Chapter 9: Ecosystems Flashcards
define ecosystem
A community of organisms in an area that interact with the living (biotic) and nonliving (abiotic) elements of their environment 
define population
A group of organisms of the same species living in a particular habitat 
define community
all of the organisms that live in the same habitat
define niche
The unique way in which an organism is adapted to living in a habitat 
biotic components of an ecosystem
producers
primary secondary tertiary consumers
decomposers
define trophic level
A feeding level in a food chain or food web 
abiotic components of an ecosystem
temperature
humidity
water
oxygen
salinity
light
pH
biotic interactions
competition
predation
pollination
mutualism (symbiotic relationship)
photosynthesis process
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
carbon cycle
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
pyramid of numbers
based on feeding level
pyramid shaped
causes of habitat loss
drainage of wetlands
intensive agriculture
deforestation
impacts of habitat loss
loss of biodiversity and genetic depletion (inbreeding and lack of adaptation)
extinction
causes of deforestation
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
impacts of deforestation
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)
importance of sustainable management of forests
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
measuring biodiversity for what
richness of different species
total number of different species
diversity or variation between different species
distribution and density of different species
methods of estimating biodiversity
pitfall traps
posters
quadrants
transects
pitfall traps
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
pooters
small jars collect species
one tube in moth
other over insect
sucked into jar
fine mesh over end of suction tube
quadrats
square frame divided into smaller squares
identify number variety and spread
transect
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
types of sampling
random - random intervals to remove bias
systematic - fixed intervals
evaluate limitations, validity and reliability of sampling methods
sample size
sample frequency (repetitions)
human error
