Opossums dispersed into North America from Europe/Asia 100 mya while the continent was still known as Laurasia

a. Opossums dispersed into North America after the Panama land bridge formed connecting North and South America

How is the phosphorus cycle different from the nitrogen cycle? a. Phosphorus does not have a gas phase b. Phosphorus is a limiting nutrient in many environments c. Phosphorus is recycled through terrestrial and aquatic ecosystems d. Phosphorus is released through decomposition e. Phosphorus is a key element in biological systems

a. Phosphorus does not have a gas phase

In a region where the alpha diversity is high but the beta diversity is low, you would expect to find a. the same species in each of the local communities b. different species in each of the local communities c. low species evenness across the local communities d. large variation in species richness across communities e. high rates of extinction and recolonization

a. the same species in each of the local communities

Excess water that falls on land is a. b.

a. transported in runoff b. transported in groundwater

when lightning, wildfires, or combustion of fossil fuels provide energy to convert N2 into NO3- this is _____ nitrogen fixation

abiotic

Researchers typically only harvest ____ ground plant growth because _____ grown biomass can be substantial & is challenging because they are deep and tend to break off when harvested

above below

Adding Iron has the potential to grow ____ and subsequently reduce CO2 in the ocean and air, but the increase in respiration of CO2 by primary consumers may counteract this effect.

algae

In a dark bottle, the decrease in O2 is a result of ___ ____

algal respiration

Net secondary productivity is: a. Portion of consumed energy that is excreted or regurgitated b. Portion of energy that a consumer digests and absorbs c. Portion of assimilated energy a consumer uses for respiration d. Rate of consumer biomass accumulation in a given area e. Rate of energy that is assimilated and converted into producer biomass in an area

d. Rate of consumer biomass accumulation in a given area

Measuring the change in producer biomass from the beginning to the end of the growing season gives an estimate of: a. egested energy. b. standing crop. c. gross primary productivity. d. net primary productivity.

d. net primary productivity

terrestrial plants contain many ____ _____, and many have tissues that cannot be ____ (ex: wood) aquatic algae is small and has no ____, and it's easily ____. This makes it easier for a higher fraction of an ecosystem's energy to move up the food chain.

defense compounds, consumed. defenses, consumed.

break down dead organic matter (i.e., detritus) into smaller particles.

detritovores

the percentage of net production from one trophic level compared to the next lower trophic level.

ecological efficiency

one or more communities of living organisms interacting with their nonliving physical and chemical environments.

ecosystem

Example: the Ganges is a 1,569 river that flows from the Himalayas through India and Bangladesh (20% of the total amount of humans on Earth) Ice melt and runoff from the Himalayas provides provisioning services downstream in the form of water, food, and timber The river also provides regulating services by absorbing runoff during the monsoon season, and by supporting communities of detritivores and decomposers

ecosystem services to humans

the portion of consumed energy that is excreted or regurgitated.

egested energy

food chains will be shorter in highly variable environments, because long food chains are less stable and more easily disturbed or disrupted

environmental stability hypothesis

On a global scale, precipitation exceeds _____ in terrestrial ecosystems, but exceeds precipitation in aquatic systems

evaporation

the mean number of transfers of energy from the base to the top of a food web

food chain length (FCL)

Estuaries and coral reefs receive abundant nutrients from the runoff of rivers and adjacent land; these systems tend to have ____ primary productivity.

high

Tropical areas have ____ NPP due to intense sunlight, warm temperatures, abundant precipitation, and rapidly recycled nutrients

high

light energy from the sun reflects off of the ground, and is measured from 380-2510 nm Used to quantify differences in land cover

hyperspectral imaging

Researchers conducted a survey of studies that examined the ratio of NPP in terrestrial ecosystems with added nutrients to NPP in terrestrial ecosystems without added nutrients. Grasslands, forests and tundra all experienced: ____ NPP when Nitrogen and phosphorus were added In some habitats, adding both causes a ______ in NPP than adding either alone

increased greater increase

In "The New Ecology" Eugene Odum proposed that Biological diversity ____ ecosystem stability

increases

ecosystem services to humans are the ____ and _____ values that humans receive from ecosystems

intrinsic & instrumental

In deserts, NPP is constrained by _____

lack of precipitation

consumers in aquatic systems are only slightly larger than the diet they eat, while terrestrial systems contain many ____

large producers and herbivores.

Low ecological efficiencies make it difficult to have _____ because there is little energy to support higher trophic levels

long food chains

larger ecosystems have ____ food chains, and there was a _____ correlation between disturbance rate and food chain length when researchers conducted experimentation in 36 river ecosystems in North America

longer, negative

Small streams are typically ____ in nutrients because a large fraction of their energy is derived from ______ leaf litter from the surrounding terrestrial habitat.

low nutrient poor

At low nutrient levels, aqutic producers are typically very small picoplankton reproduce quickly, but have short lives and thus very ____ _______ _______

low standing crops

Remains of dead animals from the upper ocean layers sink to the bottom, decompose, and release nutrients. Because nutrient regeneration is far from the ocean surface, the surface is typically _____ in nutrients and experiences _____NPP.

low, low

Within aquatic ecosystems that have similar temperatures and light levels, NPP is largely limited by ____

nutrients

The differences in CO2 within the forest and in the atmosphere provides an estimate of ____ & _____ in an area

photosynthesis & respiration

In a bottle exposed to light, the net increase in O2 is the combines result of ____ & ____ by ___ (NPP)

photosynthesis & respiration by algae

Researchers compiled NPP and secondary productivity estimates from terrestrial and aquatic biomes. They found that increases in NPP are ______correlated with increases in net secondary productivity. This correlation suggests an important role of ____ control in communities.

positively bottom-up

net secondary productivity depends on ____ for energy

primary productivity

Food chain length can impact the ____ and ____ _____ of an ecosystem

productivity and nutrient export

Organisms that have elevated rates of 15N in their bodies have acquired it from consuming other organisms. Therefore, the concentration of 15N is a _____ for the food chain position an organism occupies.

proxy

chlorophyll pigment absorbed wavelengths in the ___ & ____ range but reflects wavelengths in the green range

red & blue

Rates of decomposition are ____ in waterclogged soils. When organic matter is broken down slowly, ______

reduced fewer nutrients are available in the soil for plant growth

To access productivity across large spatial scales (ex: continents, oceans) we can use _____ _____

remote sensing

a technique that allows measurement of conditions on Earth from a distant location, typically using satellites or airplanes that take photographs of large areas of the globe.

remote sensing

the portion of assimilated energy a consumer uses for respiration; remaining energy can be used for growth and reproduction (i.e., net secondary productivity).

respired energy

one process of measuring primary productivity in aquatic systems that is identical to a light-dark bottle experiment in a sealed air chamber, but the difference is that it is done in ____

sealed water chambers

At higher latitudes, productivity is limited by _____ & ______

shorter periods of sunlight & lower temperatures

In the open ocean, other elements limit productivity: -Diatoms are often limited by ____, which is required to build _____ ___ - ____ is also limiting because it rapidly combines with phosphorous and precipitated to the ocean bottom.

silicon, silicate shells Iron

Most energy that moves through ecosystems orginates as ___ ____ that powers ____

solar energy ,photosynthesis

the movement of water through ecosystems and atmosphere; includes evaporation, transpiration, and precipitation.

the Hydrologic Cycle

(An): the percentage of consumed energy that is assimilated (i.e., material that is not egested, such as bones).

the percentage of consumed energy that is assimilated (ie: the material that isnt egested, such as bones)