Chapter 9: Ecosystems

Question 1

define ecosystem

Answer 1

A community of organisms in an area that interact with the living (biotic) and nonliving (abiotic) elements of their environment 

Question 2

define population

Answer 2

A group of organisms of the same species living in a particular habitat 

Question 3

define community

Answer 3

all of the organisms that live in the same habitat

Question 4

define niche

Answer 4

The unique way in which an organism is adapted to living in a habitat 

Question 5

biotic components of an ecosystem

Answer 5

producers
primary secondary tertiary consumers
decomposers

Question 6

define trophic level

Answer 6

A feeding level in a food chain or food web 

Question 7

abiotic components of an ecosystem

Answer 7

temperature
humidity
water
oxygen
salinity
light
pH

Question 8

biotic interactions

Answer 8

competition
predation
pollination
mutualism (symbiotic relationship)

Question 9

photosynthesis process

Answer 9

energy from sun absorbed by chlorophyll
energy converts co2 water and minerals to glucose and oxygen
glucose needed for respiration, stored for growth as proteins or carbs

co2 +h2o > sunlight + c6h12o6 + o2

Question 10

carbon cycle

Answer 10

co2 in atmosphere
converted to compounds (carbohydrates) in producers during photosynthesis
respiration releases back to atmosphere
released in different trophic levels through respiration of glucose
decayed bodies digested by decomposers
remaining compounds taken into decomposers
converted to co2 for respiration

Question 11

pyramid of numbers

Answer 11

based on feeding level
pyramid shaped

Question 12

causes of habitat loss

Answer 12

drainage of wetlands
intensive agriculture
deforestation

Question 13

impacts of habitat loss

Answer 13

loss of biodiversity and genetic depletion (inbreeding and lack of adaptation)
extinction

Question 14

causes of deforestation

Answer 14

timber extraction and logging
rapid growth of cities leading to building of roads and settlements (urban sprawl)
rock and mineral extraction
clearing woodlands so land can be farmed
setting up bed cattle ranches

Question 15

impacts of deforestation

Answer 15

habitat loss and depletion of biodiversity and gene pool diversity
(survival depends on nourishment and physical support from other organisms)

soil erosion and desertification
(remove protective cover of trees and their roots, soil washed or blown away, topsoil contains most nutrients lost through weathering, leaching of nutrients, desertification, overgrazing, construction of boreholes for water)

climate change
(forests are carbon stores, released as co2)

Question 16

importance of sustainable management of forests

Answer 16

growing forests act as carbon sinks and mature forests act as carbon stores, reducing severity of global warming

maintains water cycle as trees needed for photosynthesis respiration and transpiration

prevents soil erosion as
tree roots grow into soil to bind soil in place to prevent compaction, rain soaks into air pockets instead of run off
tree foliage protects soil from erosive impact of heavy raindrops - leaves and branches intercept rainfall and lessen its energy to soak

biodiversity as a genetic resource - medicines, building materials, clothing, energy

food, medicine, industrial raw materials - indigenous rely on plants, tourism, wood for commercial export

ecotourism - local cultural experiences, natural environments, wildlife activities, locals receive income, historical heritage, biodiversity

Question 17

measuring biodiversity for what

Answer 17

richness of different species
total number of different species
diversity or variation between different species
distribution and density of different species

Question 18

methods of estimating biodiversity

Answer 18

pitfall traps
posters
quadrants
transects

Question 19

pitfall traps

Answer 19

buried and covered container
rim in level with ground’s surface
insects fall in and can’t climb back out
identify species caught
dense woodland

Question 20

pooters

Answer 20

small jars collect species
one tube in moth
other over insect
sucked into jar
fine mesh over end of suction tube

Question 21

quadrats

Answer 21

square frame divided into smaller squares
identify number variety and spread

Question 22

transect

Answer 22

measure tape or rope with marked points
across habitat
continuous sampling
identifying and record all species touching line
systematic where presence or absence at intervals is recorded

Question 23

types of sampling

Answer 23

random - random intervals to remove bias
systematic - fixed intervals

Question 24

evaluate limitations, validity and reliability of sampling methods

Answer 24

sample size
sample frequency (repetitions)
human error

Question 25

how to conserve biodiversity

Answer 25

sustainable harvesting of wild plant and animal species
sustainable forestry
protected areas
extractive reserves
seed banks
national parks
wildlife/ ecological reserves
zoos and captive breeding
ecotourism

Question 26

sustainable harvesting of wild plants and animal species

Answer 26

not uprooting plants
hunting outside breeding season
interest among people to maintain biodiversity
harvest wildlife resources
economic asset- sell meat, ecotourism, selling animals to national parks, harvest eggs

Question 27

agroforestry

Answer 27

trees are replaced with seedlings if cut down

Question 28

designated protected areas

Answer 28

national parks
wildlife reserves
conserves biodiversity, protects landscape, enhances economic and social conditions
protects rare plant and animals, geological features and landscapes

Question 29

biosphere reserves

Answer 29

core area - ecosystems strictly protected
buffer zone - ecological research, monitoring, training, education
transition area - environmentally sustainable activity- economic and human wellbeing

Question 30

extractive reserves

Answer 30

land owned by government
used by local indigenous people
forest managers to ensure balance maintained- family based agriculture, exploit of resources

Question 31

seed banks

Answer 31

protect biodiversity in case natural reserves of seeds are destroyed other places in world by catastrophes (disasters, diseases, wars)