Transcript Ultisols in the Philippines - University of Colorado Boulder

formation, human interactions,
biology, and natural disasters
By Kate Edwards, Tyler Huntley,
Kerry Malm and Brian Murtaugh
Introduction
• What is Australasia
• Wide range of soil formation and
orders
• Specific soil formations in New
Zealand
Introduction
• Acidic soils in Australia
• Dipterocarp forests throughout the
region
• Natural Disasters in Indonesia
The Formation of Raw Volcanic
Soil in New Zealand
Tongariro Volcanic Center
• Located on New
Zealand’s North
Island.
• Raw volcanic soil
dominates the
landscape which is
formed in tephra also
know as volcanic ash.
Time and Parent Material
•Time: Raw volcanic soils are a very
heterogeneous group of soils and are
extremely young.
•Parent Material: Tephras of rhyolite,
dacite and andesite
Climate and Topography
• Climate: Cold and
high rainfalls.
• Topography: Raw
volcanic soil forms in
the vicinity of the
source volcano
Biota
• Organisms: Most soil animals and microorganisms are concentrated in the topsoil.
• Plant Life: Vegetation rapidly recovers on
volcanic soils.
Profile Characteristics
• A horizon: is dark in
color
• B horizon:10-15cm
thick
• C horizon: is pale
yellow-brown
Distinguishing features of Raw
Volcanic Soils
• Naturally low levels of organic matter
• Generally coarse in texture
• Weakly weathered
• Highly susceptible to erosion
• Low bulk density
• Well drained, very high macroporosity
Acidic Soils of Australia
Tyler Huntley
Acidic Sulfate
• Where: SE SW Australia
• Acid Subsoils 23 million
hectares in Aus.
• 1/3 of Aussi covered
• Acid sulfate soils once
made up the sea floor,
• Geologically
• pH levels
Agricultural
• Increase in acidification
• Soil nutrient uptake
Construction
• corrode metal pipes
and dissolve
concrete.
• foundations of
buildings
Surface Water
• Run-off
• Consequences
Prevention
• Identifying them
• Liming
• Loss of crop
production
Lowland Dipterocarp forests
Soil associations
General Background
•Where: South East Asia
•Climate: very warm temperatures
•Growth: year round
•Use: timber industry, land degradation issues
•Stand characteristics: uneven aged, multi-layered
•Soils: strongly acidic, infertile, vulnerable to surface
erosion
Types of Soils
• Ultisols – most common in SE Asia
• Inceptisols
– Very steep slopes
• Oxisols
• Characterized by
– Morphology
– Physiochemical properties
– Clay mineralogy
Soil Textures
• Primary factor for vertical distribution and
storage of C, N, and P
• Coarse - clay content <35%
– Thicker A and E horizons
• More roots and animals
• Larger volume of coarse pores
• Fine – clay content >50%
– Mostly kaolinite
Soil Horizons
• Typically A, Ag, Eg, E, Bt or Btg, Bg & C
• No O layer
– termites
• A Horizon
– 5 cm thick
– Grayish with mottles edged with thin layers of
iron oxide
Soil Horizons
• E Horizon
– 3-60 cm thick
– Grayish and rust colored mottles
– Clay coated in finer soils
– Lower limit of major root penetration and
animals
• B Horizon
– Argillic (shallower in fine soils)
• C Horizon
Upper Horizons:
Mechanical composition, bulk
density and porosity
• Clay eluviation and illuviation in every soil
– Usually in fines
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Bulk density increases with depth
Higher % coarse pores at surface
Higher % total pore space at surface
Water holding capacity correlated with
total porosity
Upper Horizons:
Nutrient Cycling
• Highest storage of total C, N and P in the
0-150 cm of soil
– Increase with amount of clay
• Same with available N
• Sandy soils
– Large amt of C, not N
• Exchangeable Mg and K correlated with clay
• AMOUNTS STILL VARY GREATLY, EVEN WITH
SIMILAR CLIMATE AND VEG
Charismatic Mega Fauna
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Philippine Eagle
Flying lemur
Tarsier
Philippine Cockatoo
Flying foxes
Bats
Reptiles and
amphibians
Landslides in Indonesia
Indonesia
Climate
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Tropical climate
Dry season June-September
Wet season December-March
Moderate temperatures
Large range of annual rainfall
Topography
• Indonesia has a wide range of topographic
features
Vegetation
• Tropical plants
• Flowering plants
• Many trees
Soils
• Andosol (Andisols)
– Very fertile
– Used for horticulture and plantations
• Regosols (Inceptisols)
– Quartz sand not suitable for dry-land farming
• Grumosols
– High Ca & clay content
– Used for crops in lowlands
• Latosol
– Tropical rainforests
• Lateritic
– Tropical
– High Al & Fe oxides
• Hydromorph (Oxisols)
• Alluvial
• Podsol
– Highly leached
– Coniferous forests
What is a landslide?
• Material moving down a slope due to
gravity
• Many possible triggers
• Look like an avalanche
• 3 types
– Slump
– Flow
– Lahar
Indonesia
Mt. Semeru
Conclusion
• The soils of New Zealand’s Central North
Island is mostly volcanic in origin
• Farmer’s crop yields are limited by the
acidity of the sub soils in SE/SW Australia
Conclusion
• Subsoils are as important as topsoil in
tropical Ultisols
• Tropical and volcanic soils in combination
with precipitation leads to more frequently
occurring landslides