tropical rainforests Flashcards
what are the three forest layers
emergent
canopy
undergrowth
what is the annotation for the emergent layer
(clue: very tall)
comprises of very tall trees that can grow up to 80m to reach for sunlight
what is the annotation for the canopy layer
(clue: continuous)
the trees form a continuous layer, blocking out sunlight
what is the annotation for the undergrowth layer
(clue: very little sunlight)
the plants here receive very little sunlight, and are hence shorter. lianas and epiphytes are also present here
what are lianas
they are thick woody vines that twine up trees
found mainly in the canopy and undergrowth layer
what are epiphytes
plants that perch themselves on trees
found mainly in canopy and undergrowth layer
what are buttress roots
large roots that are usually found on large tall trees
they grow 1-5m above ground
what are shallow roots
roots that are mostly found in the topsoil/top layer of the soil
why are shallow roots okay in rainforests
there is high rainfall in rainforests throughout the year
water is available all year round
hence, no need for roots that grow deep underground for water
what is the use of drip tips in leaves?
allows water to run off easily
this prevents the growth of fungi and bacteria
what is the use of waxy/leathery/hairy leaves
prevent loss of moisture through transpiration
temperature is high in rainforests, so the more water, the better for leaves
what is the use of broad leaves
capture more sunlight for photosynthesis
vegetation in rainforests is very dense
what are the three reasons tropical rainforests are important
they are carbon sinks (and also generate oxygen)
they ensure a clean water supply
the habitat to flora and fauna, and indigenous people
how do tropical rainforests help with climate change
they absorb carbon dioxide and generate oxygen
reducing the greenhouse effect
and hence helping climate change
how do tropical rainforests ensure a clean water supply
the soil help to trap impurities in the water before it flows into water sources
where are tropical rainforests located
between the tropic of cancer and tropic of capricorn
what are the four causes of deforestation
agricultural activities
commercial logging
mining
urbanisation/growth of settlements
what are agricultural activities
agricultural activities is the growing of crops and raising of animals to provide food
why do agricultural activities cause deforestation
agricultural activities (cattle ranching and crop cultivation both require large tracts of land to be cleared
this increases the rate of deforestation
what is commercial logging
the cutting down of trees for timber
what is mining
it is the clearing of forests to establish mines and construct roads
why does urbanisation cause deforestation
(include negative effects of roads)
land is cleared to make space for infrastructure and roads
roads have even more negative effects, such as providing access to previously inaccessible areas, promoting logging, mining and other rainforest damaging activities
they also attract settlements to develop and expand
what causes the deforestation of mangroves
mangroves are seen as smelly and unproductive, and hence are cleared to make room for agricultural land, settlements and infrastructure
they are also over harvested for wood, pulp charcoal and animal fodder
what is the MAIN cause of deforestation
the increasing demand/consumption of food and resources all around the world
what are the four environmental impacts of deforestation
loss of biodiversity
depletion of water resources
increase in flood frequency, soil erosion and sedimentation
climate change
what is the economic impact of deforestation
the destruction of renewable resources that significantly contributes to national economic growth
what is the social impact of deforestation
the indigenous people’s loss of their habitat
and conflict between the indigenous people and people
what are the four measures to manage deforestation
reforestation and afforestation
controlled logging
public education
protection and conservation
what is reforestation and afforestation
(answer separately)
reforestation is the planting of trees in an area where trees were cut down
afforestation is the establishment of trees in an area that was previously empty
what is controlled logging
(both meanings)
controlled logging is the careful management of trees that are being cut down
or the logging of specific species of trees
what is public education
it is the teaching of the importance of rainforests and ways to contribute to conserving rainforests to people
what is protection and conservation
it is the protection of forested areas by setting laws to prevent unfavourable activities (eg. unsustainable logging and agricultural practices)
what are the seven reasons why mangroves are important
- provide breeding ground for many seafood
- ashes or bark infusions can be applied to skin disorders such as leprosy
- used as fuel wood and charcoal
- used as tannins and dyes
- protect the coast from marine erosion > absorbs the energy of storm waves and wind
- trap sediments and prevent occurrence of cloudy water > that may cause corals to die
- absorbs pollution > including heavy metals
what are mangroves
a group of trees and shrubs that live in the coastal intertidal zone
what are the three types of mangrove roots
prop/stilt, pencil, knee roots
functions of mangrove roots
- roots filter salt at root level > some species can exclude more than 90% of salt in seawater
- special “breathing” roots > protrude from the oxygen deprived muddy soil
(called lenticels) - pores of roots absorb the air during low tide
adaptations of mangrove leaves
- some species excrete salt through glands in their leaves
- some species concentrate salt in older leaves/bark > when the leaves drop/ or the bark sheds, the stored salt will go with them
