Download Tropical Processes

Productivity
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Amount of solar radiation converted into sugars through
photosynthesis
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Gross Primary Productivity (GPP) represents all carbon fixed
Net Primary Productivity (NPP) represents GPP minus maintenance
cost
– Measured by biomass per unit area per unit time
Limits to NPP
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Light
Moisture
Nutrients
Comparative Productivity
NPP
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50-60% of energy lost to respiration, perhaps due to temperature
stress
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NPP varies seasonally due to effects of moisture and irradiation
Leaf Area Index
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Leaf area above a square meter of forest floor
– Temperate LAI = 6
– Tropical LAI = 5-10
Material Cycling
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Law of Conservation of Matter
Water Recycling
Importance of decomposition
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Release captured nutrients
Fungi, bacteria and other soil organisms
Biogeochemical Cycling
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Term that recognizes that nutrients move through living and nonliving parts of an ecosystem
Leaf Leaching
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Materials leached from leaves from rain
– Throughfall chemistry can be very different from rainfall chemistry
– Waxy cuticle prevents leaching
– Leaf shape and drip tips move water quickly
Soil Leaching
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Many nutrients are water soluble and easily leached away
Some negatively charged soil particles can attract positively charged
nutrients
– H+ ions in acidic conditions can replace nutrients
Soil Leaching
Replacement Series
Location of Nutrients
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Because of high rainfall and therefore increased leaching rates and
acidic, infertile soils, most of the nutrients in a tropical ecosystem is
found in the vegetation rather than the soil
– More evenly distributed in temperate systems
Nutrient Budget
Nutrient Acquisition
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Mycorrhizae
– Vesicular Arbuscular Mycorrhizae (VAM)
– Ecomycorrhizae (EM)
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Important in epiphytes as well
Spores can be dispersed by rodents
Tropical Soils
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Heat and heavy moisture cause formation of oxides of iron
Clay content is high
Soil processes
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Laterization
– Rapid weathering and heavy leaching leads to acidic, iron oxide rich
soils
Utisol
Oxisol
Alfisols
Inceptisols and Entisols
Root Mat
Apogeotropic Roots
Arrested Litter
Nitrogen Fixation
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Mutualism
– Legumes
– Epiphytes
– Termites
Disturbance
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Normal occurance
Happens more often in rainy season
Succession occurs
Gap specialists
Disturbance
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At La Selva, entire forest turns over every ~125 years
6% in young gaps at any time
Adult trees live ~65 years on average
Most mortality occurs in seedling stage
Closed Canopy
Anthocyanins help capture light
Tree Fall Gaps
Three types of rainforest trees (more or less)
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Large-Gap Specialists
– Seeds require high gap temperatures to germination and shadeintolerant seedlings
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Small-Gap Specialists
– Seeds germinate in shade but seedlings require gaps
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Understory Specialist
– Shade tolerant
Fire
Human Activity
Ecological Succession
Abandoned Pasture
Heliconia sp.
Piper sp.
Mimosa sp.
Cecropia sp.
Kapok Tree (Cieba pentantra)
Costa Rican Organisms
MAMMALS
Mammals
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Diaphragm
Body hair
Mammary glands
Will we see them?
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Predators are less abundant
30 our of 225 species are diurnal
~75% are in trees, underground or in water
Mammals tend to be shy
Methods of observation
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Walk quietly and observe areas of aggregation
Listen for movement and calls
Look for eyeshine at night
– Tapetum lucidum
Mammal signs
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Scat
Tracks
Remains
7 species endemic to Costa Rica
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Shrew (Cryptotis jacksoni)
Spiny pocket mouse (Heteromys oresterus)
Deer mouse (Reithrodontomys rodriguezi)
Four pocket gophers (Orthogeomys spp)
Wooly olingo (Bassaricyon lasius)
Wooly olingo (Bassaricyon lasius)
Didelphimorphia
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200 of 270 marsupials found in Australia
Many of the rest found in South America
Opossums
Order Didelmorphia
Common Opossum
(Didelphis marsupialis)
Virginia Opossum
(Didelphis virginiana)
Central American Woolly Opossum (Caluyomys derbianus)
Common Gray Four-Eyed Opossum (Philander opossum)
Anteaters, Sloths and Armadillos
Order Xenartha
Xenartha
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Found only in New World
Low body temperature and metabolism
Northern Tamandua (Tamandua mexicana)
Brown-Throated Three-Toed Sloth (Bradypus variegatus)
Hoffman’s Two-Toed Sloth (Choloepus hoffmanni)
Nine-banded Long-Nosed Armadillo (Dasypus novemcinctus)
Shrews
Order Insectivora
Insectivora
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Hodge-podge group of smallish creatures
Only 5 species in Costa Rica
Some have venomous saliva
Least shrews (Cryptotis sp.)
Bats
Order Chiroptera
Chiroptera
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More varied diet in tropics
109 species in Costa Rica
– 12% of the world’s bat species
Greater White-Lined Bat (Saccopteryx bilineata)
Parnell’s Mustached Bat (Pteronotus parnellii)
Pallas’ Long-Tongued Bat (Glossophaga soricina)
Common Tent-Making Bat (Uroderma bilobatum)
Common Vampire Bat (Desmodus rotundus)
Monkeys
Order Primates
Primates
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One third of 150 species are found in New World
Infraorder Platyrrhini
White-throated Capuchin (Cebus capucinus)
Mantled Howler Monkey (Alouatta palliata)
Central American Spider Monkey ( Ateles geoffroyi)
Rodents
Order Rodentia
Rodentia
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Rodents represent half of the world’s mammals
Incisor teeth adapted for gnawing
Red-tailed squirrel
(Sciurus granatensis)
Variegated Squirrel (Sciurus variegatoides)
Hispid Cotton Rat
(Sigmodon hispidus)
Mexican Hairy Porcupine (Coendou mexicanus)
Central American Agouti (Dasyprocta punctata)
Rabbits
Order Lagomorpha
Lagomorpha
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Used to be a suborder of Rodentia
May be more closely related to other groups
Defined by their dentition
Eastern Cottontail
(Sylvagus floridanus)
Carnivores
Order Carnivora
Carnivora
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All families except Bear, Hyena and Mongoose Families found in Costa
Rica
– Canidae (Dogs)
– Procyonidae (Racoons)
– Mustelidae (Weasels)
– Felidae (Cats
Gray Fox (Urocyon cinereoargenteus)
Coyote (Canis latrans)
Northern Racoon
(Procyon lotor)
White-Nosed Coati
(Nasua narica)
Kinkajou (Potos flavus)
Tayra (Eira barbara)
Striped Hog-Nosed Skunk (Conepatus semistriatus)
Jaguarundi (Herpailurus yagouaroundi)
Ocelot (Leopardus pardalis)
Jaguar (Panthera onca)
Tapirs
Order Perissodactyla
Perissodactyla
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Odd-toed ungulate
Weight all on third toe
Baird’s Tapir (Tapirus bairdii)
Peccaries and Deer
Order Artiodactyla
Artiodactyla
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Even-toed ungulates
Two or four toes in each foot
Collared Peccary
(Tayassu tajacu)
White-Tailed Deer
(Odocoileus virginianus)
Red Brocket Deer
(Maxama americana)
Tools of the Trade
THE SCIENTIFIC METHOD
Reproducibility
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Results should be reproducible by other scientists
Replication
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Experiments must be replicated
– In other words, treatments should be performed on more than one
group
• Can be replicated in time or space
– Good rule of thumb is 3 to 4 replicates
Costa Rican Culture
ECONOMY, PEOPLE
AND ARTS
Economy
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Tourism is number one income earner
Technology
Agriculture
Tourism
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Overtook the banana industry in 1993 as top income earner
Over 50% are Americans
50% of Costa Rica’s habitable coastline is now owned by Americans and
Europeans
Technology
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40% of economy
Intel, Motorola, 3COM, Abbott Laboratories
Internet gaming
Agriculture
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57% of land in agriculture
Cattle
– Costa Rica is leading beef exported in Latin America
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Bananas in Caribbean
Grano d’oro in highlands
Pineapple
Humpbacked Zebu
Demographics
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Most homogeneous of Central American countries
– 94% white
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Guanacaste is 50% mestizo
Puerto Limon is 30% black
Afro-Caribbeans
• 10,000 Jamaicans hired to build railroad in 1870-1880
• West Indian immigrants to work banana plantations
• Restricted to Caribbean coast until 1949
Indigenous People
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22 Indian Reserves contain 24 indigenous groups and 8 ethnic groups
Low standard of living
Alcoholism
Encroachment by plantations, roads and mining
Other groups
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Jews prominent in liberal professions
Quaker community of several hundred in Monteverde
Germans as coffee farmers
Italians in San Vito
Chinese worked on railroad
– Now many in restaurants and hotels
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New wave of anglos
Central American Immigrants
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El Salvadorans and Guatemalans provide cheap labor for coffee fields
Nicas are largest group of recent immigrants
– Many illegal
Way of Life
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Considered a “Class-less democracy”
Opportunity and personal liberty
Comparatively wealthy
Poor by developed standards
One fifth of the population lives in poverty
Half of rural and one-third of urban homes lack clean water
Child labor exploitation occurs
Ticos
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Polite
Laid-back
“Tico” time
Latin machismo relatively minor
One quarter of children born out of wedlock (los hijos naturales)
Compeñeras have same rights as wives
Pura vida
Art
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1920’s landscape movement
Teodorico Quiros
Roberto Lizano
Crafts
Music
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Cumbia
Lambada
Merengue
Salsa
Soca
Calypso
Reggae
Marimba
Chirimia
Quijongo
Some Logistics
• WC-Monteverde Luncheon
• Selvatura (~$65)
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Canopy Tour, Insect Collection, Butterfly Garden
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Walkway, Insect Collection, Butterfly Garden, Herptile Museum
• The Springs Resort (~$45)
• Free day at coast (Will pay there)
• Money ($100-150 is enough)
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Lunch at airport leaving US and breakfast at airport leaving CR
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1 lunch, 1 dinner on your own in CR
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Laundry
Items to bring
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Laptop?
Camera?
DVR?
Each person must bring:
– Field journal
– Empty thumb drive
– Leather work gloves
– LED headlamp
– Insect repellent
– Swiss Army Knife or Multi-Tool
Finals Week
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Bring finals week schedule (and payment?) next week
Will have exam and meeting to answer final questions and arrange
travelling logistics