intro to tropics Flashcards
what happens in tropical exploration during the renaissance?
Euros explored outside their continent and discovered places like central America, ie Columbus in 1492
What happened post renaissance?
-exploration continued mostly in the tropics
- specimen were brought back to Europe
Who is Alfred Russel?
- independently conceived the idea of evolution and natty selection, linked up with Charles
- spent time in Malaysia and the Amazon
Who is Charles Darwin?
- developed theory of evolution and natty selection
- on the origins of Species (Book)
- spent much time in the Galapagos
who is Alexander Von Humbolt?
- biogeography founder
-spent time in a both tropics and nootropics but focused on Central and South America - Kosoms complilation of sci knolage of world
- developed the life zone concept
What is the life Zone Concept?
- Climate changes with elevation and coincides with changes in biota
- further developed by Leslie Holdrige
- an ecological area defined by climatic variables such as temp, precip, and evap
Who is Leslie Holdridge?
-Formalized the life zone concept
Life zone rainforest grading
- tropical moist= 200-400mm/yr
- tropical wet= 400-800 mm/yr
- tropical rain = over 800mm/yr
Koppen-Geiger Classification system
- indigenous flora best expresses nature of climate
- annual and monthly mean temps along with rainfall distinguish biomes
Koppen-Geiger Classes
-Tropical
-Arid
-Temperate
-Cold
-Polar
Location of the Tropics?
23.5 N- 23.5 S (tropic od Cancer and Capricorn respectivly)
Land area infor(size, continental locations)
- 50 million km squared 40% of the global surface
- half in afirca
- substantial in,Central and South America, Asia, Nothern Australia and Pacific Islands
Location of subtropics?
23.5N-10N, 23.5S-10S
Humid and Seasonal Tropics location?
10N- 10S
Humid Tropics
seasonality
Extremely humid all year round
Seasonal Tropics
Sesonality
Distinct wet and Dry seasons
Due to taking up a large part of Earth’s surface tropics play a large role in what Global events?
- Global Nutrient cycling
- Global energy budgets
- Circulation of the atmosphere
- Global climate
What geographic features influence tropical climate?
- Latitude
- Altitude
- Distance from Ocean
- Prevaling winds (polar cell locations and that)
Plant and animal distribution is influenced by what features?
- Climate
- Soil types
- Landforms
What makes the tropics wet and warm?
- sun rays directly hit the equator due to the curvature of the earth
- warm climate creates constant clouds
What drives seasonality in the trpoics?
tropics rainfall variations
How are mountains in the tropics formed?
Volcanism
What is the soil like in mountainous regions?
Fertile compared to rest of tropics
Climate According to Altitude in the Tropics
- temp changes with altitude at 6C /1km
- Altitudinal Zonation, climactic zones corresponding to elevation
- each zone has a distinct, veg, agri and culture/lifestyle
Neo tropics zonation
- Tierra Caliente
- Tierra Templada
- Tierra Frida
- Tierra Helada
- Tiera Nevada
Tierra Caliente
- from sea to 700m
- coastal plain to low-lying interior hot and humid climate
- predominated by tropical agriculture
Tierra Templada
- from 760m to 1830m
- tropical highlands of Central America
Tierra Frida
- from 1830 to 3658m
- cold andes mountain range
Tierra Helada
- Puna(in peru)
- from 3658m to 4500m
- cold barren
-above tree line only grazing fauna
Terra Nevada
- Over 4500m
- perma ice and snow
Humid/seasonal tropics Characteristics
biologic
- high bio div, up 50% of world bio div
-High biomass 200-400 mg/ha
-Rapid nutrient cycling rate, most in plant mass - stratified by multi-story canopy
- closed ecosystem, tight cycling of water and nutirents
Tropical Rainforest Regions
- Amazon, Congo & SE Asia
-Contains 33% of total global population
Distribution of humid tropics:
45% Americas
30% Africa
25% Asia
Small fraction in Oceania & Pacific Islands
Characteristics of Tropical Rainforests (Geograpic)
location, seanonality, precip, temp
- straddles eq and 10N and S
- Major terrestrial biome
- maybe non-seasonal
- Abundant rainfall all year
- more night and day change (diurnal) than mean monthly temp change
Characteristics of Tropical Rainforests(biotic)
- two distinct characteristics stratification and biodiversity
- dominated by broad leaved evergreens
Tropical Savannas(Geograpgic)
location, size, flora
- A grassland rich in trees
- transitional zone from grassland to dry forest
- 1/5th global surface
- diverse grass and sedge species adapted for hot climate
- 10 - 20 N & S, away from coastlines
types of topical savana
- non-seasonal: wet all year & poor sandy soils
- Seasonal: stressful dry seasons, sandy poor in nutrients soil, fire important
- Hyper-seasonal: annual folds and drought periods, mostly grasses few trees
Characteristics of Tropical Savannas(biological)
soil, rain, elevation, flora, fauna?
Occur at lower elevations (up to 1200 m above sea
level) & level landscape
* SOIL: pH 4-4.8; low nutrient content; waterlogged to water deprived
* Savanna spreading to areas previously under forest
Annual rainfall between 500 & 2000 mm (8-to-10-
month wet season)
* Rainfall quantity determines if savanna is wooded or grassy
Herbivory
* African megafauna (40 species): mostly herbivores
Savanna require fire to exist
* Mild and frequent fires occurring every tew years
Human Influence on Savanna:
- Savannas Occur naturally due to environmental (climate) conditions
- Savana formation speeds occurs
- With frequent cutting burning of moist forests
- Overgrazing of pastureland
- Frequent cutting and burning of savanna vegetation
Semi-arid and Arid Eco-regions
landcoverage and types?
- 1/3 of global land
- 2 categories , tropical steepe and tropical Desert
Deserts
location, seasonality, precip
- 20 to 30 N/S
- Hot air dominates all year
- mild winters very hot summers
- little precip
- Along coastlines can create fog Deserts cloudy but warm Baja California
Wetlands
locations
- most productive
- home to both aquatic and terrestrial species
- 4 major systems Okavango(Africa) Venezuelan Andes(SA), Panatanal(SA), Sunerbans (Asia)
Pantanal
location, elevation?
- Brazil to Bolivia and Paraguay
- 200,000 km2, 70 % of this area is located in Brazil
- Low elevation (150 m.a.s.l.)
- Receives sediment from surrounding highlands
Pantanal Seasons
Hyperseasonal wetland
Dry season: May – October
Peak rainy season: Jan - Feb
Pantanal threats
- horse ranching
- fishing
- uncontrolled hinting/ tourism
- deforestation
- pollution from sewage
River systems
characterisitics
- essential habitat for the trpoical biome
- complex annual flood and drought cycles
- drainage is dominated by few but large river systems
Flow Regimes of Tropical Rivers are influenced by
- precip
- size of basin
- terrain type
- veg cover
Effects of Anthropogenic Activities
- deforestation, agriculture, industry, and dams
- increased runoff to water and erosion
- destroyed streamside habitats
- pollution of water ways
The Amazon Basin
elevation , temp
- flat af 200m above sea(bar mountains)
- 2 to 3 cm per km slope
- upper river 5- 13C, main river 28C
Flow Regimes of Tropical Rivers during dry seasons will
- get water from groundwater reservoirs to maintain discharge
- still lower
- small streams may be dry
Amazon’s Source
- Peruvian Andes snowmelt 4500m above sea
creates the Apurimac river eventually Soliomes which links with Rio negro making the Amazon
Amazonian River Types
- Whitewater rivers
- Clearwater river
- Blackwater rivers
Blackwater rivers
- Transparent
- olive-brown to coffee-brown
- Rio Negro
Whitewater rivers
- turbid waters
- Solimoes
- Rio Madeira
Clearwater Rivers
- Transparent
- Green to olive water
- Rio Xigu
- Tio Tapajos
