Tropical Rainforest Flashcards
What is one big characteristic of rivers in the Tropical Rain Forest?
They have large surpluses of rainfall resulting in some of the largest rivers in the world. Amazon River has the highest discharge (volume/time) of all rivers. 20% of all water is in the Amazon.
What is the signature of the Tropical Rain Forest?
- High rainfall in all months (annual 100 in. is typical)
2. Warm all months
Why is there a lack of seasonality in the Tropical Rain Forest?
Because it is at a low latitude
What should you do when you look at climographs?
Always look at temperature first and then rainfall
Where are tropical rainforests located? Where are 3 disjunct areas of tropical rainforests?
Located around the equator, mostly between 10 degrees N and 10 degrees S (but some are at higher latitudes)
3 Disjunct areas: Neotropical, Africa, Indonesia
What percent of the world’s forests are in the Tropical Rain Forest?
Half of the worlds forest are in the Tropical Rainforest
What are the 7 characteristics of the tropical rainforest?
- High Biomass and High Biodiversity
- Vegetation is continuous broadleaf evergreen canopy
- Multiple vertical strata (layers)
- abundant epiphytes - plants use other for physical support
- abundant lianas (woody climbers and vines) - this is another strategy to reach the canopy and LIGHT
- stranglers (special trees) - their form is a good strategy for plants to claim light, space, and nutrients
- many TRF animals live in trees
What is biomass?
Living or recently living biological material, usually measured by dry weight/ land area
What is biodiversity?
Abundance and variety of species and habitat and genetic variation
What is the number of species?
“Species richness”
What are the two major divisions of trees?
Broadleaf and needleleaf.
how are ecological niches distributed in tropical rainforests?
ecological niches are distributed vertically instead of horizontally. competition for light under the canopy is fierce!
are epiphytes parasites? how do they get their nutrients?
Epiphytes are not parasites. they get nutrients from falling debris, not their hosts. BUT, epiphyte load can make trees fall
what is a strangler fig?
an epiphyte that turns into a parasite! it gets resources at the expense of others
what kind of species are figs?
keystone species
what are keystone species?
A species that has a disproportionately large effect on its own environment relative to its abundance. Its disappearance would cause dramatic changes to ecosystems including the disappearance of many other species.
do figs have low or high density?
low
how many amazon animals eat figs?
75%
what are often the only trees left after logging?
fig trees
How do trees adapt to the physical environment in TRF (Three ways)?
- large root buttresses - help support the very tall trees with shallow roots.
- Most leaves in lower strata have “drip tips” to facilitate drainage of rainfall, promote transpiration, and reduce fungus growth
- plants in lower forest layers have large leaves to more effectively capture light, which is a limiting factor in the understory
What are roots like in TRF?
they run horizontally rather than more deep.
what are the functions of roots?
air exchange, capture nutrients in poor TRF soils
What are some typical soil types in TRF?
Oxisols
What are some characterstics of soils in TRF?
usually low fertitiliy (except near rivers and volcanos)
heavy rain washes nutrients (Ca, Mg, K) through leaving aluminum and Fe (iron) oxides which is very poor for agriculture
What turns soil red?
Oxidation
Where do most TRF animals live?
Trees (arboreal- making use of vertical niches)
What are cloud forests and where are they found?
A special type of rain forest that is only on tropical mountains
what is the climate like in cloud forests?
nearly constant fog and mist. cooler than TRF (higher elevation).
what causes cloud forests to occur?
orographic lifting
What are key characteristics of cloud forests?
abundant tree ferns
What are some human impacts on tropical forests?
More than 1/2 of the worlds original tropical rain forest are gone
What is the leading cause of deforestation?
Cattle ranching to make hamburger meat
What is another big reason to cut down TRF trees?
Commercial agriculture
what are some major crops in the TRF area?
cattle, soybeans in Amazon, tropical fruits (pineapples, bananas), cacao (coco) beans - especially in Africa, sugar cane, rubber, coffee (alot of it in cooler mountains, cloud forest)
Why is sun coffee bad?
It creates a biological desert. Only offers 1 layer of single species vegetation (monoculture)
What are some negative environmental effects of sun-grown coffee:
- 90% fewer bird species, 45% fewer mammals compared with shade-grown coffee areas.
- Requires more chemical fertilizers and pesticides
than shade coffee - Greater soil erosion & higher toxic runoff
What are advantages of Shade-Grown Coffee-
- Habitat for birds and other wildlife
- Helps with soil quality, and natural pest control (thanks to the birds).
- Higher water quality and quantity for locals
What is another type of land use that causes deforestation?
Slash and burn agriculture
What is slash and burn agriculture often called?
often called shiftingagriculture; small yields and accelerated erosion mean you have to move around often and cut MORE trees
what are the effects of slash and burn agriculture?
It kills trees and depletes good soil. its also bad in mountainous areas
What is another cause of deforestation?
logging (esp in tropical asia)
Whats a common misconception of logging in Amazon?
That it is the major cause of deforestation. It is not. Small scale agriculture is.
Why are Tropical Rainforests Important? Why should everyone care about logging in TRFs?
TRF’s regulate atmosphere. They suck up excess CO2
Why else should we care about TRFs?
25% of western pharmaceuticals come from TRF ingredients. Only 1% of plants have been tested for potential.
70% cancer drugs come from TRF
How can we preserve TRFs?
Reduce demand for tropical lumber, big macs, etc.
Find renewable forest products that don’t require cutting & burning
Involve local people in decision making
Recognize the basic needsof local people (such as for food, fuel, housing)
What is cloud forest vegetation like?
CLOUD FOREST vegetation is typically a dense tangle of trees, lianas, and epiphytes –very high biomass and diversityCosta
